Trihydrogen cation solvated by rare gas atoms: Rg_nH_3~+

摘要

The triatomic hydrogen cation solvated by rare gases, Rg_nH_3~+, n = 1 - 5, Rg = He, Ne, Ar, Kr, Xe, is investigated by density functional theory. The results indicate that while the first solvent atom distorts and destabilizes the H_3~+ center, the ion is restabilized by additional solvation. For the n = 3 species, the symmetric D_(3h) structure is the global minimum for all rare gases except Xe; the n = 4,5 solvent atoms are placed on the C_3 axis of the molecule. The computed potential energy surface of the isomerization reaction Rg_nH_3~+ -> H_2Rg_2H~+Rg_(n - 2), n = 2 - 4, provides insight into the possible H_3~+ formation and destruction mechanisms in rare gas matrices. As expected, solid neon is the most suitable medium for H_3~+ studies, with its stabilization becoming progressively more difficult in the heavier rare gas solids.