Zhang Hong Tao, Wang Xiao Long
College of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui 241000, People's Republic of China.
Acta Crystallogr C Struct Chem. 2018 Nov 1;74(Pt 11):1434-1439. doi: 10.1107/S2053229618013967. Epub 2018 Oct 22.
In recent years, much initial interest and enthusiasm has focused on the self-assembly of coordination polymers due to the aesthetics of their crystalline architectures and their potential applications as new functional materials. As part of an exploration of chiral coordination polymers, a new twofold interpenetrated two-dimensional (2D) coordination polymer, namely, poly[[tetraaquabis[μ-(2R,2'R)-2,2'-(benzene-1,4-dicarboxamido)dipropionato-κO,O':O'',O''':O'']dicadmium(II)] trihydrate], {[Cd(CHNO)(HO)]·3HO}, has been synthesized by the reaction of Cd(CHCOO)·2HO with the designed ligand (2R,2'R)-2,2'-(benzene-1,4-dicarboxamido)dipropionic acid (HL). The compound has been structurally characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction and single-crystal X-ray diffraction analysis. In the crystal structure, each Cd cation binds to three carboxylate groups from two crystallographically independent L dianions. Four carboxylate groups link two crystallographically independent cadmium cations into a 4,4-connected secondary building unit (SBU). The resulting SBUs are extended into a two-dimensional folding sheet via the terephthalamide moiety of the ligand as a spacer, which can be simplified as a (4,4)-connected 4,4L15 net with the point symbol (3.5.6)(3.5.6). In the lattice, two independent folding sheets interpenetrate each other to yield a double-sheet layer. The resulting 2D layers pack in parallel arrays through intermolecular hydrogen bonds and interlayer π-π interactions. The thermal stability and photoluminescence properties of the title compound have been investigated and it exhibits an enhanced fluorescence emission and a longer lifetime compared with free HL.
近年来，由于其晶体结构的美学价值及其作为新型功能材料的潜在应用，配位聚合物的自组装引起了广泛的关注和热情。作为对手性配位聚合物探索的一部分，通过Cd(CH₃COO)₂·2H₂O与设计的配体(2R,2'R)-2,2'-(苯-1,4-二甲酰胺基)二丙酸(HL)反应，合成了一种新的具有双重互穿结构的二维(2D)配位聚合物，即聚[[四水双[μ-(2R,2'R)-2,2'-(苯-1,4-二甲酰胺基)二丙酸根-κO,O':O'',O''':O'']二镉(II)]三水合物]，{[Cd(C₁₂H₁₄N₂O₄)(H₂O)₄]·3H₂O}。通过元素分析、红外光谱、粉末X射线衍射和单晶X射线衍射分析对该化合物进行了结构表征。在晶体结构中，每个Cd阳离子与来自两个晶体学独立的L二价阴离子的三个羧酸根基团结合。四个羧酸根基团将两个晶体学独立的镉阳离子连接成一个4,4-连接的二级结构单元(SBU)。所得的SBUs通过配体的对苯二甲酰胺部分作为间隔基扩展成二维折叠片层，其可简化为具有点符号(3.5.6)(3.5.6)的(4,4)-连接的4,4L₁₅网络。在晶格中，两个独立的折叠片层相互贯穿形成双层。所得的二维层通过分子间氢键和层间π-π相互作用以平行阵列堆积。研究了标题化合物的热稳定性和光致发光性质，与游离HL相比，它表现出增强的荧光发射和更长的寿命。
