C82笼内镧原子运动的理论研究。

Theoretical study on the motion of a La atom inside a C82 cage.

作者信息

Jin Peng, Hao Ce, Li Shenmin, Mi Weihong, Sun Zhenchao, Zhang Junfeng, Hou Qingfeng

机构信息

State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116024, P. R. China.

出版信息

J Phys Chem A. 2007 Jan 11;111(1):167-9. doi: 10.1021/jp064801l.

DOI:10.1021/jp064801l

PMID:17201399

Abstract

The motion of a single lanthanum atom inside a C82 (C2v) fullerene cage has been investigated by means of the hybrid density functional method (B3LYP). The obtained potential energy surface (PES) suggests that the encapsulated La atom can oscillate only around the minimum energy potential well, which is apparently different from the scenario of a giant bowl-shaped movement at room temperature described by Nishibori et al. (Nishibori, E.; Takata, M.; Sakata, M.; Tanaka, H.; Hasegawa, M.; Shinohara, H. Chem. Phys. Lett. 2000, 330, 497-502.) Interestingly, our calculations show that the La atom may probably undergo a boat-shaped movement when the temperature is high enough. In addition, the computed 13C NMR spectrum of the C2v [La@C82]- is in an excellent agreement with the experimental nuclear magnetic resonance (NMR) spectrum (Tsuchiya, T.; Wakahara, T.; Maeda, Y.; Akasaka, T.; Waelchli, M.; Kato, T.; Okubo, H.; Mizorogi, N.; Kobayashi, K.; Nagase, S. Anew. Chem. 2005, 117, 3346-3349), which confirms that the isomer of La@C82 with the C2v symmetry is the most stable.

摘要

利用杂化密度泛函方法（B3LYP）研究了单个镧原子在C82（C2v）富勒烯笼内的运动。所得势能面（PES）表明，被包裹的La原子只能在最低能量势阱周围振荡，这明显不同于Nishibori等人描述的室温下巨大碗状运动的情形（Nishibori, E.; Takata, M.; Sakata, M.; Tanaka, H.; Hasegawa, M.; Shinohara, H. Chem. Phys. Lett. 2000, 330, 497 - 502.）。有趣的是，我们的计算表明，当温度足够高时，La原子可能会经历船形运动。此外，计算得到的C2v [La@C82]-的13C NMR谱与实验核磁共振（NMR）谱（Tsuchiya, T.; Wakahara, T.; Maeda, Y.; Akasaka, T.; Waelchli, M.; Kato, T.; Okubo, H.; Mizorogi, N.; Kobayashi, K.; Nagase, S. Anew. Chem. 2005, 117, 3346 - 3349）非常吻合，这证实了具有C2v对称性的La@C82异构体是最稳定的。