Characterisation of a coordinated imidazole as a structural model for superoxide dismutase

摘要

The copper complex [Cu(HL)](ClO_4)_2 (centor dot) 2H_2O, where HL is N-[2-(4,7-dimethyl-1,4,7-triazacyclonon-1-yl)ethyl]-N-(benzimidazol-2-yl)methanimine, has been prepared and characterized by X-ray crystallography and solution absorption spectroscopy. Deprotonation of the benzimidazole moiety in this complex has been investigated by electronic spectroscopy. The results show a definite shift in #lambda#_(max) for [Cu(HL)]~(2+), at 632-818 nm for the deprotonated [CuL]~+, in acetonitrile. This complex has been synthesized as a structural homologue to half of the enzyme u-Zn superoxide dismutase (SOD) which contains a bridged imidazolate moiety between the two Cu and Zn metal ions.