Mn(III) complexes of the monoprotic tridentate ONN donor 2-[2-(1H-(benzo[d]imidazol-2-yl)ethylimino)methyl]phenol as a functional mimic of haloperoxidase
摘要:
The reaction of Mn-II(ClO4)(2) with 2-[2-(1H-(benzo[d]imidazol-2-yl)ethylimino)methyl]phenol (Hsalaebmz, I) under aerobic conditions results in the formation of [Mn-III(sal-aebmz)(2)]center dot ClO4 (1). In the presence of triethylamine and using MnCl2 under aerobic conditions. I forms [Mn-III(sal-aebmz-H)(sal-aebmz)] (2). These complexes are characterised on the basis of elemental and electrochemical analyses, spectroscopic (IR and UV-Vis) data and thermogravimetric studies. Single crystal X-ray analysis of 2 shows that it is stabilized in the solid state through intermolecular hydrogen bonding between the NH groups of the two benzimidazole moieties after losing one of the hydrogen atoms: the coordination sites of the ligand are the imine nitrogen of the benzimidazole ring, the azomethine nitrogen and the deprotonated phenolic oxygen. Complex 2 catalyses the oxidative bromination of styrene by H2O2, yielding 1,2-dibromo-1-phenylethane, 1-phenylethane-1,2-diol and 2-bromo-1 -phenylethane-1-ol, acting as a functional mimic of haloperoxidases. (C) 2012 Elsevier Ltd. All rights reserved.