Iron–sulphur dimers with bidentate carboxylate–thiolate terminal ligands

Abstract

The mixed-donor carboxylate–thiolate chelate ligands L1,L2 and L3 co-ordinate 2Fe–2S][²⁺ in a ligand exchange reaction with [Fe₂S₂Cl₄]^2– and the resulting complexes are characterised by electronic, n.m.r., i.r., and Raman spectroscopy and shown undergo a quasi-reversible one-electron reduction to the corresponding trianion, the e.s.r. spectra of which are compared with those for [2Fe–2S]⁺ proteins of the Rieske type.