The ring-opening of (1-phenyl-2-isopropylidenephosphirane)pentacarbonyltung
sten upon heating with [Ru-3(CO)(12)] affords a mixture of two isomers of [
eta (4)-3,3-dimethyl-1-phenyl-1-pentacarbonyltungsten-1-phosphatrimethylene
methane]tricarbonylruthenium. The X-ray analysis of one of these isomers sh
ows that the phosphatrimethylenemethane ligand adopts an umbrella shape, is
bound in an eta (4) fashion, and is staggered relative to the three carbon
yl ligands of ruthenium.