Structures and properties of octaethylporphinato(phenolate)iron(III) complexes with NH⋯O hydrogen bonds: modulation of Fe–O bond character by the hydrogen bond
作者:Daisuke Kanamori、Yusuke Yamada、Akira Onoda、Taka-aki Okamura、Seiji Adachi、Hitoshi Yamamoto、Norikazu Ueyama
DOI:10.1016/j.ica.2004.09.014
日期:2005.1
Iron(III) porphinate complexes of phenolate that have NH...O hydrogen bonds on the coordinating oxygen, [Fe-III(OEP)O-2,6-(RCONH)(2)C6H3}] (R = CF3 (1), CH3 (3)) and [Fe-III(OEP)(O-2-RCONHC6H4)] (R = CF3 (2), CH3 (4)) (OEP = 2,3,7,8,12,13,17,18-octaethyl-21 H, 23H-porphinato), were synthesized and characterized as models of heme catalase. The presence of NH...O hydrogen bonds was established by their crystal structures and IR shifts of the amide NH band. The crystal structure of 1 shows an extremely elongated Fe-O bond, 1.926(3) Angstrom, compared to 1.887(2) Angstrom in 2 or 1.848(4) Angstrom in [Fe-III(OEP)(OPh)]. The NH...O hydrogen bond decreases an electron donation from oxygen to iron, resulting in a long Fe-O bond and a positive redox potential. (C) 2004 Elsevier B.V. All rights reserved.