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基于双三氮唑柔性配体的配位聚合物的构筑及性能研究

Syntheses and Properties of Coordination Polymers Based on Flexible Bis(triazole) Ligands

【作者】 穆亚娟

【导师】 侯红卫;

【作者基本信息】 郑州大学 , 无机化学, 2012, 博士

【摘要】 配位聚合物功能材料的研究重点和方向已经从合成、结构表征变为性能方面的研究,主要表现在研究结构与性能的构效关系及开发性能更加优良的金属-有机晶体材料。合理运用晶体工程原理和方法,对金属-有机骨架结构可以实现功能上的分子裁剪和组装,使其具有更加新颖的拓扑结构和优良的性能,是现代配位化学功能性材料发展的趋势之一,成为广大科学工作者关注的焦点。目前,该研究课题的核心任务是如何选择及设计合适的构筑单元并采用相关的晶体工程策略来构筑具有预期结构与功能的晶体材料,真正实现它们在应用方面的价值。本论文致力于获得具有新颖结构和良好性能的配位聚合物材料,利用两个柔性的双三氮唑配体为基本的结构构筑模块,通过选择特定的过渡金属离子,并辅以不同芳香羧酸配体调控整个框架结构,得到32个具有新颖结构和特定功能的配位聚合物,并且系统地研究和分析了这些配位聚合物的合成条件及规律,分析了网络拓扑结构及类型,探索了其结构与性能间的构效关系。本论文主要分为以下四个部分:1.利用长柔性配体4,4’-双(1,2,4-三氮唑-1-甲基)联苯(btmb)作为主配体,刚性芳香羧酸配体作为辅助配体与金属离子自组装,在水热条件下构筑了6个三维配位聚合物。其中聚合物1是一个6-连接的三维自穿插mab网络,表明btmb用于构建特殊部分结构具有很大的潜力。同时分析了pH值、金属离子对聚合物结构的影响,并讨论了结构与催化性能之间的关系,推测了可能的催化反应机理。2.基于配体btmb,我们选用Cd(Ⅱ)作为中心金属离子,选用不同的无机阴离子(Γ,NO3-,NCS-,CH3COO-或CΓ),在水热和常温溶剂挥发的条件下得到了6个一维、二维镉配位聚合物,并且对btmb的构象进行了分析,探讨了无机阴离子对配位聚合物结构及荧光性能的影响。3.选用1,4-双(1,2,4-三氮唑-1-甲基)-2,3,5,6-四甲基苯(btmx)和不同构型的羧酸组成混合配体体系,与金属锌和镉离子在水热条件下反应得到了系列6个锌和4个镉聚合物。结果表明,合理的引入芳香羧酸可调控聚合物结构,并产生穿插和缠绕等奇特的网络部分。此外,配位聚合物15与19,17与20具有相同的主配体和辅助配体,但是具有不同的金属离子,结果导致了不同结构产生,说明金属离子类型也对结构也有调控作用。这些配位聚合物都表现出良好的热稳定性和较强的荧光,意味着它们可以用作潜在的荧光材料。4.为了丰富配体btmx的配位化学行为,其与金属铜、钴离子在水热或常温条件下,在不同的辅助羧酸配体的作用下,合成了系列结构不同的一维、二维、三维配位聚合物,其中6个铜和4个钴聚合物,并研究了两个具有相同原料但结构截然不同的铜聚合物的催化性能,进一步讨论了结构对催化性能的影响。

【Abstract】 The research focus and direction of coordination polymers as functional materials has transformed from the synthesis and structure characterizations to function, which is mainly embodied in two aspects:study the relationship of structures and properties and explore advanced crystalline metal-organic materials with more superior properties. Employment of the principle and method of crystal engineering can realize the modification and assembling of the metal-organic architectures, which is beneficial to obtain novel topological frameworks with special functions. So it becomes one of the development trends of modern coordination chemisty, which attracts much interest of chemists. At present, how to get the crystalline materials with espected structures and excellent properties is the core task in crystal engineering. It demonstrates that choosing and designing suitable building blocks should be the key factor in constructing the target products. In this paper, with the aim of preparing novel metal-organic materials with intriguing structures and good properties, we select two flexible bis(triazole) ligands as building blocks, and obtain 32 new coordination polymers under the specific transition metal ions and auxiliary polycarboxylate ligands. The coordination behavior of the ligands, synthetic conditions, rules and the topological types has been discussed. In addition, we explore the relationships between the structures and properties.This work includes the following four parts:1. The combination of a long flexible ligand 4.4’-bis(l,2,4-triazol-l-ylmethyl)biphenyl (btmb) and auxiliary polycarboxylate ligands in the presence of metal ions affords six three-dimensional (3D) coordination polymers under hydrothermal conditions. Complex 1 presents a 6-connected self-penetrating mab framework, which indicates that the existence of the long flexible ligand btmb favors the formation of peculiar motifs. The effect of pH values, metal ions on the structures of complexes was analysed. Furthermore, the relationship between structures and catalytic properties was also discussed, and a plausible reaction mechanism for the present oxidative coupling reaction was proposed.2. Six novel Cd(II) coordination polymers have been synthesized by the reactions of btmb with Cd(II) salts in the presence of different anions (I-, NO3-, NCS-, CH3COO- or Cl-) under appropriate reaction conditions. These complexes exhibit one-dimensional (1D), two-dimensional (2D) structures. We have made a comparison of conformation of btmb in these Cd(II) polymers, and discussed the influence of inorganic anions on the structures and photoluminescent properties of complexes.3. Under hydrothermal conditions, the mixed ligands of l,4-bis(l,2,4-triazol-l-ylmethyl)-2,3,5,6-tetramethylbenzene (btmx) with different polycarboxylate ligands in the presence of Zn(II) or Cd(II) ions give six Zn(II) coordination polymers and four Cd(II) coordination polymers. The results reveal that polycarboxylate ligands have a great influence on the architectures of coordination polymers and can be used as a tool to tune structures. Besides, complexes 15 and 19, 17 and 20 contain the same main ligand and auxiliary ligand but different metal ions, respectively, which finally lead to the different structures, indicating the structures of complexes can be modulated by the kinds of metal ions. These complexes display good thermal stability and intense fluorescence, which shows that they can be used as potential flourescent materials.4. In order to enrich the coordination chemistry of ligand btmx, the reactions of ligand btmx and Cu(II) or Co(II) ions with the help of polycarboxylate ligands afford six Cu(II) coordination polymers and four Co(II) coordination polymers. We investigate the catalytic properties of two different Cu(II) complexes with the same raw materials, and discuss the influence of structures on the catalytic properties.

  • 【网络出版投稿人】 郑州大学
  • 【网络出版年期】2012年 09期
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