富勒烯C36及其衍生物的量子化学研究

2019-02-24 21:14:00

The different 异构体 富勒烯 isomers









中文题名富勒烯C36及其衍生物的量子化学研究

 





副题名 





外文题名 





论文作者龚植筠   





导师李前树教授   





学科专业应用化学   





研究领域\研究方向 





学位级别博士 





学位授予单位北京理工大学   





学位授予日期2001   





论文页码总数88页   





关键词量子化学  C36  富勒烯   





馆藏号BSLW

/2001

/O641

/96 





【中文摘要】

 摘 要

   碳簇化学的迅速发展吸引了愈来愈多的国内外学者对它进行研究,一个又一个碳笼化合物的相继合成,揭开了碳笼分子家族的奥秘,使之成为国际上异常活跃的研究领域。1998年,富勒烯〓固体使用电弧放电方法合成并分离出来。到目前为止,在碳原子数小于60的富勒烯中,它是唯一可以大批量合成和分离的富勒烯化合物。本论文利用Gaussian-94程序,对〓的四种异构体及其衍生物进行了量子化学研究,它们分别具有〓和〓对称性。
结果表明,在〓及其衍生物的计算中,电子相关效应起着重要作用。在富勒烯〓的四种异构体中,稳定性顺序为〓异构体的三重态是最稳定的异构体。〓和〓异构体在保持其原有对称性的条件下,加氢形成氢化物时,由于氢原子所处的位置不同而具有不同的稳定性。在B3LYP/3-21G水平下对四种异构体作振动分析表明,〓异构体有虚频,另外三种异构体都为正的频率,说明除了〓异构体外,其余三种异构体都是振动上的稳定分子。采用HF方法,对〓的衍生物〓和〓(X=F,Cl,Br,I)进行了研究,讨论了他们的电子结构和稳定性,并得到它们的振动频率,计算结果表明:〓和〓是较为稳定的。另外,讨论了〓异构体带不同电荷的离子以及四种异构体的二价或四价离子的性质,对它们的稳定性进行了比较,其中〓离子比〓更稳定,说明富勒烯〓容易被还原。











【外文摘要】

 
ABSTRACT
:The rapid development of carbon cluster chemistry has attracted more and moreattention of experts all over the world, and the syntheses of carbon cluster compounds oneby one have told the secrets of carbon cluster molecules, which has become a very excitingresearch field in the world. In 1998, 〓 solid was synthesized and isolated using arc-discharge method, which has uniquely been synthesized and isolated among fullerenes thattheir carbon numbers are less than 60. This paper was carried out quantum chemistry studyfor 〓 four isomers and its derivative using Gaussian-94 program. The four isomers have〓 and 〓 symmetry, respectively. The results showed electron correlaton effects play an important part in calculation for〓 and its derivative.The order of stability for 〓's isomers is 〓, Thetriplet state of 〓isomer is the most stable among 〓's four isomers. The hydrogen wasadded and different hdrofullerenes was obtained when 〓and 〓 symmetry werenot changed. The different hydrofullerenes has different stability because of hydrogen atomlocating at different site. The vibrational analysis for four isomers showed 〓 isomer hadimaginary frequency and frequency of 〓 and 〓isomers was postive at B3LYP/3-21Glevel, and 〓and 〓 isomers was stable molecules for vibration. The electron structureand stability of 〓's derivative 〓 and 〓 (X=F, C1, Br, I) were discussed and theirvibrational frequency were obtained using HF method. The results of calculations show that〓 and 〓are more stable. In addition, the properties of different charged ions for 〓isomer and tow or four valence ions of the four isomers were discussed, and their stabilitywere compared. The 〓 ion is more sable than 〓, which show fulluerene 〓 is easilyreduced.