• RAKESH KUMAR

Articles written in Journal of Chemical Sciences

• Excess molar volumes and viscosities of binary mixtures of 1,2-diethoxyethane with chloroalkanes at 298.15 K

Excess molar volumes (VmE) and viscosities (η) of the binary mixtures of 1,2-diethoxyethane with di-, tri- and tetrachloromethane have been measured at 298-15 K and atmospheric pressure over the entire mole fraction range. The deviations in viscosities (δlnη) and excess energies of activation (δG*E) for viscous flow have been calculated from the experimental data. The Prigogine-Flory-Patterson (PFP) model has been used to calculateVmE, and the results have been compared with experimental data. The Bloomfield and Dewan model has been used to calculate viscosity coefficients and these have also been compared with experimental data for the three mixtures. The results have been discussed in terms of dipole-dipole interactions between 1,2-diethoxyethane and chloroalkanes and their magnitudes decreasing with the dipole character of the molecules. A short comparative study with results for mixtures with polyethers and chloroalkanes is also described.

• On the key role of water in the allylic activation catalysed by Pd (II)bisphosphinite complexes

Palladium and platinum complexes of bisphosphinites and bisphosphines derived from mandelic acid have been prepared and characterized. Their ability to catalyze allylation of imines with allyltributylstannane has been studied. Bisphophinite complexes of Pd (II) are shown to be ideal and they work best in the presence of one equivalent of water. The near neutral conditions employed make the catalysts suitable for a wide variety of substrates.

• Synthesis and characterization of some heteroleptic copper(II) complexes based on meso-substituted dipyrrins

The syntheses and characterizations of meso-substituted dipyrrins, 5-(4-imidazol-1-yl-phenyl)-dipyrromethene (4-impdpm), 5-(4-nitro-imidazol-1-yl-phenyl)-dipyrromethene, (4-nimpdpm), 5-(4-benzimidazol-1-yl-phenyl)-dipyrromethene (4-bimp-dpm) and heteroleptic complexes [Cu3(4-impdpm)2(hfacac)4] 1, [Cu(4-nimpdpm)(acac)] 2, [Cu(4-nimpdpm)(hfacac)] 3, [{Cu(4-bimpdpm)(acac)}$_n$] 4 and [{Cu(4-bimpdpm)-(hfacac)}$_n$] 5, imparting acetylacetonato (acac) and hexafluoroacetylacetonato (hfacac) groups as co-ligand have been described. The dipyrrins and complexes 1-5 have been characterized by elemental analyses and spectral (IR ESI-MS, NMR, electronic absorption and emission) studies. Crystal structures of 1, 3 and 4 have been authenticated by X-ray single crystal analyses. The reaction between 4-impdpm and Cu(hfacac)2 gave a trimetallic complex, under analogous conditions 4-nimpdpm and 4-bimpdpm reacted with Cu(acac)2 and Cu(hfacac)2·2H2O to afford mononuclear (2, 3) and 1D polymeric (4, 5) complexes.

• Triethylammonium salt of dimethyl diphenyldithiophosphates: Single crystal X-ray and DFT analysis

The present work demonstrates the single crystal X-ray and DFT analysis of $[{(2,4-CH_{3})_{2}C_{6}H_{3}O}_{2}$PS_{2}HNEt_{3}]$(1) and$ [{(3,4-CH_{3})_{2}C_{6}H_{3}O}_{2}PS_{2}HNEt_{3}]$(2) along with computational analysis of$ [{(3,5-CH_{3})_{2}C_{6}H_{3}O}_{2} $PS_{2}HNEt_{3}]$ (3) by using density functional theory (DFT) in its hybrid form B3LYP method. Compounds1 and 2 crystallize in the orthorhombic space group Pbca and triclinic space groupP1,respectively andtheir X-ray analysis reveals that phosphorus atom is coordinated to the two S and two O atoms to form tetrahedralgeometry. The structure is stabilized by cation–anion N–H.... S hydrogen bonded interactions. The structuralparameters, vibrational bands and energy gaps of frontier orbitals (HOMO–LUMO) have been calculated.The calculated geometric and spectral results matched the experimental data with good agreement. Theoreticallycalculated frontier molecular orbitals (HOMO–LUMO) and their energies suggest that charge transferoccurs within the compounds.

• Assessing therapeutic potential of molecules: molecular property diagnostic suite for tuberculosis (MPDSTB)

Molecular Property Diagnostic Suite (MPDSTB) is a web tool (http://mpds.osdd.net) designed to assist the in silico drug discovery attempts towards Mycobacterium tuberculosis (Mtb). (MPDSTB) tool has nine modules which are classified into data library (1–3), data processing (4–5) and data analysis (6–9). Module 1 is a repository of literature and related information available on the Mtb. Module 2 deals with the protein targetanalysis of the chosen disease area. Module 3 is the compound library consisting of 110.31 million unique molecules generated from public domain databases and custom designed search tools. Module 4 contains toolsfor chemical file format conversions and 2D to 3D coordinate conversions. Module 5 helps in calculating the molecular descriptors. Module 6 specifically handles QSAR model development tools using descriptors generated in the Module 5. Module 7 integrates the AutoDock Vina algorithm for docking, while module 8 provides screening filters. Module 9 provides the necessary visualization tools for both small and large molecules. The workflow-based open source web portal,(MPDSTB) 1.0.1 can be a potential enabler for scientists engaged in drug discovery in general and in anti-TB research in particular.

• # Journal of Chemical Sciences

Volume 134, 2022
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• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019

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