Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5415439 | Journal of Molecular Spectroscopy | 2010 | 5 Pages |
Abstract
Relative line intensities of trans- and cis-HONO and -DONO have been measured using absorption spectra in the far-infrared previously recorded by high-resolution Fourier-transform spectroscopy [A. Dehayem-Kamadjeu, O. Pirali, J. Orphal, I. Kleiner, P.-M. Flaud, J. Mol. Spectrosc. 234 (2005) 182-189]. These relative, experimental line intensities (120 lines for trans-HONO and 94 for cis-HONO, as well as 46 lines for trans-DONO and 31 for cis-DONO) were then least-squares fitted leading to the determination of “relative” permanent dipoles moments (b-component) and their rotational corrections for the trans- and cis-HONO and -DONO species. Then these “relative” permanent dipoles moments and their rotational corrections were scaled to the absolute values derived from Stark effect measurements [M. Allegrini, J.W.C. Johns, A.R.W. McKellar, P. Pinson, J. Mol. Spectrosc. 79 (1980) 446-454] and used to generate “absolute” line intensities. These “absolute” line intensities were used to derive the concentrations of the trans- and cis-species in the absorption cell. It was then possible, assuming thermodynamic equilibrium, to use the ratio of the concentrations of the trans- and cis-species to re-determine the energy differences (ÎE) between the ground vibrational states of trans- and cis-HONO: these energy differences are 99 ± 25 cmâ1 for HONO and 136 ± 30 cmâ1 for DONO. Finally applying zero-point-energy corrections we report an average value for ÎEHONO of 107 ± 26 cmâ1. This value is in good agreement with previous experimental studies and with recent high-level ab initio calculations.
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
V. Sironneau, J.-M. Flaud, J. Orphal, I. Kleiner, P. Chelin,