NEW MONO-PHOSPHIDO-BRIDGED AND DI-PHOSPHIDO-BRIDGED PD-I DIMERS - FORMATION OF TERTIARY DIALKYL(ALLYL) PHOSPHINES FROM AN ALLYL COMPLEX WITH A SECONDARY PHOSPHINE

Depending upon the experimental conditions, Cy(2)PH reacts with [Pd(eta(5)-C5H5)(eta(3)-C3H5)] (1) giving different Pd-1 dimers. [Pd-2(mu L-PCy(2))(mu,eta(3)-C3H5)(PCy(2)H)(2)] (2) can be isolated in high yield when performing the reaction with low ratios of phosphine to 1 in acetone, where complex 2 is only sparingly soluble. Higher ratios of phosphine to 1 and apolar solvents favour the formation of the diphosphido-bridged dimer [{Pd(mu-PCy(2))(PCy(2)H)}(2)] (3); minor amounts of [Pd-2(mu-PCy(2))(2)(PCy(2)H)(PCy(2)allyl)] (4) and [{Pd(mu-PCy(2))(PCy(2)allyl)}(2)] (5) were obs erved as by-pro ducts of the reaction. Multinuclear NMR characterization of complexes 2-5 is reported.