Characterization and X-Ray Structures of Oxovanadium(V) Complexes Derived from Hydrazone Ligands

The reaction of [VO(acac)(2)] (where acac = acetylacetonate), benzohydroxamic acid (HL) with N'-(3,5-dichloro-2-hydroxybenzylidene)nicotinohydrazide (H2L1) and N'-(2-hydroxy-4-methoxybenzylidene)-3-nitrobenzohydrazide (H2L2) in methanol affords methanol-coordinated mononuclear oxovanadium(V) complexes [(VOLL)-L-1] (1) and [(VOLL)-L-2]center dot MeOH (2), respectively. Crystal and molecular structures of the complexes are determined by the single crystal X-ray diffraction method. The complexes were further characterized by the elemental analysis and FT-IR spectra. Single crystal X-ray structural studies indicate that the hydrazone ligands coordinate to the VO core through enolate oxygen, phenolate oxygen, and azomethine nitrogen atoms, and the benzohydroxamate ligands coordinate to the VO core through the carbonyl oxygen and hydroxy oxygen atoms. The V atoms in the complexes are in the octahedral coordination. The thermal stability of the complexes are also studied.