Theoretical Study on Polynuclear Superalkali Cations with Various Functional Groups as the Central Core

A new series of polynuclear superalkali cations YLi3+ (Y = CO3, SO3, SO4, O-4, and O-5) has been created when the central group is surrounded by alkali atoms. The structural characteristics and stabilities of these systems are provided on the basis of ab initio methods. In the lowest-energy structure of the CO3Li3+, SO3Li3+, and SO4Li3+ cations, the central Y (Y = CO3, SO3, and SO4) group features a slight distortion. The global minima of O4Li3+ and O5Li3+ are of the forms O-2(-)(Li+)(3)O-2(-) and O-2(-)(Li+)(3)O-3(-), respectively, both of which contain two monovalent ion units. The structural integrity of the central Y group and the arrangement of the lithium ligands are two influencing factors on the vertical electron affinities (EA(vert)) for the YLi3+ species. The YLi3+ cation, with its lithium ligands being distributed evenly or far from each other, tends to exhibit a low EA(vert) value, whereas a greater extent of cleavage of the central Y group leads to a higher EA(vert) value and even makes some species lose their superalkali nature.