Iron complexes thiolate dimerization

However, in acetonitrile with the ratio PhS Fe 5 1, the mononuclear tetrahedral iron complex [Fe(SPh)4]2 is formed first, which reacts with sulfur to form the iron(III) dimer [Fe SPh),]2-according to equations (67) and (68). No further reaction takes place, but addition of methanol facilitates the reductive elimination of PhSSPh from the dimer to give the 2Fen2FenI cubane complex as in equation (69). Although this series of reactions has been written for PhS-, it appears similar reactions take place with alkyl as well as aryl thiolates. 

Thiolate exchange reactions of the dimeric iron(III) and the iron(II)/iron(III) cubane tetramers, [Fe2S2(SR)4]2 and [Fe4S4(SR)4]2, have been studied750,759 in some detail and provide routes to several related complexes. Exchange takes place with other thiols (R SH) as in equation (64). 

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