化学学报 ›› 2007, Vol. 65 ›› Issue (19): 2092-2096. 上一篇    下一篇

研究论文

硼碳团簇BnC2 (n=1~6)的理论研究

王若曦1,2, 张冬菊1, 朱荣秀1, 刘成卜*,1   

  1. (1山东大学理论化学研究所 济南 250100)
    (2山东警察学院刑事科技系 济南 250014)
  • 投稿日期:2007-02-08 修回日期:2007-04-18 发布日期:2007-10-14
  • 通讯作者: 刘成卜

Theoretical Study of Boron-Carbon Clusters BnC2 (n=1~6)

WANG Ruo-Xi1,2; ZHANG Dong-Ju1; ZHU Rong-Xiu1; LIU Cheng-Bu*,1   

  1. (1 Institute of Theoretical Chemistry, Shandong University, Jinan 250100)
    (2 Criminal Technological Department, Shandong Police College, Jinan 250014)
  • Received:2007-02-08 Revised:2007-04-18 Published:2007-10-14
  • Contact: LIU Cheng-Bu

应用密度泛函理论在B3LYP/6-311+G(d)水平上研究了硼碳团簇BnC2 (n=1~6)的几何结构、生长机制和相对稳定性. 计算结果表明, 对于n=2~6的簇, 平面多环状构型为最稳定的结构, 其中C原子分布于环的顶点、有尽可能多的三配位硼原子和尽可能多的B—C键. 碳原子作为杂原子倾向掺杂于团簇的顶点位置, 它的掺杂不改变硼团簇的主体结构. 与平面多环状结构相比, 随着簇尺寸的增大, 三维结构和线性链结构更不稳定. 在低能线性结构中, C原子位于链两侧的第二个位置. 计算的碎片分裂能、递增键能以及HOMO-LUMO能隙表明, B4C2为幻数簇.

关键词: 硼碳团簇, 掺杂, 几何结构, 稳定性, 密度泛函理论

The geometrical structures, growth modes, and relative stabilities of boron-carbon clusters BnC2 (n=1~6) have been investigated by performing density functional theory calculations at B3LYP/6-311+G(d) level. The calculated results show that the planar multi-cyclic geometries for n=2~6 with C atoms at the apexes with the most B—C bonds and the most three-coordination boron atoms are the most stable structures. It is also shown that the C atoms prefer the apexes of the rings, which does not change the frame structures of the B clusters. The compact 3D structures and the linear isomers, however, are energetically more unfavorable with the increasing size. In the energetically lowest linear isomers, the carbon atoms prefer the second positions of the chains. The cal-culated disproportionation energies, binding energies and HOMO-LUMO gaps show that the B4C2 is a magic cluster.

Key words: boron-carbon cluster, doping, geometric structure, stability, density functional theory