化学学报 ›› 2002, Vol. 60 ›› Issue (11): 1915-1922. 上一篇    下一篇

研究论文

富勒烯C_(36)等电子体C_(34)BN异构体的结构及其相对稳定性理论研究

杨作银;许秀芳;王贵昌;尚贞峰;潘荫明;赵学庄   

  1. 南开大学化学系.天津(300071)
  • 发布日期:2002-11-15

Theoretical Studies on Structures and Stabilities of C_(34)BN Isomers

Yang Zouyin;Xu Xiufang;Wang Guichang;Shang Zhenfeng;Pan Yinming;Zhao Xuezhuang   

  1. Department of Chemistry, Nankai University.Tianjin(300071)
  • Published:2002-11-15

用半经验的AM1和MNDO方法优化了富勒烯C_(36)的等电子体C_(34)BN所有可能 异构体的构型,分析了各异构体相对稳定性与杂原子取代位置间的关系。另外,比 较了C_(36)碳笼上同位置地取代杂原子形成的C_34BN,C_(34)B_2和C_(34)N_2间的 电子结构,并分析了C_(34)BN最稳定异构体的振动模型。结果表明以C_(36):A (D_(6h))为母体形成的最稳定C_(34)BN异构体对应于碳笼赤道位置六元环中1,4- 取代产物,而以C_(36):B(D_(2d))为母体形成的最稳定C_(34)BN异构体对应于碳笼 近赤道位置的1,2-取代产物.C_(34)BN各异构体的稳定性可能主要由体系的共轭性 质决定。前线轨道能级表明B,N原子取代所得异构体的氧化-还原活性按以下顺序 递增:C_(34)B_2

关键词: 富勒烯, 碳36, 稳定性, 电子结构, 前线轨道理论

The possible stable structures of substituted fullerenes C_(34)BN formed on the initial C_(36) cages of D_(6h) and D_(2d) symmetries have been systematically investigated at the AM1 and MNDO levels. The relationship between the stabilities of the C_(34)BN isomers and the sites where boron or nitrogen atoms dope at the C_(36) cage has been discussed. The results show that for the C_(36) cage with D_(6h) symmetry, the most stable isomer of C_(34)BN derivative is formed by boron and nitrogen atoms doping at the 1,4-sites in the six-membered ring which locates at the equatorial belt of C_(36) belt of C_(36) cage. While for C_(36) cage with D_(2d) symmetry, the most stable isomer of C_(34)BN derivative is formed by boron and nitrogen atoms doping at the sites near equatorial belt of C_(36) cage, which corresponds to 1,2-substitution pattern. It seems that the stabilities of C_(34)BN isomers are mainly determined by the conjugate effect of the cage. The activity of the redox of the C_(34)XY (X, Y = B, N) isomers increases in the following order: C_(34)B_2

Key words: C36, STABILITY, ELECTRONIC STRUCTURE, FRONTIER ORBITAL THEORY

中图分类号: