计算机模拟计算烷烃分子的构象  

Computing the Conformational Energy of Simple Molecules

作　　者：杨雪红[1] 吴承训[1] 

机构地区：[1]东华大学纤维材料改性国家重点实验室,上海200051

出　　处：《东华大学学报（自然科学版）》2004年第5期20-24,共5页Journal of Donghua University(Natural Science)

基　　金：国家自然科学基金(No.20074004)

摘　　要：根据Flory理论,通过计算机编程计算能量随二面角的变化曲线,且将3个丁烷分子的能量曲线进行比较来分析2-甲基丁烷、2-氰基丁烷的分子结构。发现2-氰基丁烷与2-甲基丁烷随二面角变化有相似的构象转变,在60°处的能量较高,导致优势构象向低角度方向偏移。且2-氰基丁烷的能量和2-甲基丁烷的能量相近,但在—180°～0°的范围内,它们的能量差别比在0°～180°时略大。因此,2-氰基丁烷与2-甲基丁烷在二面角为120°即g式时构象能为偏小和5°即t式时的构象能为最小。According to the Flory's theory of the Statistical Mechanics of Chain Molecules, we make program for computing the confornational energy of butane and draw the picture of its rotational potentials, finding that it agrees well with the picture drawn by Flory etal. Then using the program to computing the conformational energy of CH_3 CH (CH_3)CH_2 CH_3 and CH_3 CH (CN)CH_2 CH_3, we come to the conclusion that the energy minmization of CH_3 CH (CH_3)CH_2 CH_3 is at the site when the dihedral angle is 0°and—120°which is the same to the molecule CH_3CH(CN) CH_2CH_3 and the minimum energy of CH_3CH(CN)CH_2CH_3 is lower than that of CH_3CH(CH_3)CH_2CH_3. So there is an interaction between —CN and C which decreases the conformational energy.

关 键 词：二面角 构象能 2-甲基丁烷 2-氰基丁烷 

分 类 号：O631[理学—高分子化学]