位阻效应对N-(4-脱氢苯基)吡啶离子与氮氧自由基反应的理论计算研究  

Theoretical study on the reaction of N-(4-dehydrophenyl)pyridinium ion with nitroxides within the steric effects

作　　者：李慧[1] 刘翔宇[1] 汪伟[1] 晋晓勇[1] 冀永强[1] 

机构地区：[1]宁夏大学化学化工学院,宁夏银川750021

出　　处：《分子科学学报》2012年第3期192-196,共5页Journal of Molecular Science

基　　金：国家自然科学基金资助项目(21067010);宁夏大学科学研究基金资助项目(NDZR10-23);宁夏高等学校科学技术研究项目

摘　　要：应用量子化学密度泛函理论(DFT),在B3LYP/cc-pVDZ基组水平上,对N-(4-脱氢苯基)吡啶离子与不同结构的氮氧自由基反应进行了热动力学研究.优化了反应通道上反应物、中间体、过渡态和产物的几何构型并计算出它们的零点振动能(EZPV)和焓值,分析数据研究位阻效应对反应的影响.研究表明3类氮氧自由基均与N-(4-脱氢苯基)吡啶离子自由基反应经过1个无位垒的放热过程生成1个中间体,然后发生自由基的重排,开环的氮氧自由基DTBN相较于闭合的氮氧自由基TMIO和TEMPO化学性质活泼、反应过程复杂.表明反应物本身的位阻效应为此类自由基反应的主要影响因素.The reaction of N-（4-dehydrophenyl）pyridinium ion with nitroxides by using DFT method. At B3LYP/cc-pVDZ level,the reaction heat dynamics research on different structure of N-（4-dehydro phenyl） pyridinium ion and nitroxides have been calculated. The geometries of reactants, transition states and products of reactions mentioned above have been optimized. Further considering zero-point energy correction and thermal enthalpies. Analyzing data bits effect how to effect the reaction. The result of the research indicates that a series of this effect is the main influence factors. It shows that N- （4-dehydrophenyl）pyridinium ionwith different nitroxides undergo a process that without barrier generates a intermediates,then rearrangement to two new free radicals. Compared with the closed nitroxides（TEMPO and TMIO）, the chemical properties of open loop nitroxides is more complex, solvent effect also has effects, and the formation of the relevant product among reaction.

关 键 词：DFT(B3LYP)法 自由基重排 位阻效应 

分 类 号：O641[理学—物理化学]