Properties and Reactivities of Zwitterionic Platinum(II)-ate Complexes Generated by Transforming Coordination of an Alkyne–Bisphosphine Ligand

Coordination
of an alkyne–bisphosphine ligand with platinum­(II)
precursors produced a structural reorganization in the ligand backbone
to form stable zwitterionic platinum­(II) complexes bearing an anionic
platinum center. The structural properties and reactivities of these
complexes were investigated using X-ray crystallographic analyses,
computational studies, and stoichiometric reactions involving oxidative
addition and reductive elimination. These studies have shown that
the enhanced nucleophilicity of the platinum center to alkyl halides
promotes smooth oxidative addition and that the charge rebalance accelerates
the dissociation of the halide anion from the platinum­(IV) intermediate,
which is essential in the carbon–carbon bond-forming step.