Encapsulation of small base molecules and tetrahedral/cubane-like clusters of group v atoms in the boron buckyball: A density functional theory study

摘要

A density functional theory study of small base molecules and tetrahedral and cubane-like group V clusters encapsulated in B80 shows that the boron buckyball is a hard acid and prefers hard bases like NH_3 or N_2H_4 to form stable off-centered complexes. In contrast, tetrahedral and cubane-like clusters of this family are metastable in the cage. The most favorable clusters are the mixed tetrahedral and cubane clusters formed by nitrogen and phosphorus atoms such as P_2N_2@B _(80), P_3N@B_(80), and P_4N _4@B_(80). The boron cap atoms are electrophilic centers, and prefer mainly to react with electron rich nucleophilic sites. The stability of the complexes will be governed by the size and electron donating character of the encapsulated clusters. B_(80) forms stable complexes with hard materials where a bidentate interaction of the encapsulated molecule with two boron cap atoms is preferred over a single direct complex toward a single endohedral boron.