Synthesis, chemical, electrochemical characterization of oxomolybdenum(V) complexes of 2-(3,5-dimethyl pyrazol-1-yl) benzothiazole ligand: Crystal structure of ligand and oxomolybdenum(VI) complex and density functional theory (DFT) calculation

This work reports the ligational behavior of the neutral bidentate chelating molecule 2-(3,5-dimethyl pyrazol-1-yl) benzothiazole towards the oxomolybdenum(V) center. Both mononuclear complexes of the type MoVOX3L and binuclear complexes of the formula MoV2O4X2L2 (where X = Cl, Br) are isolated in the solid state. The complexes are characterized by elemental analyses, various spectroscopic techniques (UV–Vis IR), magnetic susceptibility measurement at room temperature, and cyclic voltammetry for their redox behavior at a platinum electrode in CH3CN. The mononuclear complexes MoVOX3L are found to be paramagnetic while the binuclear complexes Mo2O4X2L2 are diamagnetic. Crystal and molecular structure of the ligand and the dioxomolybdenum complex MoVIO2Br2L (obtained from the complex MoOBr3L during crystallization) have been solved by single crystal X-ray diffraction technique. Relevant DFT calculations of the ligand and the complex MoVIO2Br2L are also carried out.

A number of mononuclear MoVOX3L and binuclear MoV2O4X2L2 (where X = Cl, Br) complexes of neutral bidentate chelating ligand are isolated in the solid state. Crystal structure and DFT calculation of the ligand and the dioxomolybdenum complex MoVIO2Br2L (obtained from the complex MoOBr3L during crystallization) have been reported.Figure optionsDownload as PowerPoint slideHighlights
► Stabilization of easily oxidisable Mo(V) acceptor center by a neutral bidentate N–N chelator.
► Basicity of the ligand determines formation of salt of the anion MoVOX52− or a genuine chelate complex.
► Structures of the ligand and its complex reveal complete reversal of the donor sites from N–S-cis to N–N-cis.
► Spectroscopic and electrochemical properties of the reported complexes studied.
► Relevant DFT calculations of the ligand and structurally characterized complex MoO2Br2L.