Highly Phosphorescent Dimers of PtAu 2 Complexes and the Use in Solution-Processed OLEDs.

Two asymmetric PtAu 2 complexes having HC≡CC 6 H 4 C≡CH (1,4-diethynylbenzene) or HC≡CCarbC≡CH (2,7-diethynyl-9-(2,3,5,6-tetrafluorophenyl)-9H-carbazole) and the corresponding bis(acetylide)-linked Pt 2 Au 4 complexes are prepared and characterized. The structures of PtAu 2 complexes 1 and 3 together with Pt 2 Au 4 complex 2 are determined by X-ray crystallography. Relative to PtAu 2 complexes, bis(acetylide)-linked Pt 2 Au 4 complexes not only display a distinct red shift of the emission but also provide a much higher phosphorescent efficiency. Utilizing highly emissive Pt 2 Au 4 complexes as phosphorescent dopants, high-efficiency solution-processed OLEDs are obtained with peak current efficiency of 75.9 cd A -1 and external quantum efficiency of 19.0% at luminance of 336 cd m -2 and voltage of 5.2 V. When two PtAu 2 moieties are linked by a bis(acetylide) ligand, the corresponding Pt 2 Au 4 complexes show a much improved electroluminescent performance compared with that of asymmetric PtAu 2 complexes.