Synthesis, structural and DFT studies on thiosemicarbazone-based dioxomolybdenum(VI) complexes with co-ligands

Abstract

5-Chloro-2-hydroxybenzophenone-S-methyl-4-phenylthiosemicarbazone (Η2L1) was synthesized from 4-phenylthiosemicarbazide. Reaction of Η2L1 with [bis(acetylacetonato)dioxomolybdenum(VI)] gave the dioxomolybdenum(VI) complexes with [MoO2(L1)(L2)] composition where L2 is n-pentanol, ethylene glycol monomethyl ether, ethyl acetate, isoamyl alcohol, pyridine, or γ-picoline. The structures of the stable solid complexes were elucidated using elemental analysis, electronic, FTIR, and 1H NMR spectra. Crystallographic analysis of [MoO2(L1)(n-pentanol)] (1) clearly indicated the O,N,N-chelating thiosemicarbazone backbone and the distorted octahedral environment of the molybdenum atom. Complex 1 crystallizes in the monoclinic system with P21/n space group and Z = 4. Moreover, the quantum chemical calculations supporting the experimental data of 1–6 are also reported in this study. Geometric optimization and theoretical vibrational spectra calculations of the complexes were performed by using the B3LYP density functional level of theory with LANL2DZ basis set employing density functional theory (DFT). Also, the non-covalent interaction (NCI) plot index analysis reveals the presence of different kinds of non-covalent interactions in [MoO2(L1)(n-pentanol)] (1).