A Series of Two-Dimensional Metal−Organic Frameworks Based on the Assembly of Rigid and Flexible Carboxylate-Containing Mixed Ligands with Lanthanide Metal Salts
journal contributionposted on 03.10.2007, 00:00 by Xing-Jing Zhang, Yong-Heng Xing, Zheng Sun, Jing Han, Yuan-Hong Zhang, Mao-Fa Ge, Shu-Yun Niu
A series of lanthanide metal−organic frameworks, [Ln2 (Suc)0.5(BC)3(OH)2] (Ln = Tb (1), Eu (2), Sm (3), Pr (4); H2Suc = succinic acid; HBC = benzoic acid), have been synthesized by the reaction of nitrate salts of Ln(III) with succinic acid and benzoic acid under hydrothermal conditions and were characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. X-ray diffraction analyses reveal that they exhibit the same two-dimensional (2D) architecture and crystallized in triclinic space group P1̄ for complexes 1−4. Infinite inorganic walls were formed by lanthanide ions, μ3-OH, and an edge-sharing “...Ln−O−C−O−Ln...” chain, which link to each other through the carbon atoms of the succinate anions on the  plane and phenyl groups of the benzoic acid ligands on the  plane, leading to a two-dimensional open framework structure. The thermogravimetric analysis of 1−4 and photoluminescent properties of 1 and 2 are discussed in detail.