Infrared Spectrum of Acetylene*

Multispectrum fitting of line parameters for 12C2H2 in the 3.8-μm spectral region

“…In order to derive the acetylene concentration from atmospheric spectra or from spectra of astrophysical objects, spectroscopic data as line parameters are necessary. As soon as 1961, Wiggins et al [7] measured line positions in 11 bands located between 2500 and 4150 cm −1 with a low resolution of 0.03 cm −1 . This set included the 5 bands studied in this work.…”

“…For each band, the fitted parameters which are the vibrational transition dipole moment squared and the Herman-Wallis coefficients, are given inTable 8, together with the vibrational dipole moments squared. The calculated values 2 calc R have been obtained using Eqs (7)(8)(9). with the values of…”

“…The position column contains the measured line position in cm -1 and Dif is the difference in 10 -3 cm -1 between the measured position and the one calculated using a polynomial expansion. S obs is the measured line intensity in cm⋅molecule -1 , for pure 12 C 2 H 2 at 296 K, and S calc the one calculated (see text) using the constants ofTable 8(see Eqs [1][2][3][4][5][6][7][8][9]…”

Investigations on the infrared spectrum of acetylene between 2500 cm-1and 2800 cm-1and studies of the resonance effects

“…The rotational and rovibrational spectra of acetylene, C 2 H2, have been extensively investigated by both the infrared and Raman methods, see, e.g., references [1][2][3][4]. This paper reports a study of the vibration-rotation infrared spectrum of C2H2 between 2500cm -1 and 2800cm -I .…”

“…This paper reports a study of the vibration-rotation infrared spectrum of C2H2 between 2500cm -1 and 2800cm -I . This wavenumber region has been examined by Wiggins et al [1] and Lafferty and Thibault [5] and, more recently, by Palmer et al [3]. It was felt that the improvement in resolution and in signal to noise ratio allows us to resolve more lines and so to carry out a more detailed analysis, considering especially the effects of the Fermi and/-type resonances.…”