Chemical and Electrochemical Interrelationships of the 1-Fe, 2-Fe, and 4-Fe Analogs of the Active sites of Iron-Sulfur Proteins

Abstract

Previous studies of the reactivity properties of the complexes [Fe2S2(SR)4]2~ and [Fe4S4(SR)4]2- have demonstrated the occurrence of thiolate ligand substitution reactions with retention of Fe2S2 and Fe4S4 core structures. Described in this report are reactions which provide chemical and electrochemical interrelationships of 1-Fe, 2-Fe, and 4-Fe synthetic analogues of the active sites of iron-sulfur proteins. These reactions include (i) mononuclear → binuclear conversion, {Fe(S2-o-xyl)2]- → [Fe2S2(S2-o-xyl)2]2~ (S2-o-xyl = o-xylyl-α,α′-dithiolate); (ii) binuclear → tetranuclear conversion, [Fe2S2(SPh)4]2~ → [Fe4S4(SPh)4]2- by spontaneous reaction in protic media and [Fe2S2(SPh)4]2- → [Fe2S2(..