含卤原子碳六十C_(60)X的电子结构及导电性(英文)

ELECTRONIC STRUCTURES AND CONDUCTIVITIES OF HALOGEN-CONTAINING CARBON-SIXTY C_(60)X

用量子化学EHMO方法对碳六十C_(60)及含卤原子碳六十C_(60)X(F,Cl,Br,I)的电子结构进行了计算.据此,对C_(60)、C_(60)X 及C_(60)X_y(y=1-10)的导电性进行了讨论.

Recently it has been reported that solids KxC60 and RbxC60 (x = 1-5) can be transformed to conductors([1,2]). If x = 0 and 6, they are insulators and if x = 3, they have the largest conductivities. When the temperature goes down to 18K for solid KxC60 and to 28K for solid RbxC60, they are transformed to superconductors. These results are very interesting to scientists. Solids KxC60 and RbxC60 are very unstable in air, so that for practical purposes it is better to synthesize the atom-containing carbon-sixty MC60 or C60X, in which the metal atom M or non-metal atom X is at the center of C-60 cage. It has been known experimentally for some years that the atoms other than carbon atom C can enter into C-60 cage to form atom-containing MC60 or C60X[3,4]. The electronic structure of carbon-sixty C-60 has been calculated by some quantum-chemical methods in recent years([5-11]), but up to now, the electronic structures for the atom-containing carbon-sixty MC60 or C60X have not been calculated. In our another paper([12)], C-60 and MC60 (Li, Na, K, Rb, Cs) are computed with EHMO method, and the conductivities of the solid carbon-sixty C-60 and the solid metal-containing carbon-sixty MC60 are discussed. Furthermore, the halogen-containing carbon-sixty C60X (F, Cl, Br, I) are calculated by EHMO method in this paper, then the conductivities of them and C60Xy (y = 0-10) are discussed in terms of the electronic structures.