1,1,1-三甲胺基甲酰亚胺分子结构的量化计算

采用量子化学中的DFT/B3LYP和MP2方法研究了1,1,1-三甲胺基甲酰亚胺HC(＝O)N^-N⁺(CH₃)₃的分子结构，在计算得到的平衡几何构型基础上进行了分子轨道(MO)和自然键轨道(NBO)计算。通过几何构型全优化，发现该分子存在Z型(顺式)和E型(反式)2种异构体，2种异构体中都存在一个对称平面，胺基酰亚胺官能团C(＝O)N^-N⁺位于这个对称平面上。分子的几何结构参数及MO和NBO分析都表明在这2种异构体中，N^-的p轨道孤对电子都与羰基π键存在很强的共轭效应，Z型异构体中存在2个强度较弱的分子内氢键O…H—C。由分子总能量、离域π键的强度和H键可以表明Z型异构体比E型异构体更稳定。

Calculation of the molecular structure of 1,1,1-trimethylamine-methanimide

The molecular structure of 1,1,1-trimethylamine-methanimide,HC(=O)N-N+(CH3)3,has been investigated by DFT/B3LYP and MP2 quantum mechanical methods.MO and NBO calculations have been carried out on the optimal equilibrium geometrical conformations.Through full geometrical optimization,two conformational isomers,namely the Z(cis)-isomer and the E(trans)-isomer,are found.A mirror plane is present in both isomers and the functional group C(O)N-N+ is situated in the plane.All of the calculations of geometrical st...