Observation of stable 17 e iron(III) cyclopentadienyl radical complexes

Abstract

The EPR spectra of a series of mononuclear complexes [CpFe(dppe)SR]PF6 R = C6H5 (1), C3H7 (2), p-C6H4Br (3) and the binuclear [CpFe(dppe)-S-CH2CH2-S-CpFe(dppe)](PF6) 2 (4) were measured. All the paramagnetic complexes exhibit intense signals in both solid state as well as in CH2Cl2 solution. Analysis of the spectra indicates a pseudooctahedral structure for the complexes except for complex (2) for which a tetragonal distortion in solid state was observed. Some degree of delocalization of the unpaired electron for (3) and (4) was suggested. The stabilization of the radicals by the thiolate ligands is discussed.