Iridium carbonyl cluster complexes with bidentate phosphine ligands; the X-ray crystal structure of [Ir4(CO)8(dppa)2]·3(THF)

Reactions of [Ir4(CO)12] with 1,1-bis(diphenylphosphino)ethene, Ph2PC(CH2)PPh2 (dppen) and 1,1-bis(diphenylphosphino)amine, Ph2PN(H)PPh2(dppa) gave [Ir4(CO)12−n(L)n−2)] (L=dppen or dppa and n=2 or 4) depending upon the reaction conditions. The structures of the cluster complexes are discussed on the basis of IR, 31P-NMR spectroscopic data and FAB mass spectra. The structure of the disubstituted species [Ir4(CO)8(dppa)2]·3(THF) (THF=tetrahydrofuran, C4H8O) has been determined by X-ray crystallography.