High-Resolution Absorption Spectroscopy of the 3ν1 and 3ν1 + ν3 Bands of Propyne

• Published in: Journal of molecular spectroscopy 2000-05, Vol.201 (1), p.156-163
• Main Authors: Campargue, Alain, Bertseva, Elena, Graner, Georges, Herman, Michel
• Format: Article
• Language: English
• ISSN: 0022-2852; 1096-083X
• DOI: 10.1006/jmsp.2000.8073

The 3ν1 and 3ν1 + ν3 bands of propyne have been recorded at Doppler-limited resolution by Fourier transform spectroscopy and intracavity laser absorption spectroscopy, respectively. The two bands show a mostly unperturbed J rotational structure for each individual K subband. However, as a rule the K structure ordering is perturbed in overtone transitions of propyne and different effective parameters associated with each K subband have been determined. From the vibrational energy levels, a value of −6.6 cm−1 has been obtained for the x13 cross anharmonicity in perfect agreement with the origins of the ν1 + ν3 and 2ν1 + ν3 combination bands estimated from the FTIR spectrum. Hot bands from the v9 = 1 and v10 = 1 levels associated with the 3ν1 + ν3 combination band have been partly rotationally analyzed and the retrieved values of x39 and x3,10 are in good agreement with literature values. Finally, the 4ν1 + ν9 − ν9 band centered at 12 636.6 cm−1 has been recorded by ICLAS. The red shift of this hot band relative to 4ν1 and the ΔBv value are discussed in relation to the anharmonic interaction between the 4ν1 and 3ν1 + ν3 + ν5 levels.