Abstract:

Three novel cuprous complexes of [Cu(L)2](BF4)(a), [LCu(PPh3)2](BF4)(b) and [LCu(POP)](BF4)(c)(L=2-pyridylmethyldiphenylphosphine, POP=bis[2-(diphenylphosphino)phenyl]ether) have been prepared, and characterized by 1H NMR, 31P NMR, elemental analysis, and X-ray singlecrystal diffraction. X-ray diffraction studies have revealed that the central Cu(Ⅰ) ions of all complexes have a distorted tetrahedral coordination geometry. The complexes show intense π-π* absorption bands in the range of 261~274 nm in deaerated CH2Cl2 solution, while no characteristic metal-ligand charge transfer(MLCT) transition bands appear obviously. In rigid polymethylmethacrylate(PMMA) matrix, these CuⅠ complexes show intense blue emission at 515, 476, and 481 nm, with a quantum efficiency of 16.0%, 12.9% and 7.0%, respectively. Multilayer organic light-emitting diodes(OLEDs) using poly(N-vinylcarbazole)(PVK) and complex b were fabricated. A current efficiency of 0.36 cd/A and the maximum brightness of 217 cd/m2 have been achieved at current density of 1.0×10-3 A/cm2.

Key words: Organic light-emitting, phosphorescence, Cu(I) complexes, N^P ligand