Syntheses, Crystal Structures and Catalytic Property of Oxidovanadium(V) Complexes Derived from Tridentate Hydrazone Ligands.

Two new ethyl maltolato coordinated mononuclear oxidovanadium(V) complexes [VOLa(emt)]·DMF (1) and [VOLb(emt)] (2), where H2La = N'-(4-bromo-2-hydroxybenzylidene)-3-hydroxybenzohydrazide, H2Lb = N'-(4-bromo-2-hydroxybenzylidene)benzohydrazide, Hemt = ethyl maltol, have been synthesized and characterized on the basis of CHN elemental analysis, FT-IR and UV-Vis spectroscopy and powder XRD analysis. Structures of the complexes were further characterized by single crystal X-ray diffraction, which indicated that the V atoms in the complexes adopt octahedral coordination. The hydrazones behave as NOO tridentate ligands. The catalytic epoxidation properties on cyclooctene of the complexes were investigated.