Systematik der Bildung von Elektronentransfer-Clusterzentren {FenSn}m⊕ mit Relevanz zur Evolution von Ferredoxinen

Abstract

The cluster [Fe₄S₄Br₄]^2⊖ (Ph₄P^⊕ salt 1) containing the {Fe₄S₄}^2⊕ core (formally Fe^II₂Fe^III₂) is simply formed by bubbling H₂S through a solution of Fe^IISO₄ • 7H₂O in DMF/methanol in presence of (Ph₄P)Br, whereby oxygen acts as electron acceptor, and [Fe₂S₂(S₅)₂]^2⊖ (Ph₄P^⊕ salt 2) can conveniently be obtained from a solution of Fe^IISO₄ • 7H₂O in dimethyl formamide (DMF) and an ethanol solution of S_x^2⊖. A general equation for the reaction of Fe^II with S^2⊖ in presence or absence of simple electron acceptors is discussed regarding the possible formation of species with {Fe_nS_n}^m⊕ cores (m = 0–2) on the early earth.