【摘要】 采用PM3半经验方法和从头算密度泛函方法(B3LYP)研究了8-喹啉磺酸乙酯、异丙酯的气相热解反应机理,结果表明,此类反应经历两个基元反应步骤,第一步反应是通过一个紧密离子对过渡态的非同步的协同反应过程,其中乙基和异丙基碳正离子中的β-H原子帮助碳正离子和磺酸负离子的分离,C-O键的断裂是决定此反应的反应速度的关键。生成的8-喹啉磺酸继续进行分子内的酸碱中和反应。在B3LYP/6-311+G(2d,p)水平计算所得反应活化能分别为151.2 kJ.mol-1、137.9 kJ.mol-1,与相应的实验值相一致。更多还原

【Abstract】 The gas-phase pyrolytic reactions of ethyl-8-quinoline sulfonate and isopropyl-8-quinoline sulfonate have been investigated by semi-empirical method PM3 and density functional theory（DFT） method.The results obtained show that the gas-phase pyrolytic reactions of ethyl-8-quinoline sulfonate and isopropyl-8-quinoline sulfonate process two steps:the first step occurs via an intimate ion-pair transition state,where the β-hydrogen atom of ethyl or isopropyl carbocation facilitates C-O bond cleavage,and the cleavage of C-O bond is rate determining.The generated 2-pyridine sulfonic acid processes intramolecular acid-base neutralization.Corrected by zero-point energy,the activation energy obtained at B3LYP/6-311+G（2d,p） level was 151.21kJ·mol^-1,131.9kJ·mol^-1,respectively,which are in accordance with the available experimental data.更多还原