Synthesis and Crystal Structure of Hexakis(imidazole) nickel (II) O,O′-diphenyldithiophosphate [Ni(Im)6](Ph2O2PS2)2
The crystal and molecular structures of [Ni(Im)6](dtp)2 (Im = imidazole, dtp = O,O′-diphenyldithiophosphate) have been determined by X-ray crystallography. It crystallizes in the triclinic system, space group Pī, with cell parameters a = 9.375 (2), b = 12.324(3), c = 13.285(3) Å, α = 107.86(3), β = 102.28(3), γ = 109.24(3), and Z = 1. The crystal structure of the title compound is built up of discrete monomeric molecules of [Ni(Im)6](dtp)2. The nickel (II) ion is hexacoordinated by six imidazole molecules and the coordination environment of Ni (II) is of octahedral geometry. In the solid state, a network of N-H∙∙∙S intermolecular hydrogen bonds connect the Ni(Im)6 moieties and O,O′-diphenyl- dithiophosphate molecules, forming a three-dimensional structure.
Crystal structure, vibrational studies, optical properties and TG-DTA investigations of a new chlorocadmate templated by 1-methylimidazolium
Chemical preparation, X-ray single crystal diffraction, thermal analysis, electrochemical measurements, IR, Raman and UV spectroscopic investigations of a novel organic-inorganic hybrid material(C4H7N2)CdCl3(H2O)(1) were described. 1-Methylimidazolium aquapentachlorocadmate(II) crystallized in the monoclinic system with P21/n space group. Its structure provided a new interesting example of infinite inorganic layers of [CdCl3(H2O)]nn– centered by (–101) planes. The [CdCl5(H2O)]– anions were interconnected by O―H···Cl hydrogen bonds. Acidic protons of the chloride group were transferred to the organic molecule, giving the singly-protonated cations. The ability of ions to form a spontaneous three-dimensional structure through O―H···Cl and N―H···Cl hydrogen bonds was fully utilized. These hydrogen bonds induced notable vibrational effects. IR and Raman spectra were reported and discussed on the basis of group theoretical analysis and on quantum chemical density theory(DFT) calculation. The molecular HOMO-LUMO compositions and their respective energy gaps were also drawn to explain the activity of our compound. The role of the intermolecular interaction in this crystal was analyzed. The optical study was also investigated by UV-Vis absorption spectrum. Thermal analysis reveals the hydrous character of the compound. Cyclic voltammetry was studied to evaluate the spectral and structural changes accompanying electron transfer.
Superoxide dismutase activity of Cu(II)2(aspirinate)4 and its adducts with nitrogen and oxygen donors
Abstract Several adducts of Cu(II) 2 (aspirinate) 4 of formula [Cu(II)(aspirinate) 2 L 2 ], where L is pyridine, nicotinamide, 3-picoline, 4-picoline, imidazole, 1-methyl- imidazole, diethylamine and dimethyl sulfoxide, have been synthesized. They show an absorption wavelength maximum between 690 and 750 nm, which is assigned to the d-d transition. The infrared spectra of these adducts indicate the bonding of nitrogen to copper in their nitrogen base adducts and the bonding of oxygen to copper in the DMSO adduct. The frozen ESR spectra of the adducts suggest that the ligands are bonded in an axial environment around copper with two nitrogen donors occupying the equatorial plane. The lower g∥ value of the DMSO adduct as compared to g∥ values of the nitrogen base adducts implies that there is bonding of the oxygen atom of DMSO in its adduct. The superoxide dismutase activity of several of these adducts has been measured. The pyridine adduct of Cu(II) 2 (aspitinate) 4 shows a much higher activity than its DMSO adduct. This is also reflected in the enhanced antitumor activity of the pyridine adduct over the DMSO adduct of Cu(II) 2 (aspirinate) 4 .