Intermolecular interaction in proton-bound dimers.: Infrared photodissociation spectra of Rg–HOCO + (Rg=He, Ne, Ar) complexes

Abstract

Infrared photodissociation spectra of the proton-bound Rg–HOCO + ionic complexes (Rg=He/Ne/Ar) have been recorded in the vicinity of the ν 1 (OH stretch) vibration. The observed complexation-induced red shifts (Δ ν 1) are 47, 120, and 704 cm −1 for the He, Ne and Ar containing species and correlate linearly with the proton affinity of the rare-gas atom. Weak transitions in the 100–220 cm −1 range to the blue of the ν 1 fundamentals are assigned to combination bands of ν 1 with the intermolecular stretching mode, ν s. The geometries, vibrational frequencies and interaction energies of the Rg–HOCO + complexes have been investigated by ab initio calculations at the MP2 level, and the results are in good agreement with the experimental data.