吡嗪-2,3,5,6-四羧酸配位聚合物的合成 结构及性质研究.docx

摘 要
配位聚合物由于其结构的多样性及独特的物理性能而成为近年来人们关注的焦点。在磁性材料、催化、电化学、分子识别、离子交换、气体储存等领域具有潜在的应用前景。吡嗪羧酸类配体因其配位能力强以及配位模式的多样性, 因而备受人们的广泛关注。
吡嗪-2,3,5,6-四羧酸是一类含有 N、O 多齿功能的氮杂环配体,能与不同的金属以不同的配位方式进行配位,有利于形成结构新颖的配合物。本论文选用吡嗪-2,3,5,6-四羧酸作为配体,通过室温溶剂挥发,合成出了两种新的配位聚合物: [Cu2(PZTC)(NH3)2(H2O)2]·2H2O(2),稀土异核配合物[(H2PZTC)(H2O)6
(NO3)]·HNO3·H2O(5),并利用 X-ray 单晶衍射,红外光谱(IR),荧光分析及元素
分析,电感耦合等离子光谱发生仪(ICP)等手段对它们进行结构表征和分析。配合物的荧光研究结果表明,稀土异核配位聚合物(5)的荧光是由金属离子到配体的电荷转移(MLCT)所致,并且荧光强度较单一配合物有较明显的增强。
同时采用溶剂挥发法在酸性条件下探索了 3d-4f 异核金属配位聚合物合成的可能性。通过 ICP 检测,仅得到了单一的稀土配合物,表明在酸性条件下,稀土离子更容易与吡嗪-2,3,5,6-四羧酸相配位。
关键词:吡嗪-2,3,5,6-四羧酸;配位聚合物;荧光分析;结构分析;稀土配合物
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Abstract
In recent years, considerable interests have been focused on the coordination polymers because of their novel structures and unique physical properties. In addition, plexes exhibit promising applications in ic materials, catalysis, electrochemistry, molecular recognition, ion-exchange and gas storage as well. Pyrazine carboxylate ligands have attracted intense interest due to their strong coordination capability and varieties of coordination modes.
Pyrazine-2,3,5,6-tetracarboxylic acid is a multifunctional N-heterocyclic ligand with N/O-donors and could be employed in linking different metal atoms with different coordinative modes, resulting in plexes with novel structures. In this dissertation, pyrazine-2,3,5,6-tetracarboxylic acid (H4PZTC) is selected as the building block, two coordination polymers have been synthesized under solvent evaporation method at room temperature. They were [Cu2(PZTC)(NH3)2(H2O)2]·2H2O (2),[(H2PZTC)(H2O)6(NO3)]·HNO3·H2O
(5).They were well characterized by single crystal X-ray diffraction, infrared (IR)
spectroscopy, luminescent analysis, elemental analysis, and Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP),respectively. Luminescent studies on
hetero-metal coordination polymer (5) showed that the emission plex (5) is assigned to the emission of metal-to-ligand charge transfer (MLCT). In addition, com