Spectroscopic characterization of a mononuclear oxovanadium (IV) Schiff base complex. Oxidation catalysis applications and antibacterial activities

•Structure of oxovanadium complex determined by single crystal X-ray diffraction; the geometry is calculated and confirmed by DFT.•New oxovanadium catalyst for the oxidation of cyclohexene.•2-Cyclohexen-1-one, the major product of the catalytic reaction.•Antimicrobial activity of the oxovanadium complex shows better activity than the ligand. Herein we describe the chemical synthesis of a new oxovanadium (IV) complex of an N,N-bis(1-naphthalidimine)-o phenylenediamine (VOL). The structure has been characterized by various physiochemical and spectroscopic techniques. The single crystal X-ray diffraction confirms a tetra-coordinate chelated and a planar geometry of the complex by ONNO donor sets of the ligand. Hirshfeld's surface analysis indicates that the most important inter-molecular contact within crystal packing is C-H⋯O interaction. Density Functional Theory (DFT) calculations have been used to optimize the structure and discuss the chemical reactivity through the Frontier Molecular Orbitals (FMOs). The electrochemical properties of the complex were studied by cyclic voltammetry which shows a reversible VIV/VV redox process which is consistent with the hydrodynamic voltammograms. The complex was used as catalyst for the selective oxidation of cyclohexene to the corresponding 2-cyclohexene-1-one in DMF. Finally, antibacterial activity was determined using 3 Gram negative and 2 Gram positive bacteria using disk diffusion method, it was found to be more effective against Gram positive than the Gram negative bacteria. [Display omitted]