硝基甲烷二聚体的从头算研究

Ab Initio Study on the Nitromethane Dimer

本文用 ａｂ ｉｎｉｔｉｏ分子轨道法在ＳＴＯ－３Ｇ和６－３１Ｇ水平上，全构型优化，对硝基甲烷二聚体的稳定构型进行了研究．硝基甲烷二聚体的稳定构型具有对称中心的环状结构包含由甲基氢和硝基氧组成的两个Ｃ－Ｈ…Ｏ氢键．在ＨＦ／ＳＴＯ－３Ｇ和ＨＦ／６－３１Ｇ水平上作用能分别为－１８．６０ｋＪ／ｍｏｌ和－２５．１８ｋＪ／ｍｏｌ．

Ab initio molecular orbing calculations were performed on the stable nitromethane dimer at HF/STO-3 G and HF/6-31 G levels. The fully optimized structure of the dimer is cyclic structure with the symmetry center which contains two C - H...O hydrogen bonds. These two hydrogen bonds are composed of hydrogen in methyl and oxygen in nitro group. At HF/STO-3 G and HF/6-31G levels, the interaction energies of nitromethane dimer are - 18. 60 kJ/mol and - 25. 18 kJ/mol, repectively.