【摘要】 选择C20富勒烯分子最可能稳定存在的几种等能异构构型作为研究对象,在高斯中选用密度泛函理论,用B3LYP/6-31G*方法和基组对这几种分别属于D2h、C2h、C2、D3d和Ci对称群的C20富勒烯分子异构体进行了结构优化,得到了各个构型的键长信息并对它们进行了比较。根据对称性的不同对5种异构体分子的13C NMR谱图特征进行了分析和比较,阐述了每种异构体的NMR谱图特征线的数目以及强度差别。结果表明,通过观察C20富勒烯分子异构体13C NMR谱图中特征谱线的个数和强度,可以很好地区分5种异构体的异构类型,为实验上鉴定C20富勒烯分子所属对称群做了前期准备。更多还原

【Abstract】 The isomers of C20 fullerene which perhaps can exist steadily were choosen as the research samples.The structure optimization of the isomers with the symmetry D2h,C2h,C2,D3d and Ci were completed on the level of DFT:B3LYP/6-31G,and the length information of the C20 isomers was studied and compared.The 13C NMR spectrum characters of C20 fullerene molecules with the symmetry of D2h,C2h,C2,D3d and Ci were studied according to the basic geometry structure.The number and the strength of the 13C NMR spectrum character lines were analyzed.The results show that the 13C NMR spectrum can well distinguish one type of isomer from another,thus preparing to identify the isomers from each other in the laboratory in the future.更多还原