Quantum chemical studies on some imidazole derivatives of metal complexes

In this research, some theoretical studies were performed on the imidazole type ligands and their metal complexes.First step: The geometric parameters, atomic charges, IR and 1H NMR of 3?-PyaiH, 3?-PyaiEt ligands and Ag(I) complex were calculated using HF/3-21G, DFT/B3LYP/LanL2DZ, DFT/B3LYP/SDD, DFT/B3LYP/6-311G, DFT/B3LYP/6-311++G (d,p) and PM6 methods. It was seen that the experimental and theoretical values were in good agreement.Second step: (1H-Benzimidazole-2-yl)-N-hydroxy-1-phenylmethanimine ligand and its relationship with some different charged metals ions and the possibility of creating complexes were investigated using PM6 method. Gibbs free energy change ( ? Gf, ? G) were calculated in aqueous and ethyl alcohol phase by using the heat of formation ( ?? f), enthalpy ( ? H) and the entropy change ( ? S) values. The dipole moment, HOMO-LUMO energies and acidity constants (pKa) values were calculated. ?? Gf and ?? G values were calculated from finding ? Gf and ? G. According to ?? Gf values, the possibility of forming complexes was found to be more appropriate in aqueous phaseThird step: The relationship between (1H-Benzimidazole-2-yl)-N-hydroxy-1-phenylmethanimine ligand and some divalent metals were investigated using AM1, PM3 and PM6 methods. The values mentioned above were calculated. The correlation of these methods was investigated. It was found that Ba, Zn, Pb, and Hg may more easily formed complex with this ligand according to this calculations in aqueous and ethyl alcohol phase. There was good corelation between AM1-PM3 methods in aqueous and ethyl alcohol phase according to ?? Gf values, there was good correlation between PM3-PM6 methods in the aqueous phase and between AM1-PM6 methods in the ethyl alcohol phase according to ?? G values.