一种五元羧酸与Eu(Ⅲ)、Tb(Ⅲ)配合物的结构及光致发光性质

Structures and Luminescent Properties of Eu(Ⅲ)and Tb(Ⅲ)Complexes with a Pentacarboxylic Acid

水热条件下利用一种五元有机羧酸分别与稀土铕和铽的高氯酸盐反应合成了二维配位聚合物{[Eu4(HL)2(ox)2(H2O)10]·3H2O}n(1)和{[Tb2(HL)(ox)(H2O)5]·2H2O}n(2)(H5L=4-(4-羧基苯基)吡啶-2,3,5,6-四羧酸;ox=草酸根离子)。X射线单晶衍射结构分析表明这2个配合物为同构化合物,属单斜晶系,P21/c空间群。草酸根离子可能是由于部分五元羧酸在水热反应过程中发生分解而产生。稀土离子与五元酸及草酸根配体配位,形成了二维平面结构。配合物1和2分别发射铕或铽离子的红色或绿色特征荧光,其绝对量子产率分别为45%和38%。铕配合物中5D0激发态的寿命为1.83 ms,铽配合物中5D4激发态的寿命为1.07 ms。

Two 2 D coordination polymers{[Eu4(HL)2(ox)2(H2O)10]·3 H2O}n(1)and{[Tb2(HL)(ox)(H2O)5]·2 H2O}n(2)(H5L=4-(4-carboxyphenyl)-pyridine-2,3,5,6-tetracarboxylic acid;ox=oxalate)were synthesized by using europium or terbium perchlorate to react with a new organic penta-carboxylic acids under hydrothermal condition.Single crystal X-ray diffraction structure analyses show that the two complexes are isomorphic and crystallize in monoclinic crystal system,P21/c space group.The oxalate anions were formed perhaps by the decomposition of part of the ligands.A2 D layer is constructed by europium or terbium ions,oxalate anions and HL ligands.Both the complexes emitted the characteristic fluorescence of Eu or Tb.The absolute quantum yields of the luminescence for1 and2 were45%and 38%,respectively.The fluorescence lifetimes of 5D0 excited state for1 and 5D4 excited state for2 were also tested and the values were 1.83 and 1.07 ms,respectively.CCDC:1949202,1;1949204,2.