在水热条件下合成了一个新的2,5-吡啶二羧酸的稀土配合物{[Eu(2,5-PDA)(OAe)(H2O)]·1.5H2O}n.通过元素分析和X射线单晶衍射确定了该化合物的组成和晶体结构,并对荧光性质进行了表征.该晶体属单斜晶系,P21/n空间群,晶胞参数a=0.93501(15)nm,b=0.83477(13)nm,C=1.6779(3)nm,β=106.18°;V=1.2578(3)nm^3,Z=4,最后的一致性因子[I〉2σ(I)]:R1=0.0243,wR2=0.0605.标题化合物中醋酸根的羧基以螯合-桥联三齿的方式将2个不对称单元中的铕离子连接起来形成二核单元,2,5-PDA配体分别从与醋酸根和铕离子的平面成88°和56°夹角的方向将二核单元连接起来,从而形成了由配位键构筑的三维结构,未配位水分子通过氢键存在于晶体中.
The europium coordination polymer {[Eu(2,5-PDA)(OAc)(H2O)]·1.5H2O}( PDA = 2,5-pyridinedicarboxylate, OAc = acetate) was synthesized by hydrothermal method, and characterized by single crystal X-ray diffraction and elemental analysis. The crystallographic data show that the complex crystallizes in a monoclinic system, space group P21/n, cell parameters a =0. 935 01 (15) nm, b =0. 834 77 (13) nm, c = 1. 677 9(3) nm,β=106. 18°, V=1. 257 8(3) nm^3, Z=4, the final indentical factors [I〉2σ(I) ] : R1= 0. 024 3, wR2 = 0. 060 5. One carboxyl group of PDA ligand and OAc ligand links two europium (Ⅲ) ions of two asymmetric units to form a dinuclear unit, while PDA ligands join dinuclear units from two directions, which are 88° and 56° dihedral angles with itcetate ligands, respectively. Along the α-axis, a three-dimen- sional structure constructed by coordinated bonds is thus formed by PDA and OAc ligands, in which uncoordinated water molecules exist in the crystal via hydrogen bonds with coordinated water molecules. The photoluminescence property of the title compound was also investigated. The intensity ratio I(^5Do→^7F2/^5Do→^7TF1 ) is ca. 1.44, which indicates that the Eu(Ⅲ) ion in the title compound is not located at the center of inversion.