Vanadium(V) complexes of some bidentate hydrazone ligands and their bromoperoxidase activity. (8th May 2017)

• Record Type: Journal Article
• Authors: Adak, Piyali; Ghosh, Bipinbihari; Pakhira, Bholanath; Sekiya, Ryo; Kuroda, Reiko; Chattopadhyay, Shyamal Kumar
• Is Part Of: Polyhedron. Volume 127(2017)
• Page Start: 135
• Page End: 143
• Publication Date: 2017-05-08
• Subjects: Vanadium(V) -- Hydrazone -- Methoxy ligand -- Bromoperoxidase activity -- DFT calculations; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2017.01.054
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: Three oxido-vanadium complexes of bidentate hydrazone ligands, [VO(µ-OMe)(OMe)(L 1/2/3 )]2, are found to possess high bromoperoxidase activity with salicylaldehyde as a model substrate to produce 5-bromo salicylaldehyde in 100% selectivity, good yield and high TOF and TON. Therefore, these complexes behave as functional models of vanadate dependent bromoperoxidase enzyme. Abstract: Dinuclear methoxy bridged complexes of vanadium, [VO(µ-OMe)(OMe)(L)]2 (1 –3 ) have been synthesized from the reaction of VOSO4 ·H2 O with triethylamine and the respective hydrazone ligand. The compounds have been characterized by spectroscopic methods and determination of single crystal X-ray structure of one of them (1 ). DFT and TD-DFT calculations were used to understand the electronic structures of the complexes and their electronic spectra respectively. Though the dimeric complexes are stable in the solid state, the ESI-MS spectra as well as 1 H NMR spectra of the complexes suggest that in solution the monomeric forms of the complexes are the major species. The V(V) complexes in DMF were used to catalyze the oxidative bromination of salicylaldehyde, in aqueous H2 O2 /KBr in the presence of HClO4 at room temperature. The complexes show exceptionally high bromoperoxidase activity with salicylaldehyde as a model substrate to produce 5-bromo salicylaldehyde in good yield and high TOF and TON. Therefore, these complexes behave as functional models of vanadate dependent bromoperoxidase enzyme.