Infrared spectroscopy and anharmonic theory of H3 +Ar2,3 complexes: The role of symmetry in solvation

D C McDonald 2nd; B M Rittgers; R A Theis; R C Fortenberry; J H Marks; D Leicht; M A Duncan

doi:10.1063/5.0023205

Infrared spectroscopy and anharmonic theory of H₃ ⁺Ar_2,3 complexes: The role of symmetry in solvation

J Chem Phys. 2020 Oct 7;153(13):134305. doi: 10.1063/5.0023205.

Authors

D C McDonald 2nd¹, B M Rittgers¹, R A Theis², R C Fortenberry³, J H Marks¹, D Leicht¹, M A Duncan¹

Affiliations

¹ Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA.
² Department of Chemistry and Biochemistry, Georgia Southern University, Statesboro, Georgia 30460, USA.
³ Department of Chemistry and Biochemistry, University of Mississippi, University, Mississippi 38677, USA.

PMID: 33032436
DOI: 10.1063/5.0023205

Abstract

The vibrational spectra of H₃ ⁺Ar_2,3 and D₃ ⁺Ar_2,3 are investigated in the 2000 cm^-1 to 4500 cm^-1 region through a combination of mass-selected infrared laser photodissociation spectroscopy and computational work including the effects of anharmonicity. In the reduced symmetry of the di-argon complex, vibrational activity is detected in the regions of both the symmetric and antisymmetric hydrogen stretching modes of H₃ ⁺. The tri-argon complex restores the D_3h symmetry of the H₃ ⁺ ion, with a concomitant reduction in the vibrational activity that is limited to the region of the antisymmetric stretch. Throughout these spectra, additional bands are detected beyond those predicted with harmonic vibrational theory. Anharmonic theory is able to reproduce some of the additional bands, with varying degrees of success.