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

The complex cis-Pt(Ph3Ge)2(PMe2Ph)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, ΔH# = 105 kJ mol−1, ΔS# = 12.5 J mol−1 K−1, and Ea = 107 kJ mol−1, respectively. Heating of trans-Pt(Ph3Ge)2(PMe2Ph)2 at 50 °C for 36 days produced trans-PtPh(Ph3Ge)(PMe2Ph)2 followed by the formation of trans-PtPh2(PMe2Ph)2, Pt(PMe2Ph)4, and Ph4Ge finally via elimination of the phenyl group from Ph3Ge ligand with liberation of the Ph2Ge unit and subsequent reductive elimination of the remaining Ph3Ge ligand at 80 °C for 1 month.