摘要
采用密度泛函理论方法 B3LYP/6-311++G(d,p)计算了氯化1-(4-氨基丁基)-3-甲基咪唑离子液体气相下几何构型、离子对结合能和二阶微扰稳定化能等。得到了8种不同的稳定结构,不同结构所具有的能量差异最大为11.1 kcal·mol^(-1)。能量最小稳定构型的氯化1-(4-氨基丁基)-3-甲基咪唑自然价键前线轨道分析结果表明:超共轭作用主要发生在咪唑环内,LP(1)N1→BD*(2)N4-C5电子离域引起的稳定化能达73.54 Kcal·mol^(-1)。氯阴离子和1-(4-氨基丁基)-3-甲基咪唑阳离子作用生成氯化1-(4-氨基丁基)-3-甲基咪唑时,轨道对称性匹配占主导作用,阴离子的HOMO轨道与阳离子具有更高能量的非占据σ*轨道相互作用,形成了σ型的C-H…Cl氢键。
11 different initial structures of 1-（4- aminobutyl）-3-methylimidazolium chloride in gas phase was optimized at B3LYP/6- 311＋＋G（d ,p）level by density functional theory method. Ion-pairs binding energy and second-order perturbation stabilization energy were also obtained at the same level. 8 different stable geometries were confirmed. The biggest energy difference between the geome-tries is 11. 1 kcal · mol 1. The analysis of natural bond orbital and frontier molecular orbitals on the most stable geometry shows that hyperconjugation in the imidazolium ring is caused by the interaction between LP（1）N1 and BD ＊（ 2 ） N4-C5,which results in the stabilization energy with the value of 73. 54 kcal · mol^-1. I t is because of the orbital symmetry matching thata（C-H …Cl）hydrogen bond is formed by the interactions between HOMO of Cl anion and unoccupied ct＊ orbital of C4NH2C1 im cation.
出处
《化学研究与应用》
CAS
CSCD
北大核心
2018年第1期127-132,共6页
Chemical Research and Application
基金
国家自然科学基金项目(21505103)资助
陕西省教育厅研究基金项目(17JK0606)资助
关键词
离子液体
稳定化能
自然价键轨道
Ionic liquid
Stabilization energy
Natural bond orbital
