Cleavage of cluster iron–sulfide bonds in cyclophane-coordinated FenSm complexes

Abstract

Reaction of the tri(μ-sulfido)triiron(III) tris(β-diketiminate) cyclophane complex, Fe₃S₃L^Et/Me (1), or of the di(μ-sulfido)diiron(III) complex Fe₂S₂HL^Et/Me (5), with the related tri(bromide)triiron(II) complex Fe₃Br₃L^Et/Me (2) results in electron and ligand redistribution to yield the mixed-ligand multiiron complexes, including Fe₃Br₂SL^Et/Me (3) and Fe₂Br₂SHL^Et/Me (4). The cleavage and redistribution observed in these complexes is reminiscent of necessary Fe–S bond cleavage for substrate activation in nitrogenase enzymes, and provides a new perspective on the lability of Fe–S bonds in FeS clusters.