丁烯和丁烷自由基阳离子的分子结构和超精细结构的理论研究  

Theoretical Study of the Butene and Butane Radical Cations: Molecular and Hyperfine Structures

作　　者：刘亚军[1] 黄明宝[2] 郑世钧[2] 

机构地区：[1]中国科学院研究生院化学部,北京100039 [2]河北师范大学计算量化研究所,石家庄050091

出　　处：《化学学报》2002年第2期267-271,共5页Acta Chimica Sinica

基　　金：国家自然科学基金 (No .2 9892 16 2 );河北省自然科学基金 (No.2 98171)资助课题

摘　　要：用密度函数理论B3LYP方法和 6 31G(d ,p) ,6 311G(d ,p)及 6 311+G(d ,p)基组 ,分别对 1 C4 H+ 8,2 C4 H+ 8和C4 H+ 10 进行了构型优化和频率分析计算 .预言 1 C4 H+ 8具有非平面构型 ,与以往报道的从头算和密度函数理论计算结果不同 .在各自由基阳离子的B3LYP构型上 ,进行了B3LYP、MP2及MRSDCI方法的超精细偶合常数计算 ,得到了比以往更好的结果 ,特别是MP2 / /B3LYP计算值是至今与实验值符合得最好的理论计算结果 .The DFF B3LYP study on 1-C4H8+, 2-C4H8+, and C4H10+ has been carried out. The molecular structures were optimized at the B3LYP/6-31G(d,p), B3LYP/6-311G(d,p), and B3LYP/6-311 + G(d,p) levels, and the frequency analysis calculations were performed at the B3LYP/6-311 G(d,p) level. Based on the B3LYP/6-311G(d,p) geometries, the proton isotropic hyperfine coupling constants (hfcc's) were calculated at the B3LYP/6-311G(d,p), MP2(full)/6-311G(d,p), and MRSDCI levels. 1-C4H8+ is predicted to have a nonplanar structure, which is in contrast to the previous conclusions based on the ab initio and DFF calculations. 2-C4H8+ is predicted to have stable cis and trans conformations with planar structures, and C4H10+ is predicted to have stable trans and gauche conformations. The calculated lifcc results are in good agreement with experiment and more accurate than the previous theoretical results.

关 键 词：丁烯自由基阳离子 丁烷自由基阳离子 密度函数理论 超精细结构 分子结构 

分 类 号：O643.1[理学—物理化学]