• Volume 132, All articles

      Continuous Article Publishing mode

    • A highly selective anthraquinone appended oxacalixarene receptor for fluorescent ICT sensing of F- ions: an experimental and computational study

      MANOJ VORA ANITA KONGOR MANTHAN PANCHAL MOHD ATHAR ASHUKUMAR VERMA FALAK PANJWANI P C JHA VINOD JAIN

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      A new anthraquinone appended oxacalix[4]arene (DAQOC) has been synthesized and characterized by different 1H NMR, IR, ESI-MS and 13C NMR spectroscopic techniques. This compound was explored for its sensing abilities towards various anions. DAQOC showed selective anion sensing behaviour towards F- ions which was supported by absorption as well as emission studies. Among other anions, only in the presence of F- ions, a quenching in the fluorescence emission of over 79% was observed due to changesin the intermolecular charge transfer (ICT) process. DAQOC exhibited high selectivity and good sensitivity toward F- ions in the presence of competing ions and the detection limit was found to be 1.23 lM. -H NMR titration displays that the peak corresponding to –NH protons (at 12.91 ppm) disappears upon interaction with F-, suggesting that the sensing mechanism follows the deprotonation route. The geometrical features of F- bound oxacalixarene species were modelled by the Density Functional Theory (DFT) and NCIPlot calculations. The findings suggested that the appended substituents including nitro groups and anthraquinone can make the calix[4]arene ring electron deficient and thereby more susceptible for F- ions. Moreover, this present chemosensor has been applied for recognition of F- ions from waste water samples which is of directpractical relevance.

    • Correction to: Efficient dye-sensitized solar cell based on a new porphyrin complex as an inorganic photosensitizer

      AZAM NASIRIAN VALIOLLAH MIRKHANI MAJID MOGHADAM SHAHRAM TANGESTANINEJAD IRAJ MOHAMMADPOOR-BALTORK

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    • Microwave-assisted one-pot quick synthesis of 1-monosubstituted 1,2,3-triazoles from arylboronic acids, sodium azide and 3-butyn-2- ols

      ZHONGLIN DU FENRUI LI LI LI RAN LI

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      Microwave-assisted one-pot quick synthesis to 1-monosubstituted 1,2,3-triazoles was achieved with good to excellent yields using the widely available arylboronic acids, sodium azide and 3-butyn-2-ols within 15 min. This method features high efficient and facile as organic azides, acetylene gas and harsh conditions were avoided.

    • Alkali/alkaline earth ion-exchanged and palladium dispersed MCM- 22 zeolite as a potential catalyst for eugenol isomerization and Heck coupling reactions

      P SAHU T V HARIPRIYA A SREENAVYA G V SHANBHAG A AUGUSTIN A SAKTHIVEL

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      Alkali and alkaline earth metal ions (Na+, K+, Cs+, Mg2+) exchanged MCM-22 zeolites were prepared and subsequently palladium (2 wt.%; Pd) was dispersed on above exchanged MCM-22 zeolitematerials. All the MCM-22 materials were systematically characterized by FTIR, powder X-ray diffraction, N2 sorption analysis and temperature-programmed desorption (TPD) of CO2. The XRD pattern and FTIR data confirmed the existence of theMCM-22 framework structure even after exchanging bulkymetal ions and palladiumloading.TPDstudies using CO2 supports that the cesium and magnesium incorporated MCM-22 possess a strong and large number of basic sites. The alkali and alkaline-earth metal ions exchanged MCM-22 catalysts were explored forindustrially important eugenol isomerisation, whereas the palladium containingMCM-22 materials were utilised forHeck coupling reaction of styrene with iodobenzene. The Cs-MCM-22 showed the best activity for the eugenolisomerization with the isoeugenol yield of 76%. The Cs/Pd-MCM-22 was shown as promising heterogeneous catalyst forHeck coupling reaction of styrene with iodobenzene and yield 99%stilbene. For both isomerization and Heck coupling reaction, the catalysts retain their activities even after several runs

    • Hydrophilic meso-substituted cyanine dyes in solution and in complexes with serum albumins: spectral properties and molecular docking study

      PAVEL G PRONKIN LUDMILA A SHVEDOVA ALEXANDER S TATIKOLOV

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      The absorption and fluorescence spectral properties of three meso-substituted hydrophilic thiacarbocyanine dyes were studied in solutions and in noncovalent complexes with human and bovine serum albumins (HSA and BSA, respectively). The presence of alkyl substituents at the meso-position of the polymethine chain of the dyes determines the occurrence of a cis–trans equilibrium. Dyes form aggregates in aqueous media; the effect of electrolyte (NaCl) on aggregation has been studied. The interaction of the dyes with albumins leads to the decomposition of the aggregates and is accompanied by a shift in the isomericequilibrium. Complexation with HSA leads to accumulation of dye monomers in the trans-form. However, in the case of BSA the cis-to-trans isomeric shift is incomplete. Using the fluorescence data, the effective binding constants of the trans-isomers with albumins (Ka) and the detection limits of albumin molecules (LD and LQ) were determined. The data obtained are indicative of high selectivity of some dyes to HSA compared to BSA. The results of molecular docking experiments correspond to the data obtained from the spectra. The influence of the dyes on intrinsic fluorescence of HSA and BSA was also studied, and fluorescence quenching, static in nature, was detected.

    • DFT study of CO2 catalytic conversion by H2 over Ni13 cluster

      QIANG KE LIMING KANG XIN CHEN YOU WU

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      Understanding the mechanism and selectivity of CO2 catalytic conversion by H2 on a specific catalyst is of great significance in the context of renewable energy storage from a societal and technological point of view. In this paper, based on the density functional theory calculations, the possible reaction networks of CO2 hydrogenation on the Ni13 cluster are studied systematically. The adsorption energies of the reaction intermediates at various possible adsorption sites, the reaction energies and the activation energies of each elementary reaction are calculated. The results suggest that the adsorption properties of the CO2 and the intermediates on the Ni13 cluster are different from the specific crystal plane such as Ni(111) surface, and the intermediates are highly activated on the Ni13 surface. The most advantageous pathways for the production of HCOOH, CH3OH, and CH4 are determined, and the activation barrier of the corresponding rate-determining step is 1.63 eV, 1.55 eV, and 1.55 eV, respectively. This indicates that the Ni13 cluster has higher activity towards CO2 catalytic conversion compared with other catalysts such as Cu(111), Ni(111), and Pt/Ni(111) surface. Furthermore, the H3CO* hydrogenation or the dissociation is demonstrated to be the crucial step in determining the selectivity for CH3OH and CH4.

    • Opto-electrochemistry of pyridopyrazino[2,3-b]indole Derivatives

      POOJA S SINGH AKSHATA J SHIRGAONKAR BHARGAVI K CHAWATHE RAJESH M KAMBLE

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      Here, pyridopyrazino[2,3-b]indole based D–A assembly was designed and synthesized with modulation of various electron-donating/withdrawing substituent and characterized by various spectroscopic methods. Pyridopyrazino[2,3-b]indole derivatives show inbuilt intramolecular charge transfer (ICT) transitionwhich established D–A building in molecules and induces blue-green emission in the solution state. However, solid-state emission characteristics explore the emission property of some molecules towards aggregationinducedemission (AIE) effect which leads to the formation of emissive nano aggregates in THF/H2O mixture. Alteration of substituent on pyridopyrazino[2,3-b]indole segment effectively tune electrochemical property and resulting LUMO energy level was found to be comparable with reported electron transporting/ntypematerials. These properties and good thermal stability indicate that molecules have the potential to be used as solid-state emitter and n-type materials in optoelectronic devices.

    • Structural and spectral characterization of Cu(II) complexes of N(4)-substituted thiosemicarbazones derived from 2-hydroxyacetophenone: Crystal structure of a dinuclear Cu(II) complex

      E B SEENA M SITHAMBARESAN SUNI VASUDEVAN M R PRATHAPACHANDRA KURUP

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      Copper(II) complexes of 2-hydroxyacetophenone-N(4)-cyclohexylthiosemicarbazone (H2L1) and 2-hydroxyacetophenone-N(4)-phenylthiosemicarbazone (H2L2) have been synthesized and characterized bydifferent physicochemical techniques like magnetic studies and electronic, infrared and EPR spectral studies.[(CuL1)2] (1) is a dinuclear complex having four coordination around copper(II) with distorted square planar geometry. The two individual dinuclear complexes are interconnected through two bifurcated classical hydrogen bond interactions producing a sheet-like structure along b axis. [(CuL2)2].1/2H2O (2) also has a dimeric structure. The thiosemicarbazones bind to the metal as dianionic ONS donor ligand in all thecomplexes, except in the complexes [Cu(HL1)Cl].2H2O (3), [Cu(HL1)Br].4H2O (4) and [Cu(HL1)NO3].C2-H5OH(H2O) (5), where the ligand moieties are coordinated as monoanionic (HL¯) ones. Complexes [CuL1-dmbipy] (6), [CuL2dmbipy].3H2O (7), [CuL2bipy].H2O (8) and [CuL2phen].2C2H5OH (9) are heterocyclic base adducts.

    • Synthesis of new alkenyl iodobenzoate derivatives via Kharasch- Sosnovsky reaction using tert-butyl iodo benzoperoxoate and copper (I) iodide

      SAADI SAMADI AKRAM ASHOURI SHIVA MAJIDIAN HERSH I RASHID

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      The synthesis of new alkenyl iodobenzoate derivatives as allylic esters was investigated via the reaction of tert-butyl iodobenzoperoxoate with alkenes in the presence of copper salts. The best result was obtained using tert-butyl-iodobenzoperoxoate in the presence of copper (I) iodide (5 mol%) in refluxingacetonitrile with good yield (92%) in 32 h. The structure of peresters and alkenyl iodobenzoate derivatives were characterized on the basis of their FT-IR, 1HNMR, 13CNMR, and Mass spectra

    • Sulfated polyborate as an eco-compatible solid acid catalyst for efficient and facile solvent-free synthesis of polyhydroquinolines

      DILIP AUTE AKSHAY KSHIRSAGAR BHAGWAT UPHADE ANIL GADHAVE

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      An environmentally viable, green and efficient protocol for the synthesis of polyhydroquinolines using sulfated polyborate catalyst have been developed by Hantzsch four-component condensation between aromatic aldehydes, dimedone, ammonium acetate and ethylacetoacetate or ethylcyanoacetate at 100°Cunder solvent-free condition. The sulfated polyborate catalyst is characterized by FT-IR, XRD, SEM and EDAX techniques. The noticeable features of this methodology are mild Brønsted acidic nature of the catalyst, good to excellent product yields (85–94%), short reaction time (18–30 min), solvent-free condition,operational simplicity and applicability to a wide range of substrates (29 examples)

    • Copper(II) complexes with semicarbazones: synthesis, characterization and noncovalent interactions in their crystal structures

      CLAUDIA C GATTO FRANCIELLE C LIMA PATRICIA M MIGUEL

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      The present work reports the synthesis and structural elucidation of six novel copper(II) complexes with 2-acetylpyridine semicarbazone (HL1) and 2-acetylpyridine N(4)-phenyl semicarbazone (HL2). In all compounds, the semicarbazone ligands were find tridentate with NNO-donor atoms. The single crystal X-ray diffraction analysis showed the influences of the different copper salt starting reagent in the crystal structures. A packing architectures analysis has been undertaken to delineate the role of relevant noncovalent interactions. The p...p stacking interactions and hydrogen bonds were analyzed using the Hirshfeld surface and fingerprint plots. In addition, the compounds were also characterized by physicochemical and spectroscopic methods.

    • Sequential ring-closing enyne metathesis and intramolecular Diels– Alder reaction: an approach to the synthesis of the core structure of galiellalactone

      RITABRATA DATTA SUBRATA GHOSH

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      Development of a route for the synthesis of the core structure of galiellalactone is described. The key step involves a ring-closing enyne metathesis of an allyl propargyl ether to produce a dihydro furano diene with a latent dienophile. The dienophile, when generated from this latent functionality, underwent an in situ intramolecular Diels–Alder reaction to produce the tricyclic skeleton present in galiellalactone

    • Effect of crystalline phases and acid sites on the dehydration of 1- octadecanol to 1-octadecene over TiO2–ZrO2 mixed oxides

      TINGMING DUAN YONG XIAO GUOQUAN ZHANG BO HOU LITAO JIA DEBAO LI

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      TiO2–ZrO2 mixed oxides with different amounts of TiO2 were prepared by co-precipitation method and used to synthesize 1-octadecene from 1-octadecanol. The results show that the doping of TiO2 leads to the formation of Lewis acid sites and Brønsted acid sites on the TiO2–ZrO2 mixed oxides. For catalysts with TiO2 doping<3 wt.%, the catalysts are in an intermediate state from the monoclinic and tetragonal zirconia crystalline phases to the amorphous form, and no Ti–O–Zr bond is formed. For catalysts with TiO2 doping C >= 3 wt.%, an amorphous structure and Ti–O–Zr bond are formed. The crystalline phase of metal oxides, amount and type of acid sites simultaneously affect the performance of the catalysts. The acid sites on TiO2–ZrO2 mixed oxides with monoclinic and tetragonal zirconia crystalline phases have much lower dehydration activity than those with an amorphous form. Lewis acid sites are responsible for both thedehydration of 1-octadecanol to form 1-octadecene and the double carbon bond migration of 1-octadecene to form 2-octadecene. Brønsted acid sites mainly catalyze the double carbon bond migration of 1-octadecene.

    • Supercapacitive performance of nitrogen doped porous carbon based material for supercapacitor application

      XIANYONG HONG JINGHUA LI GUISHENG ZHU HUARUI XU XIUYUN ZHANG YUNYUN ZHAO DONGLIANG YAN KAOXIANG CHEN FANGJIE LIAO AIBING YU

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      Honeycomb nitrogen-doped porous carbon (NPC) was prepared for supercapacitor applications by hydrothermal carbonization and KOH activation process. This process used glucose as the carbon source and trans-1, 2-cyclohexane diamine tetraacetic acid as the nitrogen source. It can both control the morphology and improve the electrical performances of the as-achieved NPC. The porous carbon electrode offers improved electrochemical properties with a capacitance as high as 423 F/g at 0.5 A/g. There was excellent cycling stability with 92.5% capacitance retention after 5000 cycles at 10 A/g current density aswell as good rate performance with 300 F/g even at 20 A/g. This is due to the hierarchical porous structure,high specific surface area, numerous nitrogen groups, and good electrical conductivity. Moreover, the symmetric supercapacitor based on the porous carbon materials in neat DLC301 electrolyte delivers a highenergy density of 58.75 Wh/kg and an excellent power density of 250 W/kg. Two assembled supercapacitors were connected and utilized for the driving recorder to work normally for 15 s. These satisfactory electrochemical properties indicate that the honeycomb 3D porous carbon has good prospects as an electrode for supercapacitors.

    • Synthesis and antibacterial activity of benzothiazole and benzoxazole-appended substituted 1,2,3-triazoles

      C P KAUSHIK MANISHA CHAHAL

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      A series of benzothiazole and benzoxazole linked 1,4-disubstituted 1,2,3-triazoles was synthesized through copper(I) catalyzed azide-alkyne cycloaddition reaction. FTIR, 1H, 13C-NMR and HRMS techniques were used to examine the structure of synthesized derivatives. Further, these triazole derivatives were screened for in vitro antibacterial activities against two Gram-positive bacteria S. aureus, B. subtilis; two Gram-negative bacteria E. coli and K. pneumoniae by serial dilution technique, reflecting moderate to good activity. Compound 7s exhibited promising antibacterial activity among all the synthesized triazoles

    • Synthesis, characterization, DNA-binding and biological studies of novel titanium (IV) complexes

      RAJ KAUSHAL ARCHANA THAKUR ASTHA BHATIA SAROJ ARORA KIRAN NEHRA

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      A series of novel binuclear titanium (IV) complexes, [Ti(sal)LI-V(OBu)(l-OBu)]2, was synthesized by the reaction of salicylic acid (H2sal) and substituted indoles (LI = Tryptophol, LII = 5-Methoxyindole, LIII = Indole-5-Carboxaldehyde, LIV = 5-Cyanoindole, LV = 6-Nitroindole) with titanium(IV) tetrabutoxide in predetermined molar ratios under stirring and refluxing conditions in THF solvent.The chemical structure of synthesized complexes was found to be binuclear based on the FTIR, IH (proton) NMR and ESI-Mass (Electron-spray ionization) spectroscopic data. Each titanium metal was surrounded by two bridged butoxy groups and one terminal butoxy group along with bidentate salicylic acid and coordinated substituted indoles. These complexes were investigated for antioxidant potential using DPPH (2,2-diphenyl-1-picrylhydrazyl) assay where they exhibited moderate to good antioxidant activity. Gel electrophoresismethod was employed to study the ct-DNA (calf thymus DNA) cleavage efficiency of complexes using an agarose gel. Antimicrobial results stated that most of the complexes were ineffective against selected bacterial and fungal strains. Complexes were investigated for anticancer activity against two selected cancerous cell lines (L6 and L929). From MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay, it has been inferred that complexes 1 and 2 have better anticancer properties than their respective indoles. The DNAbinding study of synthesized complexes studied in order to check their efficacy to hinder DNA replication/transcription using electronic absorption and fluorescence spectroscopy revealed them as electrostatic/groove binder. The synthesized complexes were also evaluated for antidiabetic properties using alphaamylaseinhibition assay and complex 5 possessed better alpha-amylase inhibition activity than other complexes.

    • Synthesis, crystal structure, DFT calculation and trans ? cis isomerisation studies of bipyridyl ruthenium(II) complexes bearing 8-oxyquinolate azo ligands

      ROUMI PATRA AMIT MAITY KAJAL KRISHNA RAJAK

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      Two stable Ru(II) bipyridyl complexes were synthesized with the deprotonated forms of the azo ligands of 8-hydroxyquinoline (hq) as analogues and they were chromatographically separated. The extended azo ligands coordinated as a bidentate ligand and chelates to ruthenium(II) through 8-quinolinolate moiety,leaving the azo part free from coordination. The general formula of the complexes are [Ru(bpy)2(q)]+. Here, q- is the deprotonated form of 5-phenylazo-8-hydroxyquinoline (Hq1) and 5-(2-naphthylazo)-8-hydroxyquinoline(Hq2). The complexes were verified by 1H NMR, ESI-mass, absorption-emission spectra, cyclic voltammetry and single-crystal X-ray structure determination. UV light-induced trans͢ cis isomerization and reverse isomerism i.e. cis ͢ trans around -N=N- bond at room temperature were proposed from the UVVisspectral changes as well as the changing of the colour of the solution of the complexes. In aid of understanding the electronic charge distribution and charge-transfer properties, computational studies employing DFT and TDDFT method have been executed

    • One-pot synthesis of bimetal MOFs as highly efficient catalysts for selective oxidation of styrene

      KAI HUANG SIBING YU XIAOXIN LI ZHENYU CAI

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      A series of novel bimetallic organic framework materials (Cux-Coy-MOF) have been successfully prepared by a simple one-pot synthetic method, and their characters were evaluated via means of various techniques. The tested data showed a series of Cux-Coy-MOFs displayed good crystallinity and the doping of Co in original Cu-based framework would not change the morphology of the MOF catalysts. The catalytic activity of prepared materials was tested in the catalytic oxidation of styrene in the presence of TBHP. The effects of reaction time, reaction temperature and other reaction conditions on catalytic performance were systematically studied. The results revealed that the introduction of Co can improve the selectivity to form epoxides and reduce the yield of benzaldehyde without affecting the conversion rate of catalytic oxidation reaction of styrene. Excitingly, the Cu0.25-Co0.75-MOF showed better catalytic performance than Cu-MOF and Co-MOF under the optimal reaction conditions, the conversion rate of styrene reached 97.81%, and styrene oxide selectivity reached 83.04%, which indicated a significant synergistic effect of the Cu/Co bimetallic MOF. Furthermore, the Cu0.25-Co0.75-MOF catalyst exhibited good reusability that could be reused at least four times without significant inactivation

    • New vitamin K3 (menadione) analogues: synthesis, characterization, antioxidant and catalase inhibition activities

      NAHIDE GULSAH DENIZ AESHA F SH ABDASSALAM MUSTAFA OZYUREK EMIN AHMET YESIL CIGDEM SAYIL

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      In this study, derivatives of new vitamin K3 were synthesized by the reactions of 2-methyl-1,4-naphthoquinone 1 with some heterocyclic ring substituted nucleophiles: 1-piperonylpiperazine 2, 1-(2-furoyl)piperazine 5, 1-(2-aminoethyl)piperidine 8, 1-(2-aminoethyl)pyrrolidine 10 and 2,6-dimethyl morpholine 12 in chloroform/triethylamine (TEA) or ethanol at room temperature. Their structures were characterized by Fourier transform infrared spectroscopy (FT-IR), 1H nuclear magnetic resonance (1H NMR),attached proton test nuclear magnetic resonance (APT-NMR) and mass spectrometry (MS). Newly synthesizedvitamin K3 derivatives (3, 4, 6, 7, 9, 11, 13, 14) have shown catalase inhibition activity and compound 13 has displayed remarkable potency against catalase enzyme. These compounds were also tested for their antioxidant capacity in vitro by CUPRAC method

    • Role of supramolecular interactions in crystal packing of Strandberg-type cluster-based hybrid solids

      JISHA JOSEPH CINU WINSON BHARTI SINGH JEMINI JOSE JENCY THOMAS

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      Two new Strandberg-type cluster-based phosphomolybdates {H-2a3mp}5[{PO3(OH)}{PO4}-Mo5O15], 1 and {H-2a4mp}5[{PO3(OH)}{PO4}Mo5O15].6H2O, 2 have been crystallized via solvent evaporationtechnique using 2-amino-3-methylpyridine (2a3mp) and 2-amino-4-methylpyridine (2a4mp) respectively. The solids were characterized using single-crystal X-ray diffraction, powder X-ray diffraction,fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and cyclic voltammetry. The solid 1 crystallized in monoclinic system with space group P21/c, a = 8.394(1),b = 27.398(6), c = 21.521(4) A ° , b = 97.68(3)°, Z = 4. The solid 2 crystallized in triclinic system with space group P-1, a = 11.728(1), b = 14.234(1), c = 19.589(1) A ° , a = 68.906(3), b = 89.454(3), c = 66.559(3)°,Z = 2. The solids 1 and 2 formed a supramolecular framework stabilized by hydrogen bonding interaction between cluster anions and organic moieties. CH…p interactions between the organic moieties reinforced thecrystal packing in 1 and 2. While crystal packing effects resulted in the formation of solvent-accessible voids in 1; aggregation of lattice water molecules in 2 facilitated the formation of pentameric water cluster. In addition, electrochemical behavior of 1 and 2 has also been investigated

    • Design and synthesis of novel tetrahydrofuran cyclic urea derivatives as androgen receptor antagonists

      MURALIKRISHNA YARAGANI PRASAD YADLAPALLI SRIRAM RAGHAVAN NIRAIKULAM AYYADURAI SARAVANAN CHINNUSAMY VENKATA BASAVESWARA RAO MANDAVA RAJASEKHARA PRASAD KOTTAPALLI

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      In order to improve the antiproliferative activity of androgen receptor (AR) antagonists, which used clinically for the treatment of prostate cancer that is a major cause of male death in worldwide, we report the design and synthesis of a series of tetrahydrofuran cyclic urea-based non-steroidal small molecule ARantagonists and exhibit potent AR antagonistic activity. These molecules with higher stereochemical aspects have been achieved by changing the hydantoin analogue antiandrogens to 4-(2-oxohexahydro-1H-furo[3,4-d] imidazol-1-yl)-2-(trifluoromethyl)benzonitrile analogues. Here, the thio-hydantoin pharmacophore of the recently reported antagonists is replaced by tetrahydrofuran cyclic urea. The antiproliferative properties ofthese molecules have been evaluated against androgen-dependent (LNCaP) cell line. Among the reported molecules, 4-(2-oxohexahydro-1H-furo[3,4-d]imidazol-1-yl)-2-(trifluoromethyl)benzonitrile (AR04) showed significantly improved in vitro activity, IC50 = 3.926 lM. Molecular structure-activity relationship studiesconfirm that the oxetane analogue AR04 is distinct from other synthesized AR antagonists. These results have suggested that AR04 exhibiting their potential as a lead compound for the alternative treatment of prostate cancer.

    • Removal of Cr and Mn from aqueous medium using bentonites and their derivatives

      SOURAV MAJUMDER ASHOK KUMAR JHA

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      Bentonite minerals of Rajmahal Hills and Hazaribagh district along with their derivatives have been used to remove hexavalent chromium and manganese from aqueous medium. Bentonites are smectite group of minerals having swelling power and cation exchange properties. Blue colour with benzidine solutionindicates the presence of montmorillonite unit having SiO2, Al2O3, K2O, Fe2O3, FeO and traces of TiO2 also. The adsorption isotherm and removal performance of hexavalent chromium and manganese have been examined by shaking 100 mL 2 ppm solution with 1 gram of bentonite and their derivatives up to differentintervals of time and also with varying amount of bentonite up to fixed time intervals. The percentage removal of chromium (VI) ranges from 12% to 67.7% whereas percentage removal of manganese (VII) varies from 09% to 92.5%. Experimental data showed that the removal of Cr (VI) and Mn (VII) represented both Freundlich and Langmuir adsorption isotherms. Adsorption of Cr (VI) and Mn (VII) on to bentonites and their derivatives follow first-order kinetics. It is concluded that locally available bentonites may be exploited as a low-cost feasible adsorbent for removal of Cr (VI) and Mn (VII) in the laboratory as well as industrial level too.

    • Synthesis of ketamine from a nontoxic procedure: a new and efficient route

      NEGAR ZEKRI REZA FAREGHI-ALAMDARI BEHNAZ MOMENI-FARD

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      Ketamine [2-(2-chlorophenyl)-2-methylamino-cyclohexan-1-one] has been used in both veterinary and human medicine. In this research, a new and efficient protocol has been developed for the synthesis of ketamine, by using hydroxy ketone intermediate. Synthesis of this drug has been done in five steps. At first,the cyclohexanone was made to react with 2-chlorophenyl magnesium bromide reagent followed by dehydration in the presence of an acidic ionic liquid, 1-methyl-3-[2-(dimethyl-4-sulfobutyl-ammonium) ethane] imidazolium hydrogen sulfate to obtain 1-(2-chlorophenyl)-cyclohexene. The oxidation of the synthesized alkene by potassium permanganate gave corresponding hydroxy ketone intermediate. The imination of this intermediate by methyl amine and finally the rearrangement of the obtained imine at elevated temperatureresulted in the synthesis of ketamine. All of the intermediates and the product were characterized by 1H-NMR and IR spectroscopies. No need to use toxic bromine (which is used in most of the reported procedures for thesynthesis of ketamine), high reaction yields and use of commercially available and safe materials and no need to use corrosive acids in the dehydration step are some of the advantages of this procedure over the common reported ones for the snthesis of ketamine

    • Polymorph of trans-dichlorotetrakis(pyridine-N)ruthenium(II) influenced by a dihydrazone: crystal structure, spectral, Hirshfeld surfaces, antimicrobial, toxicity and in silico docking studies

      DEBAJANI BASUMATARY MADAN KUMAR SHANKAR KULLAIAH BYRAPPA KANDARPA KUMAR SAIKIA AJAZ AHMAD DAR VEDANT VIKROM BORAH PRANJIT SARMA PRANAMI MAHANTA MRITUNJAYA ASTHANA NAMRATHA KEERTHIRAJ

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      Many reports describe the influence of additives or impurities on the physicochemical properties of crystals. On having obtained trans-[RuCl2(C5H5N)4] as brown, needle-shaped crystals contrary to red ororange-red blocks reported previously, we herein revisit its study. This complex was obtained from the filtrate of an ensuing reaction mixture of RuCl3.3H2O, bis(2-hydroxy-l-naphthaldehyde)adipoyldihydrazone (npahH4) and pyridine in methanol. Findings from X-ray crystallographic data and spectra of IR, UV-Visible,1H and 13C NMR along with other analytical studies of the complex are presented here. A comparative study with previously reported crystal forms was performed to understand the accompanying molecular structuraldifferences in the physical (shape, size and color) morphological alteration. Further probing into molecular dynamics, the molecular interactions were analyzed and quantified using computational methods. The symmetry of intermolecular interaction in C—H_Cl is different from earlier reported crystal forms. The intercontact H_H showed a major contribution (62.9%) for Hirshfeld surfaces. Also, we report antibacterial activity of the complex against methicillin-resistant Staphylococcus aureus followed by the in silico docking study that revealed its interaction with the residue Glu58 of ATPase subunit of S. aureus GyrB. Additional studies on its toxicity using rat models revealed this complex as non-toxic to animals

    • Role of the solvent medium in the wet-chemical synthesis of CuSbS2, Cu3SbS3, and bismuth substituted Cu3SbS3

      SHALU ATRI MEENAKSHI GUSAIN PRASHANT KUMAR SITHARAMAN UMA RAJAMANI NAGARAJAN

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      Co-thermal decompositions of equimolar concentrations of thiourea complexes ([Cu(tu)3]Cl and [Sb(tu)2]Cl3) in ethylene glycol and ethanolamine were attempted. Based on the results from powder X-ray diffraction, Raman spectroscopy, and energy dispersive spectral analysis of the products, Cu3SbS3 in cubic symmetry emerged from ethylene glycol. In contrast, orthorhombic CuSbS2 resulted from the ethanolamine medium. The generation of copper-rich and copper-poor sulfides was found to be the major reason behind theformation of these stoichiometries of the Cu-Sb-S system as verified by reacting the preformed Cu-S and Sb-S species in ethanolamine and ethylene glycol. Attempts to include bismuth (up to 50 mol%) for antimony were successful only in ethylene glycol medium. The inclusion of bismuth stabilized the orthorhombic form of Cu3SbS3, possibly due to the non-bonded lone pairs present on Bi3+ and Sb3+ -ions. The inclusion of bismuth confirmed from the successful refinement of powder X-ray diffraction pattern by the Rietveld method, Ramanspectroscopy, and energy dispersive spectroscopy analysis. CuSbS22, Cu3SbS3 (cubic) and Cu3Sb0.50Bi0.50S3 showed broad absorption extending up to visible region in their UV-visible spectra. The bandgap values of 1.31, 1.40 and 0.94 eV were estimated by Tauc plots for Cu3SbS3, CuSbS2, and Cu3Sb0.50Bi0.50S3,respectively.

    • Characterization, microbial and catalytic application of V2O2 nanoparticles prepared from Schiff base complexes as precursor

      MOHAMMAD NASIR UDDIN MD SAIFUR RAHMAN WAHHIDA SHUMI MD KAMRUL HOSSAIN A K M ATIQUE ULLAH

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      Vanadiumpentoxide (V2O5) nanoparticles have gainedmuch attention due to their simple synthesis, a wide range of chemical, industrial, biological, and medicinal applications including anti-inflammation, antioxidant, anti-microbial activities. Vanadium complexes of Schiff bases were used as a precursor to synthesis vanadiumpentoxide (V2O5) nanoparticles. The precursor Schiff base complexeswere obtained by mixing vanadyl acetylacetonate with the prepared Schiff base ligands maintaining a ratio 1:1. After that V2O5 nanoparticles(denoted by C-1, C-2, C-3 and C-4) were synthesized by the direct calcination method based on thermal evaporation-condensation of vanadium complexes at 600 °C for 3 h. Finally, the analytical tools such as FTIR, XRD,EDS and SEMprovided evidence in favor of the formation of V2O5 nanoparticles. In addition,microbial study and photocatalytic activity were carried out using a spectrophotometer. An antimicrobial study showed that all the prepared V2O5 nanoparticles have inhibition capacity against the growth of some selected human pathogenic bacteria and few of them against plant pathogenic fungi. Moreover, these V2O5 nanoparticles have photocatalytic activity since these particles degrade organic dye, Eosin yellow

    • Structural investigation of barium zirconium titanate Ba(Zr0.5Ti0.5)O3 particles synthesized by high energy ball milling process

      PELIN SOZEN AKTAS

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      In this study, pure barium zirconium titanate Ba(Zr0.5Ti0.5)O3 (BZT) powders were successfully synthesized via the mechanochemical route using barium carbonate and titanium oxide as precursors. Structural properties of BZT are characterized by X-ray diffraction (XRD), Rietveld refinement, scanningelectron microscope, energy dispersive X-ray spectrometry, thermogravimetric analysis, and FT-IR spectroscopy. It was observed that the ball milling operation has a significant influence on sintering temperature. Single-phase BZT was obtained under sintering conditions at 1350°C. XRD and Rietveld refinement studies revealed that BZT composition has a cubic structure with a space group of Pm-3m (#221). As estimated by the Scherrer formula, the average crystallite size was determined as 79.2 nm for sintering temperature at 1350°C.

    • Studies towards synthesis and Lewis acid catalysed functionalization of 3-(4-substitutedphenylthio)-azetidin-2-ones

      SUVIDHA PANDEY AARTI THAKUR RESHMA SHAMSHER S BARI RENU THAPAR

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      Medicinal chemistry of heterocycles especially b-lactams have been an important discovery in today’s mankind. b-Lactam nucleus is structural feature and core of the biological activity of one of most successful classes of therapeutics to date characterized by a broad spectrum of activity and low toxicity. It constitutes classes of drugs that includes the antibiotics like penicillins, cephalosporins, clavulanic acid, monobactams and also shows wide range of important biological activities such as anti-cancer, anti-inflammatory and anti-malarial. The monocyclic b-lactams and their hetero-substituted conjugates are also applied for the synthesis of many classes of compounds which include taxol derivatives, alkaloids and amino acids. Antimicrobial resistance is one of the major and growing concerns in hospital and community acquired infections and new anti-microbial agents are therefore urgently required. So now, the organic chemists have focussed on the modification of existing molecules for the synthesis of new compounds having diverse pharmacological activities with broad spectrum activity. Monocyclic b-lactams are stable to hydrolysis by blactamases in comparison to other b-lactams and thus are attractive platform for searching anti-bacterial agents. The discovery of differently substituted 3-alkyl/aryl b-lactams having significant anti-microbial activities have given insight that substitution at C-3 and C-4 of b-lactam ring affects the biological activity of the ring. So, keeping this in mind and synthetic utility of b-lactams here we have made an attempt towards the feasibility and efficiency of 3-(p-substituted-phenylthio)-b-lactams towards Lewis acid functionalization reactions. In our previous works, we have explored the synthetic utility of cis-3-chloro-3-phenyl/benzyl/methylthio-b-lactams as suitable substrate for the Lewis acid catalysed nucleophilic substitution. The current work is designed to explore the effect of electronic changes at phenylthio group at C-3 on the products profile in the Lewis acid catalysed nucleophilic substitution reactions.

    • Cyanide selective chemodosimeter in aqueous medium, on test strips and its application in real sample analysis

      ASHISH RAINA YADVENDRA SINGH KOMAL KUMAR YADAV TAMAL GHOSH

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      In this paper, synthesis, characterization and detection of CN- by the compound (N1E,N2E)-N1,N2-bis((2-hydroxynaphthalen-1-yl)methylene)oxalohydrazide (1) have been reported. Compound 1 is synthesized by the reaction of oxalyldihydrazide and 2-hydroxy-1-naphthaldehyde and characterized byFTIR, 1H NMR and ESI-Mass spectroscopy. UV–Visible spectral band of 1 is observed to be broadened and shifted to longer wavelength upon addition of CN- ion selectively in H2O-DMSO (8:2 v/v) medium. Based on the UV–Visible spectral data, the detection limit of cyanide ion for 1 is found to be 30.2 lM. Colourlesssolution of 1 changes to yellow in the presence of cyanide ion selectively. The same colour change is also observed on Whatman filter paper test strip. Fluorescence intensity of 1 is quenched due to the nucleophilic addition reaction of cyanide with one of the two imine carbons. 1H NMR titration of 1 with CN- ioncorroborates the reaction of the latter with one of the two imine carbons of the former, leading to the appearance of cyanomethyl proton signal at 6.15 ppm and consequently, its behaviour as chemodosimeter. The above mentioned chemodosimeter nature of 1 is also validated by ESI-Mass spectroscopy data. Compound 1 is capable for the detection of CN- in water for real samples with concomitant colour change

    • Heavy-atom tunneling in organic transformations

      SHARMISTHA KARMAKAR AYAN DATTA

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      The pronounced effect of quantum mechanical tunneling in chemical reactions involving light atoms like hydrogen is well established. Recent studies have found that tunneling can also play a significant role for common organic transformations, where if the participating atom is carbon/nitrogen, etc. For thesecases, various reaction parameters like reaction barrier, barrier width and temperature play a crucial role in determining the efficiency of tunneling. In this review, we have focused on all those organic transformations where the influential role of tunneling has been documented either computationally or experimentally

    • Design, synthesis, molecular docking and cytotoxic activity of novel urea derivatives of 2-amino-3-carbomethoxythiophene

      VENUGOPALARAO VIKRAM SRINIVASA R PENUMUTCHU RAVIRAJ VANKAYALA SURESH THANGUDU KARTEEK RAO AMPERAYANI UMADEVI PARIMI

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      An efficient feasible route for the one-pot synthesis of novel series of urea derivatives (2a–2j) from 2-amino-3-carbomethoxythiophene (1) via in situ isocyanate has been developed, and their corresponding anticancer activities were accomplished. The series of urea derivatives were characterized by using 1H, 13C nuclear magnetic resonance and mass spectroscopic analysis. The cytotoxic activities were evaluated against human cervical (HeLa) and human lung (NCI-H23) cancer cell lines. These studies revealed satisfactoryactivity for some of the compounds, which could potentially serve as lead compounds for drug discovery and development. Furthermore, molecular docking studies supported in identifying the potential binding sites between the urea derivatives and eukaryotic ribonucleotidereductase (RR). High ambiguitydriven docking (HADDOCK) modelling was specifically employed to determine the model complex of RR and urea derivatives. The proposed model has provided a deep insight into the molecular level interactions of RR-urea model complexes in understanding the exact pharmacophore for designing highly potent RR inhibitors. Overall, the present work has shed light in developing a feasible and robust approach for the synthesis of novel urea derivatives of 2-amino-3-carbomethoxythiophene and identified a part of molecular structurethat is responsible for a specific biological interaction leading to potential anticancer activities

    • Macrocyclic butterfly iron cluster complexes: electrochemical investigations

      TASHIKA AGARWAL SANDEEP KAUR-GHUMAAN

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      The article primarily highlights the electrocatalytic activity towards proton reduction of macrocyclic tetranuclear iron complexes [Fe2(l-S(CH2)nS-l)(CO)6]2 (n = 4, 1 and n = 6, 2) with both acetic acid and trifluoroacetic acid as proton sources. Further, the electrochemical results have been compared with theanalogous pentanedithiolate-bridged tetranuclear complex, [Fe2(l-S(CH2)5S-l)(CO)6]2 A. The turnover frequency (TOF, acetic acid) for complexes 1 and 2 was found to be 5.7 h-1 and 9.1 h-1, respectively. An ECEC catalytic cycle (acetic acid) has been proposed for the tetranuclear iron complexes based on theexperimental data and known literature

    • Influence of sugars in preparing improved FeAl catalyst for carbon dioxide hydrogenation

      WENSHENG NING BEI LI HUI DAI SHIYE HU XIAZHEN YANG BIAO WANG BO ZHANG

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      The influences of sugars (sucrose, fructose and glucose) on the performance of FeAl catalysts were investigated for CO2 hydrogenation. FeAl catalysts were prepared with two steps. At first, the catalyst precursors were obtained by co-precipitation. During this step, three methods were used to add sucrose intothe precursors. Then, promoter K and Cu were impregnated into the precursors. The improved CO2 conversion and C5+ hydrocarbon selectivity by sucrose addition were attributed to the formation of c-Fe2O3 phase in the catalyst precursor, which was different from the popular opinion that sucrose acted as a chelating agent. With the inspiration from sucrose hydrolysis effect, FeAl oxide, mainly in c-Fe2O3 phase was prepared by adding fructose and glucose (the products of sucrose hydrolysis) into the newly centrifuged precipitate.The formation of c-Fe2O3 phase was explained based on the results of XRD and XPS. The best catalyst possessed CO2 conversion of 30.3% and C5+ selectivity of 52.2% under the reaction conditions of H2-:CO2 = 3:1, 6.0 L/(h.g-cat), 1.6 MPa and 235 °C.

    • Synthesis of meso-substituted corroles and porphyrins using iodine as a catalyst

      ANSHU DANDIA SHIVE M S CHAUHAN

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      Different types of corroles and porphyrins are synthesized from substituted aldehydes and pyrrole. The current synthetic method involves iodine as catalyst and proceeds at room temperature itself. By varying the amounts of reactants (i.e., pyrrole and aldehydes), the corrole and porphyrins were obtained ingood to excellent yields. These products were characterized by 1H-NMR, UV-visible, and HRMS techniques. The reaction approach utilizes the readily available pyrrole and substituted aldehydes as starting materials and makes this reaction highly attractive in diversity-oriented synthesis

    • Deep eutectic solvent promoted one-pot synthesis of nitriles from alcohols

      LUXIAO LIU HONG-YU ZHANG GUOHUI YIN YUECHENG ZHANG JIQUAN ZHAO

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      Various aryl nitriles were readily synthesized from aerobic oxidation of substituted benzyl alcohols in deep eutectic solvent composed of choline chloride (ChCl) and p-toluenesulfonic acid (p-TsOH) in the presence of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), followed by condensation with hydroxylamine hydrochloride. High yields of corresponding nitriles have been obtained under mild reactions conditions. This strategy belongs to a novel and environmentally benign transition-metal-free one-pot cascade process for the synthesis of nitriles.

    • Cyclic zinc organophosphate based expanded ditopic N,N-metalloligands

      GULZAR A BHAT RAMASWAMY MURUGAVEL

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      A new series of zinc phosphate based novel elongated ditopic N,N-metalloligands [Zn(Xdipp)(pyterpy)]2.2MeOH (X= H (1), Cl (2), Br (3), I (4)], exemplifying expanded 4,4-bipyridine spacer family, has been prepared by reacting 4-(4ꞋꞋ-pyridyl)-2,2:6,2ꞋꞋ-terpyridine (pyterpy), 2,6-iisopropylphenylphosphate (dippH2) or its para-halo functionalized derivatives X-dippH2 (X = Cl, Br, I) with Zn(OAc)2.2H2O in a mixture of solvents at room temperature. The formation of these metalloligands has been confirmed by their spectroscopic and analytical data. Solution and solid-state stability of these complexes have beenconfirmed by both mass spectroscopy and thermogravimetric analysis. The solid-state structures of 1–4 have further been established by single crystal X-ray diffraction studies, revealing that the N,N-distance in these systems can be expanded approximately to 23 A° , as against the 7 A° separation observed for 4,4-bipyridine.Compounds 2–4, which contain two pyridyl nitrogen centers and two C–X functionalities that are orthogonal to each other, could offer new possibilities in their use as metalloligand to build extended 2-D and 3-D solids

    • A novel reaction of 2-phenacyl mercaptoimidazole with acetic anhydride: formation of an imidazothiazole with loss of a phenyl group

      SHASHIPRABHA K NAGARAJAN SAJESH P THOMAS SURESH P NAYAK K SUNDARRAJA RAO K SHRIDHARA T N GURU ROW

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      Attempted cyclodehydration of phenacyl mercaptoimidazole hydrobromide with acetic anhydride gave an abnormal product lacking the phenyl group. The molecular structure is confirmed using X-ray crystal structure studies. Phenacyl mercaptobenzimidazole hydrobromide behaved similarly. Analysis of crystalstructure revealed an intermolecular S…Br chalcogen bonding interaction

    • Experimental and theoretical insights on the adsorption and inhibition mechanism of (2E)-2-(acetylamino)-3-(4-nitrophenyl) prop-2-enoic acid and 4-nitrobenzaldehyde on mild steel corrosion

      N ARROUSSE R SALIM G AL HOUARI F EL HAJJAJI A ZARROUK Z RAIS M TALEB DHEERAJ SINGH CHAUHAN M A QURAISHI

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      (2E)-2-(acetylamino)-3-(4-nitrophenyl)prop-2-enoic acid (NPP) was synthesized following a facile chemical method from 4-nitrobenzaldehyde (NB) and thoroughly characterized using spectroscopic techniques. These compounds were applied as novel inhibitors for corrosion of mild steel in 1M HCl using various methods such as absorbance difference, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). The results indicate that these inhibitors show an excellent protection performance and achieve the corrosion inhibition efficiency values of 94% and 84% for NPP and NB, respectively. Theadsorption of these molecules obeys the El-Awady isotherm model. The surface analysis of mild steel was investigated using scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) methods. Furthermore, quantum chemical calculations were investigated using DFT method at B3LYP/6-31G (d,p)computed by Gaussian 09 showing a good correlation with the experimental results

    • Development of a continuous process: a perspective for Mitsunobu reaction

      GIRISH BASAVARAJU RAVISHANKAR RAJANNA

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      The developments around flow processing technology have paved the way for new avenues and perspectives to consider in the field of organic chemistry and engineering. In this study, customized flow equipment was utilized to develop and optimize the Mitsunobu reaction. The flow reactor was a prototype of a simple tubular reactor based on the plug flow reactor concept. The experimentation methodology was designed through the statistical design of experiments approach to minimize the number of experiments. The molar ratios of cyclohexanol (1) and o-cresol (2) and interaction effects of triphenylphosphine, diisopropyl azodicarboxylate were studied in detail. The reaction profile of flow experiments agreed with the batch conditions adding noteworthy improvements to the overall reaction time, selectivity, and yield towards the desired product 1-(cyclohexyloxy)-2-methylbenzene (3). The Mitsunobu reaction in batch condition would take on an average of 3 to 5 h, which was effectively accomplished in 30 to 45 mins in this flow reactor. The generated mathematical model is in good agreement with the reaction conditions. We believe that the process could be executed continuously without a break, readily scaled to kilogram quantities in a short time without further development.

    • High throughput green reduction of tris(p-nitrophenyl)amine at ambient temperature over homogenous AgNPs as H-transfer catalyst

      SAEED REZA HORMOZI JANGI MORTEZA AKHOND

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      A green, facile, fast, and high throughput reusable catalytic reduction process was developed for the large-scale reduction of tris(p-nitrophenyl)amine to its corresponding amino-compound, tris(p-aminophenyl) amine (TAPA). The homogenous AgNPs and NaBH4 were used as the H-transfer catalyst and the H-donor compound, respectively. The successful reduction of TNPA was investigated by FT–IR, EDX, and XRD analysis, and its optical properties were checked by the UV–Visible and FL spectroscopies. Factors affecting the reduction yield including, temperature, reaction time, mmol of NaBH4, and catalyst volume, were optimized. Although the AgNPs are homogenous, both TNPA and TAPA are insoluble in water (AgNPs), hence the reduction process is heterogeneous. The importance of the heterogeneous reduction of TNPA was investigated, indicated that the reduction yield reached its maximum value when TNPA heterogeneously reduced on the surface of AgNPs. The reduction yield at optimal conditions was calculated at about 98.0% for the first and 72.0% after the 66th operational cycle, respectively. The mechanism of thereduction process was also established, indicated that the process works through a possible Langmuir–Hinshelwood mechanism. The easy recovery and excellent reusability of homogenous AgNPs along with high reaction yield reveal the power of the proposed method for the reduction of nitro-compounds.

    • Probing the interaction between human serum albumin and the sodium dodecyl sulphate with fluorescence correlation spectroscopy

      VAISHALI SAMANT ARGHYA DEY G NARESH PATWARI

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      The denaturation of human serum albumin (HSA) upon interaction with the surfactant sodium dodecyl sulphate (SDS) was examined by measuring the diffusion time of fluorophore (RITC) tagged HSA under near single-molecule conditions using fluorescence correlation spectroscopy. The diffusion time showsfour distinct regions as a function of SDS concentration, which corresponds to (I) opening of the tertiary structure, (II) non-specific SDS aggregation, (III) opening of the secondary structure, and (IV) aggregation of SDS around the secondary structure. Diffusion time increases from 383 ls for the free protein to 1002 ls forthe SDS bound protein, which leads to an effective increase in the hydrodynamic radius by a factor of about 2.6

    • An improved protocol for the synthesis of 3,4-disubstituted isoxazol- 5(4H)-ones through L-valine-mediated domino three-component strategy

      PARTEEK KOUR MONIKA AHUJA PRATIBHA SHARMA ASHOK KUMAR ANIL KUMAR

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      An expeditious, metal-free protocol has been demonstrated for the synthesis of isoxazolone derivatives using domino multi-component strategy. The envisaged methodology involves the L-valine promoted three-component cyclo-condensation reaction of alkylacetoacetates, hydroxylamine hydrochlorideand aldehydes in ethanol under reflux. The reaction proceeded to deliver the desired products in good to excellent yields (74–97%), exhibited good functional group tolerance and completed in less than 4 min with most of the substrates. High yields, short reaction time, noncorrosive organocatalyst, mild reaction conditions, clean reaction profiles and the absence of any tedious workup or purification are the beneficial features of this process. Moreover, quantum computational study has been performed at B3LYP/6-311G??(d, p) level toinvestigate the various DFT based molecular descriptors, HOMO–LUMO energy gap and electrostatic potential surface properties of the synthesized product

    • Cationic dye adsorption by phosphomolybdate nanoclusters immobilised on polyelectrolyte matrix

      K SHAKEELA SRUTHI GURU G RANGA RAO

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      A polyelectrolyte complex (PEC) made up of poly(di-allyl di-methylammonium chloride) and poly(styrene sulphonate) polyelectrolytes has been synthesised and used for the immobilisation of phosphomolybdate (PMo), [PMo12O40]3- nanoclusters. The material is characterised by FTIR, powder XRD, SEM, TEM and UV-Visible DRS spectroscopy. It was found that the PMo clusters are intact in the hybrid and are present as nanoaggregates within the layers of PEC. The amount of PMo present in the hybrid is estimated from thermal measurements and the optical band gap energy of the material is found to be in the semiconductor region. The presence of negatively charged PMo clusters helped in almost complete adsorption of cationic dyes, methylene blue and rhodamine B. The PMo/PEC hybrid has shown to follow Langmuir adsorption isotherm in case of both the dye molecules.

    • Synthesis and optimization of polypropylene glycol-glycidyl azide polymer-polypropylene glycol as a novel triblock copolymer binder

      FAHIMEH GHOROGHCHIAN YADOLLAH BAYAT FATEMEH ABRISHAMI

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      The novel energetic triblock copolymer of polypropylene glycol-glycidyl azide polymerpolypropylene glycol (PPG-GAP-PPG) (Mn = 1639 g.mol-1) was synthesized and optimized by cationic ringopening polymerization of propylene oxide using low-molecular-weight glycidyl azide polymer (GAP) (Mn =1127 g.mol-1) as the initiator and boron trifluoride etherate (BF3OEt2) as the catalyst. This research reveals a new method for polymerization of PPG at room temperature and atmospheric pressure. The synthesized GAP and triblock copolymer were characterized by fourier-transform infrared (FT-IR), gel permeation chromatography (GPC) and nuclear magnetic resonance spectroscopy (1H and 13C NMR). Optimization of temperature and amount of catalyst for the synthesis of PPG-GAP-PPG were also performed. The effect of the temperature and the amount of catalyst on the percentage yield of the reaction and the molecular weight of the triblock copolymer of PPG-GAP-PPG was studied. The optimized temperature and catalyst amount for thesynthesis of triblock copolymer of PPG-GAP-PPG were 10–15°C and 1% w/w respectively. The thermal stability of the triblock copolymer PPG-GAP-PPG was studied by differential scanning calorimetry (DSC) and thermogravimetry (TG) techniques. The DSC result showed that the glass transition temperature (Tg) ofthe triblock copolymer (Tg = -63°C) is lower than the neat low molecular weight GAP (Tg = –45°C). Also,the differential thermogravimetry (DTG) result indicated that this triblock copolymer is more stable than the GAP.

    • Novel chalcones as Bcl-2 inhibitor in lung cancer: docking, design and synthesis of 2,3-Tetrasubstituted-2,3-dihydrobenzofuran-3- carboxamides

      SANKAR P DEY NAYIM SEPAY ASOK K MALLIK AMARENDRA PATRA

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      Some of the chalcones and flavones are very efficient to facilitate the signal of death to the lung cancer cell through blocking the active site BH3 of Bcl-2 proteins. We designed a number of novel chalcones and flavones targeting the active site of the protein. Docking study showed that the designed compounds were very efficient as the reported compounds. We synthesized and characterized some of the designed compounds.2,3-Tetrasubstituted-2,3-dihydrobenzofuran-3-carboxamides were generated as novel products bybase-catalyzed condensation of o-hydroxyacetophenones and p-nitrobenzaldehyde in different alcohols. Detailed NMR spectroscopic analysis including COSY, homodecoupling and HETCOR (one bond as well aslong-range) studies established the structure of the compounds. Mechanistic paths have been suggested for the formation of the novel products.

    • Synthesis of diosgenin prodrugs: anti-inflammatory and antiproliferative activity evaluation

      LEYDI M CARRILLO-COCOM BETHSABE B VILLAGOMEZ GONZALEZ ROSA SANTILLAN DELIA SOTO-CASTRO PAUL M SANCHEZ OCAMPO ALEJANDRO ZEPEDA JACQUELINE CAPATAZ TAFUR

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      In this work, we evaluated the antiproliferative and anti-inflammatory activities of two diosgenin prodrugs. The prodrugs were obtained by esterification of diosgenin at position 3 with 4-oxo-4-(prop-2-yn-1-yloxy)butanoic acid followed by click reaction on terminal alkyne with 3-azidopropan-1-ol N-alkylated dendrons, resulting in a prodrug with methyl ester end-groups and a derivative with tert-butyl ester endgroups, hydrolysis of tert-butyl ester derivative afforded a prodrug with carboxylic acid terminals. All compounds were fully characterized by 1H and 13C NMR, ATR-FTIR and HR-ESI TOF. Studies of the antiinflammatoryeffects on mouse ear edema of prodrugs methyl ester and carboxylic acid, ended, using diosgenin and dexamethasone as positive controls, showed the superiority of methyl ester ended prodrug with an ED50 four times lower than that of dexamethasone. Further, carboxylic acid ended prodrug was found to bemore active than diosgenin as an antiproliferative agent, according to crystal violet assay

    • Antioxidant ferulic acid prevents the aggregation of bovine b-lactoglobulin in vitro

      SAMPA PAL SANHITA MAITY SUBRATA SARDAR SHAHNAZ BEGUM RAMKRISHNA DALUI HASAN PARVEJ KAUSHIK BERA ANIRBAN PRADHAN NAYIM SEPAY SWARNALI PAUL UMESH CHANDRA HALDER

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      Amyloids, a well-ordered b-sheet-enriched structural network, can be broadly defined as insoluble protein aggregates that are linked to a wide variety of diseases including systemic amyloidosis and some neurodegenerative disorders. Ferulic acid (FA), a phenolic acid, abundant in antioxidant and efficientpharmaceutical has beneficial effects against several ailments. Based on this, we have investigated the protective role of FA on amyloid formation of bovine b-lactoglobulin (b-lg), a model globular protein. Using a set of in vitro biophysical methods, such as UV-Vis spectroscopy, fluorescence, circular dichroism,transmission electron microscopy, etc., our research group has concluded that FA significantly inhibits the heat-induced amyloid formation of b-lg and this inhibitory effect is dose-dependent. Exposed surface hydrophobicity of b-lg amyloid fibrils decreased significantly in the presence of FA. Docking study revealed that ionic and hydrogen bonding interactions between FA and b-lg prevented protein conformational changes leading to fibrillation. We anticipate that our finding would give an insight into the protein aggregation inhibited by the antioxidant compound, FA and pave the way for finding and developing other new small molecules (protein misfolding inhibitors) that give similar result against amyloid fibril formation and its allied neurodegenerative disorders.

    • Iron(III) and cyano-bridged dinuclear copper(II) complexes: synthesis, structures and magnetic property of the copper(II) complex

      GOUTAM MAHATA ANANGAMOHAN PANJA

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      This report describes the synthesis and structural characterizations of three new complexes; [Na3Fe2(bbp)(Hbbp)(CN)6(H2O)9]4H2O (1), (Bu4N)[Fe(bbp)2].3CH3OH.2H2O (2), and a cyano-bridged dinuclear copper(II) complex, [Cu2(tren)2(CN)][Fe(bbp)2]3 6CH3OH.4H2O (3), where H2bbp = bis(2-benzimidazolyl) pyridine and tren = tris(2-aminoethyl)amine. X-ray crystallography reveals that the geometry of iron(III) centers in the complex anions of 1–3 is an octahedral, while it is a trigonal bipyramidal around copper(II) center in the complex cation of 3. Both bbp ligands meridionally coordinate iron(III) centers in the complex cations of 2 and 3, while three cyanide ions and bbp (or Hbbp) ligand occupied either of the meridional positions around the metal center in 1. In the dinuclear complex cation of 3, the Cu(II)-CN-Cu(II) bridging region is strictly linear as dictated by the symmetry with Cu...Cu separation of 5.084 (7) A° . Variable temperature magnetic susceptibility study shows that the cyano-bridge mediates the antiferromagnetic coupling between copper(II) centers with J value of -110 K in 3.

    • Preparation of a hollow cube NiCo2S4 and its application in supercapacitor

      XIAOSHAN LI YOU FU HANG MA XILONG LIU LINA LI JIAN MA CONGJIE LIANG MENG JIN YINGJIE HUA CHONGTAI WANG

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      Here reports a hollow cube NiCo2S4 nanomaterial, which was prepared via facile hydroxylation and sulfuration steps using the self-prepared ZIF-67 as a precursor. This kind of NiCo2S4 as an electrode material for supercapacitor presents a specific capacitance high up to 1350 F g-1 at 1 A g-1 due to the contribution of pseudocapacitance. Particularly, the hybrid supercapacitor PC//NiCo2S4, assembled using the NiCo2S4 as the positive electrode material and the PC as the negative electrode material, delivers a high energy density of 33 Wh kg-1 at the power density of 800 W kg-1. Meanwhile, it presents a good cyclic stability with 67% capacitance retention after 10,000 cycles of charge–discharge at the current density of 5 A g-1. However, the rate capability is not good enough because of the polarization effect of NiCo2S4 as a battery-type electrode material. Therefore, this research provides a reference for enhancing capacitance performance of an electrode material. For instance, reversibility in redox reaction and stability in structure are more important than the capacity in many cases.

    • Synthesis, biological evaluation and molecular docking of 3- substituted quinazoline-2,4(1H, 3H)-diones

      LUMADHAR SANTOS-BALLARDO FERNANDO GARCIA-PAEZ LORENZO A PICOSCORRALES ADRIAN OCHOA-TERAN PEDRO BASTIDAS LORANDA CALDERO NZAMORA GUADALUPE RENDON-MALDONADO ULISES OSUNA-MARTINEZ JUAN I SARMIENTO-SANCHEZ

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      The quinazoline-2,4-diones scaffold is found in bioactive compounds, commercial drugs and exhibit important biological activities. However, their antidiabetic activity is rarely explored. For this purpose, an easy one-pot three-components and straightforward synthesis of 3-substituted quinazoline-2,4-diones was designed, in both, the catalyst- and solvent-free conditions under microwave irradiation. Additionally, the synthesized compounds were screened for in vitro a-amylase and a-glucosidase inhibitory activity, as well as antioxidants and cytotoxicity. The quinazoline-2,4-diones were isolated, with yields in the range of 30-65%.The compounds 3d, 3e, 3g and 3h displayed moderate activity against a-amylase and/or a-glucosidase enzymes compared with the acarbose drug. The molecular docking study revealed that all active compounds displayed a different type of intermolecular interaction in the pocked site of these enzymes. Interestingly, inthe Artemia salina assay, the compound 3d exhibited a higher cytotoxic effect than 5-fluorouracil. All these results support the pharmacological potential of quinazoline-2,4-diones since all evaluated compounds behave as moderate inhibitors of the enzymes a-amylase and/or a-glucosidase.

    • Luminescent metal–organic frameworks and their potential applications

      RITESH HALDAR SOHINI BHATTACHARYYA TAPAS KUMAR MAJI

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      The metal–organic frameworks (MOFs) or porous coordination polymers (PCPs) are a class of porous, crystalline material with numerous possibilities of real-world applications including storage, separation, catalysis, sensing etc. The possibility of intrinsic crystallinity and virtually infinite metal/metal-oxo node and organic linker combination make it a perfect material for photophysical studies. In the last decade, luminescent MOFs have emerged as an excellent modular material for various optical applications, and here, we have discussed about its design strategies. In this review, with relevant examples we have highlighted the rational design approach, possible applications (light emitting diodes, sensing) and future directions in luminescent MOFs

    • New oxygen-containing androstane derivatives: Synthesis and biological potential

      MARINA P SAVIC IVANA Z KUZMINAC DUSAN Ð S KORIC DIMITAR S JAKIMOV LUCIE RAROVA MARIJA N SAKAC EVGENIJA A DJURENDIC

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      New steroidal D-homo androstane derivatives with 5b,6b-epoxy-3,16-dicarbonyl, 6a- and 6bhydroxy-3,16-dicarbonyl and 3b,5a-dihydroxy-6,16-dicarbonyl moieties were synthesized and confirmed by NMR spectroscopy. Novel and starting compounds were evaluated for their potential cytotoxicity in vitro against seven human cancer cell lines (MCF-7, MDA-MB-231, PC3, HeLa, HT-29, A549 and CEM) and one human noncancerous cell line (MRC-5). The most sensitive cell line was MDA-MB-231 derived from female reproductive tissue, wherein all compounds showed moderate to strong cytotoxic activity. Also, new compound with 5b,6b-epoxy-3,16-dicarbonyl moieties showed strong cytotoxic activity against colon adenocarcinoma (HT-29). In this work, in silico ADME properties of novel compounds were assessed by comparing calculated molecular properties with Lipinski, Veber, Egan, Ghose and Muegge criteria

    • Mechanistic pathways for halogen dance reactions in bromothiophenes: a cascade-like pattern

      NADER SAKHAEE SAHAR SAKHAEE AKBAR MOBARAKI AHMAD TAKALLOU MOHAMMAD HOSSEIN SAKHAEE

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      Ever since the halogen dance reaction was discovered by Bunnet et al, synthetic chemists have utilized the transformation in many desirable ways to build substituted heterocyclic target molecules of all kind. Using DFT-Cam-B3LYP/ land2dz computations and focused on Hannes Frohlich et al. Halogen Dance(HD) reactions of bromothiophenes, a new bromo-bridged Transition State (TS) is proposed. This bromobridged TS was then used to put forth eight possible isomerization as well as eight possible disproportionation paths. These mechanistic pathways were then carefully inspected based on TS’s energy and protonation/deprotonation steps to find the most suitable pathways. Collectively these mechanistic pathways joined like a jigsaw puzzle to give, for the first-time, a fully comprehensive cascade-like pattern for base-catalyzed halogen dance in its entirety. The present work may well shed light on a dynamic domino mechanism which dominates the realm of nonaqueous strongly basic medium, organic chemistry, reactions

    • Efforts toward the synthesis of (+)-Lyconadin A

      SATISH KARELLA SADAGOPAN RAGHAVAN

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      Synthetic efforts toward the synthesis of (?)-lyconadin A are described. B-Alkyl Suzuki coupling is utilized for combining 2-iodo cyclohexenone with the piperidine subunit. The piperidine subunit is derived from 5-bromo-3-nicotinic acid, and iodo cyclohexenone from commercially available (R)-pulegone. An intramolecular Michael reaction is employed for the creation of the C6-C7 bond.

    • Study of photophysical behaviour of some Sm(III) complexes with 4- oxo-4H-1-benzopyran-3-carboxaldehyde and other N,N¢-donor pconjugated ligands

      ARCHANA CHAUHAN RITU LANGYAN

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      Trivalent lanthanide ions show interesting optical properties. Keeping this in view, five Sm(III) complexes were synthesized using 4-oxo-4H-1-benzopyran-3-carboxaldehyde (L) as primary ligand along with 1,10-Phenanthroline (Phen); Bipyridine (Bipy); Bathophenanthroline (Bathophen) and Neocuproine(Neo) as secondary ligands. Characterizations of prepared complexes were carried out by means of FTIR, elemental analysis, UV–vis, ESI-MS+, thermal studies, PXRD, FESEM, and luminescence studies. Thermal studies confirmed the good thermal stability of complexes. Sharp peaks in X-ray diffractograms suggest their crystalline nature. The photoluminescence process in complexes has been thoroughly studied and discussed in liquid and powder state. The complexes show 4G5/2®6Hj transitions where j = 5/2, 7/2, and 9/2, analogous tocharacteristic emission peaks of Sm(III) ion at ~ 566, 601, and 648 nm, respectively. The complexes demonstrate intense emission peaks at ~ 601 in liquid and ~ 648 nm in a powder state, which is responsiblefor bright orange and red emission, respectively. The synergistic effect of secondary ligands was responsible for longer luminescence lifetime and enhanced emission intensity in ternary complexes. Attractive photoluminescenceproperties of complexes could play a vital role in electroluminescent devices, bio-assays, liquid lasers, OLEDs, etc.

    • Design and synthesis of novel isatin derivatives as potent analgesic, anti-inflammatory and antimicrobial agents

      KOSARAJU LAHARI RAJA SUNDARARAJAN

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      A powerful analgesic, anti-inflammatory and antimicrobial drug was developed by synthesizing a set of new indole-2,3-dione derivatives. The chemical structures of the synthesized derivatives were confirmed by spectroscopic and elemental analyses. Tail flick method, carrageenan-induced foot paw edema technique and agar streak dilution methods were employed to evaluate analgesic, anti-inflammatory and antimicrobial activities (in vitro) of drugs, respectively. In addition, ulcerogenicity of potent derivatives was also estimated. Most of the synthesized derivatives displayed low-to-reasonable ulcer index, with mild-togoodanalgesic, anti-inflammatory and antimicrobial potency. The SARs between the biological activity and differences in the functional group of the title compounds have been explained. 1-(4-Chlorobenzylidene)-4-(4-(1-((dimethylamino)methyl)-5-nitro-2-oxoindolin-3-ylideneamino)phenyl)thiosemicarbazide VIc has beenfound as the potent derivative of this series.

    • C-halogen…pi interactions in nucleic acids: a database study

      DEBARGHYA MITRA NAMRATA BANKOTI DALIAH MICHAEL K SEKAR T N GURU ROW

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      A Protein Data Bank study was conducted to check the role of C-halogen(X)…pi interactions (X = F, Cl, Br, I) in nucleic acids. The presence of halogens can be attributed to not only the modified residues of the nucleic acid but also the ones associated with the ligand. The study reports the presence of bromine amongst modified residues of the nucleic acid being the maximum than any other halogens. It is important to consider these interactions as they seem to be responsible for increasing the affinity of the ligand to the biomolecule concerned. The role of halogen-pi interactions becomes important to be assessed in orderto design halogenated ligands that will certainly be more effective in increasing the binding of the corresponding ligand to the target nucleic acid. The study attempts at listing the halogens that are prominent in the existing nucleic acid and ligand interactions which are deposited in the PDB. Inter-atomic interactions based on C-X…pi were analyzed to be found in several PDB IDs and similar ligand halogenation can be carried out to effectively increase binding affinity of halogenated ligands to nucleic acid based targets in case of severaldiseases.

    • Catalytic assay of Schiff base Co(II), Ni(II), Cu(II) and Zn(II) complexes for N-alkylation of heterocycles with 1,3-dibromopropane

      SUJIT HEGADE YUVRAJ JADHAV SANJAY CHAVAN GANPATRAO MULIK GAUTAM GAIKWAD

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      N-alkylation of heterocycles with 1,3-dibromopropane using Schiff base Co(II), Ni(II), Cu(II) and Zn(II) transition metal complexes as a catalyst was studied in 1:1 and 2:1 coupling ratios under mild conditions. It was observed that all the complexes worked as efficient catalyst with product yield 78–92% for coupling ratio 1:1 and product yield 63–78% for coupling ratio 2:1. N-alkylation of heterocycles with 1,3- dibromopropane in 1:1 coupling ratio is easier with higher yields as compared with N-alkylation in 2:1 coupling ratio.

    • Extraction of Th, Zr and Sc from rock matrix using silica modified with arsenazo-III and their determination by inductively coupled plasma atomic emission spectrometery

      BINCY CYRIAC MASTAN VALI NISHMA OJHA SMEER DURANI

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      A simple, selective and rapid determination procedure for Th, Zr and Sc in rock samples using adsorbent silica modified with arsenazo-III is described. Silica modified with arsenazo-III (SAR-III) was synthesised by a single step process in presence of cationic surfactant cetyltrimethylammonium bromide. Effect of pH, amount of adsorbent, contact time for adsorption and the optimum eluent for the quantitative recovery of Th, Zr and Sc were investigated. Optimum conditions selected for the selective extraction of these elements by SAR III are pH-3, 0.2 g adsorbent, contact time 30 minutes and 10 mL of 5 % ammonium oxalateas eluent. Adsorption capacities of SAR III for Th, Zr and Sc are 5.68, 23.9 and 4.42 mg g-1, respectively. Effect of major elements present in the rock on the pre-concentration of these elements was investigated. Interference of iron was eliminated by reducing ferric iron with hydroxylamine hydrochloride. The methodwas validated by applying the procedure to synthetic rock sample solutions and certified geological reference materials SY-2 (CCRMP, Canada), BCR-1 (USGS), GSN (ANRT, France) and AGV-1(USGS). Detection limits obtained for Th and Zr by this method are 1 mg g-1 and that of Sc is 0.1 mg g-1. The relative standarddeviation of the method at 1 mg g-1 was in the range of 1.0–2.5%

    • Intramolecular cyclization of N-hydroxy-2-phenoxyacetamides and 3-phenoxypropanamides

      VISWANATH NAGALINGAM REDDYMASU SREENIVASULU NAGARAJAN MADHAVARAO RAMACHANDRAN DITTAKAVI KRISHNAMURTHY MANNAM

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      A novel route for the preparation of 2H-1,4- benzoxazin-3(4H)one and 1,5 benzoxazepinones by intramolecular cyclization of N-hydroxy 2-phenoxyacetamide and N-hydroxy -3 phenoxypropanamide using PPA and Lewis acid has been discussed

    • A ninhydrin–thiosemicarbazone based highly selective and sensitive chromogenic sensor for Hg2+ and F- ions

      V RAJU R SELVA KUMAR S K ASHOK KUMAR G MADHU SHILPA BOTHRA SUBAN K SAHOO

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      This study demonstrates the design, synthesis and sensing applications of a simple and efficient chemosensor, 2-(1,3-dioxo-1H-inden-2(3H)-ylidene)hydrazinecarbothioamide (R) for quick detection of Hg2+ and F- in aqueous media using a colorimetric test, UV–Vis spectral analysis, and silica gel support Sensor R showed the typical absorption peak at 305 nm for Hg2+ which is responsible for color change from yellow to colorless, while in the case of F-, R exhibits a major peak at 415 nm and a color change from yellow to red. The limit of detection (LOD) of R for the analysis of Hg2+ was calculated as 1x10-6 M while for F-, it was found to be 3.4x10-7 M. The binding modes of R with Hg2+ and F- have been investigated by the Job’s plot, Benesi–Hildebrand (BH) method, 1H NMR, FTIR and theoretical studies. The sensor R was reversible after treating it with reagents such as EDTA and calcium nitrate solution after contacting with Hg2+ and F-, respectively. The performance of R can be successfully applied for the analysis of F- contents present in toothpastes

    • Synthesis and characterization of (E)-2-(1-hydrazonoethyl)-4, 5-dimethylphenol from 2-hydroxy-4,5-dimethylacetophenone

      DINKAR GAGARE RAJU PATIL RAMA LOKHANDE POONAM DWIVEDI AJAY DESHMUKH

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      This study reports the development of a novel substituted hydrazone prepared from 2-hydroxy-4,5-dimethylacetophenone and hydrazine in alkaline medium at controlled conditions which yields as corresponding hydrazone [(E)-2-(1-hydrazonoethyl)-4,5-dimethylphenol]. The structure of synthesized (E)-2-(1-hydrazonoethyl)-4,5-dimethylphenol was elucidated by elemental analysis and spectroscopic techniques like infrared spectroscopy, ultraviolet–visible spectroscopy, high-performance liquid chromatography, proton nuclear magnetic resonance and mass spectrum.

    • Synthesis, characterization of polystyrene-phosphate films and their application as heterogeneous catalyst for Knoevenagel condensation in solvent-free conditions

      HALIMA EL AADAD ZAKARIA BENZEKRI SAID BOUKHRIS ABDELKRIM CHAHINE

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      Novel film catalysts of the polystyrene (Ps) and trimethyl phosphate (P) nanoparticles were synthesized on glass substrates by soft chemistry using doctor blade method. Subsequently, the prepared Ps–P film catalysts were characterized by various techniques, including fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), density (d), polarizing microscope (PM), X-ray diffraction (XRD) and thermal analysis. According to the results, the structure and morphology of film catalysts were confirmed by all analyses. The Ps–P films, as heterogeneous solid catalysts, have demonstrated strong activity for Knoevenagel condensation, producing alkenes of high purity. The recovered yields are excellent, up to 96% in solvent-free conditions at room temperature. Further, the film catalysts have showed high stability, good reusability (up to five times) while maintaining their efficiency and productivity

    • Design, synthesis and characterization of functionalized pyrazole derivatives bearing amide and sulfonamide moieties from aza-aurones

      MOHAMMED CHALKHA MOHAMED BAKHOUCH MOHAMED AKHAZZANE MOHAMED BOURASS YOHANN NICOLAS GHALI AL HOUARI MOHAMED EL YAZIDI

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      In this work, we report the synthesis of new pyrazole derivatives bearing amide and sulfonamide frameworks from aza-aurones. Firstly, the intermediate spiropyrazolines were obtained through a highly regioselective 1,3-dipolar cycloaddition of nitrilimines with aza-aurones. Subsequently, the obtainedcycloadducts were subjected to hydrochloric acid in hot ethanol which conducts to 5-(2-aminobenzoyl)-3,4-diaryl-1-phenylpyrazoles. Finally, the target compounds were obtained separately by the action of acetic anhydride, benzoyl chloride and tosyl chloride on the intermediates 2-aminobenzoylpyrazoles, respectively.Structures of all the synthesized compounds were established using IR, 1H NMR and 13C NMR and mass spectroscopy.

    • A robust Co(II)-MOF with nitrogen-rich micropores for CO2 transformation and protective effect on acute heart failure treatment by increasing the expression of Hif-1a

      WEIWEI SONG SHASHA SONG XIN FENG QIAN YU MEI CHEN

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      A 3D neutral porous MOF (1), [Co2(tdc)2(Hdatz).DMF(H2O)3]n (H2tdc = 2,5-thiophenedicarboxylic acid, Hdatz = 3,5-diamino-1,2,4-triazole), which has aplenty micropores along with free groups of NH2 was assembled via combining 2,5-thiophenedicarboxylic acid ligands and nitrogen-rich 3,5-diamino-1,2,4-triazole as well as Co(II) ion. The activated MOF (1a) has a fine affinity for CO2 molecules and a fine catalytic performance for the conversion of CO2 with internal epoxides along with various terminal ones. Furthermore, the protective activity of 1a on acute heart failure was evaluated by measuring left ventricular ejection fraction and Left ventricular fraction shortening. And the mechanism of this compound was explored by detect the Hif-1a expression level

    • A facile and efficient synthesis of benzimidazole as potential anticancer agents

      THI-KIM-CHI HUYNH THI-HONG-AN NGUYEN NGOC-HOANG-SON TRAN THANH-DANH NGUYEN THI-KIM-DUNG HOANG

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      This study reports a simple process to synthesize and separate of 2-(substituted-phenyl) benzimidazole derivatives with high yield and efficiency. Specifically, by reacting ortho-phenylenediamines with benzaldehydes using sodium metabisulphite as an oxidation agent in a mixture of solvent under mild condition,twenty-three compounds of benzimidazoles were obtained and separated easily using hexane and water to wash, respectively. The structure of all obtained compounds was identified by FTIR, NMR and HRMS. The SAR analysis of synthesized benzimidazoles on human lung (A549), breast (MDA-MB-231) andprostate (PC3) cancer cell lines showed that the presence of methyl group at 5(6)-position on benzimidazole scaffold was a contributing factor influencing the anticancer activity. The presence of electron-donating groups (OH, OMe, –NMe2, –O–CH2–C6H5) also caused significant increase of anticancer activity, while thepresence of electron-withdrawing groups (–NO2, –CF3) on the phenyl group at 2-position of benzimidazole ring decreased the ability of inhibition of synthesized benzimidazoles. The compounds 2f and 2g displayed the significant anticancer activity on both A549 and PC3 cell lines.

    • Multicomponent click reactions catalysed by copper(I) oxide nanoparticles (Cu2ONPs) derived using Oryza sativa

      RANDHIR RAI DILLIP KUMAR CHAND

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      A procedure for the expedient synthesis of well-characterized Cu(I) oxide nanoparticles (Cu2-ONPs) from Cu(II) salts by employing Rice (Oryza sativa) as a cheap and ready source of reducing as well as stabilizing agent has been demonstrated. The judicious choice of rice as a catalyst has helped in the symbiotic combination of two events: viz., acidic hydrolysis of starch to form glucose and the subsequent formal reduction of Cu2+ by the in-situ generated monosaccharide reducing sugar (glucose) under the alkaline condition to produce Cu2O. Further, rice was also found to be effectively stabilizing the nanoparticles from agglomeration. Optical and microscopic techniques were suitably employed for the characterization of the nanoparticles of approximately 10 nm size. Furthermore, the specifically generated nanoparticles were foundto be active catalysts in an aqueous medium for Azide-alkyne Huisgen cycloaddition (Click reaction) under base free condition via one-pot multi-component addition for the synthesis of mono-, bis- and tris-1,2,3-triazoles in good to excellent yields.

    • A conjugated Schiff base-based chemosensor for selectively detecting mercury ion

      AHRAN KIM SEHOON KIM CHEAL KIM

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      A novel conjugated Schiff base-based chemosensor DAP, N¢-((1E,2E)-3-(4-(dimethylamino) phenyl)allylidene)-3-nitrobenzohydrazide, has been synthesized. DAP showed significant selectivity toward mercury ion by color change of pale yellow to orange. Detection limit was 0.11 lM, which is lowerthan the value (2.48 lM) recommended by Health Canada. DAP could recognize and quantify mercury ion in real water samples. The binding mode of DAP and Hg2+ was demonstrated, based on Job plot, IR spectra and ESI-MS.

    • DFT calculations, Hirshfeld surface analysis and docking studies of 3-anisaldehyde thiosemicarbazone

      MRIDULA GUIN SONIA KHANNA BEGAM ELAVARASI PARATPAR SARKAR

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      We report herein the synthesis, quantum chemical electronic structure, Hirshfeld surface and molecular docking studies of 3-anisaldehyde thiosemicarbazone (I). The compound has been characterized by NMR (1H, 13C) and IR spectroscopy. Hirshfeld surface analysis has been performed to understand the intermolecular interactions. The quantum chemical calculations show good consistency between the predicted and experimental parameters. Molecular docking studies of I with two different cancer target enzymes exhibit higher binding energy than its ortho substituted analogue

    • Platinum(II), palladium(II) and gold(I) benzimidazolin-2-ylidene as potential probes for determination of N-heterocyclic carbene donor strengths and steric bulks by DFT calculations

      VAN HA NGUYEN THI HONG NGOC DINH THANH TUAN DANG

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      Correlation between the donor strength of N-heterocyclic carbenes (NHC) and the M–Ccarbene bond distances in complexes of the type trans-[MX2(iPr2-bimy)(NHC)] (MX2 = PtCl2, PdBr2; iPr2-bimy = 1,3-diisopropylbenzimidazolin-2-ylidene) and [Au(iPr2-bimy)(NHC)]? was investigated for a selection of 20 carbenes.The structures of the complexes were first optimized in gas phase. The bond lengths betweenmetal (Pt, Pd and Au) and the carbene carbon of iPr2-bimy probe andNHCcarbene under studiedwere thenmeasured. Their correlation to the donor strength, evaluated using Huynh’s electronic parameter (HEP) was then examined. The results show good linear fitting betweenHEP value and Pd–Cprobe carbene distances or Hirchfeld atomic charge of the iPr2-bimy probe(Cprobe), suggesting the possibility of using theoretical approach for evaluation of donor strength forN-heterocyclic carbenes. In addition to the determination ofNHC donicity, the optimized geometries can also be utilized as inputsfor calculation of the steric properties, namely percent volume buried of the NHC ligands

    • Synthesis of multilayer polymer-immobilised nanosilver for catalytic study in condensation reaction of aniline and acetylacetone

      SUPRIYA NITAI CHANDRA MAJI JAYANTA KUMAR BASU SONALI SENGUPTA

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      Silver nanoparticles were synthesized in green route with non-hazardous polyvinyl alcohol and polyvinylpyrrolidone as stabilizing as well as reducing agents and water as green solvent. This silver nanoparticle-embedded polymer composite film, Ag/PVA–PVP was characterized by UV–Vis spectroscopy,SEM and TEM. The catalytic activity of this film was evaluated in reduction of p-nitrophenol, acylation of aniline and synthesis of a b-enaminone, 4-phenylamino-pent-3-en-one with appreciably good results. benaminonesynthesis reaction was chosen to study the effects of kinetic parameters such as reactant quantity, catalyst loading, solvents and temperatures. In a typical reaction, 89% conversion was achieved. A probable chemical reaction mechanism is suggested. Kinetic model fitting for the synthesis of b-enaminone reaction was done for the first time here. Heterogeneous kinetic model following Eley-Rideal pathway showed an excellent data fitting for the reaction. The rate law parameters were estimated.

    • Efficient and selective catalytic N-Alkylation of pyrimidine by ammonium Sulfate@Hydro-thermal carbone under eco-friendly conditions

      SOUMIA BELKHARCHACH HANA IGHACHANE ABDESSADEK LACHGAR MUSTAPHA AIT ALI HASSAN B LAZREK

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      An efficient and inexpensive method for the N-alkylation of pyrimidines using ammonium sulfate coated Hydro-Thermal-Carbone (HTC) (AS@HTC) as reused heterogeneous catalyst was developed. The catalyst was characterized by several analytical techniques such as SEM, XRD, and FTIR. The effect ofvarious parameters was studied including catalyst loading, mole ratio, to achieve excellent selectivity and yields in 80–90%. Significantly, the present protocol offers the use of an inexpensive and environmentally friendly catalyst and simple workup. The simplicity of the procedure, excellent yield of the products, and therecyclability of the catalyst are the main advantages of this method.

    • Microwave-assisted rapid synthesis of arylazoxy sulfides

      N MURTHY GANDIKOTA NARENDER MENDU I V KASIVISWANATH R SEKHAR BOLLA PRADEEP KUMAR BRAHMAN

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      An efficient, fast, and straightforward procedure for the synthesis of arylazoxy sulfides can be achieved by coupling reaction between aryl nitrasocompounds and tribenzenesulphenamide under microwave irradiation. Using the present method, different kinds of aryl nitrasocompounds containing various dioxolanerings and various tribenzenesulphenamide derivatives were rapidly converted to the corresponding arylazoxy sulfides in good yield and short reaction time. The use of non-toxic solvent, simple and clean work-up, short reaction times and good yields are the advantages of this method.

    • Highly efficient endo'- selective synthesis of (dispiro 3,2¢- pyrrolidinyl) bisoxindoles containing three contiguous chiral stereocenters with two contiguous quaternary spirostereocenters

      PANNEERSELVAM YUVARAJ HUIDROM BIRKUMAR SINGH ARUN PRASATH LINGAM KANDAPALAM DEVARAJAN KATHIRVELAN SANKARANARAYANAN NAGARAJAN

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      An efficient, atom economical, one-pot synthesis of endo'- selective (dispiro 3,2¢-pyrrolidinyl) bisoxindole containing three contiguous chiral stereocenters with two contiguous quaternary spirostereo centers have been achieved by three-component reaction of isatins, malononitrile (cyanoacetic ester) and 1,3-dicarbonyl compounds in water in the presence of L-proline. One-pot, azomethine ylide cycloaddition with a dipolarophile without using any catalyst have also been achieved in good yields. This new methodology offers many advantages of catalyst-free, mild reaction conditions, shorter reaction time, environmental friendliness, regio- and stereoselective processes in higher yields

    • Efficient dye-sensitized solar cell based on a new porphyrin complex as an inorganic photosensitizer

      AZAM NASIRIAN VALIOLLAH MIRKHANI MAJID MOGHADAM SHAHRAM TANGESTANINEJAD IRAJ MOHAMMADPOOR-BALTORK

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      The synthesis of new porphyrin complexes that can absorb light in a broad range of the spectrum is very important for getting a high efficiency in dye-sensitized solar cells. The primary reason for using these complexes is good photophysical characteristic like good absorption and high quantum efficiency. Most of themetal porphyrin shows good photophysical characteristics with changing their ligands. In this work, the synthesis of a new Zn-porphyrin complex, that has a good spectral and electrochemical characteristic, is reported. Then, this complex is used as a dye in dye-sensitized solar cells, using titanium dioxide as a semiconductor. The application of this complex in a dye-sensitized nanocrystalline TiO2 solar cell has indicated a short circuit density of 11.60 mA, an open circuit potential of 0.65 V with an overall efficiency of 5.33%. The overall conversion efficiency of this system is due to the efficient electron injection into the conduction band during light absorption.

    • All-inorganic perovskite CsPb2Br as a promising photovoltaic absorber: a first-principles study

      PENG XU

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      Hybrid organic-inorganic halide perovskites as promising solar cell materials have great concern on their stability. Recently, all-inorganic perovskite CsPbI2Br has been considered as a first-class alternative with good stability as well as a suitable bandgap, and the highest solar cell efficiency has been achieved up to16%. Using the first-principles calculations, we found that (i) CsPbI2Br is stable in tetragonal cell with a direct bandgap of 1.67 eV under PBE functional calculations approximating to the experimental value (1.92 eV). The upper valence band is derived from the antibonding states of s-p coupling, and the CBM ismainly composed of Pb-p states. (ii) The optical absorption is as strong as 104 cm-1 in the visible light range which can compare to that of the popular halide organic-inorganic hybrid perovskite. (iii) The electron transport material (ETM) in popular perovskite solar cells such as TiO2, ZnO, SnO2, PCBM and C60 togetherwith the hole transport material (HTM) such as P3HT, CuI, NiO, PTAA and Spiro are suitable for CsPbI2Br solar cell devices. The band offset between different perovskites demonstrates that it is easier for CsPbI2Br to be doped p-type than for CsPbBr3 but harder than for CsPbI3.

    • Synthesis and characterization of tetrathiafulvalene-r-thiophene dyads

      SHI-XIONG DENG YU-HAO LI PENG-FEI CAI CHENG-YUN WANG HAN WANG YONG-JIA SHEN

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      Three Tetrathiafulvalene (TTF)-assembled thiophene molecules were synthesized with the different linkages of s bridge via Steglich esterification and classical SN2 reaction. The results of UV and CV showed the different substitution effects existed in the new molecules formed by the molecule assembling. Among the new molecules, TTF-Th-2 (TTF-methylene-thiophene), linkage in the shortest s bridge, exhibited the most obvious substitution effects. Meanwhile, the result of theoretical calculation indicated that TTF-Th-2 exhibited lower bandgap with the evident electron transfer in the LUMO energy level.

    • Catalyst-free green synthesis of dihydropyrano[2,3-c]pyrazole scaffolds assisted by ethylene glycol (E-G) as a reusable and biodegradable solvent medium

      FARZANEH MOHAMADPOUR

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      We revealed a catalyst-free, green and rapid one-pot four-component tandem strategy for the preparation of dihydropyrano[2,3-c]pyrazoles – a biologically significant scaffold – via Knoevenagel-Michael cyclocondensation based on green chemistry principles. Highlights of the current practice are the applicationof non-hazardous reaction circumstances, catalyst-free, operational simplicity, use of inexpensive initiating substances, isolation of pure product via easy filtration thus preventing the requirement for column chromatography, metal-free, excellent yields, time-saving aspects of the reaction. However, the green ethyleneglycol (E-G) can be recycled at least six times with no considerable reduction in activity making it greatly advantageous in addressing the industrial requirements and environmental worries.

    • Investigation on the structural, thermal and hydration properties of gold-fullerene nanocomposite

      G JAYABALAJI L RAMYA J MEENA DEVI

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      In this article, we report the self-assembly process, structural features, thermal and hydration properties of the gold fullerene nanocomposite at room temperature by applying molecular dynamics simulation technique. The gold-fullerene systems constituting alkanethiol capped gold nanoparticle and pristinefullerene in explicit water have been simulated to gain insights on the influence of the terminal methyl (hydrophobic) and hydroxy (hydrophilic) groups on their structure and properties. The physisorption of the fullerene molecule into the thiol layer of the gold nanoparticle has been demonstrated and elucidated. Thechemical functionality of the terminal groups was found to affect the structure, specific heat capacity and the wetting behavior of the gold-fullerene nanocomposite. The findings from this computational study may aidthe understanding and development of novel gold-fullerene nanostructures for modulating their structural, thermal and hydration properties through the modification of their surface functional groups

    • Novel acentric D-p-A-p-D nonlinear optical (2E, 4E)- [dimethylamino) phenyl]-1-(4methylphenyl)penta-2,4-dien-1-one crystal for second and third order nonlinear applications

      S RAGHAVENDRA T CHANDRA SHEKHARA SHETTY C S CHIDAN KUMAR S NAVEEN SIDDEGOWDA CHANDRAJU SHIVARAJ R MAIDUR PARUTAGOUDA SHANKARAGOUDA PATIL G S ANANTHNAG S M DHARMAPRAKASH

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      A novel organic crystal namely (2E, 4E)-[dimethylamino) phenyl]-1-(4methylphenyl) penta-2,4-dien-1-one has been grown successfully from the slow evaporation method. The single-crystal X-ray diffraction study revealed that the compound belongs to the orthorhombic crystallographic system with noncentrosymmetric P212121 space group with lattice parameters a = 7.1354(3) A° , b = 11.2112(7) A° and 20.0744(11) A° . The thermal properties have been studied by using Thermo Gravimetric (TG) and Differential Scanning calorimetry (DSC). The second harmonic generation (SHG) efficiency of the compound is 2.9 times that of urea for Nd-YAG laser operating at wavelength 1064 nm. We also report the results of thermally induced third-order nonlinear optical (NLO) properties of NLO material investigated by Z-scan technique using continuous wave (CW) laser. The calculated values of cR(3),ci(3) and c(3) are of the order of 10-7esu, 10-8 esu and 10-7 esu, respectively. The estimated value of the non-linear refractive index is found to be - 4.21 x 10-8 cm2/W. The compound also exhibits promising optical limiting properties at 532 nm wavelength.

    • Sensitive determination of kojic acid in tomato sauces using Ni–Fe layered double hydroxide synthesized through Fe-MIL-88 metalorganic framework templated route

      DHARMENDRA KUMAR YADAV VELLAICHAMY GANESAN RUPALI GUPTA MAMTA YADAV PANKAJ KUMAR RASTOGI

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      A sacrificial template, Fe-MIL-88 is used to synthesize Ni–Fe layered double hydroxide (Ni–FeLDH). The metal-organic framework (Fe-MIL-88) is synthesized from the precursors, ferric nitrate and terephthalic acid. Electrocatalytic oxidation of kojic acid (KA) is realized by Ni–Fe LDH film which is coated on a glassy carbon electrode (GC). Under the optimized conditions, amperometry measurements at the Ni–Fe LDH coated GC as a function of KA concentration demonstrates a sensitive determination of KA. The calibration curve shows two linear ranges, 1–1500 lM and 1500–4500 lM for the KA determination.Detection limit for the KA determination is estimated as 0.73 lM. The practical applicability of this method is confirmed by measuring the KA concentration present in various real samples.

    • Copper oxide immobilized clay nano architectures as an efficient electrochemical sensing platform for hydrogen peroxide

      DHARMENDRA KUMAR YADAV VELLAICHAMY GANESAN RUPALI GUPTA MAMTA YADAV PIYUSH KUMAR SONKAR PANKAJ KUMAR RASTOGI

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      An electrochemical sensor for hydrogen peroxide (H2O2) present in face bleach cream is fabricated using a composite based on bentonite (Bt) clay and copper oxide (CuO) nanoparticles (CuO-Bt). The CuO nanoparticles’ immobilization into Bt was carried out by a two-step process in which Cu2+ is ionexchangedinto Bt layers (Cu2+-Bt) in the first step followed by the chemical reaction of NaOH with Cu2+-Bt in the second step to get the target material, CuO nanoparticles immobilized Bt (CuO-Bt). The successful immobilization of CuO nanoparticles into Bt is investigated by a variety of techniques like scanning electron microscopy, transmission electron microscopy, FT-IR spectroscopy, UV-Vis spectroscopy, and electrochemical methods. The CuO-Bt composite is coated on a glassy carbon electrode and used as a selective electrochemical sensing platform for the determination of H2O2 based on the significant electrocatalyticproperty of CuO-Bt towards the H2O2 oxidation. This amperometric electrochemical sensor shows two linear detection ranges (5–50 lM and 50–10000 lM) with a limit of detection of 4.9 lM. The sensitivity is calculated to be 0.06 mA mM-1 cm-2. This electrochemical sensor exhibits high selectivity, stability, and practical applicability for the H2O2 determination in real samples.

    • [Fesipmim]Cl as highly efficient and reusable catalyst for solventless synthesis of dihydropyridine derivatives through Hantzsch reaction

      AKANSHA AGRWAL VIRENDRA KASANA

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      In the present investigation, magnetic ferrite nanoparticles (ferrite NPs) were synthesized and coated with silica (ferrite@SiO2NPs) by using the sol-gel method. After that, silica propylmethylimidazolium chloride ionic liquid [Sipmim]Cl was prepared and linked with the above-prepared ferrite@SiO2NPs tosynthesize ferrite silica propylmethylimidazolium chloride [Fesipmim]Cl catalyst. The formation of [Fesipmim] Cl catalyst was confirmed by Fourier-transform infrared (FT-IR) spectroscopy analysis. X-ray diffraction (XRD) analysis confirmed the structure of ferrite NPs and ferrite@SiO2 NPs. Transmission electron microscopy (TEM) evidenced the successful formation of ferrite NPs and ferrite@SiO2 NPs. Scanning electron microscopy (SEM) results revealed the change in morphology of ferrite NPs, ferrite@ SiO2NPs and [Fesipmim]Cl. The magnetic properties of [Fesipmim]Cl catalyst were measured by vibrating sample magnetometer (VSM). The efficiency of the [Fesipmim]Cl catalyst was checked by using it for the synthesis of different derivatives of dihydropyridine through Hantzsch reaction via a three-component coupling reaction of substituted benzaldehydes, ethyl/ methyl acetoacetate and ammonium acetate. Theformation and structures of all the synthesized compounds were confirmed by FT-IR, 1HNMR, 13C NMR spectral analyses. The reusability of the catalyst [Fesipmim]Cl was checked up to seven cycles and found to have excellent activity up to five cycles

    • Design synthesis and anti-proliferative activity of some new coumarin substituted hydrazide–hydrazone derivatives

      NONGNAPHAT DUANGDEE WIRATCHANEE MAHAVORASIRIKUL SAISUREE PRATEEPTONGKUM

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      A series of 21 coumarin hydrazide–hydrazone derivatives were designed, synthesized and evaluated potential cytotoxicity effects at 25 lg/mL for 48 h against liver cancer (HepG2) cell line in vitro. Then, seven out of 21 compounds with % cell viability lower than 60% were selected for evaluation of in vitro anti-proliferative activity against liver cancer (HepG2), breast cancer (SKBR-3) and human colon cancer (Caco-2) cell lines. Among the test compounds, 5g, 6d and 6f showed potent activities against both Hep-G2 and SKBR-3 cell lines. More significantly, compound 6d, having a 4-bromophenyl moiety, exhibited best cytotoxic activity against Hep-G2 cell line with IC50 value of 2.84 ± 0.48 lg/mL which is comparable to the standard doxorubicin (IC50 = 2.11 ± 0.13 lg/mL). In addition, compound 6f, having 4-methoxyphenyl moiety, demonstrated the most potent activity (IC50 = 2.34 ± 0.68 lg/mL) against SKBR-3 cell line oncomparison with other tested coumarin hydrazide–hydrazone derivatives. Unfortunately, all test compounds, as well as doxorubicin, showed no cytotoxicity toward drug-resistant cell line, Caco-2. Our preliminary results indicated that coumarin hydrazide–hydrazone derivatives could be exploited as leading structures for further anticancer-drug development.

    • A molecular electron density theory study to understand the interplay of theory and experiment in nitrone-enone cycloaddition

      NIVEDITA ACHARJEE AVIJIT BANERJI

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      [3 ? 2] cycloaddition (32CA) reaction of C,N-diaryl nitrone with benzylidene acetone has been studied to analyse the mechanism, selectivity and polar character of this nitrone-enone cycloaddition. Topological analysis of the electron localization function (ELF) shows the absence of pseudoradical andcarbenoid centre in the nitrone, which allows its classification as a zwitter-ionic (zw) type three atom component (TAC) and hence participation in zw- type cycloadditions is associated with high activation energy barriers. This 32CA reaction follows a one-step mechanism with asynchronous TSs. Endo/meta product is obtained as the major cycloadduct experimentally, which can be rationalized from its calculated lowest activation energy among the four possible reaction pathways. Global electron density transfer (GEDT) at theTSs predict the non-polar character of this 32CA reaction. Topological analysis of the ELF and QTAIM parameters was performed at the TSs. Finally, non-covalent interaction (NCI) gradient isosurfaces are computed to obtain a visualization of non-covalent interactions at the interatomic bonding regions

    • Synthesis, characterization, X-ray structure and DNA binding study of palladium(II) complex with new thioether containing ONS donor ligand

      SUBRATA JANA RAHUL NASKAR CHANDAN KUMAR MANNA TAPAN KUMAR MONDAL

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      A palladium(II) complex, [Pd(L)Cl] (1) with a new ONS donor azo–thioether ligand (L) (where L = 2,4-dihydroxy-5-((2-(methylthio)phenyl)diazenyl)(phenyl)(phenyl)methanone) is successfully synthesized. The ligand and complex are thoroughly characterized by several spectroscopic techniques. The geometry ofthe complex is confirmed by single-crystal X-ray analysis. Electronic structure and spectral properties are interpreted by DFT and TDDFT calculations. The interaction of the complex with CT DNA was investigated by UV-vis method and binding constant is found to be 5.42 x 104 M-1. Competitive binding titration withethidium bromide (EB) by fluorescence titration method was carried out to understand the efficiency of the complex to displace EB from EB-DNA complex. From fluorescence titration Stern-Volmer dynamic quenching constants, Ksv was calculated and is found to be 4.15 x 104 M-1. Cyclic voltammogram of thecomplex exhibits significant shifting of the reduction couple to the negative potential region and decrease in current height in the presence of CT DNA

    • A mechanistic insight into the acid catalyzed, one-pot synthesis of isoindole-fused quinazolin 4-ones

      MOHABUL A MONDAL SUDIPTA MONDAL ABDUL A KHAN

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      One-pot synthesis of isoindole fused quinazolin 4-ones via intramolecular 1,3 hydride transfer in the presence of acid catalyst has been described. Substrate scope and mechanistic insights were investigated. Substituents on the amide side have a negligible influence on the key step and therefore the method have widescope for accessing various bicyclic core structure.

    • 1, 4-Diazabicyclo[2.2.2]octane-sulfonic acid immobilized on magnetic Fe3O4@SiO2 nanoparticles: a novel and recyclable catalyst for the one-pot synthesis of 4-aryl-NH-1, 2, 3-triazoles

      MASOUMEH JADIDI NEJAD FARZANE PAZOKI SEPIDEH BAGHERI ELAHE YAZDANI AKBAR HEYDARI

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      In this study, the surface of silica-coated magnetic nanoparticles (Fe3O4@SiO2) were successfully functionalized by an organic ligand of 1, 4-Diazabicyclo[2.2.2]octane (DABCO)-sulfonic acid and used as ahighly efficient catalyst for the synthesis of 4-aryl-NH-1, 2, 3-triazoles from the benzyl alcohol derivatives,nitromethane and sodium azide in ethanol. Furthermore, this catalyst could be recovered and reused five times without noticeable loss of activity

    • Dimeric complexes of copper (II) arylcarboxylate with 4-cyanopyridine: synthesis, structural characterization and linear absorption properties

      FUREYA ELIF OZTURKKAN OZBEK

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      Two new dimeric copper (II) complexes containing 2-chlorobenzoato/4-formylbenzoato and 4-cyanopyridine ligands, [Cu2(m2-O2CC6H4-Cl)4(C5H4N-CN)2] (1) and [Cu2(m2-O2CC6H4-CHO)4(C5H4NCN) 4] (2), were synthesized and characterized by elemental analysis, FT-IR and ESR spectroscopy andsingle-crystal X-ray diffraction methods. In the structure of 1, each copperII cation was surrounded by four oxygen atoms from four different carboxylate of four 2-chlorobenzoate molecules and one nitrogen atom of one 4-cyanopyridine ligand. In the crystal structure of 2, each copperII cation was coordinated by four oxygenatoms from one chelating and two bridging 4-formylbenzoate anions and two nitrogen atoms of two4-cyanopyridine ligands. C–H...O and C–H...Cl hydrogen bonds (for 1) and C–H...O hydrogen bonds and weak C–H...p interactions (for 2) further stabilize the crystal structures. The linear optical absorptioncharacterizations of the complexes were performed by using UV-Vis spectrophotometer. The results obtainedfrom the linear absorption spectra of the complexes observed that these complexes can be used for opticalfiltration among nearly 600 and 950 nm wavelengths for concentrations which are higher than 4 g/L.

    • trans-4-[4-(Dimethylamino)styryl]-1-methylpyridinium iodide@cyclopentanocucurbit[6]uril as a fluorescent probe for anion recognition

      SI YUAN CHENG XI NAN YANG ZHU TAO LIAN TONG WEI WEI WEI ZHAO DAO FA JIANG YAN MEI JIN JIE GAO PEI HUA MA

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      The host–guest binding characteristics of cyclopentanocucurbit[6]uril (CyP6Q[6]) and cyanine dye trans-4-[4-(dimethylamino)styryl]-1-methylpyridinium iodide (t-DSMI) have been studied. The results show that CyP6Q[6] and t-DSMI form a 1:1 inclusion system, generating strong fluorescence. On this basis, the fluorescent probe t-DSMI@CyP6Q[6] has been constructed, and its anion recognition ability has been investigated. In a neutral environment, BF4-, H2PO4 -, and I- elicit obvious specific responses from the probe, since they have stronger binding forces. This probe shows greater sensitivity than the previously reported probe t-DSMI@HMeQ[6].

    • Design, synthesis and biological evaluation of novel 1,2,3-triazolebased xanthine derivatives as DPP-4 inhibitors

      SIRASSU NARSIMHA KUMARA SWAMY BATTULA M RAVINDER Y N REDDY VASUDEVA REDDY NAGAVELLI

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      Inhibitors of dipeptidyl peptidase-4 (DPP4) have been shown to be effective treatments for type 2 diabetes. A series of novel 1,2,3-triazole based xanthine derivatives were designed and evaluated for in vitro dipeptidyl peptidase-4 (DPP-4) activity. Among them, the representative compounds 7b, 7e, 7g and 6eshowed excellent inhibitory activity of DPP-4 with IC50 values ranging from 87.41 to 16.34 nM, respectively. The SAR of these xanthine derivatives have been discussed, which would be useful for developing novel DPP-4 inhibitors as treating type 2 diabetes

    • Single site MIL-101 for novel low-temperature liquid-phase toluene methylation

      HOWAIDA MAMDOUH ABD EL SALAM DALIA RADWAN ABD EL-HAFIZ

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      P-xylene is one of petrochemical products eagerly in demand. Until recently, the process for preparing of p-xylene was done via gas-phase toluene methylation reaction at high temperature using a strong acid catalyst. In this work, high surface area, shape-selective and single-site MIL-101(Cr) was used as acatalyst to perform toluene methylation reaction in a liquid phase at low reaction temperature (60-120 °C). Toluene conversion and p-xylene selectivity are up to 50% and 90%, respectively. Under the optimum operating conditions; 1:1 toluene: methanol molar ratio, the reaction temperature is 120 °C. The catalyst wassynthesized via the hydrothermal method and the MIL-101 structure was confirmed by different analytical techniques: TGA, XRD, FTIR and BET surface area. The remarkably high toluene conversion and xylene selectivity at a low reaction temperature, in comparison to previous research, was attributed to the suppression of side reactions that could convert methanol to linear hydrocarbons, and to the inhibition of p-xylene isomerization. This suppression can be attributed to the single site properties and to the uniform pore sizedistribution of the prepared MIL 101 catalyst

    • Synthesis and application of carboxyethylthiosuccinic acid by thiolene click reaction: as a novel rust remover with corrosion inhibition properties

      HUAJING GAO NING XIE JIANXIN ZHANG JIAN SUN JIANLIN ZHANG ZHAOHUI JIN

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      Carboxyethylthiosuccinic acid (CETSA) was synthesized by thiol-ene click reaction and determined by various characterization methods, such as 1H NMR, IR and TG. A novel rust remover with corrosion inhibition was prepared by using CETSA as the main component. The results of rust removal were tested by the difference method and intuitive comparison method, and its rust removal mechanism was explored. The corrosion inhibition effect of the composite reagent for A3 steel in 1 M HCl solution was investigated by static weight loss test, the adsorption isotherm was calculated and fitted

    • Mixed cerium nanooxides as efficient and selective C-alkylation catalysts for gas phase methylation of phenol

      CHRISTY KUNJACHAN MANJU KURIAN

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      Phenol methylation is an acid-base catalysed reaction that produces valuable chemicals that are used in fine chemical synthesis. Methylation of phenol was studied over iron, vanadium and zirconium doped cerium nano oxides under optimized reaction conditions such as catalyst weight 0.5 g, phenol/methanol molar ratio 1/3 and WHSV 1.4 h-1 at 300°C and 2 h. 80-90% conversion and 90% ortho selectivity are achieved with all prepared mixed oxides. o-cresol and 2,6-xylenol are the major products of the reaction. Catalytic activity depends on the number and strength of moderate and strong acidic sites on the surface which in turn depends on the nature and composition of the catalyst. Structural stability of the catalyst substantiates the heterogeneous nature of the catalyst

    • Photoelectrochemical detection of chromium (VI) using layered MoS2 modified BiOI

      RU CHEN RONGQING TANG CHENG CHEN

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      In recent years, BiOI has been extensively studied due to its excellent absorption ability of visible light. However, low energy conversion efficiency affects its potential for practical application. In this paper, MoS2/BiOI composite was synthesized by two-step ways and applied to the photoelectrochemical (PEC)detection of hexavalent chromium (Cr (VI)). Through a series of optical characterization, the structure and morphology of the material were measured in detail. UV–Vis diffuse reflection spectra and photoluminescence (PL) further proved that MoS2/BiOI have the excellent PEC properties. The PEC experiment proved that the prepared MoS2/BiOI has a wide linear range (0.05–160 lM) and low detection limit (0.01 lM, at S/N = 3), moreover, it has great application potential in actual samples

    • Sulfur Nested with Mixture of MnO2/AB Composite as Efficient Host for High-Performance Li–S Batteries

      G RADHIKA R SUBADEVI M SIVAKUMAR

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      Lithium–sulfur (Li–S) batteries have established a tremendous interest in recent years because of their high specific capacity (1675 mAh g-1) and energy density (2600 Wh kg-1). In the present work, the electrode comprising carbon source viz., Acetylene Black (AB) and Manganese Oxide (MnO2) to serve as anefficient sulfur host in two different ratios (MnO2:AB as 10:20 (M1) and 20:10 (M2)) for Li/dissolved polysulfide batteries. The composite was characterized and studied by X-ray diffraction (XRD), Raman Spectroscopy, Nitrogen adsorption/desorption measurements, High-resolution transmission electron microscopy (HRTEM), X-ray photon spectroscopy (XPS), Thermogravimetric analysis (TGA) and electrochemical performance such as cyclic voltammetry (CV) and charge–discharge (C/D) tests. It shows good cycle performanceand exhibits an initial capacity of 1540 mAh/g at 0.1 C between 1.5 and 3.0 V for MnO2 rich sample. Performance enhancement was also brought about by the adsorptive properties of MnO2 which help in locking the polysulfide discharge products within the cathode structure

    • Insight into 1:1 complexes of H2O with NF3 and CF2Cl2: a quantum chemical approach

      NAZILA ABDI ABDOL VAHAB SEIF KHALED AZIZI MOEIN GOODARZI ALIMORAD RASHIDI

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      The competition of hydrogen, halogen and pnicogen bonding to the stability of the atmospheric complexes is interesting, especially where the molecules by the most abundant greenhouse effect in the atmosphere are subject of interest. In the present work, we have computationally studied the addition of H2O to the NF3 and C2FCl2 molecules to reveal the electronic and structural features of the NF3-H2O and CF2Cl2-H2O complexes through DFT, MP2 and CCSD (T) methods. The interaction energies, geometry and electronic properties including charge transfer, energy gap, NEDA and AIM analyses of all the complexes werecalculated to discuss the nature and strength of intermolecular interactions. The results indicate that the role of halogen bonding is more obvious than that of hydrogen and pnicogen bonding, and compared with the NF3,CF2Cl2 is more effectively stabilized by the H2O molecules

    • A new PEPPSI type N-heterocyclic carbene palladium(II) complex and its efficiency as a catalyst for Mizoroki-Heck cross-coupling reactions in water

      DHRUBAJIT BORAH BISWAJIT SAHA BIPUL SARMA PANKAJ DAS

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      A new air and moisture stable PEPPSI (PEPPSI: pyridine-enhanced pre-catalyst preparation, stabilisation, and initiation) themed palladium N-heterocyclic carbene (NHC) complex [Pd(L)Br2(Py)] (1) [L:2-flurobenzyl)-1-(4-methoxyphenyl)-1H-imidazolline-2-ylidene] was synthesized and characterized. The structure of complex 1 was determined by X-ray single-crystal analysis. The palladium center in 1 adopted a square planar geometry with carbene and pyridine ligands occupying the mutual trans position. The complex 1 was employed to catalyze the Mizoroki-Heck cross-coupling reactions of aryl bromides/iodides with styrene in water. To the best of our knowledge, this is the first report where a Pd-PEPPSI catalyst was successfully employed in aqueous-phase Mizoroki-Heck reaction. Good to excellent yields of cross-coupling products were obtained with a range of representative aryl bromides/iodides under relatively mild conditions(100 °C, 1 mol% of 1).

    • Exploring the binding mode of triflamide derivatives at the active site of Topo I and Topo II enzymes: In silico analysis and precise molecular docking

      ANDRADE-PAVON DULCE GOMEZ-GARCIA OMAR ALVAREZTOLEDANO CECILIO

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      The DNA topoisomerase enzymes, Topo I and Topo II, have been used as molecular targets for drug design of anticancer agents. The search is for new anticancer therapies that respond to the toxicity of current drug treatments and tumor resistance. The present study provides insights into a likely dual inhibitoryeffect on Topo I and II of trifluoromethylsulfonamide (triflamide) derivatives by computational docking studies. The physicochemical properties of these compounds were evaluated by Lipinski’s rules. Molecular docking simulations were conducted to determine the possible molecular target, mode and energy binding of the triflamide derivatives. An in silico analysis indicated that the triflamide derivatives interact with amino acid residues at the active site of Topo I and Topo II. The highest binding energy for the Topo I complex was shown by 1g and for the Topo II complex by 1e; these studies were validated by the analysis of decoys. Virtual mutations of Topo I and Topo II were tested, revealing the importance of certain active site residues on the binding mode and binding energy of the test triflamide derivatives. Overall, the results suggest that thecompounds 1g and 1e could be drugs promising for the future design and development of anticancer agents

    • Ninhydrin reaction with phenylethylamine: unavoidable by-products

      ANDRE´S GONZALEZ-ONATE RODOLFO QUEVEDO

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      Ninhydrin and phenylethylamine reacted to form a complex mixture from which four products were isolated: a benzo-fused spiroheterocyclic and a pyrrole product resulting from tricomponent condensation between ninhydrin, phenylethylamine and phenylacetaldehyde produced in situ, a 2-amino-1,3-indandione dimerisation-dehydrogenation product and a Schiff base. This article analyses these compounds’ structure and proposes reaction mechanisms contributing to knowledge regarding ninhydrin and phenylethylamine chemical reactivity.

    • Lewis acid catalyst system for Diels–Alder reaction

      RISHIR KALEPU SATYENDRA MISHRA

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      Ca(OTf)2/Bu4NPF6 catalytic system has been illustrated for the synthesis of Diels–Alder adduct for the first time. This procedure tolerates substrate diversity and delivers high yield. Use of environmentally benign catalyst, high yields and substrate diversity are the highlight of the existing method

    • Microwave-assisted synthesis of some new 1,2,3-triazole derivatives and their antimicrobial activity

      DONGAMANTI ASHOK M RAM REDDY RAVINDER DHARAVATH KATTA RAMAKRISHNA NALAPARAJU NAGARAJU M SARASIJA

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      A series of new 1,2,3-triazole derivatives were designed and synthesised through Cu(I) catalysed 1,3-dipolar cycloaddition of alkynes and organic azides namely click reaction, under both conventional and microwave irradiation methods. Higher yields were achieved in lesser time under microwave irradiationmethod by using CuI as the catalyst. Herein, the two triazole moieties are linked through the O-alkoxy oxime linkage. All the synthesised molecular structures are elucidated by 1H-NMR, 13C-NMR, IR and mass spectral analysis and screened for their in vitro antimicrobial activity.

    • Supramolecular inorganic chemistry leading to functional materials

      OLIVIA BASU SAMAR K DAS

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      Functional inorganic materials are very important today to meet the needs of our society. The most demanding needs are sustainable and clean energy (it would be nice if that can be achieved from water splitting), smart materials for sensing toxic volatile as well as water-soluble substances (health care) andefficient catalysts that can cycle multiple times without deterioration for useful chemical reactions. Supramolecular chemistry, that plays a vital role to design and synthesize such functional molecules, controls over the intermolecular interactions, thereby the molecular recognition processes leading to molecularfunctions, e.g., sensing, catalysis, etc. This article deals with inorganic supramolecular chemistry of a number of mono-nuclear coordination complexes to selected di-nuclear systems through trinuclear metal basic carboxylates,mostly in their solid-state, leading to the functional inorganic materials. We have demonstrated that some of the very old inorganic systems can be explored in the light of supramolecular chemistry to describe them as functional materials, which have potential in serving our society to some extent

    • Iodine-catalyzed regioselective C-3 arylation of indoles with pquinols

      NEHA DUA RAMA KRISHNA PEDDINTI

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      Iodine-mediated highly convenient strategy for the C-3 arylation of indoles with p-quinols is presented. The present work surpasses in forming a C–C bond at the meta-position of the phenols, which is traditionally challenging to functionalize. This protocol further leads the way to have ascendable, forthright access to phenol-assimilated heterocycles which have powerful applications both in synthetic and medicinal chemistry.

    • Carbonyl releasing Schiff base complex of Fe (III): synthesis, physicochemical characterization, antimicrobial and anticancer studies

      R V KUPWADE V J SAWANT

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      The carbonyl releasing Schiff base chelate derived Fe(III) complex has been synthesized following the simple wet chemical method. The rhombohedral packing of ligands with the metal ion in the complex was confirmed by its XRD pattern and FTIR spectrum. Compounds were characterized by UV-Vis.,PL, FTIR, XRD and TEM techniques. Better biocompatibility of the complex than that of the pure Schiff base had been elaborated on gram-positive and gram-negative bacteria by Agar well disc-diffusion antibacterial screening. The complex also displayed pH-responsive in vitro anticancer therapy on MCF-7 breast cancercells as revealed by MTT assay. The release of CO and Schiff base as well as the interaction of Fe(III) with the mitochondria inside the cell are the key factors of cell biocompatibility. This CORM complex had exhibited higher anticancer activity on MCF-7 cells than the Schiff base and thus potential candidate for thefuture biomedical applications

    • reversible, benzothiazole-based ''Turn-on'' fluorescence sensor for selective detection of Zn2+ ions in vitro

      DULAL MUSIB MD KAUSAR RAZA SALAM SUJATA DEVI MITHUN ROY

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      Temperature-driven, highly sensitive and selective ''TURN-ON'' fluorometric detection of Zn2+ by benzothiazole-based probes (L1 and L2) was reported in physiological pH in the present work. Iron(II) acted as the reversible switch or trigger for the reversible detection of Zn2+ ions by the probes resulting in

      ''TURN-OFF'' fluorescence at room temperature. However, selective detection of Zn2+ in the presence of Fe2+ was irreversible at 0–5 °C. Such temperature dependence on reversible fluorometric detection of Zn2+ in the presence of Fe2+ was explained from the thermodynamic perspective as well as DFT calculations inwhich the absolute enthalpy (H) and Gibbs free energy (G) of the resultant complexes and the fluorophores (L1 and L22) at different temperatures were determined. Enhanced fluorescence of the Zn2+ bound probes wasdue to the inhibition of excited-state intramolecular proton transfer (ESIPT). Effect of solvents, pH, and temperature on the fluorometric detection of Zn2+ was also probed in the present work. The results were translated into the visual detection of Zn2+ on paper-based fluorescence probe and later we demonstrated thesensing of mobile Zn2+ ions by the probes in living HeLa cells as the proof of concept of our present investigations

    • Synthesis of metabolites of dapagliflozin: an SGLT2 inhibitor

      KISHORE KARUMANCHI SENTHIL KUMAR NATARAJAN RAMADAS CHAVAKULA RAGHU BABU KORUPOLU KISHORE BABU BONIGE BADARINADH GUPTA PERURI

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      Dapagliflozin is one of the gliflozin class drugs, useful for the treatment of type-2 diabetes. Dapagliflozin undergoes extensive metabolism and transforms to metabolites in humans. The contribution of pharmacologically active metabolites in drug discovery and development is significant. A streamlined synthetic approach is devised to access three metabolites of dapagliflozin namely, benzylic hydroxy dapagliflozin, oxo dapagliflozin and desethyl dapagliflozin.Two synthetic protocols have been proposed for the synthesis of benzylic hydroxy dapagliflozin and oxo dapagliflozin. An enantioselective deethylation of dapagliflozin is also reported

    • Diastereoselective Mannich reaction with prolinated MWCNTs as a heterogeneous organo-nanocatalyst

      MAHSA KHOSHNEVIS HOSSEIN ESHGHI

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      We intended to convert proline as a homogeneous catalyst to a heterogeneous catalyst by prolination of MWCNTs to improve proline efficiency as a catalyst by the ease of separating, catalytic economy, reusability, etc. To reach these goals, we sketched Pro-MWCNT catalyst and characterized it by different analyses such as FT-IR, SEM, EDX, CHNS. The efficiency of this heterogeneous catalyst was investigated and compared with proline homogeneous catalyst in Mannich reaction. The results hold out improvements in stereoselectivity, ease of separating and reusability.

    • Coumarin-based Trisubstituted Methanes as Potent Anthelmintic: Synthesis, Molecular Docking and in vitro Efficacy

      GRACE BASUMATARY ERRINI DECRUSE DHAR DHARITRI DAS RAMESH CH DEKA ARUN K YADAV GHANASHYAM BEZ

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      A series of coumarin-based trisubstituted methanes (TRSMs) having uracil scaffold was synthesised employing a green, chromatography-free, and a highly efficient sonochemical multicomponent reaction of diverse aldehydes with 1,3-dimethyl-6-aminouracil and 4-hydroxy-coumarin in the presence of acatalytic amount of DABCO at room temperature and tested their anthelmintic efficacy against helminth parasites, Raillietina echinobothrida and Syphacia obvelata. Some of the TRSMs with substituents in the para position of the phenyl ring showed excellent anthelmintic activity in comparison to the commonly used drugs such as albendazole and praziquantel. The docking study revealed the binding interaction of all the optimizedcompounds with several amino acid residues in the active site of b-tubulin. The compounds showing gooddocking score with b-tubulin showed comparable anthelmintic activity experimentally as well.

    • Highly efficient hydrotalcite supported palladium catalyst for hydrodechlorination of 1, 2, 4-tri chlorobenzene: Influence of Pd loading

      ARSHID M ALI SEETHARAMULU PODILA MUHAMMAD A DAOUS ABDULRAHIM A AL-ZAHRANI AISHAH MAHPUDZ

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      The influence of Pd loading was studied for the gas phase catalytic hydrodechlorination of 1,2,4-trichlorobenzene over Pd supported on Mg-Al mixed oxide support with Mg:Al ratio 2:1. The Mg-Al support was prepared from hydrotalcite precursor. A series of catalysts was prepared with different loadings of Pd (1–6 wt%) on Mg-Al mixed oxide support. The performance of catalytic material was evaluated at different temperatures ranging from 425–575K. The fresh and used catalysts were characterized with different analyticaltechniques such as BET surface area, X-ray diffraction studies, Temperature programmed reduction, X-ray photoelectron spectroscopy and CO-chemisorption studies. H2-Temperature programmed desorption studies was also performed to understand the metal-support interaction and suitable active sites. The 4wt% ofPd on Mg-Al mixed oxide catalyst showed the highest conversion and selectivity among all catalysts and maintained steady activity with 10 h of time-on-stream studies. The main reasons for high activity are suitable metal-support interactions, Pd particle size, high surface area, and high surface Pd atomicconcentration.

    • One-pot three-component synthesis of 1,8-dioxooctahydroxanthenes and 14-Aryl-14Hdibenzo[a,j]xanthenes using a new nanostructure zeolite

      SEYEDEH FATEMEH HOJATI MARYAM MOOSAVIFAR NASRIN MOEINIEGHBALI

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      A new modified zeolite containing Fe nanoparticles loaded in zeolite X (Fe-X) has been synthesized and characterized by FT-IR, XRD, EDX and SEM techniques and its catalytic activity has been investigated in the synthesis of two series of xanthene derivatives. We have described an efficient and novel method using Fe-X as a new and reusable catalyst for the synthesis of 1,8-dioxooctahydroxanthenes and 14-aryl-14H-dibenzo[a,j]xanthenes derivatives from one-pot three-component condensation of aromatic aldehyde and dimedone or b-naphthol under solvent-free conditions. The significant advantages of the present method are high yields of products, short reaction time, easy separation of the catalyst from the reaction mixture, easy product isolation, solvent-free condition and reusability of the catalyst

    • A new Keggin-based organic-inorganic nanohybrid in the role of a dual-purpose catalyst

      ALI JAMSHIDI FARROKHZAD MOHAMMADI ZONOZ YONGGE WEI

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      A new organic-inorganic hybrid consisting of Keggin-type polyoxometalate ([BW12O40]5-) and protonated piperazine, namely [H5O2]2[Hpip]2.5[BW12O40].4H2O (pip = piperazine, C4H10N2) (1), has been created under reflux state and identified through material identification devices like single-crystal crystallography, FT-IR and 1H-NMR spectroscopies, Powder XRD, TG-DT Analysis, Field Emission SEM, elemental-analysis and cyclic voltammetry. Crystallography investigation exhibits that the main factor in the formation of 1 is the numerous number of hydrogen bonding between organic and inorganic species. The arrangement of Hpip groups creates holes in which the [BW12O40] clusters fit into the holes. Furthermore, the electrochemical and photochemical attributes of 1 have been considered, and the outcomes present that 1 owns privileged electrocatalytic activity against the reduction of nitrite ions as well as an appropriate photochemical effect on methylene blue (MB) dye depredation

    • Green catalyst-free one-pot synthesis of novel tetrahydropyridine-3- carboxamides by microwave-assisted approach

      MANDLENKOSI KHUMALO SURYA NARAYANA MADDILA SURESH MADDILA SREEKANTHA B JONNALAGADDA

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      A clean, facile and catalyst-free four-component domino reaction of aromatic aldehyde, ethyl cyanoacetate, acetoacetanilide and ammonium acetate in ethanol under microwave irradiation (MWI) conditions is described. Eleven novel and diverse tetrahydropyridine-3-carboxamide derivatives were synthesized in excellent yields (91–97%) using this green protocol. The significant benefits of this method are simple handling, ethanol as solvent, catalyst-free reaction under mild conditions, short reaction times ( less than 10 min) and excellent product yields. Easy workup procedure and simple purification technique of the target molecules evade column chromatography.

    • Understanding the interactions between hydrogen-bonded complexes of xylose and water: Quantum Chemical Investigation

      AMOL R KOLI SACHIN D YEOLE

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      Hydrogen-bonded complexes between xylose and water, modelled by xylofuranose…H2O complexes were explored employing ab initio quantum chemical framework. The Møller–Plesset secondorder perturbation theory (MP2) in conjugation with aug-cc-pVDZ basis set, is used for investigating the H-bonding interactions. The complete basis set limit interaction energies for a-and b-xylofuranose and xylopyranose water complexes were calculated at MP2 level. It is observed that the addition of water molecule does not change the conformational structure of xylose moieties. Further water is found to interactwith xylose mainly through the O atom present in a ring and its neighboring OH group. Energy decomposition analysis by LMO-EDA approach indicates that the electrostatic and exchange interactions are the two largest contributing terms to the total interaction energy for bonding between Xylose and water

    • Half-sandwich arene ruthenium, rhodium and iridium thiosemicarbazone complexes: synthesis, characterization and biological evaluation

      AGREEDA LAPASAM VENKANNA BANOTHU UMA ADDEPALLY MOHAN RAO KOLLIPARA

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      A series of ruthenium, rhodium and iridium complexes with 4-phenyl-1-(pyridin-4yl)methylene thiosemicarbazide (L1) and 4-phenyl-1-(pyridin-4yl)ethylidene thiosemicarbazide (L2) ligands were synthesized and isolated with hexafluorophosphate as a counter ion. All these complexes were fully characterized with the help of FT-IR, UV-Vis, 1H NMR, 13C NMR and elemental analysis. An agar-well diffusion method was employed for evaluation of antibacterial activities against one Gram-positive bacteria Staphylococcusaureus and two Gram-negative bacteria Escherichia coli, Klebsiella pneumoniae. Antimicrobial activity evaluation revealed that Cp* rhodium complexes has a significant antibacterial activity for all the three strains, Cp* iridium and p-cymene ruthenium complexes have shown moderated activity against the microorganisms but none of the complexes surpass the activity of their reference drugs. Results indicated that all the complexes reported here inhibit the growth of bacteria.

    • Two efficient ligand-assisted systems of two different ionic Schiff base ligands for palladium chloride catalyzed in Suzuki-Miyaura reaction

      FARZANEH NEHZAT GHOLAMHOSSEIN GRIVANI

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      The bis- methyl imidazolium chloride-salophen Schiff base ligand as cationic Schiff base ligand (L1) was synthesized by the reaction of methyl imidazoliumsalicylaldehyde chloride (S1) and phenylendiamine.The phenylendiamine was also reacted by monosodium 5-sulfonatosalycilaldehyde (S2) to give the bis-sodium sulfonate-salophen Schiff base ligand (L2) as the anionic ligand. These two ligands were characterized by the 1H-NMR, 13C-NMR, IR, UV–visible and mass spectroscopy, as well as elemental analysis.The ligand assisted PdCl2 catalyst was investigated in the Suzuki-Miyaura reaction by using the L1 and L2 as cationic and anionic Schiff base ligands and different reaction conditions such as temperature, solvent and mol% of PdCl2 were optimized. The results revealed that the anionic ligand assistance had a better activity forthe catalytic system of PdCl2 in Suzuki-Miyaura reaction

    • A facile route to synthesize N-(Boc-Aminoethylglycin)thymine Ethyl Ester, application to the synthesis of PNA-oligonucleotide conjugates

      ANURADHA DAS BISWARANJAN PRADHAN

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      Peptide nucleic acid oligonucleotide conjugates are attracting immense interest currently because of their use in the biomedical and diagnostic field as antigene and molecular sensors. The efficient PNA synthesis methods can reduce their cost and may increase availability for their wider use. Here we described afacile synthesis of the peptide nucleic acid monomer N-(Boc-Aminoethylglycin)thymine Ethyl Ester [Ethyl2-(N-(2-((tert-butoxycarbonyl)amino)ethyl)-2-(5-methyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)acetamido) acetate]. The monomer N-(Boc-Aeg)thymine Ethyl Ester has been prepared in a good yield (96%) by highly efficient procedure involving direct coupling of nucleobase thymine with the backbone Ethyl N-(Bocaminoethyl)-N-(chloroacetyl)glycinate, which was prepared from the reaction of Ethyl N-[(2-Boc-amino)-ethyl]glycinate with chlroacetylchloride. The key intermediate Ethyl N-[(2-Boc-amino)-ethyl]glycinate involved in the synthesis has been prepared via a scalable and cost-effective route with a yield of (98%). The thyminyl PNA monomer was reported to be used in various synthetic applications, and our cost-effective, highly scalable method of synthesis will expand its wider use.

    • Squaric acid: an impressive organocatalyst for the synthesis of biologically relevant 2,3-dihydro-1H-perimidines in water

      SUSHIL KHOPKAR GANAPATI SHANKARLING

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      Squaric acid, a green, metal-free and eco-friendly organocatalyst, has been exploited for the synthesis of biologically interesting 2,3-dihydro-1H-perimidines. The reaction was performed using water as a green reaction medium and the organocatalyst can be easily recovered and reused up to four consecutivecycles without much decrease in catalytic activity. Several advantages of the present methodology are low catalyst loading, excellent catalytic performance, easy catalyst handling, mild reaction conditions, operational simplicity, ease of product isolation, avoidance of column chromatographic separation, a higher yield of the desired product in short reaction time, high atom economy and synthesis of benzophenone based perimidine

    • Diphenyl phosphate creatine immobilized on magnetite nanoparticles: an efficient and recyclable catalyst for Aza-Michael reaction

      FARZANE PAZOKI FAHIMEH MOHAMMADPANAH AREFE SALAMAT MANESH JAMSHID AZARNIA MEHRABAN AKBAR HEYDARI

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      In this paper, diphenyl phosphate creatine was successfully immobilized on Fe3O4 nanoparticles and used as the highly efficient catalyst for the aza-Michael reaction of 5-substituted tetrazole and a,bunsaturated carbonyl. The prepared nanocatalyst was fully analyzed by various techniques such as FouriertransformInfrared Spectroscopy (FT-IR), Field Emission Scanning electron microscope (FE-SEM), Vibrating Sample Magnetometer (VSM), Thermal Gravimetric Analysis (TGA) and X-ray Diffraction (XRD). This procedure possesses numerous advantages such as simple work-up, high yield and short reaction times.

    • Silver(I)-selective PVC membrane potentiometric sensor based on 5,10,15,20-tetra(4-pyridyl)-21H, 23H-porphine and potentiometric applications

      OMER ISILDAK OGUZ OZBEK

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      In this study, all-solid-state contact PVC membrane silver(I)-selective sensor has been prepared and 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine used as ionophore. Optimum membrane composition; 3.5% ionophore, 59.6% Bis(2-ethylhexyl) sebacate (BEHS), 1.0% potassium tetrakis (p-chlorophenyl) borate(KTpClPB) and 35.9% polyvinyl chloride (PVC). The developed silver(I)-selective sensor exhibited a linear response (E = -51,57 (-log[Ag+]) + 1690,6 and R2 = 0,9986) in the varying concentration range of 1.0 x 10-1 to 1.0 x 10-5 mol L-1 silver ions. The limit of detection of the sensor was calculated as 1.9 x 10-6 mol L-1. The silver(I)-selective sensor exhibited good selectivity towards some alkali, alkali earth and heavy metal ions. The sensor can be used in thepHrange from 4.0 to 10.0. The sensor has been shown to have good reusability and response time less than 8 s. The sensor was used as an indicator electrode in titrations of silver nitrate with sodium chloride solution and was successfully applied for the determination of the different water samples.

    • The one-pot four-component eco-friendly synthesis of spirooxindoles in deep eutectic solvent

      THOKCHOM JEETA DEVI THOKCHOM PRASANTA SINGH OKRAM MUKHERJEE SINGH

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      An efficient and facile synthesis of spirooxindole derivatives bearing pyrano[2,3-c]pyrazole moiety has been achieved using deep eutectic solvent (DES) promoting a four-component reaction. The protocol avoids the use of costly and toxic catalysts and organic solvents which encounters many side effects on the environment and human beings. The simplicity and versatility of this eco-friendly green method isdescribed.

    • Influence of pH on the structures of two Cd phosphonate compounds

      LING YAN ZHAO XIAO CHEN DENG GANG LIANG XI BAO ZHENG XI YUE LI

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      Two novel Cd-based coordination polymers Cd(H2BCP)2(phen)2 1 and {[Cd6(BCP)4(phen)3]-2H2O}n 2 (Phen=1,10-phenanthroline) have been hydrothermally synthesized from a combination of 4-(phosphonomethyl) benzoic acid 4-HOOCC6H4CH2PO3H2 (H3BCP) and 1,10-phenanthroline. The X-raycrystal structure analyses revealed that 1 is a 0D mononuclear molecular structure and 2 is a 3D structure existing the novel Cd6 cluster unit. It is worth mentioning that 1 and 2 have the same constitutional units, namely the Cd ion, H3BCP ligand and second ligand- Phen. However, their structures are different and it results from the different solution pH value. In order to explore the structural characteristics, FTIR, photoluminescent and solid UV-Vis spectra are employed.

    • Preparation of Ni2P on twinned Zn0.5Cd0.5S nanocrystals for highefficient photocatalytic hydrogen production

      XIAOPENG ZHOU LINXIN YIN KAIQING DAI XIANGYANG GAO YANAN FENG YAFEI ZHAO BING ZHANG

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      Developing efficient non-precious metal semiconductor photocatalysts is highly desirable for photocatalytically splitting water. In this work, the composite of the nanocrystal twinned Zn0.5Cd0.5S (ZCS) solid solution decorated with highly dispersed Ni2P nanoparticles was successfully formed by in situ growthmethod, and it exhibited remarkable photocatalytic hydrogen production activity of visible light. A high rate of hydrogen production of 30473 lmol h-1 g-1 was achieved, and the apparent quantum yield (AQY) was as high as 83.5% at 420 nm. Moreover, the sample could maintain outstanding photocatalytic hydrogenation activity after 4-cycle continuous catalytic process. The unique nano-twinned structure of ZCS and synergistic effects between the Ni2P and the twinned ZCS are responsible for the dramatically improved catalytic activities of photocatalysts composite.

    • Cobalt (II) complex catalyzed polymerization of lactide and coupling of CO2 and styrene oxide into cyclic styrene carbonate

      HARISH CHANDRA PRADHAN SOMANATH MANTRI ANITA ROUTARAY TUNGABIDYA MAHARANA ALEKHA KUMAR SUTAR

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      In the present study, the cobalt (II) complex [Co-HMBED] has been prepared and characterized by spectrochemical techniques, which confirmed its square planar structure. The catalytic activity of the cobalt complex was evaluated towards solvent-free conversion of CO2 and styrene oxide into cyclic styrene carbonate and polymerization of lactide

    • Correction to: Syntheses and structures of chalcogen-bridged binuclear group 5 and 6 metal complexes

      MOULIKA BHATTACHARYYA RINI PRAKASH CHANDAN NANDI MONOJIT GHOSAL CHOWDHURY BEESAM RAGHAVENDRA THIERRY ROISNEL SUNDARGOPAL GHOSH

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    • Half-sandwich iron complexes bearing vinyl-selenocarboxylato ligands

      TAGHREED AL-JAZZAZI MOHAMMAD EL-KHATEEB LAMA QURAAN HASSAN ABUL-FUTOUH HELMAR GORLS WOLFGANG WEIGAND

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      Vinyl selenocarboxylato iron complexes of the formula CpFe(CO)2SeCOCH=C(R1)(R2) {R1 = H, R2 = Me, R1 = R2 = Me, R1 = H, R2 = CH=CHMe} are synthesized by the reaction of (l-Se)[CpFe(CO)2]2 with the corresponding vinyl acid chlorides ClCOCH=C(R1)(R2). Photolytic substitutionsof CpFe(CO)2SeCOCH=CMe2 with EPh3 gave the monosubstituted complexes CpFe(CO)(EPh3)-SeCOCH=CMe2 (E = P, As, Sb) in good yields. The new complexes have been characterized by UV-Vis, IR,1H-NMR, 13C{1H}-NMR, 77Se{1H}-NMR, 31P{1H}-NMR spectroscopy and elemental analysis. The solidstate structures of CpFe(CO)2SeCOCH=CMe2 and CpFe(CO) AsPh3)SeCOCH=CMe2 were determined by X-ray crystallography. The cyclic voltammetric measurements of CpFe(CO)2SeCOCH=CMe2 were recorded.

    • Vinylic-thiocarboxylate complexes of iron: synthesis, characterization and reactions

      MOHAMMAD EL-KHATEEB KHALEEL JASALI BATOOL AL-JUNEIDI HASSAN ABUL-FUTOUH HELMAR GORLS WOLFGANG WEIGAND

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      Half-sandwich iron thiocarboxylate complexes of the general formula CpFe(CO)2-SCOCH=C(R¢)(RR¢¢){R¢ = H, R¢¢ = Me, R¢ = R¢¢ = Me, R¢ = H, R¢¢ = CH=CHMe}) are obtained from the reaction of (l-Sx)[CpFe(CO)2]2 (x = 1–5) with the vinyl acid chlorides ClCOCH=C(R¢)(R¢¢). The substitution reaction of CpFe(CO)2SCOCH=C(R)Me with EPh3 produced the monosubstituted complexesCpFe(CO)(EPh3)SCOCH=C(R)Me (R = Me, E = P, R = H, E = As, Sb). All the new complexes have been characterized by UV-Vis, IR, 1H-NMR, 13C{1H}-NMR, 31P{1H}-NMR spectroscopy and elemental analysis.The solid state structures and the cyclic voltammetric measurements of CpFe(CO)2SCOCH=CMe2 andCpFe(CO)(PPh3)SCOCH=CMe2 were determined.

    • Detection of hydrogen sulfide using BODIPY based colorimetric and fluorescent on-off chemosensor

      NAVENDU PAUL RUDRA SARKAR RIPON SARKAR ANANYA BARUI SABYASACHI SARKAR

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      A colorimetric and fluorescence turn-off probe 10-(4-azido phenyl)-5,5-difluoro-5h-dipyrrolo[1,2-c:1¢,2¢-f][1,3,2] diazaborinin-4-ium-5-uide, 1, for selective detection of H2S is reported. The probe displayed a robust decrease in fluorescence intensity with high sensitivity, specificity and least toxicity to detect exogenous H2S and also in live normal human oral fibroblast cells loaded with probe 1. The detectionlimit of probe 1 being 0.17 lm for H2S.

    • Rational design of novel N-doped polyaromatic hydrocarbons as donors for the perylene based dye-sensitized solar cells

      MASIYAPPAN KARUPPUSAMY VENKATA SURYA KUMAR CHOUTIPALLI DOLLY VIJAY VENKATESAN SUBRAMANIAN

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      This paper reports designing a series of new D-p-A topology-based metal-free organic dye molecules using ullazine and perylene by DFT methods. This work emphasizes the combination of ullazine analogs as donors and perylene dicarboxylic anhydride as an acceptor along with acetylene linker as p-bridgefor DSSC applications. The structural and optoelectronic properties of dyes before and after adsorption on to TiO2 semiconductor have been investigated. The screening of the designed dyes is carried out based on the energy gap (Eg), maximum absorption wavelength (kmax), light-harvesting efficiency (LHE), excited-state lifetime (s), the free energy of electron injection (DGinj) and regeneration (DGreg). DFT results reveal that the presence of ullazine analogs as a donor reduces the energy gap (Eg) and leads to red-shift in absorptionmaximum. Further, two different binding modes of dye molecules with (TiO2)38 cluster have been investigated to unravel the binding associated changes in the electronic structure. The results show that the completely dissociated bidentate bridging (CBB2) mode is more favorable, which contains two carboxylic groups.Findings emphasize the remarkable charge transfer characteristics which favors the fast electron injection from excited dye to the conduction band of TiO2. For the first time, this study provides comprehensive structural and electronic information combined with the Dye-TiO2 interactions for the development of perylene based dyes for DSSC applications

    • Quantitative investigation on the intermolecular interactions present in 8-(4-ethoxyphenyl)-1,3-dimethyl-3,7-dihydro-1H-purine-2,6-dione with insight from interaction energies, energy framework, electrostatic potential map and fingerprint analysis

      RAHUL SHUKLA PRABAL BANDOPADHYAY MANISHA SATHE DEEPAK CHOPRA

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      In this study, we have performed a detailed quantitative analysis of the different intermolecular interactions present in 8-(4-ethoxyphenyl)-1,3-dimethyl-3,7-dihydro-1H-purine-2,6-dione (I). The molecule crystallizes in the P-1 space group with one molecule in the asymmetric unit. The molecule had a layeredcrystal packing wherein the molecular sheets are primarily formed by hydrogen bonds and the stabilization is dominated via the electrostatic energy contribution. This molecular sheet is then interconnected to other similar sheets via different stacking motifs with significant contribution from dispersion energy components

    • Substituent effects on the halogen and pnictogen bonds characteristics in ternary complexes 4-YPhNH2...PH2F...ClX (Y = H, F, CN, CHO, NH2, CH3, NO2 and OCH3, and X = F, OH, CN, NC, FCC and NO2): A theoretical study

      TAHEREH TONDRO HOSSEIN ROOHI

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      The synergistic relationship between pnictogen and halogen non-covalent interactions in 4-YPhNH2...PH2F...ClX (Y = H, F, CN, CHO, NH2, CH3, NO2 and OCH3; X = F, OH, CN, NC, FCC and NO2) complexes were explored using Aug-ccpVDZ basis set and M06-2X and M06-2X-GD3, B2PLYP-GD3and mPW2PLYP-GD2 functionals. The effects of the substituents included at pnictogen bond and halogen bond segments on the correlation between BEs and pnictogen as well as halogen bond distances, electron density at both non-covalent interactions, charge transfer energies between components and the NMR properties were evaluated. The energy analysis indicates that the pnictogen bond interaction has a much greater stabilizing effect than the halogen bond one. In addition, the auxiliary effect of a pnictogen bond on a halogen bond is more pronounced than that of a halogen bond on a pnictogen bond

    • Autocatalyzed oxidation of amino acid, L-Citrulline by diperiodatocuprate(III) complex in aqueous alkaline medium: a kinetics and mechanistic approach

      SANTOSH B KONNUR SHARANAPPA T NANDIBEWOOR

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      Autocatalysed oxidation of important amino acid, L-Citrulline(L-Cit) by coordination complex, diperiodatocuprate(III) in aqueous alkaline medium at a constant ionic strength of 0.05 mol dm-3 wasstudied spectrophotometrically. Autocatalysis was observed by one of the products formed, i.e., Cu (II). 1:4 stoichiometry (L-Cit:DPC) exhibited between the reaction of L-Cit and DPC in aqueous alkaline medium. The path is of first-order in [DPC], less than unit order in [L-Cit] and independent in [OH-]. Periodate has aretarding effect on the rate of reaction. Ionic strength has a negligible effect on the reaction rate. The main reaction products were identified by spot tests and spectroscopic analysis. A composite mechanism involving uncatalysed and an autocatalysed reaction path (via free radical) was proposed. The activation parameters for the slow step of the mechanism and also the thermodynamic quantities for different steps of the mechanism were determined and discussed.

    • The investigation of cooperative binding between psulfonatocalix[ 6]arene and fluorescein with transition metal ions by spectrometrically

      SHARADCHANDRA GAWHALE NILESH RATHOD SANHITA PATIL RUPALI THORAVE VRASHALI KALYANI RAJESH SAPKAL VILAS SAPKAL GAJANAN CHAUDHARI DIPALEE MALKHEDE

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      The ternary complexes are formed by self-assembly through cooperative hydrogen bonding between p-SCX6-FL and M2+ through water molecule which is reinforced by columbic and electrostatic interactions. The binding efficiency of Cu2+ and Zn2+ is observed at a greater extent than Co2+ and Ni2+. Furthermore, the kinetic study of p-SCX6-FL-Cu2+ and Zn2+ reveals that the process of complexation isslower than the binary system (FL+p-SCX6).

    • A hydrogel based on dialdehyde carboxymethyl cellulose–gelatin and its utilization as a bio adsorbent

      SAPNA SETHI BALBIR SINGH KAITH MANDEEP KAUR NEERAJ SHARMA SADHIKA KHULLAR

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      In the present study, the dialdehyde carboxymethyl cellulose (DCMC) was cross-linked covalently to gelatin via the Schiff base reaction to form a three-dimensional hydrogel (DCMC-cl-G). The crosslinking degree of DCMC and gelatin was estimated to be 50.31 ± 2.65. The maximum swelling capacityof the hydrogel in aqueous medium was around 74 g/g at pH 10.0 and 37°C with equilibrium swelling attained in three hours and the compressive strength of the hydrogel was found to be 55 ± 0.76 kPa at 60% strain. The biodegradation studies confirmed 82.67% degradation of the hydrogel sample within a period oftwelve weeks. Further, the hydrogel was evaluated as a bio adsorbent for the removal of hazardous dyes, namely Rhodamine B (RhB) and Methyl Violet (MV) from water due to its decent swelling capacity and good mechanical strength. The maximum percentage of RhB and MV removed from the respective dye solutionsusing DCMC-cl-G hydrogel was 96.5% and 90% at pH 6.0, respectively. Both dyes followed Langmuir adsorption isotherm, which considers monolayer adsorption of adsorbate over adsorbent, with a pseudosecond-order kinetic model.

    • An equation of motion approach for the vibrational transition energies in the effective harmonic oscillator formalism: the Random phase approximation

      T DINESH LALITHA RAVICHANDRAN M DURGA PRASAD

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      A theory for calculating vibrational energy levels and infrared intensities is developed in the equation of motion framework at the random phase approximation level. The vibrational Hamiltonian is expanded in the harmonic oscillator ladder operators making a Hamiltonian a bosonic Hamiltonian. Theexcitation operator is expanded to include at most two creations and two annihilation operators making it equivalent to the random phase approximation. The method is applied for the calculation of vibrational spectral properties of two molecules. The results are found to be satisfactory, making this approach a viable option for large molecular systems.

    • Synergistic cobalt–nickel co-catalyst for enhanced visible light-induced photocatalytic water oxidation

      PEGAH NAZARI OMID NOURI SHAHRBANOO RAHMAN SETAYESH

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      The loading of co-catalyst is an efficient way to increase the activity of synthesized carbon-based photocatalysts in the energy and environmental applications. Herein, Co and Ni decorated on g-C3N4 was synthesized as a visible light active photocatalyst and characterized with XRD, FT-IR, BET, DRS, TGA, FESEM, EDX, and EIS techniques. From the characterization results, it was demonstrated that cobalt and nickel which were present in the structure of the nanocatalyst, were in the metallic form. The decoration of Ni and Co reduced bandgap energy of g-C3N4 and made the synthesized nanocomposite active under visible light. The operating condition of O2 photocatalytic generation was optimized (193.75 lmol L-1 O2 productions using 0.2 g Co2Ni1/g-C3N4/rGO at 7 h without sacrificial reagents). The effect of sacrificial reagents (Fe(NO3)3, AgNO3, and methanol) was investigated and Fe(NO3)3 showed the best results during water oxidation. The kinetics study indicates that the presence of cocatalysts could be helpful in reducing the apparent activation energy about 3.5 times. The photocatalyst represented acceptable stability (2% Ni and 3%Co leaching) and reusability up to six cycles. According to the obtained results, we can introduce Co2Ni1/g- C3N4/rGO as a potential powerful photocatalyst for water oxidation reaction under visible light.

    • Graphene oxide: an efficient carbocatalyst for the solvent-free synthesis of 2-(substituted benzoyl)-3-(substituted phenyl)imidazo[1,2-a]pyridines

      DILPREET KOUR SONAKSHI SASAN KAMAL K KAPOOR

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      GO has been found as a remarkable heterogeneous carbocatalyst for the solvent-free synthesis of 2-(substituted benzoyl)-3-(substituted phenyl)imidazo[1,2-a]pyridines from chalcones and 2-aminopyridine. The present methodology offers a novel and eco-friendly approach with appreciable yields of the desired products.

    • Fluxional nature in cyclohexane and cyclopentane: spherical conformational landscape model revisited

      SAHAR SAKHAEE MOHAMMAD HOSSEIN SAKHAEE AHMAD TAKALLOU FATEMEH FOROUZANFAR NADER SAKHAEE

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      Spherical conformational landscape model was revisited to include yet another class of cyclic compounds; the derivatives of cyclohexane. The updated model is not only capable of explaining Raman spectral features in fluxional cyclopentane but is also capable of revealing similarities between cyclopentane and cyclohexane derivatives for the first time. At the heart of the model lies the aspect of B/T ring coordinates (B/T conformational platform) that represents different levels of puckering (q). DFT-wb97xd/6-311 + G* computations confirmed by MP2/aug cc-pVTZ computations were used to fully investigate 16 differentderivatives of both cyclohexane and cyclopentane. Intrinsic reaction coordinate, IRC, computations were performed to gain insight into patterned inter-platform pathways connecting ring coordinates. These pathways revealed the coupling strength between bent/boat, B, and twist, T, ring coordinates. The coupling is found to be stronger for cyclopentane compared to cyclohexane. Some spectral features in the overlap region near 1400 cm-1 show promising signs on spin–spin relaxation, T2, mechanism. The work opens up an avenue for conformational studies of medium-sized rings. Also, ongoing studies to unravel potential relationships between conformational flexibility and bioactivity of cyclic compounds are underway.

    • Effect of aggregated Ab protofilaments on intermolecular vibrational spectrum of confined water

      PRABIR KHATUA SOUVIK MONDAL SANJOY BANDYOPADHYAY

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      Alzheimer’s disease, one of most common neurodegenerative diseases, is believed to be caused due to the self-assembly of amyloid beta (Ab) peptides into insoluble fibrils in the brain. Atomistic molecular dynamics simulations have been carried out to probe the effects of non-uniform structural distortions ofaggregated Ab17-42 protofilaments of different sizes, ranging from pentamer to tetradecamer, on the lowfrequency vibrational spectrum of water confined within their amphiphilic nanocores. The calculations revealed increased back scattering of water molecules present either at the exterior surfaces of the protofilaments or confined within their cores, thereby leading to blue shifts of the band corresponding to O ... O ... O bending or restricted transverse motions of water. Due to more restricted environment, the effect is more for the core water molecules. It is observed that the extent of such shifts is sensitive to the degree of confinement within the protofilament cores and the nature of hydrogen bonding. Importantly, the structural crossover of the protofilaments with increased core volume at decamer has been found to be associated with characteristic effect on the low-frequency modes of the water molecules confined within its core.

    • Two acetylenedicarboxylato-bridged 4-styrylpyridine appended 1D coordination polymers: synthesis, structural characterization and variable temperature magnetism

      BASUDEB DUTTA AKHTARUZZAMAN HIROKI SATO TAKASHIRO AKITSU ALEXANDRA M Z SLAWIN UDDALOK KAR CHITTARANJAN SINHA MOHAMMAD HEDAYETULLAH MIR

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      Two hitherto unknown one-dimensional coordination polymers (1D CPs) [M(adc)(4-spy)2 (H2O)2]n, (M = Mn(II) (1) and Co(II) (2); H2adc = acetylenedicarboxylic acid and 4-spy = 4-styrylpyridine) have been characterized by infrared spectra, elemental analysis, thermogravimetric analyses (TGA), powder X-ray diffraction (PXRD) patterns and single-crystal X-ray diffraction techniques. Both these compounds 1 and 2, are isostructural and construct 3D supramolecular networks by the combination of hydrogen bonding and C–H...p interactions. Interestingly, these two materials exhibit variable temperature magnetic moment

    • Effect of aggregation on hydration of HSA protein: Steady-state Terahertz absorption spectroscopic study

      BISWAJIT MANNA AMITABHA NANDI MASAHITO TANAKA HIROYUKI TOYOKAWA RYUNOSUKE KURODA DIPAK K PALIT

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      Terahertz (THz) absorption behaviour of HSA protein in aqueous buffer solutions has been investigated in the 0.1–2 THz frequency range using a highly intense THz source based on coherent transition radiation (CTR) generated using a femtosecond electron accelerator of 42 MeV energy (for 0.3–2 THz) and aklystron (at 0.1 THz). Like in the cases of other proteins reported earlier, THz absorbance of the protein solutions follow nonlinear behaviour with increasing concentration of HSA protein monitored through the entire frequency range. THz absorbance of the solution initially increases to follow an apparently linearbehaviour up to the concentration of ~6 9 10-4 mol dm-3 but decreases gradually with further increase in HSA concentration. The linear behaviour in low concentration regime could be explained considering the increase in concentration of the monomer HSA molecules in solution with a well-defined hydration layer of thickness of about 22 A° around it. However, the study of dynamic light scattering measurements suggest the presence of increasing number of protein aggregates in solution with increasing concentration of protein. THz absorbance of each of these samples could be calculated to show that absorbance decreases with increasing number of aggregates in solution and also the relative concentrations of the monomer and aggregated particles existing in solutions could be estimated. This work, for the first time, explains the nonlinear change in THz absorbance of protein solutions with increasing protein concentration considering the protein aggregation effect at very high concentration.

    • Effect of nano-confinement on the structure and properties of water clusters: An ab initio study

      MANOJ K TRIPATHY DEVENDRA K MAHAWAR K R S CHANDRAKUMAR

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      An ab initio investigation on water clusters confined to armchair carbon nanotubes (CNT) with varying diameters has been performed using the density functional theory-based calculations. Different parameters have been investigated including structure, hydrogen bonding pattern and vibrational spectra of water-CNT complexes. Our results reveal that one-dimensional water chain parallel to CNT axis is formed in narrow nanotubes CNT(4,4) and CNT(5,5), whereas in CNT(6,6), zigzag structure is observed. An increase in the CNT diameter results in more symmetric structures similar to the gas phase. The vibrational analysis shows a redshift in stretching frequency of the hydrogen bond assisted O–H in CNT(6,6) due to the reduction in O—O separation whereas a significant blue shift in stretching frequency mode is observed in highlyconfined CNT(4,4) and CNT(5,5). It implies that the hydrogen bond strength between water molecules is strongest in CNT(6,6). It is also observed that water cluster tends to be near CNT wall due to H...p interaction between water molecule and the p-electron cloud of CNT. An inverse relation between the electronic charge transfer (from CNT to water) and the diameter is also established. This study demonstrates that the degree of confinement is extremely important in deciding the properties of confined water molecules.

    • Core–shell-structured MnO2@carbon spheres and nitrogen-doped activated carbon for asymmetric supercapacitors with enhanced energy density

      JIE WEN XIAOPING CHEN MAOLIN HUANG WEN YANG JIE DENG

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      Asymmetric supercapacitors have potential applications in renewable-energy technology owing to their remarkable electrochemical properties. A high-voltage asymmetric supercapacitor was developed based on a core–shell-structured MnO2@carbon sphere composite (MnO2@CS) as the cathode, nitrogendopedactivated carbon as the anode and a neutral aqueous Na2SO4 solution as the electrolyte. MnO2@CS was successfully fabricated by hydrothermally growing MnO2 on the surface of carbon spheres. A nitrogencontaining benzoxazine resin was adopted as a precursor to produce in situ nitrogen-doped activated carbon.Such an aqueous electrolyte-based asymmetric supercapacitor can be cycled reversibly in the high-voltage region of 0–1.9 V and exhibits a superior energy density of 8 Wh kg-1 at an ultrahigh power density of 9627 W kg-1 owing to the matching of MnO2@CS and porous nitrogen-doped activated carbon. Moreover,the asymmetric supercapacitor presents acceptable cycling performance, with 74.4% retention after 1000 cycles at 1 A g-1, and a charge–discharge efficiency of the electrode of almost 100%.

    • Profiling of LINS01 compounds at human dopamine D2 and D3 receptors

      MICHELLE F CORREA DAVID REINER GUSTAVO A B FERNANDES MARINA T VARELA CECILIA M S Q ARANHA HOLGER STARK JOAO PAULO S FERNANDES

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      Histamine and dopamine neuronal pathways display interesting overlapping in the CNS, especially in the limbic areas, making them very attractive to designing drugs with synergistic and/or additive effects. The roles of these systems to treat schizophrenia, drug addiction, Parkinson’s and Alzheimer’s diseases, among others are widely known. The LINS01 compounds were previously reported as histamine H3 receptor (H3R) antagonists and some of them are under evaluation in rodent memory models. Considering their pharmacological potential and similarities to literature dopamine D2 receptor (D2R) and dopamine D3 receptor (D3R) ligands, this work aimed to evaluate these compounds as ligands these receptors by using [3H]spiperone displacement assays. A set of 11 compounds containing the dihydrobenzofuranyl-piperazine core with substituents at 5-position of dihydrobenzofuran ring and at the piperazine nitrogen was examined. The compounds showed low to moderate affinities at both, D2R and D3R. N-Phenyl compounds LINS01005 (1d), LINS01011 (1h), LINS01012 (1i) and LINS01016 (1k) showed the highest affinities in the set to D3R (Ki 0.3–1.5 mM), indicating that N-phenylpiperazine moiety increases the affinity to this receptor subtype with some selectivity, since they showed lower affinities to D2R (Ki 1.3–5.5 mM). With the LINS01 compounds showing moderate binding affinity, new lead structures for optimization with regards to combined H3R and D2R/D3R-ligands are provided.

    • Conceptual approach to the synthesis of symmetrical 1,3-diynes from b-bromo vinyl carboxylic acids

      RAJU SINGHA

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      A conceptual route has been developed for the synthesis of 1,3-diyne from b-bromo vinyl carboxylic acids. The reaction of the b-bromo vinyl carboxylic acid with palladium catalyst is conceptually similar to the decomposition of 2-diazoniumbenzoic acid to benzyne. In the presence of palladium catalyst,the b-bromo vinyl carboxylic acid undergoes a fragmentation to generate terminal alkyne. The terminal alkyne undergoes dimerisation in the presence of palladium catalysts to produce the product 1,3-diyne.

    • Lowest order perturbative approximation to vibrational coupled cluster method in bosonic representation

      T DINESH SUBRATA BANIK

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      We propose a perturbative approximation to the vibrational coupled cluster method in bosonic representation to reduce the cost of calculating the cluster matrix elements by considering only the first order of S and r for the construction of the effective Hamiltonian ese-SHeSes. With the systematic analysis of theresults of two molecules, H2O and 1,1-difluoroethylene, we find that the accuracy of the transition energies with such low order approximation is comparable to the fully converged VCCM

    • First principles investigation on the applicability of ruthenium as a potential ORR catalyst

      SURAJIT NANDI AKHIL S NAIR BISWARUP PATHAK

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      Exploration of new materials for oxygen reduction reaction has long been a major area of research in heterogeneous catalysis. As the currently available oxygen reduction catalysts have not achieved the optimal efficiency, search for alternative resources is a continuing effort. Realizing the wide acceptance ofruthenium as a promising catalyst for various catalytic reactions, we have investigated the plausibility of Ru to perform in the bulk as well as nanoparticle forms as an efficient oxygen reduction reaction catalyst. Two nanoclusters with face-centred and hexagonal symmetry were scrutinized for ORR activity along with Ru(111) and Ru(0001) surfaces as periodic counterparts and compared the activity with Pt(111) surface. We report here that Ru cannot be an alternative to the Pt-based catalysts owing to a high overpotential

    • Electrochemical aspects of restricted rhenium(I)-based supramolecular complexes with semi-rigid benzimidazolyl and rigid hydroxyquinone ligands

      SARITA YADAV MOOKAN NATARAJAN MALAICHAMY SATHIYENDIRAN SANDEEP KAUR-GHUMAAN

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      Supramolecular coordination complex [(Re(CO)3)2(dhnq)(L2)] (3) containing two fac-Re(CO)3 cores, rigid dianionic dhnq (H2-dhnq = 6,11-dihydroxy-5,12-naphthacenedione) motif and semi-rigid ditopic nitrogen donor 1,2-bis(2-nonylbenzimidazol-1-ylmethyl)benzene (o-Nbenzbix = L2) was synthesized.Compounds o-Nbenzbix and 3 were characterized using various analytical and spectroscopic methods. The electrochemical properties of 3 were studied using cyclic voltammetric measurements. SCCs [(Re(CO)3)2(-dhnq)(L1)] (1) and [(Re(CO)3)2(dhaq)(L1)] (2) possessing p-xylene spacer 1,4-bis(2-nonylbenzimidazol-1-ylmethyl)benzene (L1) and 1,4-dihydroxy-9,10-anthraquinone (H2-dhaq) were also synthesized as reported previously. SCCs 1–3 were investigated via electrochemical methods. A plot of the Randles-Sevcik equation yielded a straight line for complex 3 thus, establishing that the redox processes were diffusion-controlled.

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