Dinuclear iron-sulfur species

Fig. 5.10. Synthesis of dinuclear iron-sulfur species [Fe2S2(SR)4] ...

The reactions of the anion [Fe2S2(NO)4]2 with electrophiles have already been described (Section II,B,2). Apart from these reactions, most of the chemistry so far reported for iron-sulfur-nitrosyl systems involves the dinuclear complexes [Fe2(SR)2(NO)4], the tetranuclear [Fe4S3(NO)7] and [Fe4S4(N0)4], and the paramagnetic mononuclear species [Fe(NO)2(SR)2] and [Fe(NO)(SR)3] , which prove to be important reactive intermediates in a wide range of reactions. 

Dinuclear and tetranuclear complexes are also suitable starting materials, and much of the synthetic and substitutional chemistry of these species reflects the ability of the systems to sustain monomeric solvated dinitrosyl species such as [Fe(NO)2(solvent)2]+ or [Fe(NO)2(SR)(solvent)]. The latter tend to be formed in solvents having poor and the former in ones having good tt-acceptor capabilities. A review of nitrosyl complexes of iron-sulfur complexes is available. 

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