Известия Томского политехнического университета: Инжиниринг георесурсов (May 2019)
Analysis of the high-resolution spectra of methyl fluoride in the region of 2400-2800 cm-1
Abstract
The relevance of the current research is caused by the need of knowledge about the high resolution ro-vibrational spectra of the symmetric top molecules, which is an essential doorway towards the understanding of the fundamental physical properties of this type of molecules. For that reason an experimental spectrum of CH3F molecule was measured for the first time with the high resolution and analyzed in the range of 2400-2800 cm-1. Estimation method for the values of spectroscopic parameters was used to describe numerous resonance interactions between the states v2+v6(E) and v5+v6(A1,E), which are the subject of the present research. The main aim of the study is theoretical description of the experimental high-resolution spectra of the trifluoromethane molecule in the range of infrared bands v2+v6(E) and v5+v6(A1,E); the resonance interaction parameters between mentioned states are estimated and found out fitting procedure as well as the spectroscopic parameters describing the spectrum structure. The methods used: methods of the Fourier-transform high resolution spectroscopy, methods of quantum mechanics, methods of the irreducible tensorial sets theory, model of the effective ro-vibrational hamiltonian operators. The results obtained. The high-resolution spectrum of methyl fluoride molecule was registered in the spectral region of 2400-2800 cm-1 for the first time. The structure of the ro-vibrational bands v2+v6(E) and v5+v6(A1,E) was described with the model of effective ro-vibrational operators. The author has obtained the set of spectroscopic parameters, which defines the structure of the spectrum. The resonance interactions between the different states are included in the model. The results obtained can be further used for describing the highly excited ro-vibrational states of the molecule as well as for more applied problems of atmospheric optics.
