Theoretical Study On Structure And Spectrum Of Derivatives Of Fullerene

For a long time, carbon had been known as two allotropes, charcoal and diamond. But the first fullerence-C₆₀ discovered in 1985, brought a new knowledge to people about carbon, and led to a fire-new fuUerenes subject established. In recent two decades, FuUerenes have widely influenced many study fields such as physics, chemistry, material, bionomy and medical science and hold great promise for applications.The investigations of fullerenes have been severely limited because of a lack of information obtained by means of traditional structures determining method due to their typically formed in extremely low yields. Recently, with the development of the computer technology and the accomplishment on quantum chemistry theory, quantum chemistry calculation as an assistant plays a huge role in determining the structures of fuUerenes.Since the method for producing macroscopic quantities of C₆₀ was discovered in 1990, methodical studies on fuUerenes expand quickly. Chemical modification is an important area in fullerenes research. In chapter 2, basing on the limited data (HPLC and UV-Vis spectrum) of 2 isomers of C₆₀O₃ obtaining from experiment, 5 kinds possible isomers were selected, and their stable structure, dipole moment, HOMO-LUMO gap, electronic spectrum and IR spectrum were calculated. Comparing with the HPLC and UV-Vis spectrum, two possible structures were proposed which matching the experiment products very well.Fullerene is a general term acknowledging the family of hollow-cage carbon clusters made up of an even number of triply coordinated Carbons arranged with twelve pentagonal rings and a varying numbers of hexagonal rings. All discovered fuUerenes in experiment have symmetry. The point group symmetry is important for both theoretical and spectroscopic studies of the fuUerenes. So, group theory becomes a powerful tool in studying the structures and other properties of fuUerenes. In chapter 3, by means of group theory, the representative patches of I_h-C₆₀ and D_3h-C₇₄ explained in detail.The first report of preparation of metallofullerenes La@C₈₂ in macroscopic quantities in 1991 raised an upsurge of research on metallofullerenes. In chapter 4, by means of quantum chemistry calculation, PES and vibratory spectrum of metallofullerenes Sr@C₇₄ and Ba@C₇₄ were studied, and a possible channel of two C_2v symmetry isomers inverting in room temperature were presented. In chapter 5, according to ¹³C NMR spectrum obtaining by other researcher and the PES of Ca@C₇₄ and Yb@C₇₄, a motion model of M²⁺@C₇₄² were propounded. According to this motion model, all 9 lines on ¹³C NMR of Ca@C₇₄ and Yb@C₇₄ were identified.