Synthesis, Structure and Photoluminescent Properties of A Novel Oxadiazole-Functionalized Europium(Ⅲ) Complex

A new oxadiazole-functionalized ligand, 2-benzamide-5-phenyl-[1,3,4] oxadiazole （HL1） was synthesized. With it as the first ligand, 2-Phenyl-imidazo[4,5-f] 1, 10-phenanthroline （L2） as the second ligand, a novel europium complex [Eu（L1）3L2] was prepared and characterized by X-ray structure analysis and photoluminescent spectrum. The complex crystallizes in triclinic with space group of Pī. The crystal data are as follows: a=1.4892（3） nm, b=1.6639（3） nm, c=1.7258（4） nm, α=9.290（3） nm, β=11.014（3） nm, γ=11.554（3） nm, V=3520.7（12） nm3, Z=2, M=1244, Dc=1.292 g·cm -3, μ=1.381 mm -1 and F（000）=1389. The final R and wR values are 0. 0680 and 0.1557 for 6607 [I>2σ（I）] unique reflections. In the complex, each Eu（Ⅲ） ion is eight-coordinated by three carbonyl oxygen atoms and three oxadiazole nitrogen atoms from L1, two nitrogen atoms from the L2, forming a distorted square antiprism coordination geometry. The complex shows intense red emission typical of Eu 3+ ion under UV excitation, both ligands L1 and L2 exhibit strong antenna effects.