Improved synthesis of mononuclear platinum(0) compounds which contain tertiary phosphines and carbon monoxide

Abstract

Pt(CO)L₃ compounds (L = PPh₃ and PPh₂Me) have been obtained in good yields by reduction of an alkali chloroplatinite in the presence of 4–5 mol. of the phosphine and of carbon monoxide, or from compounds PtL₄(L = PPh₃ and PPh₂Me) and PtL₃(L = PPh₃ and PPh₂Ph·CH₂) and carbon monoxide. Pt(CO)₂L₂ compounds (L = PPh₃, PPh₂Et, PPh₂Prⁱ, and PPh₂Ph·CH₂) have been similarly obtained by reduction of a chloroplatinite in the presence of carbon monoxide and 2 mol. of the phosphine. In solution in the presence of carbon monoxide the Pt(CO)L₃ and Pt(CO)₂L₂ species are in equilibrium; increasing steric requirements of the group R of the ligand PPh₂R increased the stability of the Pt(CO)₂L₂ compounds.