The simulation of infrared bands from the analyses of rotational spectra: the 2ν9–ν9 and ν5–ν9 hot bands of HNO3

Autor: K.W. Jucks, Manfred Winnewisser, F. C. De Lucia, Brenda P. Winnewisser, Rebecca A. H. Butler, Paul Helminger, Douglas T. Petkie
Rok vydání: 2005
Předmět:
Zdroj: Journal of Quantitative Spectroscopy and Radiative Transfer. 92:129-141
ISSN: 0022-4073
DOI: 10.1016/j.jqsrt.2004.03.003
Popis: The results of millimeter and submillimeter wave rotational spectroscopy are used to simulate the complex structure of the 2 ν 9 – ν 9 (438 cm −1 ) and ν 5 – ν 9 (421 cm −1 ) hot bands. The comparison data were obtained with a high-resolution Bruker FTIR. The combination of the quality of these data and the complexity of the spectra of these interacting states represents a stringent test for the simulation. It is shown that the agreement is very good and that this approach is generally advantageous. From this simulation, the ratios of the transition dipole moments for the 2 ν 9 – ν 9 and ν 5 – ν 9 hot bands with respect to the ν 9 fundamental band were found to be 1.38(11) and 0.67(20), respectively. Using these results, the calculated integrated band intensities for the hot bands at 296 K were determined to be S v (2ν 9 – ν 9 )=1.63×10 −18 cm −1 /( mol cm −2 ) and S v (ν 5 – ν 9 )=0.36×10 −18 cm −1 /( mol cm −2 ) . These results were used to successfully simulate high-resolution stratospheric spectra obtained from a balloon flight of the FIRS-2 spectrometer. The more general problem of the rotation–vibration database and the optimal use of both microwave and infrared data to define it is discussed. It is concluded that it is best if the combination of data takes place at the level of the original spectra.
Databáze: OpenAIRE