OH stretch overtone spectroscopy and transition dipole slignment of HOD

Published

October 16, 2008

Author(s)

David Nesbitt, J R. Fair, O Votava

Abstract

Photoscoustic spectroscopy in room-temperature H₂O/HOD/D₂O cells has been used to probe the 3v_OH and 4v_OH overtone bands in HOD via excitation with a single mode (160 MHz) injection-seeded optical parametric oscillator (OPO) and pulsed dye laser, respectively. Transitions corresponding to HOD are isolated by compresion between H₂O/HOD/D₂O and pure H₂O overtone spectra and are analyzed with a Watson asymmetric top Hamiltonian. Least-squares fits yield the vibrational dependence of A_vB_vand C_v rotational constants as well as Birge-Sponer analysis of the vibrational overtone series for up to v_OH=4. Relative intensities of a-type and b-type bands are reported for 3v_OHand 4v_{OH which indicate that the transition dipole moment vector tilts away from the OH bond with increasing v}dOH^ excitation. This observation is qualitatively inconsistent with simple local-mode, bond-dipole model predictions of the vibrational dynamics. However, the results are in excellent agreement with full 3D quantum variational calculations based on the H₂O potential of Polyansky, et al. [J. Chem. Phys. 105, 6490 (1996)] and dipole moment surface of Gabriel, et al. [J. Chem. Phys. 99,897(1993)].

Citation

Journal of Chemical Physics

Pub Type

Journals

Keywords

dipole, HOD, moment, overtone, photoacoustic, spectroscopy, transition

Citation

Nesbitt, D. , Fair, J. and Votava, O. (2008), OH stretch overtone spectroscopy and transition dipole slignment of HOD, Journal of Chemical Physics (Accessed April 25, 2024)