Superalkali character of alkali-monocyclic (pseudo)oxocarbon clusters

摘要

A series of polynuclear superalkali cations C_3X _3Li_3 ~+, C_3(NCN)_3Li _3 ~+, C_3X(NCN)_2Li_3 ~+, C_3C(CN)_2_3Li_3 ~+, C_3(NCN)C(CN)_2_2Li _3 ~+, C_3XC(CN)_2_2Li _3 ~+ (X = O, S, Se) and their corresponding neutral species were investigated by using the density functional theory. Except for C _3Se_3Li_3, the ionization potentials for the studied neutral species are in the range of 2.52-3.75 eV, which are lower than the ionization potential of Cs atom (3.89 eV). For C_3Se _3Li_3, although it has larger IP value of 4.51 eV than 3.89 eV of Cs, it is still less than IP = 5.39 eV of Li atom. Hence, they can be classified as superalkalies. In addition, the calculated results also indicated that besides the hyperlithiated configuration and segregated configuration, the excess electron may fully delocalize over various atoms (both center and ligands) in superalkalies. The present investigation gives hints to scientists that the search to a superatom can be extended by using more complicated cyclic (pseudo)oxocarbons as the central core of polynuclear superalkalies. This journal is