可见光下PdZrO2催化芳香类醛与硫酚制备二苯巯基甲基苯类化合物毕业论文
2022-01-26 13:00:04
论文总字数:23367字
摘 要
光催化有机合成反应最早出现于上世纪七十年代,随后引起研究者们广泛关注并迅速发展起来。维持人类社会的可持续发展要求化学家尽可能地减少化学工业活动对环境的影响,从而促进绿色化学的诞生。绿色化学最重要的任务之一是开发新的环境友好的合成方法和反应条件,以取代原来不友好的合成方法。在过去的十年中,可见光(氧化还原)催化已经成为新型“绿色”有机反应的重要平台。相较于热反应来说,光催化反应具有环保,节能,可持续发展等特点,而且光催化操作简单易于控制,在常温下就能发生。在可见光的照射下,金属钯在正常温度下作为非等离子体纳米粒子可以显著增强其固有的催化性能,金属钯的使用具有高效性和经济性等特点。在有机合成领域金属钯的竞争力较强,是许多科研工作者热衷的领域之一。因此利用过渡金属钯纳米粒子作为光催剂而形成的催化体系应运而生。
我们通过可见光照射Pd/ZrO2催化以苯甲醛与苯硫酚为底物直接合成双(苯硫基)甲基苯。经过反应条件筛选优化,当使用3wt%Pd/ZrO2作为光催化剂,乙腈为溶剂,产率能达到85%。在进行底物拓展时,不同取代基的反应实验都很乐观。本反应的反应条件简单温和,不需要加入额外的添加剂,其中加入的催化剂还可以循环反复使用。
关键词:光催化 二苯巯基甲基苯类化合物 Pd/ZrO2 缩醛反应
Abstract
Photocatalytic organic synthesis first appeared in the 1970s, and it has attracted widespread attention and rapid development. Sustainable development of human society requires chemists to minimize the impact of chemical industry activities on the environment, thus promoting the birth of green chemistry. One of the most important tasks of green chemistry is to develop new environmentally friendly synthetic methods and reaction conditions to replace the original unfriendly synthetic methods. In the past decade, visible light (redox) catalysis has become an important and powerful platform for the development of novel "green" organic reactions with high synthesis efficiency and functional group tolerance. Compared with thermal reaction, photocatalytic reaction has the characteristics of green, energy saving and sustainable development. Moreover, photocatalytic operation is simple and easy to control, and can occur at room temperature. Under visible light irradiation, palladium, as a non-plasma nanoparticle at normal temperature, can significantly enhance its inherent catalytic performance. The use of palladium is highly efficient and economical. Palladium is highly competitive and is one of the most popular areas of organic synthesis. Therefore, transition metal palladium nanoparticles are used as photocatalysts to form a catalytic system.
Bis (phenylthio) methylbenzene was synthesized directly from benzaldehyde and phenylthiophenol under Visible Light Irradiation Catalyzed by Pd/ZrO2. After screening and optimizing the reaction conditions, when using 3wt% Pd/ZrO2 as photocatalyst and acetonitrile as solvent, the yield can reach 85%. The reaction experiments of different substituents are optimistic when the substrate is expanded. The reaction conditions are simple and mild, and no additional additives need to be added. The catalyst added in the reaction can be recycled and reused.
Keywords:Photocatalytic; Diphenylmercaptomethylbenzene compounds; Pd/ZrO2; Acetal reaction
目 录
摘 要 I
Abstract II
第一章 绪论 1
1.1 合成硫代缩醛的意义 1
1.2 双(苯硫基)甲基苯类化合物反应的研究 1
1.3 光催化技术的研究进展 3
第二章 实验部分 6
2.1 前言 6
2.2 实验试剂及仪器 7
2.3 实验方法 9
第三章 结果与讨论 11
3.1 催化剂对反应的影响 11
3.2溶剂对反应产率的影响 11
3.3时间对反应产率的影响 12
3.4 反应底物的拓展.........................................................................................13
3.5 反应机理的探究.........................................................................................14
3.6 可能的反应机理.........................................................................................15
3.7 产物表征.......................................................................................................16
3.8 本章小结.......................................................................................................18
第四章 结论与展望..............................................................................................19
参考文献 20
附图 23
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