Analysis of two infrared bands of CH2D2

Abstract

T'Yo i~frared absorption bands of CHzDz have been analyzed in the semirigid rotor approXlmatlOn. These are the A-type band at 2671.67 em-I and the C-type band at 4425.61 em-I .. The A~type band has ~reviou sJy been assigned as Va+ V9, and the C-type band is tentatively assl~ned as va+ v6. rt:e ~pp er state of the A-type band is peTturbed presumably by the close I Ylll~ level 2V5 . rr:lus IllteractlOn has not been investigated . The following values were found for the rotatIOnal constants of the ground vibrational state: Ao= 4.303 em-I, Bo = 3.504 em-I, Co= 3.049 em-I.

High-Resolution Near Infrared Spectroscopy and Vibrational Dynamics of Dideuteromethane (CH2D2)

“…Table summarizes the nine vibrational fundamentals as known today. A total of 22 vibrational bands had been studied at moderate to high resolution prior to the present work, where we reanalyze also three of the previously known bands. − The far-infrared pure rotational spectrum has also been studied with the main goal of deriving the permanent dipole moment of CH 2 D 2 including the answer to the long standing question of its sign. , …”

“…A total of 22 vibrational bands had been studied at moderate to high resolution prior to the present work, where we reanalyze also three of the previously known bands. [48][49][50][51][52][53][54][55][56][57][58][59][60] The farinfrared pure rotational spectrum has also been studied with the main goal of deriving the permanent dipole moment of CH 2 D 2 including the answer to the long standing question of its sign. 61,62 In our two previous papers, we have complemented the lowenergy spectra by observing and analyzing previously undetected, weak, or forbidden transitions for example to levels of A 2 symmetry or weaker overtone and combinations levels.…”

High resolution Fourier transform spectroscopy of CH2D2in the region 2350–2650 cm−1: the bands ν5+ ν7, 2ν9, ν3+ ν4, ν3+ ν7and ν5+ ν9

“…High resolution studies of the first overtone and combination bands have been reported in refs. [33][34][35][36] where the bands 5 , n 5 þ n 9 and 2n 3 were analyzed. It should be mentioned, however, that ro-vibrational transitions with J up to J max ¼ 9 were assigned for the bands included in refs.…”

Analyse de la bande de vibration-rotation ν9 du méthane bideutéré vers 8 μ

“…C'est dans ce cadre qu'on obtient la numérotation des vibrations qui est utilisée ici. Le tableau I permet de faire la correspondance entre cette numérotation déjà employée par Olson [2] et la numérotation de la référence [6] qui rattache les vibrations de tous les dérivés isotopiques du méthane aux vibrations de la molécule CH4.…”

“…Dans la branche R nous avons mesuré une raie AALi = -2, AK, = + 3 à 1 277, 917 cm -1. Des raies résiduelles de la vapeur d'eau apparaissent à partir de 1 271 cm-1 mais ne sont vraiment gênantes qu'au-dessus de des résultats précédemment publiés par Olson et al [2] nous avons pu obtenir les valeurs des constantes rotationnelles du fondamental A°, B°, CI. Les informations en notre possession ne permettent pas de déterminer les 5 constantes de distorsion de Watson mais seulement 3 d'entre elles.…”