Deposition of mass-selected ions in neon matrices: CS₂⁺ and C₆F₆⁺

Abstract

Infrared and visible absorption spectra and laser-induced fluorescence (LIF) and excitation spectra are obtained for several simple cations deposited from a mass-selected ion beam. In the present preliminary study we demonstrate successful and clean mass selection by presenting spectra of samples obtained by depositing the isotopic ³⁴S¹²C³²S⁺ ion in natural isotopic abundance, and analyzing its spectrum. Spectra of C₆F₆⁺ deposited from a 20 eV ion beam exhibit quite different inhomogeneous line profiles, suggesting that even the relatively low kinetic energy results in considerable damage to the solid. Analysis of the spectra indicates that the Jahn–Teller-distorted vibrational structure in the doubly degenerate ground state of C₆F₆⁺ is strongly perturbed in the newly formed sites, which are presumably of lower symmetry. A 33–46 cm−1 splitting of the origin and other totally symmetric bands in emission is tentatively attributed to the spin–orbit splitting in the ²E₁g ground state.