Synthesis and structural characterisation of some cyclopentadienyliron–bismuth complexes

Abstract

Treatment of BiCl3 with 2 equivalents of Na[Fe(CO)2(η-C5H4Me)] in tetrahydrofuran affords the green iron–bismuth complex [{[Fe(CO)2(η-C5H4Me)]2BiCl}3], identified by X-ray crystallography and containing a planar Bi3Cl3 six-membered ring derived from the cyclotrimerisation of Fe(BiCl)(CO)2(η-C5H4Me) units. Similar compounds are formed with C5H5 and C5Me5 ligands although in the latter case significant amounts of the iron chloro species [FeCl(CO)2(η-C5Me5)] are also formed, an X-ray structure of which is reported. Treatment of BiCl3 with 3 equivalents of Na[Fe(CO)2(η-C5H4Me)] affords the tri-iron–bismuth complex [Bi{Fe(CO)2(η-C5H4Me)}3], containing a trigonal-pyramidal bismuth bonded to three Fe(CO)2(η-C5H4Me) fragments. Photolysis of this compound leads to loss of three carbonyl groups and formation of the closo Fe3Bi complex [Fe3(η-C5H4Me)3(µ-CO)3(µ3-Bi)]. Both of the tri-iron–bismuth complexes were characterised by X-ray crystallography.