Vanadium(IV) and Vanadium(V) Complexes of Salicyladimine Ligands

The synthesis and characterization of a V(IV) and a V(V) complex of the salicyladimine ligand system are described. The reaction of salicylaldehyde and 1,3-diaminohydroxypropane with vanadyl sulfate produced a monomer (VOL1) which, upon heating in methanol, crystallized as a V(V) complex (VO2L1). The reaction of 3-methoxysalicylaldehyde, 1,3-diaminohydroxypropane, and vanadyl sulfate resulted in a binuclear complex held together by hydrogen bonding (VOL2). VOL1 was determined to catalyze the epoxidation of cyclohexene better than VOL2. The synthesis and characterization of VOL1, VOL2, and VO2L1 are described. The role of each complex as a catalyst for the epoxidation of cyclohexene is investigated. Results indicate that the V(V) complex performs better than either of the V(IV) complexes.