Synthetic Analogs of the Active Sites of Iron-Sulfur Proteins. VIII. Some Electronic Properties of [Fe\u3csub\u3e4\u3c/sub\u3eS\u3csub\u3e4\u3c/sub\u3e(SR)\u3csub\u3e4\u3c/sub\u3e]\u3csup\u3e3\u3c/sup\u3e; Analogs of Reduced Bacterial Ferredoxins

Abstract

One-electron reduction of the synthetic tetramers [Fe4S4(SR)4]2- (R = CH2Ph, Ph), by chemical and electrochemical methods affords the corresponding trianions. The collective results from optical, electron paramagnetic resonance, and Mössbauer spectroscopy, when compared to available data for reduced 4-Fe and 8-Fe ferredoxin proteins and super-reduced Chromatium high-potential protein, reveal that [Fe4S4(SR)4]3- are electronic analogs of the [Fe4S4(S-Cys)4] active sites of these proteins