摘要
The structures and stabilities of cage Si20F2o and its endohedral complexes X^2-@Si20F20 （X=O, S, Se） were determined at the B3LYP/6-31G（d） levels of density functional theory （DFT）. It is found that the adiabatic electron affinity （EAad） of host cage Si20F20 （1h） is higher than that of isolated O atom （4.24 vs. 1.46 eV）. This suggests the Si20F20 cage can selectively trap and stabilize the capsulated spherical anions. The calculations predict that X=S and Se are nearly located at the center of the cage, and O dramatically deviates from the center in C3v symmetry. Moreover, the corresponding X^2- @Si20F20 complexes have more negative inclusion energies （AEinc） and thermodynamic parameters （AZ） than X2 @C20F20. The amount of charge that is being transferred from the encapsulated anions to the cage increases with the atomic radius, i.e., from O^2- （ca. 45%）, S^2- （ca. 51%） to Se^2- （ca. 59%）, and such a novel model of cage may have practical uses as potential and electrical building units of nanoscale materials.
The structures and stabilities of cage Si20F2o and its endohedral complexes X^2-@Si20F20 （X=O, S, Se） were determined at the B3LYP/6-31G（d） levels of density functional theory （DFT）. It is found that the adiabatic electron affinity （EAad） of host cage Si20F20 （1h） is higher than that of isolated O atom （4.24 vs. 1.46 eV）. This suggests the Si20F20 cage can selectively trap and stabilize the capsulated spherical anions. The calculations predict that X=S and Se are nearly located at the center of the cage, and O dramatically deviates from the center in C3v symmetry. Moreover, the corresponding X^2- @Si20F20 complexes have more negative inclusion energies （AEinc） and thermodynamic parameters （AZ） than X2 @C20F20. The amount of charge that is being transferred from the encapsulated anions to the cage increases with the atomic radius, i.e., from O^2- （ca. 45%）, S^2- （ca. 51%） to Se^2- （ca. 59%）, and such a novel model of cage may have practical uses as potential and electrical building units of nanoscale materials.
基金
Project supported by the Natural Science Foundations of Zhejiang Province.
