内嵌复合物X@C_(60)中相互作用的变化规律与键本质

Investigation on Characteristics of Interaction and Bonding Nature in C_(60) Cage of Endohedral Complexes X＠C_(60)

系统地研究了内嵌复合物X＠C60（X＝第IA族或第VIIA族元素）形成过程的能量变化，以及其中笼环境下X与C60间相互作用的变化特征与键本质.结果表明：（1）C60笼环境力场具有球对称性；（2）各种分解与总相互作用与内嵌原子的原子序数或原子半径呈现出规则的递变规律；（3）除I外，其余元素原子与C60间的作用对各自复合物的稳定性都有正效应的较大贡献。（4）X在C60笼环境中居心或偏心的稳定位置是各种作用的合力表现，而非形成了经典意义上的化学健；（5）C60笼环境中相互作用在本质上表现为一种以静电作用占优（＞90％）、排斥和色散为辅的非化学性的作用.

The energy variation during the formation of the titled endohedral complexes X＠C60 (X=atoms of the Group IA or the Group VIIA), and the bonding nature andthe variation character of the interaction in C60 cage all have been investigated from the viewpoint of intramolecular interaction. The results demonstrated that:①the force field in C60 cage is of nearly spherical symmetry; ②the total interaction and its components vary regularly with the atomic numbers or redii, of X; ③all concerned endohedral atoms except for I, contribute considerably to the stabilities of X＠C60 by way of the interaction between C60 cage and them; ④each X has a special energy minimum location in the cage,at or off the cage center, and this location is due to the resultant effect from the various interactions, but not to the formation of chemical bond between X and C60 cage; ⑤in essence, the interastion in C60 cage is of typical non-bonding characteristics, with ~90%electrostatic interaction and ~10% repulsive and dispersive interactions.