季铵功能化金属有机框架材料的合成及其催化性质
发布时间：2018-10-16 09:07
【摘要】：CO_2的转化利用是当今绿色化学的研究热点,CO_2的转化反应也多种多样,其中CO_2与环氧化物的环加成反应以其条件温和、原子经济性和无毒无害等优点成为最重要的一类转化方式。很多多孔催化剂都被用于该转化反应。金属有机框架材料(Metal-OrganicFrameworks,MOFs)作为一种具有高孔隙率、高比表面积、孔道有序且可调、可通过预修饰和后修饰引入特定功能位点等优点的多孔功能材料,近年来在包括非均相催化的各领域内被广泛使用。在MOFs的催化应用中最受关注的反应之一当属CO_2与环氧化物的环加成反应(cycloaddition of carbon dioxide to epoxides,CCE)。该反应通常需要一种促使环氧化物开环并在碳酸酯闭环步骤中离去的亲核阴离子(一般为卤素离子)。然而绝大多数MOFs材料的框架结构呈电中性,不含亲核阴离子。为了提升MOFs催化剂对CCE反应的催化效果,一般需要外加均相的离子化合物(如四丁基溴化铵)以引入亲核阴离子。这种含有均相助催化剂的催化系统并不是完全的环境友好型非同相系统。解决这一问题的有效途径是将MOFs离子化:在框架上引入阳离子基团,获得正电性框架结构,从而将抗衡阴离子包封在孔道内,实现MOFs和亲核阴离子的一体化。本文利用2-甲酰基对苯二甲酸配体在酰胺溶剂热反应条件下可发生Leuckart-Wallach甲酰基还原胺化反应的性质,发展了 MOFs材料的原位叔胺基修饰方法。再通过对叔胺基的N-甲基化后修饰和离子交换,合成了一系列以不同卤素离子为抗衡阴离子的季铵功能化MOFs催化剂。催化实验结果表明,这种MOFs催化剂在CCE反应中表现出很好的催化活性并而无需外加助催化剂。本论文内容包括以下三个部分:1.利用甲酰基原位转化反应合成叔胺功能化MOFs利用2-甲酰基对苯二甲酸配体在DMF溶剂热合成MOFs过程中的原位Leuckart-Wallach还原胺化反应,合成了叔胺功能化的MOFs材料UiO-66-CH_2-N(CH_3)_2;利用BDC和BDC-CHO混合配体合成了混配型叔胺功能化UiO-66-CH_2-N(CH_3)_2-MLx。此外,我们还将这种原位转化策略扩展,通过改变酰胺溶剂合成了叔胺基种类不同的叔胺功能化UiO-66,通过改变金属离子获得叔胺基功能化的MIL-101材料,从而发展了利用配体原位转化制备功能化MOFs的方法。利用X射线衍射仪、热重分析仪和核磁共振仪等手段对合成的MOFs材料的骨架结构、热稳定性和修饰比例进行了表征。2.季按离子功能化UiO-66的制备及其对CCE反应的催化性质通过N-甲基化修饰及阴离子交换对前一部分得到的叔胺功能化UiO-66进行后合成修饰,合成了含有不同种类卤素抗衡阴离子的季铵离子化MOFs催化剂;研究了其对CCE反应的催化性能,考察了混合配体比例、抗衡阴离子种类和催化剂用量、反应温度、压力以及时间等反应条件的影响。实验表明,混合配体的UiO-66-CH_2-N~+(CH_3)_3Br~--ML0.72材料因其适中的孔道尺寸及后修饰比例作为催化剂更具优势;最适宜的反应条件为:底物14.29mmol、温度100℃、压力1 MPa、时间4 h、催化剂100 mg。此外,我们还扩展了反应底物的种类,用氧化苯乙烯、环氧氯丙烷、环氧丁烷和环氧环己烷等物质作为反应底物。结果表明反应均能不同程度的发生,并且催化产率与底物分子尺寸和取代基种类有关。3.溴甲基化功能化MOFs的合成尝试溴甲基功能化MOFs材料可作为离子型MOFs的前体。这一部分我们分别尝试了两种路线来合成溴甲基化的MIL-101-CH_2Br材料。在后合成卤化路线中,成功合成了 MIL-101-CH_3,但是接下来的溴代后修饰反应不能发生;而在配体预修饰路线的研究中,我们发现2-溴甲基对苯二甲酸甲酯的水解反应并不生成希望的2-溴甲基对苯二甲酸配体而是生成了 4-羧基苯酞,以此为原料未能得到MIL-101类型的MOFs产物。上述尝试性研究尽管未得到目标MOFs产物,但也获得了有用的化学信息。
[Abstract]:The conversion and utilization of CO _ 2 is a hot spot of green chemistry today. CO _ 2 conversion is also varied, and the cycloaddition reaction of CO _ 2 and epoxide is the most important type of transformation in terms of its mild condition, atom economy and non-toxic and harmless. Many porous catalysts are used for this conversion reaction. Metal organic framework materials (MOFs), as a porous functional material with high porosity, high specific surface area, orderly and adjustable pore channel, can introduce specific functional sites through pre-modification and post-modification, have been widely used in various fields including heterogeneous catalysis. One of the most important reactions in the catalytic application of MOFs is the cycloaddition of CO _ 2 and epoxide (CCE). This reaction generally requires a nucleophilic anion (typically a halogen ion) that causes the epoxide to ring open and leave in the carbonate closed loop step. However, the framework structure of most MOFs materials is neutral and does not contain nucleophilic anions. In order to improve the catalytic effect of the MOFs catalyst on CCE reaction, it is generally necessary to add homogeneous ionic compounds (such as tetraisobutyl bromide) to introduce nucleophilic anions. This catalytic system containing both the aid catalysts is not a complete environmentally friendly non-phase system. The effective way to solve this problem is to ionize the MOFs: the cation groups are introduced into the frame to obtain the positive electrical framework structure, so that the counter anion is encapsulated in the pore canal, and the integration of the MOFs and the nuclear anions is realized. In this paper, the properties of the reductive amination reaction of Leuckart-Wallach A with 2-methylterephthalic acid ligand can take place under the thermal reaction conditions, and the in-situ tertiary amine modification method of MOFs material has been developed. After N-methylation modification and ion exchange on tertiary amine groups, a series of quaternary amine functional MOFs catalysts with different halogen ions as counter anions were synthesized. The results of catalytic experiments show that this kind of MOFs catalyst shows good catalytic activity in CCE reaction without addition of cocatalyst. The contents of this thesis include the following three parts: 1. In this paper, the functional MOFs of the tertiary amine functionalized MOFs were synthesized by the in-situ LeBuckart-Wallach reduction amination reaction in DMF solvent thermal synthesis by the in situ conversion reaction of toluidine, and a tertiary amine functionalized MOFs material UiO-66-CH _ 2-N (CH _ 3) _ 2 was synthesized. Mixed-type tertiary amine functionalized UiO-66-CH _ 2-N (CH _ 3) _ 2-MLx was synthesized by using the mixed ligand of hydrogen bromide and poly-CHO-CHO. In addition, we extended the in-situ conversion strategy, and synthesized a tertiary amine functionalized UiO-66 with different tertiary amine groups by changing the diethylamine solvent, and by changing the metal ions to obtain the tertiary amine-functionalized MIL-101 material, the method for preparing the functional MOFs by in-situ conversion of the ligand is developed. The skeleton structure, thermal stability and modification ratio of synthetic MOFs were characterized by Xray diffractometer, thermogravimeter and nuclear magnetic resonance instrument. According to the preparation of the ion functionalized UiO-66 and the catalytic properties of the CCE reaction, the tertiary amine functionalized UiO-66 obtained from the previous part is synthesized and modified through N-methylation modification and anion exchange, and a quaternary ammonium salt ionized MOFs catalyst containing different kinds of halogen counter anions is synthesized; The catalytic performance of the CCE reaction was studied, and the effects of the ratio of the mixed ligand, the type of counter anion and the amount of catalyst, reaction temperature, pressure and time on the reaction conditions were investigated. The experiments show that the UiO-66-CH _ 2-N ~ + (CH _ 3) _ 3Br ~-ML0.072 material of the mixed ligand has the advantages of moderate pore size and post-modification ratio as the catalyst; the most suitable reaction conditions are: substrate 14.29mmol, temperature 100 鈩，
本文编号：2273886
[Abstract]:The conversion and utilization of CO _ 2 is a hot spot of green chemistry today. CO _ 2 conversion is also varied, and the cycloaddition reaction of CO _ 2 and epoxide is the most important type of transformation in terms of its mild condition, atom economy and non-toxic and harmless. Many porous catalysts are used for this conversion reaction. Metal organic framework materials (MOFs), as a porous functional material with high porosity, high specific surface area, orderly and adjustable pore channel, can introduce specific functional sites through pre-modification and post-modification, have been widely used in various fields including heterogeneous catalysis. One of the most important reactions in the catalytic application of MOFs is the cycloaddition of CO _ 2 and epoxide (CCE). This reaction generally requires a nucleophilic anion (typically a halogen ion) that causes the epoxide to ring open and leave in the carbonate closed loop step. However, the framework structure of most MOFs materials is neutral and does not contain nucleophilic anions. In order to improve the catalytic effect of the MOFs catalyst on CCE reaction, it is generally necessary to add homogeneous ionic compounds (such as tetraisobutyl bromide) to introduce nucleophilic anions. This catalytic system containing both the aid catalysts is not a complete environmentally friendly non-phase system. The effective way to solve this problem is to ionize the MOFs: the cation groups are introduced into the frame to obtain the positive electrical framework structure, so that the counter anion is encapsulated in the pore canal, and the integration of the MOFs and the nuclear anions is realized. In this paper, the properties of the reductive amination reaction of Leuckart-Wallach A with 2-methylterephthalic acid ligand can take place under the thermal reaction conditions, and the in-situ tertiary amine modification method of MOFs material has been developed. After N-methylation modification and ion exchange on tertiary amine groups, a series of quaternary amine functional MOFs catalysts with different halogen ions as counter anions were synthesized. The results of catalytic experiments show that this kind of MOFs catalyst shows good catalytic activity in CCE reaction without addition of cocatalyst. The contents of this thesis include the following three parts: 1. In this paper, the functional MOFs of the tertiary amine functionalized MOFs were synthesized by the in-situ LeBuckart-Wallach reduction amination reaction in DMF solvent thermal synthesis by the in situ conversion reaction of toluidine, and a tertiary amine functionalized MOFs material UiO-66-CH _ 2-N (CH _ 3) _ 2 was synthesized. Mixed-type tertiary amine functionalized UiO-66-CH _ 2-N (CH _ 3) _ 2-MLx was synthesized by using the mixed ligand of hydrogen bromide and poly-CHO-CHO. In addition, we extended the in-situ conversion strategy, and synthesized a tertiary amine functionalized UiO-66 with different tertiary amine groups by changing the diethylamine solvent, and by changing the metal ions to obtain the tertiary amine-functionalized MIL-101 material, the method for preparing the functional MOFs by in-situ conversion of the ligand is developed. The skeleton structure, thermal stability and modification ratio of synthetic MOFs were characterized by Xray diffractometer, thermogravimeter and nuclear magnetic resonance instrument. According to the preparation of the ion functionalized UiO-66 and the catalytic properties of the CCE reaction, the tertiary amine functionalized UiO-66 obtained from the previous part is synthesized and modified through N-methylation modification and anion exchange, and a quaternary ammonium salt ionized MOFs catalyst containing different kinds of halogen counter anions is synthesized; The catalytic performance of the CCE reaction was studied, and the effects of the ratio of the mixed ligand, the type of counter anion and the amount of catalyst, reaction temperature, pressure and time on the reaction conditions were investigated. The experiments show that the UiO-66-CH _ 2-N ~ + (CH _ 3) _ 3Br ~-ML0.072 material of the mixed ligand has the advantages of moderate pore size and post-modification ratio as the catalyst; the most suitable reaction conditions are: substrate 14.29mmol, temperature 100 鈩，
本文编号：2273886
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