Nuclear magnetic resonance investigations of configurational non-rigidity in dinuclear platinum(IV) complexes. Part 7. Intramolecular rearrangements in complexes of tris(methylthio)methane

Abstract

The ligand tris(methylthio)methane, HC(SMe)₃, has been used to form dinuclear platinum(IV) complexes of type [(PtXMe₃)₂{HC(SMe)₃}](X = Cl or Br), where the ligand bridges the pair of Pt atoms via two of its SMe groups. Variable-temperature ¹H n.m.r. studies in the range –90 to 70 °C revealed inversion of the pyramidal S atoms, a 1,3-metal pivoting fluxion, and a scrambling of the Pt-methyl environments by a PtMe₃ rotation mechanism. The latter two fluxions are concerted and involve a common transition state. Activation energies for the various dynamic processes are in the range 45–72 KJ mol^–1.