【作者】 王华静；

【导师】 郭庆祥；

【作者基本信息】 中国科学技术大学 ， 有机化学， 2009， 博士

【摘要】 有机负氢化合物是有机化学中一类重要的化合物,在化学和生物化学反应中能给出负氢离子。许多重要的生物合成和代谢过程均有天然有机负氢化合物烟酰辅酶的参与。从物理有机的角度来看,有关负氢化合物负氢解离的热力学性质的研究几乎是个空白,主要是因为实验上很难获得这些重要的热力学参数。本文使用量子化学的方法,从物理有机的角度研究了负氢化合物的负氢解离能,单电子转移电位等热力学性质。?在第一章中,概述了有机负氢化合物热力学和动力学的研究背景、现状和意义,并简要概述了有机化合物结构和热力学性质的关系,以及本论文主要的研究目的和创新点。?在第二章中,简要介绍了理论有机化学方法,主要包括量子化学方法,重点介绍了组合从头算方法。?在第三章中,主要报道了负氢化合物的负氢解离能的理论研究。我们运用新发展的高精度ONIOM/G4理论方法,用于负氢解离能的精确计算,对于负氢解离能的计算精度达到1.8 kcal/mol,在此基础上,我们系统的设计了一系列新的负氢化合物,并详细研究了其结构与负氢解离能之间的结构性能关系。在第四章中,我们使用资源消耗少的DFT方法,准确地计算了乙腈溶剂中负氢化合物的单电子转移电势,并研究了其结构与单电子转移能力之间的关系。在第五章中,我们使用高精度分层ONIOM/G3方法,研究了DMSO中叶立德前体的pKa值,并系统地研究了含N、O、S、As、Se、Te的叶立德前体的pKa值,进而建立了一个较为全面的叶立德热稳定性序列。?在第六章中,对一类含氯的环境污染物中碳氯键的解离能进行了研究,运用经过检验的DFT方法,对于一系列环境危害较大,但可通过光化学降解和生物降解的氯代有机物的碳氯键离解能值进行预测,并讨论了影响碳氯键离解能的结构性质关系。本文以量子化学方法为工具,物理有机化学为指导,系统地研究了一系列有机化合物的结构活性关系。本文的研究成果为生物和有机合成化学的发展提供了有价值的基础资料。更多还原

【Abstract】 Organic hydride donors are one class of very important organic compounds that can provide hydride anions in chemical and biochemical reactions. From the view of physical organic chemistry, very few papers were found to report the determination of the thermodynamic driving forces of the compounds as organic hydride donors to release hydride anion in solution so far. In this study, we employ theoretical calculations to study the thermodynamic driving forces of the compounds.In the first chapter, we reviewed the back ground of the organic hydride donor and the studies on its thermodynamics and kinetics. Then we introduced the structure-activity relationship of compounds.In the second chapter, several computational methods were introduced, including quantum chemistry method, and most importantly, the ONIOM method.In the third chapter, the new developed ONIOM/G4 method was used to accurately predict the hydricities of organic hydride donors in acetonitrile. In this work we successfully established an effective tool with high precision (1.8 kcal/mol) for predicting the hydricities. Based on the data we obtained, we systematically studied the structure-activity relationships in hydricities of organic hydride donors.In the fourth chapter, DFT method was used to predict the redox potentials of organic hydride donors, whose reliability has been tested against almost all the available experimental data. By using this method, the important thermodynamic properties of organic hydride donors were investigated and the mechanisms of hydride transfer progress were explained.In the fifth chapter, we construct a complete ylide thermodynamic stability scale on the basis of accurately calculated C-H pKa’s of ylide precursors. For the first time, corresponding substituent effects were rationalized systematically.In the sixth chapter, DFT method was used to predict the BDE of Environmental Pollutants. Armed with this powerful tool, the C-Cl bond dissociation enthalpies (BDEs) of some persistent environmental pollutants are calculated. Further, the substituent effects are discussed.更多还原