have essentially square planar coordination geometries, being ligated by one alkylidynetungsten fragment and two PMe,Ph groups. All the CO ligands, except C(7)0(7) and C(9)0(9), semibridge W-Pt bonds.
Experimental
Sa: A cold ( 0 T ) ethylene-saturated solution of [Pt(cod),] (0.05 g, 0.12 mmol) in T H F (20 mL) was treated with a solution of 4 a (0.15 g, 0.09 mmol) in the same solvent (25 mL). After 4 hours' stirring, the solvent was removed in vacuo and the residue was dissolved in CH,Cl,/light petroleum (15 mL, 411) and chromatographed on alumina. Elution with the same solvent mixture gave a brown eluate from which microcrystals of Sa (0.1 1 g, 62%) were recovered after removal of solvent.
7:AsolutionofSa(0.15g,0.08mmol)inTHF(15mL)wasadded toasolution of6 (0.10 g, 0.30 mmol) in T H F (10 mL). The mixture was stirred under C,H, pressure ( 2 atm) for 3 h. The solveiit was removed in vacuo, and the residue was dissolved in CH,CI, (10 mL) and chromatographed on alumina. Elution with the same solvent removed initially unreacted 6 followed by a brown fraction containing 7. Removal of solvent in vacuo and crystallization from CH,CI,/ light petroleum gave 7 (0.17 g, 92%). 8,9: A solution of 7 (0.15 g, 0.06 mmol) In T H F (20 mL) was slowly added to a C,H,-saturated solution of [Pt(cod),] (0.06 g, 0.17 mmol) in T H F (20 mL. 0Β°C). After warming to room temperature in vacuo and stirring for 3 h the residue was dissolved in CH,CI, (10 mL) and chromatographed. Elution with the same solvent removed a brown fraction, removal of solvent from which gave 8 (0.15 g, 80%), crystallized from CH,Cl,/light petroleum. Treatment of 8 (0.15 g, 0.05 mmol) in CH,CI, (15 mL) with PMe,Ph (0.04 g, 0.30 mmol) for 30 min gave 9 (0.15 g. 90%).