Synthesis, characterization and reactivity of platinum-substituted ketenes [PtX{η1-C(PPh3)CO}L2]BF4, (X=Me, Cl; L2=1,5-cyclooctadiene, 1,2-bis(diphenylphosphino)ethane, cis-1,2-bis(diphenylphosphino)ethene). Steric and electronic effects of the ancillary ligands

Abstract Ketenylidenetriphenylphosphorane, Ph 3 PCCO, 1 , has been used to synthesize platinum-substituted ketenes [PtMe{η 1 -C(PPh 3 )CO}L 2 ]BF 4 , 2a , b (L 2 =1,5-cyclooctadiene, cod ( a ), 1,2-bis(diphenylphosphino)ethane, diphos ( b )). Parent compound [PtCl{η 1 -C(PPh 3 )CO}L 2 ]BF 4 , 3 , with L 2 = cis -1,2-bis(diphenylphosphino)ethene, diphoe, was also synthesized, which is stable only at low temperature. The stability of 2 and 3 and the reactivity of the CCO moiety have been examined and discussed in terms of the electronic and steric characteristics of the ancillary ligands, also taking into account the reactivity of the ‘PtXL 2 ’ fragment with other carbonyl stabilized phosphorus ylides, Ph 3 PCHCOR (R=Me, Ph, OMe, OEt).