Generation of ArnH3+ cluster ions by laser vaporization and their black-body radiation induced dissociation

Abstract

Ar_n⁺H₃ ions are produced in a laser vaporization source, and their stability against black-body radiation is tested in an FT-ICR mass spectrometer. Using a magnesium target and hydrogen doped argon as carrier gas, Ar_n⁺H₃ are formed with n = 1–3 in large quantities and traces of n = 4. Ar_n⁺H, n = 1–3 are also present. Both Ar₃⁺H₃ and Ar₂⁺H₃ are heated by room temperature black-body radiation and decay on a timescale of seconds. The observed rate constants are compared with recently calculated IR spectra. The results are in agreement with the presence of strong IR absorptions around 350 cm⁻¹, which may serve as a fingerprint for the identification of H₃⁺ in solid argon.