Thermal reactivity of cis- and trans-bis(triphenylgermyl)bis(tertiary phosphine)platinum(II)

Abstract

The complex cis-Pt(Ph 3Ge) 2(PMe 2Ph) 2 underwent smooth isomerization to give the trans-isomer at room temperature via an associative five-coordinated intermediate. Thermodynamic parameters and activation energy for the cis to trans isomerization were obtained, Δ H # = 105 kJ mol −1, Δ S # = 12.5 J mol −1 K −1, and Ea = 107 kJ mol −1, respectively. Heating of trans-Pt(Ph 3Ge) 2(PMe 2Ph) 2 at 50 °C for 36 days produced trans-PtPh(Ph 3Ge)(PMe 2Ph) 2 followed by the formation of trans-PtPh 2(PMe 2Ph) 2, Pt(PMe 2Ph) 4, and Ph 4Ge finally via elimination of the phenyl group from Ph 3Ge ligand with liberation of the Ph 2Ge unit and subsequent reductive elimination of the remaining Ph 3Ge ligand at 80 °C for 1 month.