Elaborate Design of AgAu Cluster [2]Catenane Phosphors for High-Efficiency Light-Emitting Devices.

In this work, rational design of highly soluble and phosphorescent Ag-Au cluster complexes with exceptional [2]catenane structures is conducted using 1,8-diethynyl-9-carbazole (Hdecz) as a rigid U-shaped ligand with a distinguished hole-transport character. The self-assembly reaction of Hdecz, Au, and Ag generated phosphorescent AgAu cluster (Φ = 0.22 in CHCl) with Hdecz having a free ethynyl (-C≡CH) group. When the four free C≡CH groups in the AgAu complex are further bound to four (PPh)Au and four (PPh)Ag moieties through M-acetylide linkages, the formation of AgAu cluster not only eliminates nonradiative ethynyl C-H vibrational deactivation process but also improves dramatically the molecular rigidity so that the phosphorescent efficiency of the AgAu cluster (Φ = 0.63) is nearly 3 times that of the AgAu cluster . The AgAu cluster structure is further rigidified using diphsophine PhP(CH)PPh (dppb) in place of PPh so that the phosphorescence of the AgAu cluster (Φ = 0.77) is more efficient than that of . Making use of the AgAu clusters as phosphorescent dopants, high-efficiency solution-processed organic light-emitting diodes (OLEDs) were achieved with current efficiency (CE) and external quantum efficiency (EQE) of 47.2 cd A and 15.7% for complex and 50.5 cd A and 14.9% for complex .