Aminoacid-derivatized oxidovanadium complexes: Synthesis, structure and bromination reaction activity

A new family of aminoacid-derivatized oxidovanadium complexes as potential functional model of vanadium haloperoxidases: [VVO(sal-phe)(OMe) (MeOH)] (1), [VIVO(sal-ala)(2,2′-bipy)]·H2O (2), [VIVO(sal-ala)(1,10-phen)]·0.5H2O (3) and [VIVO(sal-his)(1,10-phen)]·2MeOH (4) (H2sal-phe = Schiff base derived from salicylaldehyde and dl-β-phenylalanine, H2sal-ala = Schiff base derived from salicylaldehyde and dl-α-alanine, H2sal-his = Schiff base derived from salicylaldehyde and l-histidine) have been synthesized. All the complexes were characterized by elemental analysis, IR spectra and UV–Vis spectroscopy. In particular, molecular structures of three representative complexes (1, 2 and 3) were determined by X-ray crystallography. In addition, bromination reaction activity of the starting material and the complexes has been tested by a method with phenol red as organic substrate in the presence of H2O2, Br− and phosphate buffer, the studying results indicate that the vanadium complexes can catalyze the visible conversion of phenol red to bromophenol blue under weak-acid conditions and the different structural characterizations of the complexes exhibit different catalytic activity, therefore, the complexes can be considered as a potential functional model of VHPO.