Synthesis, Characterization, X-Ray Crystal Structures, and Catalytic Epoxidation Activity of cis-Dioxomolybdenum(VI) and Oxovanadium(V) Complexes With N'-(2-Hydroxy-4-methoxybenzylidene)-4-trifluoromethylbenzohydrazide

A new cis-dioxomolybdenum(VI) complex, [MoO2LMeOH] (1) and a new oxovanadium(V) complex, [VOL(OMe)MeOH] (2), with potentially tridentate ONO aroylhydrazone Schiff base derived from 4-methoxysalicylaldehyde with 4-trifluoromethylbenzohydrazide, have been synthesized and fully characterized on the basis of elemental analysis, FT-IR, molar conductivity, and electronic spectra. Structures of the complexes have been accomplished by single-crystal X-ray diffraction. The complexes have distorted octahedral structures in which the aroylhydrazones behave as binegative ligands. It is also revealed from the crystal structures that the Mo(VI) and V(V) centers adopt NO5 donor environment, and the octahedral coordination is furnished by oxido groups and oxygen atoms of methanol or deprotonated methanol molecules. The catalytic properties were investigated for epoxidation of cyclooctene using aqueous tert-butyl hydroperoxide as the oxidant.