Synthesis, Characterization and X-Ray Crystal Structures of 2-Chloro-N'-(2-hydroxy-5-methoxybenzylidene)Benzohydrazide and Its Oxidovanadium(V) Complexes with Catalytic Oxidation Property

Abstract

A new aroylhydrazone compound 2-chloro-N′-(2-hydroxy-5-methoxybenzylidene)benzohydrazide (H₂L) was synthesized. With the aroylhydrazone compound and 2-hydroxybenzohydroxamic acid (HL^a) or maltol (HL^b) as ligands, two new oxidovanadium(V) complexes [VOLL^a]∙CH₃OH (1) and [VOLL^b] (2) were synthesized. Both the aroylhydrazone and the complexes have been characterized by elemental analysis, IR, UV-Vis and ¹H NMR spectra, as well as single crystal X-ray determination. X-ray analysis indicates that the V atoms in the complexes are in octahedral coordination. Crystal structures of H₂L and the complexes are stabilized by hydrogen bonds. Thermal analysis of the complexes was performed. The complexes show effective catalytic property for the epoxidation of styrene, with conversion over 80% and selectivity over 90%.