New molybdenum(VI) complex with ONS-donor thiosemicarbazone ligand: Preparation, structural characterization, and catalytic applications in olefin epoxidation

New dioxomolybdenum(VI) complex was prepared by reacting 1-(2,4-dihydroxybenzylidene)-N-methyl-N-phenylthiosemicarbazone (H2L) as ligand and [MoO2(acac)2] in acetonitrile solution. The doubly deprotonated ligand is coordinated to molybdenum through sulfur atom, hydrazinic nitrogen atom and phenolic oxygen atom. The resulting complex with the formula [MoO2L(CH3CN)] which contains an acetonitrile molecule in sixth site of coordination, was characterized by elemental analyses, 1H NMR, IR and electronic spectroscopic studies and single crystal X-ray diffraction analysis. This complex was tested as a catalyst for the homogeneous epoxidation of olefins using tert-butyl hydrogen peroxide (TBHP) as an oxidant. The catalyst shows efficient reactivity in the olefins epoxidation reactions giving high yield and selectivity under atmospheric conditions, in most cases.

Graphical abstractNew dioxomolybdenum(VI) complex with the formula [MoO2L(CH3CN)] which contains an acetonitrile molecule in sixth site of coordination, was prepared and structurally characterized. The complex shows efficient catalytic reactivity in the olefins epoxidation reactions using tert-butyl hydrogen peroxide (TBHP) as an oxidant.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► New mononuclear dioxomolybdenum(VI) complex was prepared and characterized. ► The MoO22 + moiety is coordinated to ONS-donor ligand and acetonitrile molecule. ► The complex shows efficient catalytic reactivity in the olefins epoxidation.