Complexes of the type [M(CO)(5)(p-Ph2BiC6H4BiPh2)] and [M(CO)(5)}(2)(p-Ph2BiC6H4BiPh2)] (M = Cr or W) have been prepared and characterised by chemical analysis,H-1- and C-13H-1}-NMR and IR spectroscopies. The crystal structure of p-Ph2BiC6H4BiPh2 is reported. The reaction of [CpFe(CO)(2)(THF)](+) with p-Ph2BiC6H4BiPh2 in refluxing CH2Cl2 results in cleavage of one Bi-C bond to form [CpFe(CO)(2)(BiPh3)](+) identified by an X-ray study. A survey of BiPh3 and its compounds has established that the C-Bi-C angles increase upon complex formation. (C) 1999 Elsevier Science S.A. All rights reserved.