摘要
采用abinitio从头计算方法在不同基组水平上对二氟乙烯异构体几何构型、谐振频率作了理论计算,计算结果与实验结果符合得很好,并且在优化几何构型的基础上,用MP4SDTQ方法对稳定构型单点能和前沿轨道能隙作了理论计算,结果发现计算所得的两种构型分子电子总能量的相对次序为顺式<反式,与实验测得的相对稳定性次序一致,并通过Mulliken布居数分析考察了该构型分子顺式效应的内在原因.
The geometries and their harmonic frequencies of the difluoroethylene isomers were gradient optimized using ab initio methods at the different levels. High-level methods give very good structural parameters in comparison to experiment. The single energy of stable structure and the frontier orbital energy gap were calculated using MP4SDTQ/6-311 ＋＋ G（2df,2pd） method, and it is found that the single energy of stable structure of c/s isomer is lower than that of trans isomer. This is consistent with the experimental result. Mulliken population analyses were also performed to interpret the internal nature of c/s preference of difluoroethylene isomers.
基金
ProjectsupportedbytheScientificResearchFoundationfortheReturnedOverseasChineseScholars
StateEducationMinistryandtheEducationDepartmentofHenanProvince(2003KYCX005).
