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Parimal K Bharadwaj - One of the best experts on this subject based on the ideXlab platform.
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a reusable zigzag copper ii coordination polymer with bio essential constituents as a facile dna scission agent
Inorganica Chimica Acta, 2005Co-Authors: Sanjib Das, C Madhavaiah, Sandeep Verma, Parimal K BharadwajAbstract:Abstract A copper(II) coordination polymer has been synthesized in the form of an infinite zigzag chain where each metal is bonded to one glycine, two adenine, one nitrate anion and a water molecule giving a distorted octahedral coordination geometry with N 3 O 3 donor set. Each chain is hydrogen-bonded through C–H⋯O and N–H⋯O interactions on both sides leading to an overall Polymeric Structure. This compound not only shows facile chemical nuclease activity for pBR322 supercoiled DNA but also can be reused keeping its scission activity unchanged.
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puckered boat conformation hexameric water clusters stabilized in a 2d metal organic framework Structure built from cu ii and 1 2 4 5 benzenetetracarboxylic acid
Inorganic Chemistry, 2004Co-Authors: Sujit K Ghosh, Parimal K BharadwajAbstract:1,2,4,5-Benzenetetracarboxylic acid (btcH4) reacts with Cu(NO3)2·6H2O to form 2D coordination Polymeric Structure {[Cu2(btc)(Py)4·2H2O]·4H2O}n, 1, in the presence of pyridine from water at room temperature. Puckered-boat-shaped hexameric water clusters resulting from four free water molecules and two water molecules coordinating to metal ions join these sheets to make a 3D network. These water clusters behave as pillars to join those sheets which is the key factor stabilizing the 3D network. Thermal analysis, X-ray powder diffraction, and X-ray Structure analysis have been used to characterize this compound. Crystal data for 1 follow: triclinic space group P1, a = 8.905(3) A, b = 11.137(4) A, c = 17.484(2) A, α = 82.342(6)°, β = 81.312(3)°, γ = 82.361(4)° V= 1687.5(1)A3, Z = 2, R1 = 0.0331, wR2 = 0.0886, S =1.066.
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coexistence of water dimer and hexamer clusters in 3d metal organic framework Structures of ce iii and pr iii with pyridine 2 6 dicarboxylic acid
Inorganic Chemistry, 2003Co-Authors: Sujit K Ghosh, Parimal K BharadwajAbstract:Ce(NO3)3·6H2O or Pr(NO3)3·6H2O and pyridine-2,6-dicarboxylic acid form a linear coordination Polymeric Structure under hydrothermal conditions. Hexameric water clusters join these linear chains through bonding to the metal ions. Other coordinated water and the carboxylate oxygen form an intricate array of hydrogen bonding resulting in a 3D network where each metal ion shows 9-coordination with an approximate D3 symmetry. Dimeric water clusters are also located in the void spaces. In the Structure containing Pr(III), the water dimers are hydrogen-bonded to the hexamers, whereas in the Ce(III) Structure, the dimers and the hexamers are far apart.
Sujit K Ghosh - One of the best experts on this subject based on the ideXlab platform.
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puckered boat conformation hexameric water clusters stabilized in a 2d metal organic framework Structure built from cu ii and 1 2 4 5 benzenetetracarboxylic acid
Inorganic Chemistry, 2004Co-Authors: Sujit K Ghosh, Parimal K BharadwajAbstract:1,2,4,5-Benzenetetracarboxylic acid (btcH4) reacts with Cu(NO3)2·6H2O to form 2D coordination Polymeric Structure {[Cu2(btc)(Py)4·2H2O]·4H2O}n, 1, in the presence of pyridine from water at room temperature. Puckered-boat-shaped hexameric water clusters resulting from four free water molecules and two water molecules coordinating to metal ions join these sheets to make a 3D network. These water clusters behave as pillars to join those sheets which is the key factor stabilizing the 3D network. Thermal analysis, X-ray powder diffraction, and X-ray Structure analysis have been used to characterize this compound. Crystal data for 1 follow: triclinic space group P1, a = 8.905(3) A, b = 11.137(4) A, c = 17.484(2) A, α = 82.342(6)°, β = 81.312(3)°, γ = 82.361(4)° V= 1687.5(1)A3, Z = 2, R1 = 0.0331, wR2 = 0.0886, S =1.066.
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coexistence of water dimer and hexamer clusters in 3d metal organic framework Structures of ce iii and pr iii with pyridine 2 6 dicarboxylic acid
Inorganic Chemistry, 2003Co-Authors: Sujit K Ghosh, Parimal K BharadwajAbstract:Ce(NO3)3·6H2O or Pr(NO3)3·6H2O and pyridine-2,6-dicarboxylic acid form a linear coordination Polymeric Structure under hydrothermal conditions. Hexameric water clusters join these linear chains through bonding to the metal ions. Other coordinated water and the carboxylate oxygen form an intricate array of hydrogen bonding resulting in a 3D network where each metal ion shows 9-coordination with an approximate D3 symmetry. Dimeric water clusters are also located in the void spaces. In the Structure containing Pr(III), the water dimers are hydrogen-bonded to the hexamers, whereas in the Ce(III) Structure, the dimers and the hexamers are far apart.
Kuolun Tung - One of the best experts on this subject based on the ideXlab platform.
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molecular dynamics simulations of Polymeric Structure and alcohol membrane surface affinity of aromatic polyamide membranes
Journal of Membrane Science, 2011Co-Authors: Kaishiun Chang, Yanlin Wang, Chaohsiang Kang, Hwajou Wei, Yuhsiang Weng, Kuolun TungAbstract:Abstract A molecular dynamics (MD) technique was adopted to investigate the free volume, operational temperature effects, feed solution–membrane surface affinity, and water/alcohol diffusion mechanism of aromatic polyamide (PA) membranes for pervaporation (PV) applications. An isothermal–isobaric ensemble (i.e. NPT ensemble) was adopted to analyze the fractional free volume, the fractional accessible volume, and the cavity size distribution of PA membranes at different operational temperatures. The free volume and cavity size analyses indicated that bulkier side groups enhanced the formation of larger free volumes, which increased permeation rates. Increased temperature induced chain mobility and enlarged the cavity size of the membrane. During feed solution–membrane affinity analysis, the alcohols showed a higher interaction with the membrane surface as compared to the water molecules. The diffusion mechanism of water/methanol in the membrane matrix suggested that methanol had a shorter displacement distance relative to the water due to its larger size and stronger interaction with the membrane. Results from the MD simulation agreed well with those from experimental studies reported in the literatures, which demonstrated that this theoretical method is a promising tool for characterizing membrane Structures and analyzing feed solution transport at a molecular scale during PV processes.
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free volume and Polymeric Structure analyses of aromatic polyamide membranes a molecular simulation and experimental study
Journal of Membrane Science, 2010Co-Authors: Kaishiun Chang, Yunhsuan Huang, Kueirrarn Lee, Kuolun TungAbstract:Molecular simulation techniques were adopted to investigate the membrane free volume morphologies and alcohol sorption behaviors of aromatic polyamide (PA) membranes for pervaporation applications. A molecular dynamics (MD) technique was adopted to analyze the fractional free volume (FFV), the fractional accessible volume (FAV), and the size and shape distributions of the free volume. Experimental FFV results from Bondi's group contribution method and positron annihilation lifetime spectroscopy were also adopted to compare with the simulation data. The radial distribution function was also used to analyze the polymer chain stiffness and mobility. A Monte Carlo (MC) method was used to analyze the membrane absorption behavior. The FFV, FAV, and free volume morphology analyses revealed that bulky groups in the PA membranes contributed to the formation of a larger and more continuous free volume. The sorption analysis indicates that high carbon number alcohols have a higher affinity with the membranes, which might lead to a higher attractive force, reducing the permeability. The MD and MC results demonstrate good agreement with the experimental data, validating the feasibility of molecular simulation techniques in PV membranes at the molecular scale.
Igor O Fritsky - One of the best experts on this subject based on the ideXlab platform.
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catena poly aqua copper ii bis μ bis 3 5 dimethyl 1h pyrazol 4 yl selenide bis tetra fluorido borate bis triphenyl phosphine oxide monohydrate
Acta Crystallographica Section E-structure Reports Online, 2010Co-Authors: Maksym Seredyuk, Kateryna O Znovjyak, Yurii S Moroz, Vadim A Pavlenko, Igor O FritskyAbstract:The title compound, {[Cu(C10H14N4Se)2(H2O)](BF4)2·2C18H15PO·H2O}n, has a Polymeric Structure where each CuII ion adopts a square-pyramidal coordination constituted by four N atoms of pyrazole moieties in the equatorial plane and an axial O atom of a water molecule. A pair of bis(3,5-dimethyl-1H-pyrazol-4-yl) selenide ligands bridges the CuII centres into a chain extending along the c axis. The water molecules, anions and triphenylphosphine oxide molecules are involved in intermolecular hydrogen bonding, which links the chains into a three-dimensional network.
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catena-Poly[[[aquacopper(II)]bis[μ-bis(3,5-dimethyl-1H-pyrazol-4-yl) selenide]] bis(tetrafluoridoborate) bis(triphenylphosphine oxide) monohydrate]
International Union of Crystallography, 2010Co-Authors: Maksym Seredyuk, Kateryna O Znovjyak, Yurii S Moroz, Vadim A Pavlenko, Igor O FritskyAbstract:The title compound, {[Cu(C10H14N4Se)2(H2O)](BF4)2·2C18H15PO·H2O}n, has a Polymeric Structure where each CuII ion adopts a square-pyramidal coordination constituted by four N atoms of pyrazole moieties in the equatorial plane and an axial O atom of a water molecule. A pair of bis(3,5-dimethyl-1H-pyrazol-4-yl) selenide ligands bridges the CuII centres into a chain extending along the c axis. The water molecules, anions and triphenylphosphine oxide molecules are involved in intermolecular hydrogen bonding, which links the chains into a three-dimensional network
Shabana Noor - One of the best experts on this subject based on the ideXlab platform.
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antimicrobial and sod activities of novel transition metal complexes of pyridine 2 6 dicarboxylic acid containing 4 picoline as auxiliary ligand
European Journal of Medicinal Chemistry, 2010Co-Authors: Zafar A Siddiqi, Mohd Khalid, Sarvendra Kumar, Mohammad Shahid, Shabana NoorAbstract:Abstract Ternary complexes are potential models for several mono and polynuclear metal enzymes. The present ternary complexes [Fe(dipic)(4-picoline)]Cl, [M(dipic)(4-picoline)] [M = Co or Ni] and [Cu(dipic)(4-picoline)]n were prepared to exploit as novel antimicrobial agents. The chemical Structure and bonding etc. were elucidated by spectral studies. Single crystal X-ray data of the Cu(II) complex indicated formation of 1D coordination Polymeric Structure. The antimicrobial activities investigated against Escherichia coli (K-12), Bacillus subtilis (MTCC-121), Staphylococcus aureus (IOA-SA-22), Salmonella typhymurium (MTCC-98), Candida albicans, Aspergillus fumigatus and Penicillium marneffei (isolates from Department of Microbiology, Faculty of Agricultural Science, AMU) showed significant activities. The superoxide dismutase (SOD) activity of the Cu(II) complex was also assessed by NBT assay.