• Volume 132, All articles

      Continuous Article Publishing mode

    • 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 MOHAMMADPOUR 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 asemiconductor. 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 of5.33%. 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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