Platinum(II) Complexes with π-Conjugated, Naphthyl-Substituted, Cyclometalated Ligands (RC^N^N): Structures and Photo- and Electroluminescence

• Published in: Chemistry : a European journal Vol. 13; no. 2; pp. 417 - 435
• Main Authors: Kui, Steven C. F., Sham, Iona H. T., Cheung, Cecil C. C., Ma, Chun-Wah, Yan, Beiping, Zhu, Nianyong, Che, Chi-Ming, Fu, Wen-Fu
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.01.2007; WILEY‐VCH Verlag; Wiley
• Subjects: Chemistry; Chemistry, Multidisciplinary; electroluminescence; OLEDs; photoluminescence; Physical Sciences; pi interactions; platinum; Science & Technology; photoluminescence; SPECTROSCOPIC PROPERTIES; CENTER-DOT-PT; CRYSTAL-STRUCTURES; PHOSPHORESCENT MATERIALS; OLEDs; PHOTOPHYSICAL PROPERTIES; pi interactions; ALPHA-DIIMINE LIGANDS; EXCITED-STATES; LIGHT-EMITTING-DIODES; platinum; ELECTROPHOSPHORESCENT DEVICES; electroluminescence; ELECTRONIC-SPECTRA
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.200600686

The crystal structures and photophysical properties of mononuclear [(RC^N^N)PtX](ClO4)n ((RC^N^N)=3‐(6′‐(2′′‐naphthyl)‐2′‐pyridyl)isoquinolinyl and derivatives; X=Cl, n=0; X=PPh3 or PCy3, n=1), dinuclear [(RC^N^N)2Pt2(μ‐dppm)](ClO4)2 (dppm=bis(diphenyphosphino)methyl) and trinuclear [(RC^N^N)3Pt3(μ‐dpmp)](ClO4)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)2Pt2(μ‐dppm)](ClO4)2 (R=Ph, 3,5‐tBu2Ph or 3,5‐(CF3)2Ph) are in a nearly eclipsed configuration with torsion angles close to 0°. [(RC^N^N)PtCl], [(RC^N^N)2Pt2(μ‐dppm)](ClO4)2, and [(RC^N^N)3Pt3(μ‐dpmp)](ClO4)3 are strongly emissive with quantum yields of up to 0.68 in CH2Cl2 or MeCN solution at room temperature. The [(RC^N^N)PtCl] complexes have a high thermal stability (Td=470–549 °C). High‐performance light‐emitting devices containing [(RC^N^N)PtCl] (R=H or 3,5‐tBu2Ph) 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. Shine a light! The platinum complexes reported here (see picture) exhibit strong luminescence, with an emission quantum yield of up to 0.68, and extensive intra‐ and/or intermolecular π⋅⋅⋅π interactions. High‐performance light‐emitting devices with a maximum luminance of 63 000 cd m−2 and CIE 1931 coordinates at x=0.36, y=0.54 are also demonstrated.