Preparation and photoluminescence of a novel β-diketone ligand containing electro-transporting group and its europium(III) ternary complex

A novel β-diketone with an electro-transporting oxadiazole group, 1-(4′-(5-(4-methylphenyl)-1,3,4-oxadiazol-2-yl)biphenyl-4-yl)-4,4,4-trifluorobutane-1,3-dione (MPBDTFA), was prepared with high yield. With this synthesized ligand as the first ligand and 1,10-phenanthroline (Phen) as the secondary ligand, a new europium(III) ternary complex, Eu(MPBDTFA)₃Phen, was synthesized. The new β-diketone and its europium(III) ternary complex were characteristized by elemental analysis, thermo-gravimetric analysis, IR and UV-visible spectroscopies. Photoluminescence measurements indicated that the energy absorbed by the organic ligands was efficiently transfered to the central Eu³⁺ ions, and the complex showed intensely and characteristically red emissions due to the ⁵D₀ → ⁷F_j transitions of the central Eu³⁺ ions. With an electro-transporting group in molecule and highly thermal stability, the synthesized Eu(III) ternary complex is expected as a red-emitting candidate material for fabrication of organic light-emitting diodes (OLEDs).