C_(40)H_2各种可能异构体稳定性的理论研究

Theoretical Studies on the Stabilities of All Possible C_(40)H_2 Isomers

采用 AM1和 PM3两种半经验方法 ,对 D5d对称性的 C4 0 及 C4 0 H2 所有可能异构体的几何构型进行了非限制对称性全优化 ,得到 5 1种稳定异构体 ,在此基础上研究了氢的加成反应规律及本体 C4 0 和最稳定及最不稳定 C4 0 H2 异构体的红外光谱 ,讨论了影响 C4 0 (D5d)氢加成异构体稳定性及加成位置选择性的三种主要因素 :(1 ) C4 0 本体几何结构 ;(2 )共轭效应 ;(3 )

The electronic structures of all possible C 40 H 2 isomers and C 40 based on D 5d symmetry have been calculated with no symmetry constraints at the AM1 and PM3 semiempirical molecular orbital levels. Some rules on addition of H 2 to C 40 are predicted from the calculations of 51 isomers. Three sorts of main influence factors on isomers stabilities and adding positions, namely, (1) geometric structure of C 40 , (2) conjugative effect and (3) charge population, are discussed.