-(1,2-DIPHENYLETHYL)-PHENYLPHOSPHINITO]TRIOSMIUM(2 OS-OS)

The reaction of 1,2,3-triphenylphosphirene with [H2Os3-(CO)(10)] leads to the title compound, [Os-3(CO)(9){(C6H5)(3)-C2PO}], which displays an open Os-3(CO)(9) cluster [Os-Os 2.703(1) and 2.867(2) Angstrom, and Os-Os-Os 124.24(4)degrees]. This moiety is mu(3),eta(3)-bonded to a p hosphirene ligand with a cleaved P-C bond, PhC-C(Ph)-P. An O atom was incorporated into the molecule resulting in an unusual five-membered m etallacycle, Os-C-C-P-O, with distances Os-C 2.10(1), C-C 1.46(2), C-P 1.76(1), P-O 1.628(9) and O-Os 2.136(9) Angstrom. This ring makes a d ihedral angle of 57.3(2)degrees with the plane of the metal atoms.