Qi Yanjuan, Wang Yonghui, Hu Changwen, Cao Minhua, Mao Li, Wang Enbo
Institute of Polyoxometalate Chemistry, Northeast Normal University, Changchun, P R China 130024.
Inorg Chem. 2003 Dec 15;42(25):8519-23. doi: 10.1021/ic034796p.
A new family of single-stranded helices coordination polymers with mixed ligands, [M2(phen)2(e,a-cis-1,4-chdc)2(H2O)2]n (1, M=Co; 2, M=Ni; chdc=cyclohexanedicarboxylic acid; phen=1,10-phenanthroline), were prepared under hydrothermal conditions and characterized by elemental analyses, IR spectra, TG analysis, and single-crystal X-ray diffraction analysis. X-ray crystal structural analyses reveal that 1 and 2 are isomorphic and belong to the monoclinic system. C40H36Co2N4O10, P2(1)/c, a=10.0566(5) A, b=8.8843(5) A, c=20.2912(14) A, beta=100.052(3) degrees, Z=2 for 1; and C40H36Ni2N4O10, P2(1)/c, a=9.8921(6) A, b=9.0151(4) A, c=20.1628(17) A, beta=100.31(2) degrees, Z=2 for 2. In the structures of 1 and 2, the 1,4-chdc ligand possesses only one kind of e,a-cis-conformation although there are both cis- and trans-conformations in the raw material. Two oxygen atoms of one carboxyl in 1,4-chdc ligand and another oxygen atom of contraposition carboxyl link adjacent Co or Ni atoms into an infinite 1-D zigzag chain. The most attractive structural feature of 1 and 2 is that they both exhibit an infinite chiral chainlike structure with 2(1) helices along the b axis. In addition, the right-handed and the left-handed chains are alternate. Meanwhile, the adjacent chains of 1 and 2 are linked via hydrogen bonds into 2-D network structures, which further form 3-D frameworks via pi-pi interactions of 1,10-phen.
通过水热法制备了一系列新型的含混合配体的单链螺旋配位聚合物[M₂(phen)₂(e,a - cis - 1,4 - chdc)₂(H₂O)₂]ₙ（1，M = Co；2，M = Ni；chdc = 环己烷二羧酸；phen = 1,10 - 菲咯啉），并通过元素分析、红外光谱、热重分析和单晶X射线衍射分析对其进行了表征。X射线晶体结构分析表明，1和2同构，属于单斜晶系。对于1，化学式为C₄₀H₃₆Co₂N₄O₁₀，空间群为P2(1)/c，a = 10.0566(5) Å，b = 8.8843(5) Å，c = 20.2912(14) Å，β = 100.052(3)°，Z = 2；对于2，化学式为C₄₀H₃₆Ni₂N₄O₁₀, 空间群为P2(1)/c，a = 9.8921(6) Å，b = 9.0151(4) Å，c = 20.1628(17) Å，β = 100.31(2)°，Z = 2。在1和2的结构中，尽管原料中存在顺式和反式构象，但1,4 - chdc配体仅具有一种e,a - 顺式构象。1,4 - chdc配体中一个羧基的两个氧原子和对位羧基的另一个氧原子将相邻的Co或Ni原子连接成无限的一维锯齿链。1和2最引人注目的结构特征是它们都沿b轴呈现出具有2(1)螺旋的无限手性链状结构。此外，可以观察到右手链和左手链交替排列。同时，1和2的相邻链通过氢键连接成二维网络结构，该结构通过1,10 - phen的π - π相互作用进一步形成三维框架。
