摘要
应用密度泛函理论(DFT)的B3LYP/6-31G*方法,对C20-2nX2n(X=B,N;n=1、2、3、4)各异构体进行几何构型全优化和振动频率计算,确定了基态结构,对它们的取代方式、电子结构、张力和芳香性进行了研究.氮掺杂不能显著降低分子的张力,C12N8的张力甚至比C20的还要大,极不稳定.C18B2的两个最稳定异构体1,14-C18B2和1,3-C18B2都有比较大的能隙和结合能,具有很强的芳香性,其张力与C20的相比均显著降低.1,14-C18B2和1,3-C18B2具有较高的稳定性,可以用红外光谱区分这两个构型异构体.
The geometries of various isomers of heterofullerenes C20-2nX2n （X=B, N; n=1, 2, 3, 4） were fully optimized at the B3LYP/6-31G^ ＊ density functional level of theory, and the corresponding frequency calculations at the same level were used to characterize the ground state structures. The substitutional patterns, electronic structure, strain, and aromaticity of these heterofullerenes have been investigated. In general, nitrogen doping could not significantly decrease the strain of the cage. The strain of CnN8 was even larger than that of C20 this nitrogen analogue was extraordinarily unstable. The two most stable isomers of C18B2, 1,14-C18B2 and 1,3-C18B2, both have large HOMO- LUMO gaps and binding energies. They were highly aromatic. The strains of these two molecules were very small, compared with that of Cz0. 1,14-C18B2 and 1,3-C18B2 were predicted to be highly stable small heterofullerenes, these two configurational isomers could be distinguished from each other by their IR spectra.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2007年第10期1647-1651,共5页
Acta Physico-Chimica Sinica
基金
浙江省教育厅(20061681)资助项目
关键词
富勒烯C20
硼、氮掺杂
结构
稳定性
密度泛函理论
Fullerene C20
Boron- or nitrogen-doped
Structure
Stability
Density functional theory
