DFT Computational Studies on Some Cobaloximes

Abstract

This study carried out quantum chemical investigations on cobaloxime complexes: [Co(dpgH)2Cl(H2O)] (C1), [Co(dpgH)2(Pz)Cl] (C2), [Co(dpgH)2(Im)Cl] (C3), [Co(dpgH)2(py)Cl] (C4) and [Co(dpgH)2 (CH3)(py)Cl] (C5), where dpgH− is diphenyl glyoximate, Pz is pyrazine, Im is imidazole and py is pyridine. The stable molecular geometries of these complexes were achieved using density functional theory (DFT) methods. The values of the geometrical parameters obtained from optimized cobaloxime complexes were compatible with experimental data. In order to predict the chemical reactivity of the complexes, their frontier molecular orbital (FMO) energies and their reactivity parameters based on DFT were calculated for optimized cobaloxime complexes. The interaction of the cobaloximes with different DNA bases and Watson–Crick base pairs (A–T and G–C) were explored on the basis of the different reactivity parameters of density functional reactivity theory (DFRT). The results revealed that cobaloximes studied generally acted as an electron-acceptor agent in their interaction with biomolecules. The order of interaction of cobaloximes with all biomolecules followed the sequence C1 > C2 > C3 > C4 > C5.