Qin Chao, Wang Xin-Long, Wang En-Bo, Su Zhong-Min
Institute of Polyoxometalate Chemistry, Department of Chemistry, Northeast Normal University, Changchun, PR China.
Inorg Chem. 2005 Oct 3;44(20):7122-9. doi: 10.1021/ic050906b.
The complexes of formulas Ln(pydc)(Hpydc) (Ln = Sm (1), Eu (2), Gd (3); H2pydc = pyridine-2,5-dicarboxylic acid) and Ln(pydc)(bc)(H2O) (Ln = Sm (4), Gd (5); Hbc = benzenecarboxylic acid) have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, TG analysis, and single-crystal X-ray diffraction. Compounds 1-3 are isomorphous and crystallize in the orthorhombic system, space group Pbcn. Their final three-dimensional racemic frameworks can be considered as being constructed by helix-linked scalelike sheets. Compounds 4 and 5 are isostructural and crystallize in the monoclinic system, space group P2(1)/c. pydc ligands bridge dinuclear lanthanide centers to form the three-dimensional frameworks featuring hexagonal channels along the a-axis that are occupied by one-end-coordinated bc ligands. From the topological point of view, the five three-dimensional nets are binodal with six- and three-connected nodes, the former of which exhibit a rutile-related (4.6(2))(2)(4(2).6(9).8(4)) topology that is unprecedented within coordination frames, and the latter two species display a distorted rutile (4.6(2))(2)(4(2).6(10).8(3)) topology. Furthermore, the luminescent properties of 2 were studied.
已在水热条件下合成了通式为Ln(pydc)(Hpydc)（Ln = Sm (1)、Eu (2)、Gd (3)；H2pydc = 吡啶-2,5-二甲酸）和Ln(pydc)(bc)(H2O)（Ln = Sm (4)、Gd (5)；Hbc = 苯甲酸）的配合物，并通过元素分析、红外光谱、热重分析和单晶X射线衍射对其进行了表征。化合物1 - 3是同构的，结晶于正交晶系，空间群为Pbcn。它们最终的三维外消旋骨架可认为是由螺旋连接的鳞片状片层构成。化合物4和5是同构的，结晶于单斜晶系，空间群为P2(1)/c。pydc配体桥连双核镧系中心形成沿a轴具有六边形通道的三维骨架，通道中填充有一端配位的bc配体。从拓扑学角度看，这五个三维网络是双节点的，具有六连接和三连接节点，前者呈现出在配位框架内前所未有的与金红石相关的(4.6(2))(2)(4(2).6(9).8(4))拓扑结构，后两种呈现出扭曲的金红石(4.6(2))(2)(4(2).6(10).8(3))拓扑结构。此外，还研究了2的发光性质。
