Synthesis and Crystal Structures of Benzohydroxamate-Coordinated Vanadium(V) Oxo Complexes with Aroylhydrazone Ligands

Abstract

Reaction of [VO(acac)₂] (where acac = acetylacetonate), benzohydroxamic acid (Hbha), and two similar aroylhydrazone ligands in methanol produced two benzohydroxamate-coordinated mononuclear vanadium(V) oxo complexes with general formula [VOL(bha)], where L = L¹ = N'-(5-bromo-2-hydroxybenzylidene)-2-fluorobenzohydrazide (H₂L¹), and L = L² = N'-(3-bromo-2-hydroxybenzylidene)-2-fluorobenzohydrazide (H₂L²). Crystal and molecular structures of the complexes were determined by single crystal X-ray diffraction method. All of the investigated compounds were further characterized by elemental analysis, and FT-IR and UV-Vis spectra. Single crystal X-ray structural studies indicate that the benzohydrazone ligands coordinate to the VOcores through phenolate O, imino N, and enolate O atoms, and the benzohydroxamate ligands coordinate to the VO cores through deprotonated hydroxyl O and carbonyl O atoms. The V atoms in both complexes are in octahedral coordination. Thermal stability of the complexes was studied.