Synthesis, X-Ray Crystal Structures and Catalytic Epoxidation of Oxidovanadium(V) Complexes with Aroylhydrazone and Ethyl Maltolate Ligands

Abstract

Two oxidovanadium(V) complexes, [VOL1L] (1) and [VOL2L] (2) (L = ethyl maltolate), derived from the aroylhydrazones 4-bromo-N’-(2-hydroxy-5-methylbenzylidene)benzohydrazide (H2L1) and N’-(3,5-dibromo-2-hydroxybenzylidene)- 4-methoxybenzohydrazide (H2L2), respectively, have been synthesized and characterized by elemental analysis, infrared and electronic spectroscopy. Structures of the complexes were further confirmed by single crystal X-ray determination. The V atoms in the complexes are coordinated by the ONO donor atoms of the aroylhydrazone ligand, OO donor atoms of the ethyl maltolate ligand, and one oxido O atom, forming octahedral coordination. The complexes function as effective olefin

Systematic Development of Vanadium Catalysts for Sustainable Epoxidation of Small Alkenes and Allylic Alcohols

“…In this sense, the formation of peroxy-vanadium(V) species in the epoxidation mechanism showed that only the reactions using CHCl 3 and CCl 4 as solvents provided viable conversion rates. This is also reported with vanadium(V) complexes [77,78] including a tridentate ONO aroylhydrazone ligand using a solvent mixture of CH 3 OH/CH 2 Cl 2 . With solvent effect studies, the best epoxidation results were found by Grivani with CHCl 3 as solvent and TBHP as an oxidizing agent, presenting a conversion ratio of 84%.…”