基于氮杂环羧酸配体金属—有机配位聚合物的构筑及性质研究

发布时间：2018-02-28 21:04

本文关键词： 金属-有机配位聚合物晶体结构催化磁性稳定性　出处：《青岛科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：金属-有机配位聚合物(metal-organic coordination polymers)是由有机配体与金属离子构筑的一种新兴晶态材料,因为有机配体种类繁多且金属中心离子配位方式较为复杂,所以配位聚合物具有多变的结构和优异的性能,在气体的吸附与分离、催化、光电磁及药物储存与缓释等诸多领域展现出了极大的应用价值,受到了研究者的广泛关注。本论文中,我们采用了常规的水热及溶剂热的合成方法,构筑了8个结构新颖的金属-有机配位聚合物材料,并对它们的结构进行了表征,对它们的性能做了初步探索,总结了这类材料的合成、结构及性能规律。具体研究内容如下:(1)选用5,5-(quinoxaline-5,8-diyl)-diisophthalate(H4L1)作为桥连配体,与金属钴离子构筑了两个具有三维框架结构的配位聚合物WN-1和WN-2。探究了WN-1的催化活性,表现为惰性;后将材料进行缓慢热处理制备了新型Co基催化材料,CoOx物种以3-5 nm左右的粒子均匀镶嵌在碳骨架中,该催化剂在硝基苯加氢反应中仅需要10 min即可将底物几乎完全转化,相同条件下其催化活性明显高于氧化钴(40 min转化10%)和碳载氧化钴(40 min转化2%)催化剂。与传统的非贵金属氧化物催化剂相比,通过高温焙烧配位聚合物所得的Co基催化材料CoOx具有更高的催化活性。(2)利用水热及溶剂热的合成方法,基于含氮羧酸配体6-(3-pyridyl)isophthalic acid(H2pip),通过辅助配体的调节,成功构筑了一系列具有不同维度(从零维、二维到三维)的金属-有机配位聚合物(WN-3—WN-6)。实验表明WN-4和WN-5具有良好的热稳定性及有机溶剂稳定性,甚至在沸水中连续煮72 h、在乙醇中浸泡72 h后扫描XRD,其结构依然没有坍塌。此外,磁性测试表明,WN-4和WN-5也展现出了反铁磁性。(3)选取了一个与H2pip类似的有机配体2-(pyridin-4-yl)terephthalic acid(H2pta),依旧采用简单的溶剂热方法合成了两个多孔金属-有机配位聚合物,这两个结构的孔道尺寸较大,分别为52.8%及35.4%,可进一步探究其吸附性能。
[Abstract]:Metal organic coordination polymers (metal-organic coordination polymers) is a new crystalline material formed by organic ligands and metal ions and organic ligands because of the variety and center of metal ion coordination method is complex, so the coordination polymer has changeable structure and excellent performance in adsorption and separation, catalysis, gas. Photoelectric and magnetic fields of drug storage and release showed great application value, has attracted much attention of researchers. In this thesis, we use the conventional synthetic method hydrothermalsolvothermal, constructed 8 novel metal organic coordination polymers, and their structure the characterization, made a preliminary exploration on their performance, summarizes the synthesis of this kind of materials, structure and properties of the law. The specific contents are as follows: (1) using 5,5- (quinoxaline-5,8-diyl) -diisoph Thalate (H4L1) as bridging ligand and metal cobalt ion has constructed two three-dimensional frame structure coordination polymer of WN-1 and WN-2. on the catalytic activity of WN-1, after the material is inert; slow heat treatment of new Co based catalytic materials were prepared, CoOx species with about 3-5 nm particle uniform embedded in the carbon skeleton, the catalyst requires only 10 min substrate can be almost completely transformed in the hydrogenation of nitrobenzene in the same conditions, the catalytic activity was significantly higher than that of cobalt oxide (40 min 10%) and carbon supported cobalt oxide (40 min 2%) catalyst. Compared with the traditional non noble metal oxide catalysts the Co based catalyst CoOx through high temperature roasting coordination polymer obtained has higher catalytic activity. (2) synthesized by hydrothermal method and solvothermal, nitrogen ligands based on 6- (3-pyridyl) isophthalic acid (H2pip), assisted by the Ligand regulation, the successful construction of a series of different dimensions (from zero dimensional, two-dimensional to three-dimensional) metal organic coordination polymers (WN-3 - WN-6). The results showed that WN-4 and WN-5 have good thermal stability and stability in organic solvents, even in boiling water for boiling 72 h in ethanol for 72 h after XRD scanning, the structure is still not collapsed. In addition, the magnetic test shows that WN-4 and WN-5 also show antiferromagnetism. (3) the selection of a H2pip like ligand 2- (pyridin-4-yl) terephthalic acid (H2pta), still using a simple solvothermal method two porous metal organic coordination polymer synthesis, the two structure of the pore size is larger, respectively 52.8% and 35.4%, can be used to investigate the adsorption performance.

【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O641.4

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