Energy relationship and the polarization of C60 cage in the endohedral complexes (X@C60)

✍ Scribed by Xu Zhi-Jin; Zhu Chuan-Bao; Yan Ji-Min

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 641 KB
• Volume: 16
• Category: Article
• ISSN: 0256-7660
• DOI: 10.1002/cjoc.19980160302

✦ Synopsis

In this paper, we carry out the calculation on the system (XOCm)(X=Li, Na, K, Rb, Cs; F, C1, Br, I), where the position of X changes along 5 typical symmetry directions. For the calculation of quantum chemistry we use EHMO/ASED method, for the calculation of molecular mechanics we uee Buckingham potential (exp6-1) function, and for the calculation of t h e r m d e m i c a l cycle we use individually isolating the proccssca such .as the structure variation, charge transfer and charge distribution, and their interactions ek. The calculation raults rhow that (1) In the region of radius tz0.2 nm of the Cm cage, the potential field k nearly spherical; (2) E x a p t for Li and Na, the systems are the m a t stable with minimum energies at the center of Cm cnge. For Li and Na, the systems are the mcnt stable with minimum energies at ta0.16 nm and rz0.13 nm, respectively. In view of the interactive region of chemical bonds, the interactions between X and the Cm cage do not belong to the classical chemical bondr; (3) The non-bonding interaction between the X and Coo cage are not purely elect-static, in which the electro-static interactions only occupy -90% at m a t on an average. The repulsion owing t o the overlap of the electron cloud and the attraction owing to the dispersion can not be neglected. These two interactions determine the variations of size and trend of the system energies with r ; (4) The polarization due to the position of X deviating from the center of C a cage plays an important role at the moat stable positions of Li and Na.