A dioxidomolybdenum(VI) complex of tridentate ONO aroylhydrazone ligand: Synthesis, crystal structure and catalytic activity

A new dioxidomolybdenum complex with the formula [MoO2L(MeOH)], derived from the tridentate aroylhydrazone 2-amino-N'-(3,5-dichloro-2-hydroxybenzylidene)benzohydrazide (H2L), has been prepared and characterized by elemental analysis, FTIR, H-1 NMR, and single-crystal structural X-ray diffraction. The complex has a distorted octahedral structure in which the aroylhydrazone ligand behaves as a binegative donor one, leaving the amino-N uncoordinated toward the metal center. Single-crystal structure analysis reveals that the Mo(VI) center is coordinated by the donor atoms of the binegative aroylhydrazone ligand, two oxido groups and one oxygen atom of a methanol ligand. Crystal of the complex is stabilized by hydrogen bonds. The complex functions as an effective olefin epoxidation catalyst with hydrogen peroxide as terminal oxidant and sodium hydrogen carbonate as a cocatalyst.