The Blue Xe₄⁺ Cation: Experimental Detection and Theoretical Characterization

Abstract

Feeling blue: Green Xe2+ reacts with excess xenon under pressure to form a blue compound. According to spectroscopic measurements and theoretical calculations, the blue compound, as shown in the picture, is most likely Xe4+ with a linear, symmetric structure (D∞h).

Heterocations in Superacid Systems

“…1035,1036 Since then, extensive mass spectrometric studies of H 2 , D 2 , and their mixtures have been carried out in an effort to study thermodynamic and kinetic aspects of ion-molecule reactions of (H,D) 3 þ cations. 1051 Of the possible cationic species (Xe n mþ , n ¼ 2-4; m ¼ 1, 2), calculated vibrational spectra and energies agree well with those observed for Xe 4 þ , but the presence of higher xenon aggregates (Xe 4 þ ÁXe n ) cannot be ruled out. 1049 Drews and Seppelt 1050 were the first, however, to report the isolation and molecular structure of Xe 2 þ Sb 4 F 21 À (365) [Eq.…”

Neutral noble gas compounds exhibiting a Xe–Xe bond: structure, stability and bonding situation

“…4 Moreover, Seidel et al have experimentally detected and theoretically characterized a blue Xe 4 + cation, which has a linear, symmetric structure. 5 Quite recently, we proposed the viability of the HXeXeF species, a metastable molecule protected by an energy barrier of ca. 13 kcal mol À1 which could be observed in a low temperature Xe matrix.…”

Unexpected Trend in Stability of Xe–F Compounds under Pressure Driven by Xe–Xe Covalent Bonds

“…Drews et al isolated a salt of cationic Xe 2 + containing a Xe–Xe bond with an interatomic distance of 3.087(1) Å. Stein et al also identified Xe 2 + experimentally. Seidel et al detected and characterized by calculations a blue Xe 4 + cation with a linear, symmetric structure. Fernández and Frenking proposed the viability of a metastable HXeXe X (X = F to I) molecule with an energy barrier of 13 kcal mol –1 .…”