Cai Xia, Lin Jing-Jun, Chen Hao-Zhao, Chen Lai-Chen, Zeng Rong-Hua
Acta Crystallogr Sect E Struct Rep Online. 2011 Sep 1;67(Pt 9):m1310-1. doi: 10.1107/S1600536811034337. Epub 2011 Aug 27.
In the title coordination polymer, catena-poly[[[triaqua-europium(III)]-bis-(μ-1H,3H-benzimidazol-3-ium-5,6-dicarb-oxyl-ato-κ(3)O(5),O(5'):O(6))-[triaqua-europium(III)]-di-μ-sulfato-κ(3)O:O,O';κ(3)O,O':O'] hexahydrate], [Eu(2)(C(9)H(5)N(2)O(4))(2)(SO(4))(2)(H(2)O)(6)]·6H(2)O}(n), the 1H,3H-benzimidazol-3-ium-5,6-dicarb-oxy-l-ate ligand is protonated at the imidazole group (H(2)bdc). The Eu(III) ion is coordinated by nine O atoms from two H(2)bdc ligands, two sulfate anions and three water mol-ecules, displaying a bicapped trigonal prismatic geometry. The carboxyl-ate groups of the H(2)bdc ligands and the sulfate anions link the Eu(III) ions, forming a chain along [010]. These chains are further connected by N-H⋯O and O-H⋯O hydrogen bonds and π-π inter-actions between the imidazole and benzene rings [centroid-centroid distances = 3.997 (4), 3.829 (4) and 3.573 (4) Å] into a three-dimensional supra-molecular network.
在标题配位聚合物{[Eu₂(C₉H₅N₂O₄)₂(SO₄)₂(H₂O)₆]·6H₂O}ₙ，即链状聚[[[三水合铕(III)]-双-(μ-1H,3H-苯并咪唑-3-鎓-5,6-二羧酸根-κ(3)O₅,O₅':O₆)]-[三水合铕(III)]-二-μ-硫酸根-κ(3)O:O,O';κ(3)O,O':O']六水合物中，1H,3H-苯并咪唑-3-鎓-5,6-二羧酸根配体在咪唑基团（H₂bdc）处质子化。Eu(III)离子由来自两个H₂bdc配体、两个硫酸根阴离子和三个水分子的九个O原子配位，呈现出双帽三棱柱几何构型。H₂bdc配体的羧酸根基团和硫酸根阴离子连接Eu(III)离子，沿[010]方向形成一条链。这些链通过N-H⋯O和O-H⋯O氢键以及咪唑环和苯环之间的π-π相互作用[质心-质心距离 = 3.997 (4)、3.829 (4)和3.573 (4) Å]进一步连接成三维超分子网络。
