Luminescent donor-acceptor platinum(II) complexes

The emission properties of the complexes [Pt(dppm)(5,6-Me2phen)](ClO4)2, [Pt(phen)(C≡CPh)2], [Pt(5-Ph-phen)(CN)2] and [Pt(CNN-dpp)(NCCH3)](ClO4) have been studied. The large percentage of metal-ligand charge transfer character in the lowest excited states of these platinum(II) complexes has been demonstrated. Excited state oxidation and reduction potentials of [Pt(phen)(C≡CPh)2] have been determined. The 3MLCT excited state of Pt(II) is highly electrophilic as suggested by the large kinetic isotope effect (kH/kD = 6.7) observed in the quenching of the photoexcited [Pt(dppm)(5,6-Me2phen)](ClO4)2 complex by cyclohexene and d10-cyclohexene. Facile replacement of the coordinated acetonitrile in [Pt(CNN-dpp)(NCCH3)](ClO4) by pyridine ligands provides an entry to a new class of emissive donor-acceptor cyclometallated platinum(II) complexes.link_to_subscribed_fulltex