摘要
用MP2方法,在6-311++G(d,p)基组水平上研究了CH自由基与HNCO的反应机理.全参数优化了反应过程中反应物、中间体、过渡态和产物,选用更高水平的QC ISD(T)/6-311++G(d,p)和G3方法计算了相应的能量.研究结果表明:CH自由基与HNCO反应存在4条反应通道,分别为(1)CH+HNCO→IM1→TS1→CH2+NCO;(2)CH+HNCO→IM1→TS2→IM2→TS3→H2CN+CO;(3)CH+HNCO→IM(c is)→TS(c is)→HCNH+CO;(4)CH+HNCO→IM(c is)→TS(c is-trans)→IM(trans)→TS(trans)→HCNH+CO.其中通道(3)具有相对较低的活化能,且为放热通道,是反应的主要通道.
In this paper, MP2 method was performed to study the reaction mechanism of the reaction of CH radical with HNCO. The geometries of reactants, intermediates, transition states and products were optimized by MP2 method with 6-311 ＋ ＋ G （d, p） basis sets. The energies of stationary points along the pathways were calculated at QCISD（ T）/6-311 ＋ ＋ G（d,p） and G3 levels. Intermediates and transition states were confirmed by the results of vibration analyses. The results show that ,in this reaction, there exist four re- action pathways ： （ 1 ）CH＋HNCO→IM1→TS1→CH2＋NCO;（2）CH＋HNCO→IM1→TS2→IM2→TS3→H2CN＋CO;（3）CH＋HNCO→IM（cis）→TS（cis）→HCNH＋CO;（4）CH＋HNCO→IM（cis）→TS（cis-trans）→IM（trans）→TS（trans）→HCNH＋CO has the smallest activation energy and it is an exother- mic pathway. So, pathway （3） is the main reaction pathway.
出处
《四川师范大学学报（自然科学版）》
CAS
CSCD
北大核心
2006年第2期219-223,共5页
Journal of Sichuan Normal University（Natural Science）
基金
国家自然科学基金(20277014)
四川省青年基金资助项目
关键词
CH自由基
HNCO
反应机理
过渡态
活化能
CH radical
HNCO
Reaction mechanism
Transition state
Activation energy
