基于三芳基咪唑聚合物—钯催化剂的制备及其应用研究

发布时间：2018-06-25 11:05

本文选题：三芳基咪唑 + 聚合物-钯催化剂　；参考：《湘潭大学》2017年硕士论文

【摘要】：聚合物负载钯催化剂具有催化活性高、分离简便、可重复利用等优点,近年来引起了广泛关注。其中,基于N-乙烯基咪唑均聚物或共聚物负载钯的催化剂因其优异的催化性能而备受重视。本论文合成了两种基于三芳基咪唑的聚合物,并利用其咪唑环负载钯,制备了两种聚合物-钯催化剂,分别用于催化Suzuki偶联反应和氰基化反应。主要研究内容如下:(1)PDD-Pd催化剂的制备及其对Suzuki偶联反应的催化性能研究。先采用RAFT聚合反应合成了一系列组成不同的聚(1-(4-(4,5-二苯基-1H-咪唑-2-基)苯基)-4-乙烯基-1,2,3-三唑)-co-N,N-二甲基丙烯酰胺)共聚物(poly(DVT-co-DMA),简称为PDD)。而后以该系列共聚物为载体负载Pd,制备得到相应的聚合物-钯催化剂(PDD-Pd),依次催化模型Suzuki反应,优选出单体摩尔配比DVT/DMA为3/7的PDD进行研究。采用该共聚物制备出的PDD-Pd催化剂的Pd主要以0价形式存在,其粒径约为7 nm,Pd的含量为64.1 wt%。该PDD-Pd催化剂用于Suzuki偶联反应,催化性能优良。例如用于催化水作溶剂、溴代芳烃和氯代芳烃为底物的Suzuki偶联反应,其产物收率均高于95%。同时PDD-Pd催化剂可重复利用,如用于4-甲氧基溴苯和苯硼酸为底物的Suzuki偶联反应,5次循环使用后的产物收率仍高于95%,显示出优越的重复使用性能。(2)Poly(TMI)-Pd催化剂的制备及其对氰基化反应的催化性能研究。先以2,4,5-三(4-溴苯基)-1-甲基咪唑)(TMI)为单体,双(1,5-环辛二烯)镍(0)为催化剂,采用Yamamoto偶联反应合成有机多孔聚合物poly(TMI)。N2吸附脱附测试结果表明poly(TMI)的比表面积为514.83 m2g 1,总孔容为0.35 cm3g 1。而后用poly(TMI)负载Pd,制备得到poly(TMI)-Pd催化剂。由于负载的Pd占据了多孔聚合物的部分孔隙,poly(TMI)-Pd催化剂的比表面积降为299.41 m2 g 1,孔容降至0.18 cm3g 1。此外发现负载的Pd主要以0价形式存在,Pd纳米粒子的粒径约为2.7 nm,Pd含量仅为1.4 wt%。该催化剂用于催化碘代芳烃的氰基化反应,产物收率高于90%,并且可以重复使用5次以上。
[Abstract]:Polymer supported palladium catalysts have attracted wide attention in recent years for their advantages of high catalytic activity, simple separation and reusability. Among them, the catalyst based on N-vinylimidazole or copolymer supported palladium has attracted much attention because of its excellent catalytic performance. In this paper, two kinds of polymers based on triaryl imidazole were synthesized, and two kinds of polymer-palladium catalysts were prepared by imidazole ring supported palladium, which were used to catalyze Suzuki coupling reaction and cyanide reaction respectively. The main contents are as follows: (1) preparation of PDD-Pd catalyst and its catalytic performance for Suzuki coupling reaction. A series of copolymers (1- (4- (4- (4- (4- (4- (4-) diphenyl -1H-imidazolyl) phenyl) -4vinyl -2azole-3-triazole) -co-Na-N-dimethylacrylamide) copolymers (poly (DVT-co-DMA) with different composition were synthesized by raft polymerization. Then the corresponding polymer-palladium catalyst (PDD-Pd) was prepared by using the series of copolymers as the carrier to prepare the PDD-Pd. The model Suzuki reaction was followed by the optimal selection of PDD with a monomer molar ratio of DVT / DMA of 3 / 7. The PD of PDD-Pd catalyst prepared by the copolymers was mainly in the form of 0 valence, and the particle size of PDD-Pd was about 7 nm and the content of PD was 64.1 wt. The PDD-Pd catalyst has good catalytic performance for Suzuki coupling reaction. For example, Suzuki coupling reaction of brominated aromatics and chlorinated aromatics is used as a solvent to catalyze water, and the yield of the product is higher than 95%. At the same time, PDD-Pd catalyst can be reused. For the Suzuki coupling reaction of 4-methoxybromobenzene and phenylboric acid, the yield of the product is still higher than that of 95, which shows excellent reusability. (2) the preparation of Poly (TMI) -PD catalyst and its catalytic performance for cyanidation reaction. The adsorption and desorption of organic porous polymer poly (TMI). The results showed that the specific surface area of poly was 514.83 m2g / 1 and the total pore volume was 0.35 cm3g / 1. The adsorption and desorption of the organic porous polymer poly (TMI.N2) were studied by Yamamoto coupling reaction. The results showed that the specific surface area of poly was 514.83 m2g / L and the total pore volume was 0.35 cm3g / L ~ (-1). The adsorption and desorption of the organic porous polymer poly (TMI.N _ 2) was carried out by Yamamoto coupling reaction. Then, poly (TMI) -Pd catalyst was prepared by using poly (TMI) supported PD. The specific surface area of poly (TMI-Pd) catalyst was reduced to 299.41 m ~ 2 g ~ (-1) and the pore volume decreased to 0.18 cm3g ~ (-1) because the supported PD occupied part of the porous polymer. In addition, it is found that the supported PD mainly exists in the form of 0 valence. The particle size of Pd nanoparticles is about 2.7 nm and the content of PD is only 1.4 wt. The catalyst was used to catalyze the cyanylation of iodide aromatics, the yield of the product was higher than 90%, and the catalyst could be reused for more than 5 times.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36

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