Rovibrational and Rotational Spectroscopy of Levels of Propyne around 1000 cm−1

✍ Scribed by P. Pracna; G. Graner; J. Cosléou; J. Demaison; G. Wlodarczak; V.-M. Horneman; M. Koivusaari

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 183 KB
• Volume: 206
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.2000.8282

✦ Synopsis

Four vibrational levels in the energy region around 1000 cm -1 were studied. These were the v 5 = 1 and v 8 = 1 fundamental levels, both components of the v 9 = v 10 = 1 combination level (l 9 = l 10 = ±1 and l 9 = -l 10 = ±1), and both components of the v 10 = 3 overtone level (l 10 = ±1 and ±3). New FTIR spectra with a synchrotron radiation source were recorded in the region of the "superhot" v 10 = 3 ← 2 bands, which made possible the first assignment of levels of the v 10 = 3 ±1 sublevel. More than 330 new rotational transitions in the combination and overtone levels were measured by millimeter-wave spectroscopy betwen 50 and 360 GHz. The new data were analyzed simultaneously together with the previously assigned rovibrational data for the fundamental and combination levels and rotational data for the fundamental levels using a global model with all anharmonic, Coriolis, l-type, and α-resonances. Significant improvement of data reproduction and very good consistency with the Hamiltonian parameters of the lower vibrational levels v 9 = 1 and v 10 = 1, 2 were achieved. A strong dependence of the A v constant on the l 10 quantum number is found for propyne: this is shown to be characteristic of skeleton C-C≡C or C-C≡N bending modes in H 3 CCCH, H 3 CCN, and their fully deuterated species.