物理化学学报 >> 2005, Vol. 21 >> Issue (03): 244-249.doi: 10.3866/PKU.WHXB20050304

研究论文 上一篇    下一篇

CnBδ(δ=0, ±1; n =1~6)团簇的结构、稳定性和光谱

王利江; 张聪杰; 武海顺   

  1. 山西师范大学化学与材料科学学院,临汾 041004
  • 收稿日期:2004-07-20 修回日期:2004-09-25 发布日期:2005-03-15
  • 通讯作者: 张聪杰 E-mail:zcjwh@dns.sxtu.edu.cn

Structure, Stability and Spectra of CnBδ(δ=0, ±1; n=1~6) Clusters

WANG Li-Jiang; ZHANG Cong-Jie; WU Hai-Shun   

  1. School of Chemistry and Material Science, Shanxi Normal University, Linfen 041004
  • Received:2004-07-20 Revised:2004-09-25 Published:2005-03-15
  • Contact: ZHANG Cong-Jie E-mail:zcjwh@dns.sxtu.edu.cn

摘要: 采用密度泛函理论(DFT)的B3LYP方法,在6-31G*和6-311+G(3df)水平上对CnB(n=1~6)团簇及其阴离子和阳离子的几何构型和电子结构进行了优化和振动频率计算.得到了CnB(n=1~6)团簇的电离能,绝热电子亲合势以及CnBδ(δ=0,±1)团簇的能隙.结果表明CnB(n=1~6)团簇的基态构型均为线形,这与等电子的Cn簇合物的结构是一致的; CnB(n=1~6)团簇的基态构型中,除C2B为不对称的三角形,C6B为具有C2v对称性的环状结构外,其余均为线形结构.阳离子团簇中n=2、3、6的基态结构具有C2v对称性外,其它几个均为线形结构.从几何参数和振动频率上发现,采用密度泛函B3LYP方法在6-311+G(3df)和6-31G*两种基组上计算得到的键长参数和振动频率非常接近,说明B3LYP方法在计算CnB簇合物结构参数上对于基组的选择是不太敏感的.通过对CnB(n=1~6)的光电子能谱性质的研究发现,C4B容易获得一个电子形成阴离子团簇,但失去一个电子是很困难的,这与实验上观测到的结果非常吻合.

关键词: 碳硼团簇, 密度泛函理论, 结构与稳定性

Abstract: Using density functional theory associated with B3LYP method with 6-31G* and 6-311+G(3df) basis sets, the optimization of the geometries and electronic structures and the calculation of frequencies for CnBδ(δ=0,±1; n=1~6) clusters have been carried out. In addition, the detachment energy ,adiabatic electron affinities of CnB and energy gap of CnBδ(δ=0, ±1) were obtained. The results show that the ground state structures of CnB(n=1~6) clusters are linear as Cn clusters due to their isoelectrons. For CnB (n=1~6) clusters, the ground state structure of C2B is asymmetric triangle and C6B is C2v symmetry planar monocycle, while the other clusters are linear.C2B ,C3Band C6B are C2v symmetry in CnB+(n=1~6) clusters. From the geometrical parameters and vibrational frequencies of boron-carbon clusters from 6-311+G(3df) and 6-31G* basis sets, it was found that the B3LYP functional is less sensitive to the selection of the basis set in investigating the boron-carbon clusters. The photoelectron spectrum of CnB(n=1~6) clusters indicates that C4B is easy to accept one electron and difficult to lose one electron, which is in good agreement with the experimental result.

Key words: Carbon boron clusters, Density functional theory, Stucture and stability