Synthesis, Characterization, and Reactivity of Mononuclear O,N-Chelated Vanadium(V) and -(IV) Complexes [VO(acac)2(SA)] and [VO(acac)(MP)]

The reactions of one equivalent each of [VO(acac)(2)] with salicylic acid (HSA) and 2-methyl-6-[(2-morpholin-4-ylethylimino) methyl]phenol (HMP; derived from 2-hydroxy-3-methylbenzal dehyde and 2-morpholin-4-ylethylamine) in methanol under aerobic conditions provide two mononuclear O,N-chelated vanadium (V) and -(IV) complexes [VO(acac)(2)(SA)] (1) and [VO(acac)(MP)] (2). The complexes have been characterized by analytical and spectroscopic measurements. The structures of the complexes have been determined by X-ray crystallography. In both complexes, the metal centers are in distorted octahedral coordination spheres. The SA ligand coordinates the metal ion through one carboxylate oxygen, and the MP ligand coordinates the metal ion through the imine-N, the phenolate-O, and the morpholin-N atoms in a meridional fashion. The remaining three coordinate sites are occupied by the bidentate O,O-donor acetylacetonate (acac) and the oxo group.