New spectroscopic data for 15N15O isotopologue in the region 1.86 mm. Determination of Dunhem type constants
Yu.G. Borkov, O.N. Sulakshina, L.N. Sinitsa
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: 15N18O isotopologue, experimental spectrum, vibration band 3-0, transition frequency, relative intensity, Dunhem type constant
Abstract
In this work, the analysis of the recorded spectrum of the 15N18O molecule in the region 5100-5500 cm-1 was performed. As a result of the analysis, 187 positions of rotational lines in the vibrational band 3-0 of the main transitions between the electronic states 2Π1/2 and 2Π3/2 with the maximal rotational quantum number J = 32.5 were found. For the first time, Λ-splitting was observed in this band. The positions and relative intensities of both the resolved component of the Λ-doublets and unresolved doublets are determined. A joint weighted processing of all known vibrational-rotational frequencies of the transitions in the microwave and infrared spectral regions was carried out. As a result of the processing, “Dunham-type" constants for 15N18O isotopologue in the ground electronic state were determined. Using the found “Dunham-type" constants, predictive calculations of the rotational line positions of all bands corresponding to vibrational transitions between states with v ≤ 3 and J ≤ 37.5 were carried out.
|
