Crystal structure, vibrational studies, optical properties and TG-DTA investigations of a new chlorocadmate templated by 1-methylimidazolium

Abstract

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.