硼碳团簇B_nC_2(n=1～6)的理论研究  

Theoretical Study of Boron-Carbon Clusters B_nC_2 (n=1～6)

作　　者：王若曦[1] 张冬菊[1] 朱荣秀[1] 刘成卜[1] 

机构地区：[1]山东大学理论化学研究所

出　　处：《化学学报》2007年第19期2092-2096,共5页Acta Chimica Sinica

基　　金：国家重点基础研究发展计划(973计划)(No.2004CB719902);国家自然科学基金(Nos.20473047;20633060;20773078);山东警察学院(No.Y2005L03)资助项目.

摘　　要：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.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 calculated disproportionation energies, binding energies and HOMO-LUMO gaps show that the B4C2 is a magic cluster.

关 键 词：硼碳团簇 掺杂 几何结构 稳定性 密度泛函理论 

分 类 号：O641.1[理学—物理化学]