摘要
采用密度泛函(DFT)中的B3LYP方法研究肉桂醛选择性加氢产物的互变异构过程.在6-311++G**基组水平下,对肉桂醛选择性加氢的产物和互变异构过程中的过渡态进行几何构型优化,通过振动频率分析确认过渡态,内禀反应坐标(IRC)计算对过渡态进行验证,并运用分子中的原子理论(AIM)分析这些物质的成键特征及轨道间相互作用.研究结果发现,肉桂醛选择性加氢可能生成3种产物,分别为苯丙醛(P1)、3-苯基丙烯醇(P2)和肉桂醇(P3);在气相和乙醇、甲苯、THF 3种不同溶剂中,这3种产物互变异构的活化能均大于250.00 kJ/mol;在酸性条件下,ΔE2(即P2→TS2→P3过程活化能)为142.30 kJ/mol,表明1,4加成产物3-苯基丙烯醇有可能转换成肉桂醇;在碱性条件下,ΔE'1(即P2→TS1→P1过程活化能)和ΔE2(即P2→TS2→P3过程活化能)分别为44.23和80.59 kJ/mol,活化能均较小,表明3-苯基丙烯醇易转换成肉桂醇和苯丙醛;而肉桂醇和苯丙醛在乙醇、甲苯、THF、酸性及碱性条件下都难发生互变异构.
The isomerization reaction mechanism for the products of selective hydrogenation of cinnamaldehyde is studied by density functional theory B3LYP method.All of the products and transition states are optimized at B3LYP/6-311 ＋ ＋ G ＊ ＊ level.All of the transition states have been confirmed by vibration analysis and intrinsic reactions coordinate （IRC）,and atoms in molecules （AIM） theories have been used to analysis bond natures and orbits interaction.The results find that the three kinds of products,benzene propanal （P1）,3-phenyl allyl alcohol（P2） and saturated alcohol（P3）,are generated by selective hydrogenation of cinnamaldehyde.The activation energies of the isomerization are more than 250.00 kJ/mol under the gas phase and different solvents （ethanol,toluene,THF）.In acid condition,△E2 （P2→TS2→P3） is 142.30 kJ/mol,which meant the 1,4 products 3-phenyl allyl alcohol can be converted to saturated alcohol ; in alkaline conditions,△E＇1 （P2 → TS1 → P1） is 44.23 kJ/mol、△E2 （P2 → TS2 → P3） is 80.59 kJ/mol,and activation energies show relatively minimum that 1,4 products 3-phenyl allyl alcohol can easily be converted to saturated alcohol and benzene propanal; in any case（ethanol,toluene,THF,acid,alkaline） isomerization of saturated alcohol and benzene propanal is difficult to occur.
出处
《四川师范大学学报（自然科学版）》
CAS
CSCD
北大核心
2014年第5期697-702,共6页
Journal of Sichuan Normal University（Natural Science）
基金
四川省科技厅基础应用基金(2014JY0099)
四川省教育厅重点基金(13ZA0150
14ZB0028)资助项目
关键词
肉桂醛
选择性加氢
互变异构
密度泛函理论
cinnamaldehyde
selective hydrogenation
isomerization
density functional theory
