Binuclear doubly cyclometallated platinum-(II) and -(IV) compounds †

Doubly cyclometallated binuclear platinum-(II) and -(IV) complexes, as well as their non-cyclometallated platinum(II) precursors, were prepared from the reactions of [Pt2Me4(µ-SMe2)2] with imine ligands derived from terephthalaldehyde. All compounds were characterized by NMR and UV/VIS spectroscopy and the reactivities of the cyclometallated platinum complexes towards phosphines were studied. Electrochemical and spectroelectrochemical (UV/VIS/NIR and EPR) studies were carried out and indicated that while the oxidation of the platinum(II) complexes leads to unstable platinum(III) species, the reduction of the platinum compounds leads to an uptake of an electron into a MO mainly centred on the bridging ligand and is followed by either scission of the bridging ligand for the platinum(II) compounds or scission of the axial ligands for the platinum(IV) compounds.