Theoretical search for small linear doubly charged anions

Abstract

studied at the Hartree-Fock level with Gaussian basis sets including diffuse and polarization functions, as well as at the second-order Mprller-Plesset level. Vertical first detachment energies of several dianions were also calculated at the fourth-order Meller-Plesset level. All diatomic, triatomic, and tetratomic dianions were found to be unstabZe to electron loss. The pentatomic Mg2Si-dianion is predicted to be stable to electron loss with an electron detachment energy of 0.2 eV. This species is likely to be the smallest electronically stable linear dianion.

Small Multiply Charged Anions as Building Blocks in Chemistry

“…22 Cotton and Wilkinson report the existence of As 4 2-, Sb 4 2-, Bi 4 2-, As 5 3-, As 6 4-, Sb 7 3-, P 11 3-, As 11 3-, Ge 5 2-, Sn 5 2-, Pb 5 2-, Sn 9 3-, Sn 2 Bi 2 2-, and SnTl 4 4-in condensed phases. In view of the low electron affinities of the group IVA and VA elements, we do not expect any of these anions to survive in the gas phase.…”

“…We performed preliminary self-consistent-field (SCF) calculations for Bi 4 2-and Pb 4 4-Zintl anions, and our results are reported in Table 3. Both anions are geometrically stable when a medium-quality basis set (LANLDZ) is used.…”

“…4 In these species, the electronegative atoms (O or S) are placed at the termini to minimize the Coulomb repulsion. Moreover, the corresponding termini atoms -O and -S have unsaturated valences and quite high EAs.…”

“…These building block ions can be singly or multiply charged (e.g., NaCl(s) consists of Na + and Clions, and MgSO 4 (s) contains Mg 2+ and SO 4 2-ions), but they are expected to be stable to the extent that they can be characterized in the laboratory. Dividing crystals, melts, and ionic molecules into positive and negative ions is usually performed via the octet rule.…”

“…Dividing crystals, melts, and ionic molecules into positive and negative ions is usually performed via the octet rule. For example, K 2 SO 4 salt is considered to be composed of K + cations and SO 4 2-anions, within which all constituent atoms possess full octets of valence electrons. Within this point of view, chemists interpret the physical, reactivity, optical, and other properties of crystals, melts, and liquid ionic salts in terms of properties intrinsic to the corresponding positive and negative ions.…”