The Mössbauer spectra of some phosphorus- and sulphur-bridged derivatives of di-iron enneacarbonyl

Abstract

Mössbauer spectra are reported for a series of phosphorus- and sulphur-bridged derivatives of Fe₂(CO)₉. Substitution of a terminal carbonyl group by triethylphosphine has only a small effect on the Mössbauer parameters and these are also rather insensitive to substitution of an alkyl by an aryl group in the bridging units. Much larger effects are observed when terminal carbonyl groups are replaced by a π-cyclopentadienyl group and a change in the bridging atom from phosphorus to sulphur also has a considerable effect. The implications of these observations on the bonding and structure of these compounds is discussed.