DIPHOSPHINE MONOXIDE LIGANDS: COMPLEXES OF TETRAPHENYLDIPHOSPHINE OXIDE WITH GROUP VIB METAL CARBONYLS

Article abstract of DOI:10.1016/S0022-328X(00)85571-0

Tetraphenyldiphosphine monoxide forms complexes of the type (CO)5M with Group VIB metals (M=Cr, Mo, W).The crystal and molecular structure of the Mo-complex has been determined: MoP2O6C29H20, Monoclinic Space Group P2₁/n, a 13.776(1), b 16.811(2), c 12.162(1) Angstroem, β 90.36(1) deg; Z=4 and D_c 1.47 Mg m^-3.R_F is 0.038 for 5006 observed reflections.The Mo atom is found to be coordinated to the originally trivalent phosphorus atom while the ligand P-P bond remains intact and the oxygen atom is uncomplexed.The overall conformation around the P-P bond is staggered.Heating of these complexes in diglyme resulted in loss of CO and tautomerization of the diphosphine oxide ligand into the chelating diphosphoxane in products identified as .Reaction of excess OP2Ph4 with cis-(CO)4M(NHC5H10)2 yielded H-bonded heterocycles of the type which are inert towards displacement of the remaining piperidine ligand.