FE (II) - FE (III) electronic and magnetic interaction through a thiopyridine bridge

Abstract

Reaction of CpFe(dppe)I with dithiopyridine in methanol and in presence of NH4PF6 affords the new mixed valence complex {[CpFe(dppe)]2 - n - S - Py}(PF6)2 (1 ). Observation of an intervalence electron transfer affords the Hush parameters that permit to classify this compound as a type II Robin Day complex. The electron transfer across the pyridinethiolate ligand occurs at a rate estimated to be about 10s seg-'. Variable - temperature magnetic susceptibility measurements have been carried out in the range of 5-300 °K. Results can be interpreted as principally due to weak intermolecular antiferromagnetic interactions between Fe (II) - Fe (III) dimers in the solid state.