CnSi(n=49,50)的理论研究

用量子化学从头算方法研究了C_nSi(n=49,50)的各种可能的构型.结果表明,C₄₉Si为硅取代碳笼C₅₀中一个碳原子而形成的骨架硅杂碳笼,C₄₉Si与C₅₀相比稳定性较低,化学活性较高.C₅₀Si有两种类型结构:Ⅰ为外接型,Ⅱ为四连接型.计算结果表明,对C₅₀Si,外接硅型化合物更稳定,即Ⅰ为主要成分.计算结果与实验结果是一致的.

Theoretical Studies of Various Possible Structures of CnSi(n=49,50)

The possible structures of C_nSi( n =49, 50) are studied by using quantum chemistry ab initio method. Our studies show that C₄₉Si has a closed cage structure with the silicon atom networked into the fullerene cage, and C₄₉Si has a lower stability and higher chemical activity than the C₅₀fullerene. There are two kinds of structures for C₅₀Si, namely, Ⅰ exohedral and Ⅱ hole defect(the silicon atom connects to four carbon atoms). The calculated results show that, for C₅₀Si, the exohedral complexes are more stable, i. e ., complexes Ⅰ are the main ingredient. The calculated results are in agreement with those of experimental observations.