Supersonically Cooled Moleculear Ions in a Slit-Jet Discharge: High-Resolution Infrared Spectrscopy and Tunneling Dynamics of HD2O+

Published

June 1, 2005

Author(s)

Feng Dong, D Uy, S Davis, Mark Child, David Nesbitt

Abstract

Jet-cooled high-resolution infrared spectra of partially deuterated hydronium (HD₂O+) in the O-H stretch region (v_{3 band) are obtained for the first time, exploiting the high ion densities, long absorption path lengths, and concentration modulation capabilities of the slit jet discharge spectrometer. Least-square analysis with a Watson asymmetric top Hamiltonian yields rovibrational constants and provides high level tests of ab initio molecular structure predictions. Transitions out of both lower (v}d3O+) and upper (v₃-O^-) tunneling levels are observed, as well as transitions across the tunneling gap (v₃-O+). The v₃-O+ transitions in HD_2O+ acquire oscillator strength by loss of C_{3 symmetry, and permit both ground (27.0318(72) cm}-1) and excited state (17.7612(54) cm^-1) tunneling splittings t be determined to spectroscopic precision from a single rovibrational band. The splittings and band origins calculated with recent high level ab initio 6D potential surface predictions for H₃O^+ and isotopomers [Huang et al.,J. Chem.Phys. 118, 5431 (2003); Rajamaki et al., J. Chem. Phys. 118, 10929 (2003)] are in very encouraging agreement with the current experimental results.

Citation

Journal of Chemical Physics

Volume

122

Pub Type

Journals

Keywords

hydronium ion, IR spectroscopy, slit jet discharge, tunneling

Citation

Dong, F. , Uy, D. , Davis, S. , Child, M. and Nesbitt, D. (2005), Supersonically Cooled Moleculear Ions in a Slit-Jet Discharge: High-Resolution Infrared Spectrscopy and Tunneling Dynamics of HD₂O+, Journal of Chemical Physics (Accessed November 3, 2025)