半硫靛半对称二苯代乙烯分子光异构化反应的非绝热动力学研究

发布时间：2018-11-12 16:18

【摘要】：本文主要是分为三部分,第一部分是介绍顺反异构化的机理,为更方便研究HTI起到一定作用,第二部分主要是介绍研究半硫靛半对称二苯代乙烯(HTI)光异构化反应的理论方法。第三部分是本文中最重要的部分,主要介绍了采用轨迹系间窜越分子动力学模拟进行详细研究HTI的Z→E和E→Z光异构化反应机理。第一章前半部分是绪论部分,主要介绍了顺反异构化的机理以及有关顺反异构化的化合物。第一章后半部分主要是对这篇论文中所应用的方法进行了简单的介绍,特别是我们应用到了基于改进的Zhu-Nakamura公式,因为这个公式的应用使我们动力学能够顺利进行,得到准确的结果。第二章主要是介绍激发态的HTI反式到顺式的光异构化机理,我们先采用静态电子结构计算得到7个圆锥相交点,并根据各个构型的特点和能量推测轨迹主要经过的CI,最后我们采用两个根态平均CASSCF方法计算结合Zhu-Nakamura方程探讨了激发态HTI的E→Z的光异构化机理。我们得出双键的扭转是主要的异构化路径,并且得到的反应轨迹就是经过这个机理,然而文章中其他两个机理主要是他们在经过圆锥相交点后混合着双键和苯环的扭转,且产物为反式。在332条模拟轨迹中,仅仅66条轨迹跃迁到基态,其中19条轨迹产物为顺式。因此,估计的量子产率0.057是很好的与实验值0.053土0.016相对应。我们得到的反应路径对以后研究HTI机理提供了很好的指导。第三章主要是介绍了激发态HTI的Z→E的光异构化机理,采用的方法和第三章一样,我们仅仅达到初步的动力学结果,我们也验证了轨迹主要经过的CI与E→Z主要经过的CI是一致的,产物更多的为顺式结构。
[Abstract]:This paper is mainly divided into three parts. The first part is to introduce the mechanism of cis-trans isomerization, so as to facilitate the study of HTI. In the second part, the theoretical method for the photoisomerization of (HTI) is introduced. The third part is the most important part of this paper. The mechanism of photoisomerization of HTI is studied in detail by means of molecular dynamics simulation of trajectory intersystem transition. The first half of the first chapter is the introduction part, which mainly introduces the mechanism of cis-trans isomerization and the compounds related to cis-trans isomerization. The second half of the first chapter mainly introduces the methods used in this paper, especially we apply the improved Zhu-Nakamura formula, because the application of this formula can make our dynamics go smoothly. Get accurate results. In the second chapter, we introduce the photoisomerization mechanism of excited state from HTI to cis. We calculate the intersection points of seven cones by static electronic structure, and estimate the CI, which is the main path according to the characteristics of each configuration and energy. Finally, the photoisomerization mechanism of excited HTI is discussed by using two root average CASSCF methods and Zhu-Nakamura equation. We find that the twisting of double bond is the main isomerization path, and the reaction path obtained is through this mechanism. However, the other two mechanisms in this paper are mainly the twisting of double bond and benzene ring after they pass through the conical intersection point. And the product is trans. Of 332 simulated trajectories, only 66 trajectories have been transferred to the ground state, of which 19 locus products are cis. Therefore, the estimated quantum yield of 0.057 corresponds well to the experimental value of 0.053 earth 0.016. The reaction path we obtained provides good guidance for the further study of HTI mechanism. In chapter 3, we mainly introduce the photoisomerization mechanism of the excited state HTI. The method is the same as in the third chapter, and we only get the preliminary kinetic results. We also verify that the CI with the main trajectory is the same as the CI that the E ~ (2 +) Z mainly passes through, and the products are more cis structure.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.12

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