Platinum(II) complexes with π-conjugated, naphthyl-substituted, cyclometalated ligands (RC∧N∧N): Structures and photo- and electroluminescence

Abstract

The crystal structures and photophysical properties of mononuclear [(RC∧N∧N)PtX](ClO 4) n ((RC∧N∧N) = 3-(6′-(2″-naphthyl)-2′-pyridyl)isoquinolinyl and derivatives; X = Cl, n = 0; X = PPh 3 or PCy 3, n = 1), dinuclear [(RC∧N∧N) 2Pt 2(μ-dppm)]-(ClO 4) 2 (dppm = bis(diphenyphosphi-no)methyl) and trinuclear [(RC∧N∧N) 3Pt 3(μ-dpmp)](ClO 4) 3 (dpmp = bis(diphenylphosphinomethyl)phenylphosphine) complexes are presented. The crystal structures show extensive intra- and/or intermolecular π⋯π interactions; the two (RC∧N∧N) planes of [(RC∧N∧N) 2Pt 2(μ-dppm)]-(ClO 4) 2 (R = Ph, 3,5-tBu 2Ph or 3,5-(CF 3) 2Ph) are in a nearly eclipsed configuration with torsion angles close to 0°. [(RC∧N∧N)PtCl], [(RC∧N∧N) 2Pt 2-(μ-dppm)](ClO 4) 2, and [(RC∧N∧N) 3Pt(μ-dpmp)](ClO 4) 3 are strongly emissive with quantum yields of up to 0.68 in CH 2Cl 2 or MeCN solution at room temperature. The [(RC∧N∧N)PtCl] complexes have a high thermal stability (T d = 470-549°C). High-performance light-emitting devices containing [(RC∧N∧N)PtCl] (R = H or 3,5-tBu 2Ph) as a light-emitting material have been fabricated; they have a maximum luminance of 63 000 cd m -2 and CIE 1931 coordinates at x = 0.36, y = 0.54. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.