摘要
主要用PM3法对N -乙基、N -异丙基和N -叔丁基 - 2 -嘧啶的气相热解反应进行了研究 ,并用内禀反应坐标 (IRC)理论对N -乙基 - 2 -嘧啶热解反应作了剖析 ,在此基础上用RHF/ 6 - 31G从头计算对其作了对比计算 .结果表明反应是一个H17带正电迁移引发的途经六元环过渡态的单分子热消除反应 .反应的活化能分别为 2 2 4.95 5 (2 92 .378/RHF/ 6 - 31G) ,2 2 1.34 0和 2 2 1.115kJ·mol-1,与实验结果基本吻合 .
The calculation with RHF/PM3 has been applied to study the gas-phase pyrolytic reaction mechanism of N-Ethyl, N-Isopropyl and N-t-butyl substituted 2-Aminopyrimidine.The results obtained show that these compounds undergo unimolecular first-order pyrolytic reaction via a six-center cyclic transition state. This kind of the reaction is controlled by migrating of the atom H 17 with positive charge .The energy differences of these pyrolytic reactions ΔE are 127.422(N-Ethyl Substituted),116.517 (N-Isopropyl Substituted) and 103.276 kJ·mol -1 (N-t-butyl Substituted) ,respectively . The activation energies of those are 224.955 (N-Ethyl Substituted),221.340 (N-Isopropyl Substituted) and 221.115 kJ·mol -1 (N-t-butyl Substituted) ,respectively,which are agreed with the experiment data .
出处
《江西师范大学学报（自然科学版）》
CAS
2002年第2期105-109,共5页
Journal of Jiangxi Normal University(Natural Science Edition)
基金
江西省自然科学基金资助课题 (0 0 2 0 0 0 6 )
