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      Volume 130, Issue 7

      July 2018,   pages  i-100

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    • Editorial:Special Issue on Modern Trends in Inorganic Chemistry XVII

      SAMIR H CHIKKALI VENKATARAMANARAO G ANAND DARBHA SRINIVAS AVINASH S KUMBHAR

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    • Cyclometallated imidazo-phenanthroline iridium complexes and their anticancer activity

      PALAK GARG UMASANKAR DE NIRANJAN DEHURY HYUNG SIK KIM SRIKANTA PATRA

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      Cyclometallated mononuclear iridium complexes (1–3) were synthesized using dimeric precursor [(ppy)2Ir III(μ-Cl)]2 and imidazo-phenanthroline-based ligands (L1–L3). The complexes were characterised using various analytical techniques. The complexes exhibited spin forbidden metal-to-ligand charge transfer (MLCT) transitions at wavelengths >300 nm and high energy ligand-based transition below 300 nm. The complexes were found to be emissive and displayed emission bands at 580 nm upon excitation at 380 nm with quantum yields 0.07 with respect to standard [Ru(bpy)3] Cl2. The complexes 1–3 showed dose-dependentsuppression of cell viability (IC50 values ∘ 245 μM) towards human breast (MCF7) cancer cell line. The hydrophobicity measurements and flow cytometry analysis suggest that cellular uptake is primarily responsible for observed cytotoxicity.

    • Hierarchical lithographic patterning of two abrupt spin cross-over Fe(II) complexes into micro-cross-stripes

      UPPARI VENKATARAMUDU SUPRATIM BASAK MAHAMAD A MOHIDDON RAJADURAI CHANDRASEKAR

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      We have fabricated high-resolution microscale cross-patterns from two different Fe(II) spin crossover (SCO) complexes having transition temperatures (T1/2) 259 K and 323 K, through lithographic techniques. We hope that our original approach will be useful to create futuristic multi-component SCO devices.

    • Fixation and sequestration of carbon dioxide by copper(II) complexes

      SETHURAMAN MUTHURAMALINGAM MARAPPAN VELUSAMY RAMASAMY MAYILMURUGAN

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      The fixation of carbon dioxide (CO2) is an important global challenge. A significant increase of the atmospheric CO2 due to the industrial emissions and a steady increase in combustion of fossil fuels is widespread environmental concern. This article is a short literature review on the recent developments in the field of CO2 activation and fixation by bioinspired copper(II) catalysts. In our laboratory, copper(II) complexes of bidentate ligands have been reported as catalysts for the fixation of CO2. The molecular structure of one of the complexes has shown unusual trigonal bipyramid geometry (τ, 0.936) by the coordination of two ligand units and a water molecule. All the complexes exhibited a well-defined Cu(II)/Cu(I) redox potentials around 0.352 to 0.401 V in acetonitrile. The rhombic EPR spectra of the complexes indicate the existence of a geometrical equilibrium between trigonal bipyramidal and square pyramidal at 70 K. The d-d transitions around 750–800 and 930–955 nm further supports five coordination geometry in solution. These copper(II) complexes have successfully fixed atmospheric CO2 as CO322- by using Et3N as sacrificial reducing agent and afforded [Cu(L)CO3(H2O)]. The CO322-bound complex has shown a distorted square pyramidal geometry (τ, 0.369) around copper(II) center via the coordination of only one ligand unit, a carbonate, and water molecules. The catalysts are active enough to fix CO2 for eight repeating cycles without any change in the efficiency. The fixation of CO2possibly proceeds via the formation of Cu(I)-species. This is supported by X-ray structure, which reveals distorted tetrahedral geometry by the coordination of two units of ligand.

    • Ferrocene and triphenylamine appended boranils

      NEHA MANAV AYUSHI TYAGI VIJAYALAKSHMI PANDEY ITI GUPTA

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      Abstract. Boranils containing ferrocene and triphenylamine groups were synthesized and well characterized by IR, 1H,13C,11B and 19F NMR and ESI-MS spectrometry. UV-Vis absorption, steady-state and time-resolved fluorescence techniques were employed to study their photophysical properties. The presence of electron rich substituents caused significant alterations in their absorption and emission spectra. As compared to the parent boranil compound (λabs=342 nm), boranil-triphenylamine and boranil-ferrocene conjugates exhibited red shifted absorption maxima (λabs=384, 375 nm, respectively). The boranil-triphenylamine and boranilferrocene conjugates displayed red shifted emission spectra (λem=524, 489 nm, respectively), as compared to the parent boranil (λem=471 nm). Also, large Stokes shifts (6217 −6958 cm -1) were observed for both theconjugates in solution phase

    • Metal directed self-assembly of Tetranuclear CuII and NiII clusters

      AVINASH LAKMA SAYED MUKTAR HOSSAIN RABINDRA NATH PRADHAN AKHILESH KUMAR SINGH

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      The self-assembly of two pyridine hydrazone based tritopic ligands appended with terminal carboxylate groups with CuII and NiII have been investigated. These polytopic ligands with tridentate coordination pockets were designed to produce homoleptic [3×3] grid complexes on reaction with transition metals. Despite the formation of anticipated metallogrids as the final self-assembly outcome, metal ion geometric preferences and ligand flexibility lead to the formation of tetranuclear clusters in the self-assembly process with CuII and NiII metal ions. These results illustrate the dynamic nature of the metal–ligand interactions and flexible nature of the ligand backbone in coordination self-assembly. The synthesis, structure and magnetic properties of three tetraanuclear species {[Cu4(H2Llb)2(OTf)4(OH)2(H2O)2]6H2O}n (1), [Ni4(L2a)2(OCH3)4]4H2O (2), [Cu4(L2b)2(OTf)4(H2O)4]6H2O (3) involving two tritopic ligands with central pyridine framework are described.

    • Sterically hindered 5,15-tetraphenylbenzene-porphyrins: syntheses, structures, atropisomerism and photophysical properties

      R V RAMANA REDDY BIJU BASUMATARY MUTHUCHAMY MURUGAVEL KARUNESH KESHAV ADIKI RAJA SEKHAR JEYARAMAN SANKAR

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      Meso-Tetraphenylbenzene (TPB) substituted porphyrin hybrids have been designed and synthesized. The meso-TPB-porphyrin hybrids exhibit two discrete atropisomers due to restricted rotation around Cmeso–CTPB bond. Both the atropisomers could be structurally characterized. The photophysical and electrochemical properties of the synthesized hybrids have been investigated with respect to tetraphenylporphyrin (TPP) and tetraphenylporphyrinatozinc(II) (ZnTPP). These hybrids exhibit reminiscent absorption and emission properties.Moreover, the redox potentials of the TPB conjugates are found to be sensitive to the meso-substituents as in the case of meso-aryl substituents.

    • Three atropisomers of biphenyl: twist by tunable para substituents

      RAMESH KARUPNASWAMY PRABUSANKAR GANESAN

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      The geometrical twist of aryl-aryl bond in biphenyl by weakly coordinating anion and selone at the para position has not been clear so far. We report here the synthesis and investigation into the diverse structural properties of biphenyl with weakly coordinating biphenyl imidazolium salts and neutral imidazole selone thatexhibit three atropisomers of biphenyl. The approaches underline the diversity of the effects of para substituent with dynamic nature at biphenyl molecule.

    • Coordination-polymer anchored single-site ‘Pd-NHC’ catalyst for Suzuki-Miyaura coupling in water

      MOUMITA MONDAL JINU JOJI JOYANTA CHOUDHURY

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      A single-site, heterogeneous Pd–NHC-based catalyst was designed on a coordination polymer platform via metal-terpyridine interaction. The catalyst was successfully applied in Suzuki-Miyaura coupling in water showing good activity and reusability.

    • Chromogenic and fluorogenic detection of selected anions by bis-terpyridine Fe(II) complex through displacement approach

      SHRUTI MUKHERJEE POULAMI PAL MANORANJAN BAR SUJOY BAITALIK

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      This paper deals with synthesis, characterization and anion recognition properties of a homoleptic bis-terpyridine Fe(II) complex covalently coupled with diarylethene unit. The recognition event was examined in both organic as well as mixed aqueous–organic medium through different optical channels and spectroscopic techniques by taking advantage of metal–ligand interaction in the complex. The complex acts as sensor for F-, OAc- and CN- among the other studied anions (F-, Cl-, Br-, I-, CN-, OAc-, H2PO- 4 , SCN-, BF - 4 and ClO- 4) without selectivity. In contrast to acetonitrile, the complex acts as highly selective chromogenic and fluorogenic sensor for only CN- in water. Detection limit of the metalloreceptor towards CN- was determined from the absorption and emission titration data and the observed values lie in the order of 10-9 M in acetonitrile and 10-8 M in mixed aqueous–organic media

    • Modulation of iron spin in ethane-bridged diiron(III) porphyrin dimer: anion dependent spin state switching

      FIROZ SHAH TUGLAK KHAN ANJANI KUMAR PANDEY SANKAR PRASAD RATH

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      The multiheme cytochrome c involves extensive interaction among the heme centers to enable them to perform a wide variety of enzymatic activities. In an attempt to exploit such heme–heme interactions in the synthetic diheme, an ethane-bridged diiron(III) porphyrin dimer has been utilized that can switch easilybetween syn and anti conformations due to highly flexible nature of the bridge. Upon protonation using 5% aqueous Brønsted acid, the dichloromethane solution of diiron(III)-µ-oxo porphyrin dimer immediately changes its color from green to red leading to the formation of a series of µ-hydroxo complexes. However, long exposure of the Brønsted acid converts the µ-hydroxo complex to five-coordinate diiron(III) porphyrin dimer in which the counter anion switches its position to act as an axial ligand. In the present study, the investigation has been extended further using Brønsted acids containing strongly coordinating anions such as HN3, HNCS and l-(+)-Lactic acid (HLA) in which the anions eventually coordinate to iron centers directly as axial ligands. A comprehensive account of the anion-mediated spin state change in the ethane-bridged diiron(III) porphyrin dimer has also been presented here.

    • Coordination driven architectures based on metalloligands offering appended carboxylic acid groups

      GULSHAN KUMAR RAJEEV GUPTA

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      The field of coordination polymers (CPs) has grown rapidly in the recent time and exemplifies one of the most exciting fields in the solid state and structural chemistry. In order to search for new CPs with desirable structural features and attractive functional properties, various synthetic strategies have been adopted including the challenging metalloligand approach. This approach relies on developing a metalloligand that is capable of placing the appended functional groups to limited directions thus resulting in limited structural variations—alandmark step towards predictable architectures. Consequently, a variety of metalloligands offering assorted functional groups have been developed and explored for the construction of noteworthy CPs. This perspective article summarizes an important class of metalloligands offering appended carboxylic acid groups with a focus on the design strategies to understand the architectures of the resultant CPs being controlled by the metalloligands. In addition, a concise discussion has been included about the applications of selected CPs to demonstrate their practical utilization.

    • Ruthenium-bipyridine complex catalyzed C–H alkenylation of arylpyrazole derivatives

      SANCHARI SHOME SURYA PRAKASH SINGH

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      Direct dehydrogenative alkenylation of N-arylpyrazoles by acrylates has proven to be efficient under Ru(II) carboxylate complexes SPS-BPY and SPS-DB-BPY catalyst along with Cu(OAc)2·H2O as an oxidant. The reaction was found to be atom-economical and was characterized by a number of substituted Narylpyrazoles with excellent chemoselectivity. The reaction allowed a direct alkenylation to be performed under the eco-friendly solvent system. The diverse functional group tolerance of this protocol opened up a new insight to the use of ruthenium(II) bipyridine complexes as a productive method for the oxidative heterocoupling of N-arylpyrazole.

    • Manganese-salen catalyzed oxidative benzylic chlorination

      SHEULI SASMAL SUJOY RANA GOUTAM KUMAR LAHIRI DEBABRATA MAITI

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      Metalloporphyrins are well-known to serve as the model for mimicking reactivities exhibited by cytochrome P450 hydroxylase. Recent developments on selective C–H halogenation using Mn-porphyrins provided the way for understanding the reactivity as well as mechanism of different halogenase enzymes. In this report, we demonstrated a method for benzylic C–H chlorination using easily prepared Mn(salen) complex as the catalyst, which shows a complementary reactivity of Mn-porphyrins. Here, NaOCl has been used as a chlorinating source as well as the oxidant. Efforts towards understanding the mechanism suggested the formation of the high-valent Mn(V)=O species which is believed to be the key intermediate to conduct this transformation.

    • Synthesis and structural characterization of a diruthenium pentalene complex, [Cp∗Ru{(Cp∗Ru)2B6H14}(Cp∗Ru)]

      BENSON JOSEPH SUBRAT KUMAR BARIK SOUMYA KUMAR SINHA THIERRY ROISNEL SUNDARGOPAL GHOSH

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      Treatment of nido-[1,2-(Cp*Ru)2(μ-H)2B3H7], 1 with five equivalents of Te powder led to the isolation of diruthenium pentalene analogue [(Cp*Ru){(Cp*Ru)2B6H14}(RuCp*)], 2 and a metal indenyl complex [(Cp*Ru)2B2H6C6H3 CH3], 3. The [(Cp*Ru)2B6H14] fragment in 2 may be considered as a true metal–boron analogue of η55-pentalene ligand (C8H6) and [(Cp*Ru)B2H6C6H3 CH3] fragment in 3 is an analogue of η5-indenyl ligand. The solid-state X-ray structures were unambiguously determined by crystallographic analysis of compounds 2 and 3. Further, the density functional theory (DFT) calculationswere performed to investigate the bonding and the electronic properties of 2a (Cp analogue of 2). The frontier molecular orbital analysis of both 2a and 2b (Cp analogue of [(Cp*Ru)B8H14(RuCp*)]) reveals a lower HOMO–LUMO gap indicating less thermodynamic stability

    • Synthesis and anion binding properties of the smallest meso-expanded calix[4]pyrrole

      B SATHISH KUMAR PRADEEPTA K PANDA

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      The smallest core expanded calix[4]pyrrole derivative (5) was synthesized via incorporation of an additional sp3 meso-carbon at the periphery of the macrocycle. Anion binding study of the macrocycle reveals clearly the effect of core size on its affinity towards various tested ions (F-, Cl-, Br-, I-, AcO-, H2PO-4, HSO- 4 , ClO - 4 , PF- 6 , NO- 3 , NO- 2 , N- 3 and CN -). The macrocycle displays the highest affinity towards fluoride and acetate ions, albeit with reduced affinities compared to parent octamethylcalix[4]pyrrole.

    • Steric influence of adamantane substitution in tris-urea receptor: encapsulation of sulphate and fluoride-water cluster

      SANTANU KAYAL UTSAB MANNA GOPAL DAS

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      Tris(2-aminoethyl)amine (tren)-based bulky adamantane group-substituted tris-urea (L) has been developed as the potential tripodal receptor exhibiting strong binding affinities towards small spherical fluoride anion as well as large tetrahedral sulphate anion in its neutral and protonated form, respectively. Structural elucidation reveals that the divalent sulphate ion is fully engulfed inside the complementary space created by two face-to-face oriented symmetry-independent protonated receptors, whereas the smaller fluoride ion is encapsulated as fluoride-water cluster (F--H2O) assemblage within the neutral unimolecular capsular assembly of receptor L.

    • Reactions of 4-diphenylphosphino benzoic acid with organotin oxides and -oxy-hydroxide

      RAMAKIRUSHNAN SURIYA NARAYANAN PAKKIRISAMY THILAGAR JOYDEV ACHARYA PAWAN KUMAR DODDAPUNENI KRISHNA RAO VADAPALLI CHANDRASEKHAR ANUKUL JANA

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      The reactions of p-diphenylphosphinobenzoic acid (LCOOH) with various organotin precursors have been carried out. Accordingly, the reaction of [n-BuSn(O)(OH]n with LCOOH afforded the hexameric compound, [n-BuSn(O)O2C–C6H4–p-PPh2]6(1). On the other hand, the reaction of LCOOH with [n-Bu2SnO]n gave the tetrameric compound [{n-Bu2SnO2C–C6H4–p-PPh2}2O]2 (2). The 1-D coordination polymers [R3SnO2C–C6H4–p-P(O) Ph2]n,[ R=n-Bu (3), R=Ph (4)] were prepared in the reaction of [n-Bu3Sn]2O or [Ph3Sn]2O with LCOOH. The compounds 1–4 were structurally characterized by multinuclear NMR spectroscopic and single crystal X-ray diffraction studies

    • Cobalt based functional inorganic materials: Electrocatalytic water oxidation

      OLIVIA BASU SUBHABRATA MUKHOPADHYAY SAMAR K DAS

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      Water splitting is considered to be one of the most promising sources of sustainable energy, as it can produce hydrogen (H2) fuel. To have successful water splitting in a sustained manner, it is necessary to develop efficient and robust catalysts that can perform water oxidation, the bottleneck process of water splitting either electrochemically or photochemically. Here, we have presented a brief descriptive analysis of different aspects of designing such catalysts in connection with our recent works on the same field. The focus of the article is to discuss contemporary works in the field of designing cobalt-based heterogeneous water oxidation electrocatalysts. To the best of our knowledge, although cobalt is the most extensively studied 1st row transition metal for water oxidation catalysis reaction, no such report has been found where the simplest cobalt complex, [Co(H2O6]2+ , has been employed as a water oxidation catalyst. Not only that, reports of cobalt-based simple and small molecular catalysts are also not very frequent. With the help of our recent works, we have tried to detail here a wide aspect of the study on cobalt-based simple and small molecular catalysts, starting from the reasons behind the scarcity of such water oxidation catalysts, to development of new ideas addressing the challenges in utilization of such small cobalt complexes for water oxidation catalyst. Here, we have addressed the scope of encapsulation chemistry in designing robust and efficient heterogeneous water oxidation catalysts using cobalt-based small molecular guest species. With the help of structural insight, gained from the recent results, we published in the field of water oxidation catalysis; here, we try to formulate a general approach that can help to prepare water oxidation catalyst based on host-guest chemistry. The article critically evaluates our recent results in connection with the approach of addressing the problem.

    • Modification of the toxicity of an azo compound through complex formation help target bacterial strains

      TATHAGATA DEB DURBA GANGULY SAURADIP SEN PANKAJ GIRI PUBALI DHAR SAURABH DAS

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      The antibacterial efficacy of a Cu(II) complex of 2-hydroxyphenyl-azo-2' -naphthol (HPAN) was studied on gram-positive Bacillus subtilis and gram-negative Escherichia coli. In vitro antimicrobial activity was determined by an agar-well diffusion assay and minimum inhibitory concentration. CuII (HPAN)2 was found to be better than HPAN in antibacterial activity. Although both bacterial strains succumbed to high concentrations of each compound, at low concentrations only CuII (HPAN)2 was active on B. subtilis. To explain the observations, reductive cleavage of the azo-bond to aromatic amines was followed by an in vitro enzyme assay using cell extracts of E. coli containing azo-reductase. Interaction of CuII (HPAN)2 with calf thymus DNA was comparedwith HPAN for correlation with antibacterial activity. Enzyme-assay on the reductive degradation of azo bond and DNA interaction do not individually explain trends observed in antibacterial activity. Comparable binding of CuII (HPAN)2 and HPAN with calf thymus DNA was attributed to the presence of anionic species of the complex in solution. Significant activity of the complex was probably due to effective cellular uptake of it by bacterial cells as shown by a fluorescence study. The activity of the complex resembled some established antimicrobial agents. Since the complex has a moiety, not common to most antibacterial agents, resistance towards it should be significantly less, hence an advantage.

    • Effect of methyl at the 1-phenyl of tetraaryl substituted imidazole boron difluoride complexes: synthesis, characterization, photophysical and electrochemical studies

      SANKET SAMAL BASAVA PUNNA RAO ARADHYULA KRISHNAN VENKATASUBBAIAH

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      Two new imidazole-based boron complexes were synthesized and characterized by multinuclear NMR and single crystal X-ray analysis. The photophysical and electrochemical properties of these boron complexes were compared with analogues of reported complexes.

    • Linear and circular helicates: A brief review

      ARUNA PRIYADARSINI PANEERSELVAM SRABANI SROTOSWINI MISHRA DILLIP KUMAR CHAND

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      Helical self-assembled coordination complexes are broadly classified under linear and circular helicates. While the number of strands of the ligand units in a molecule of the linear helicates is used for further classifications such as single-stranded, double-stranded and so on, the circular helicates are not classified further. The compositions of helicates are considered as MxLy where the terms x and y stand for the number of metal ion(s) and ligand strands, respectively. However, more than one type of metal centers/ligand in helicates are also known. The linear helicates of a given number of strands are further classified under the number of metal centers such as binuclear, trinuclear and so on. Representative examples are included to exemplify the varieties of helicates.

    • Bimetallic aluminum alkyl and iodide complexes stabilized by a bulky bis-guanidinate ligand

      THOTA PEDDARAO BAISHYA SURAJ KUMAR HOTA SHARANAPPA NEMBENNA

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      A series of bulky bis-guanidine ligands such as L 1(2H), L2 (2H) and L3 (2H), where L = {ArNCNAr}2{ μ-N(C2H4)2N}, for L1 (2H) (Ar = 2, 6-Me2-C6H3), L2(2H) (Ar=2, 4, 6-Me3-C6H2) and (L3 (2H)) (Ar = 2, 6-iPr2-C6H3) have been utilized to synthesize four-membered dinuclear aluminum heterocycles. Deprotonation of L11-3 (2H) (1.0 equiv.) upon treatment with trimethyl aluminum (2.1 equiv.)in toluene led to the formation of bimetallic aluminum alkyls: [L1 (AlMe2)2](1), [L2 (AlMe2)2] (2) and [L3 (AlMe2)2] (3). Aluminum halide complex i.e., [L3(AlI2)2](4) was obtained by the reaction of compound 3 with four equivalents of molecular iodine in toluene at 80°C, in which alkyl-halide exchange occurred. All the compounds (1–4) were confirmed by multinuclear (1H and 13C) magnetic resonance spectroscopy. Furthermore, compounds 2–4 were confirmed by single crystal X-ray structural analysis. All the compounds 1–4 display theexpected number of signals in the 1H and 13C NMR spectra and are consistent with their compositions. The solid state structures of 1–4 reveal that each aluminum center is bonded to the monoanionic guanidinate ligand in N,N' -chelated fashion and the other two sites are occupied by alkyl or halide ligands, resulting in a distorted tetrahedral geometry.

    • Intermolecular dihydrogen bonding in VI, VII, and VIII group octahedral metal hydride complexes with water

      KARAKKADPARAMBIL S SANDHYA GEETHA S REMYA CHERUMUTTATHU H SURESH

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      The nature of dihydrogen bonding (DHB) in VI, VII, and VIII group octahedral metal hydride complexes with H2O has been studied systematically using quantum theory of atoms-in-molecule (QTAIM) analysis. A dihydrogen bond (H···H) between hydride ligand and hydrogen of H2O is revealed in QTAIM analysis with the identification of a bond critical point (bcp). The DHB is due to the donation of electron density from the hydride ligand to the hydrogen of H2O. A strong linear correlation is observed between intermolecular H···H distance (dHH) and electron density (ρ) at the bcp. Structural parameters suggested the highly directional nature of DHB. Weak secondary interactions between oxygen of water and other ligands contribute significantly to the binding energy (Eint) of DHB complex (2.5 to 13.2 kcal/mol). Analysis of QTAIM parameters such askinetic- (Gc), potential- (Vc) and total electron energy density (Hc) revealed the partially covalent character of DHB in majority of the complexes while a few of them showed closed shell character typical of purely non-covalent interactions

    • New reactions of allenes, alkynes, ynamides, enynones and isothiocyanates

      K C KUMARA SWAMY G GANGADHARARAO MANDALA ANITHA A LEELA SIVAKUMARI ALLA SIVA REDDY ADULA KALYANI SRINIVASARAO ALLU

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      Abstract. This perspective article is related to transformations (both catalytic and non-catalytic) involving allenes, alkynes/enynones/ynamides and isothiocyanates. Part of the work from the author’s group has been reviewed along with some new reactions of (i) allenylphosphonate/allenylphosphine oxide and (ii) a P(III) isothiocyanate. Thus, the allenylphosphine oxide Ph2P(O)C(Ph)=C=CH2 undergoes base (DBU) catalyzed addition to the β-ketophosphonate (OCH2CMe2CH2O)P(O)CH2C(O)CH3 at 90°C to afford the addition product Ph2P(O)C(Ph)=C(Me)CH[C(O)Me][P(O)(OCH2CMe2CH2O)]. In an analogous reaction, with DBU as the base at 140°C, isomeric vinylphosphine oxides (Z)-Ph2P(O)C(Ph)=C(Me)CH2[C(O)Me] and (E)-Ph2P(O)C(Ph)=C(Me)CH2[C(O)Me] were isolated. The E-isomer has been characterized by single crystal X-ray structure determination. In another set of studies, the reaction of P(III) isothiocyanate (OCH2CMe2CH2O)P(NCS) with N-(2-bromomethyl)sulfonamide afforded an unusual product with the formula(OCH2CMe2CH2O)P(O)SCH2CH2NHS(O)2-(C6H4-4-Me) as shown by X-ray structure determination. This result is different from that obtained in the recently reported analogous reaction using phenyl isothiocyanate.

    • Investigations on the reactivity of arylantimony halides with N,O-donor ligands

      PILLI V V N KISHORE JUNAID ALI GUJJU NARASIMHULU VISWANATHAN BASKAR

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      The reactions of organoantimony(V) halides with N,O-donor ligands in presence of a base were investigated. The synthesis and crystal structure of three novel organoantimony(V) compounds (Ph2Sb)2(Q)2(O)2 1, (Ph3Sb)(PM)Cl 2 and (Ph2Sb)(TEA) 3 [where Q = 8-hydroxyquinoline, PM = 2-pyridinemethanol and TEA = triethanolamine] are reported herein. 1 crystallizes as a dimer resulting inthe formation of a four-membered Sb22O2 ring while 2 and 3 are monomeric in the solid state. Interestingly, compound 3 crystallizes in orthorhombic chiral space group P212121 and is a rare example of spontaneous chirality exhibited in organoantimony(V) compounds.

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