Associative reactions of dihydridobis(trimethylphosphine)platinum(II). Molecular structures of (diphenylacetylene)bis(trimethylphosphine)platinum and hydridotris(trimethylphosphine)platinum(II) tetraphenylborate

In recent years sterically unhindered platinum dihydrides PtH/sub 2/L/sub 2/ (L = PMe/sub 3/, PEt/sub 3/) have been isolated and found to be much more reactive than related compounds containing bulky phosphine ligands. Such compounds may be involved as intermediates int he catalysis of alkene hydrogenation, nitrile and olefin hydration, alcoholysis, hydrosilation, and the water gas shift reaction. Oxidative addition and reductive elimination of H/sub 2/ from sterically unhindered dihydrides has been the subject of experimental and theoretical studies, since these reactions model the behavior of hydrogen on platinum surfaces. This paper examines reactions of the PMe/sub 3/ derivative in detail to define its reactivity. In particular the authors were interested in the competition between H/sub 2/ dissociation to generate Pt(PMe/sub 3/)/sub 2/ vs associative attack at platinum in the substitution and oxidative addition reactions of these complexes.