Oxovanadium and dioxomolybdenum complexes: synthesis, crystal structure, spectroscopic characterization and applications as homogeneous catalysts in sulfoxidation

New oxovanadium and dioxomolybdenum Schiff base complexes, [VO(L)(OCH3)](n) and [MoO2(L)(CH3OH)], were synthesized by treating an ONO donor Schiff base (H2L) derived by condensation of 3-ethoxysalicylaldehyde and nicotinic hydrazide with oxo and dioxo acetylacetonate salts of vanadium and molybdenum (VO(acac)(2) and MoO2(acac)(2)), respectively. The synthesized ligand and complexes were characterized by FTIR, multinuclear (H-1, C-13) NMR, elemental and single crystal X-ray diffraction analysis. In both complexes, the geometry around the central metal ions was distorted octahedral as revealed by diffraction studies. Theoretical calculations of the synthesized compounds were carried out by DFT at B3LYP/Def2-TZVP level of theory, which showed good correlation with the experimental results. Moreover, the catalytic efficiency of both complexes was investigated by oxidizing aryl and alkyl sulfides in the presence of 30% H2O2 in ethanol.

Automated summary

New oxovanadium and dioxomolybdenum Schiff base complexes were synthesized and characterized by various analytical techniques. Distorted octahedral geometry around the central metal ions was observed in both complexes as revealed by X-ray diffraction studies.