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 adiabat...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.展开更多
基金Project supported by the Natural Science Foundations of Zhejiang Province.
文摘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.
