New mono- and di-phosphido-bridged PdI dimers. Formation of tertiary dialkyl(allyl) phosphines from an allyl complex with a secondary phosphine

Article abstract of DOI:10.1016/0022-328X(94)00002-T

Depending upon the experimental conditions, Cy2PH reacts with 5-C5H5)(η³-C3H5)> (1) giving different Pd^I dimers. 3-C3H5)(PCy2H)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 <2> (3); minor amounts of (4) and <2> (5) were observed as by-products of the reaction.Multinuclear NMR characterization of complexes 2-5 is reported. Keywords: Palladium; Metal-metal bonds; Phosphide-bridges; Allyl; Dimers; Insertion