High-Resolution Fourier Transform and Diode–Laser Spectroscopy of the ν6 Fundamental of C2F6 and Associated Hot Bands

✍ Scribed by K.M. Ward; G. Duxbury; M. Lorono; W. Henze; P.B. Davies; D.A. Newnham

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 292 KB
• Volume: 204
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.2000.8228

✦ Synopsis

High-resolution infrared spectra of the 6 (713 cm Ϫ1 ) band region of C 2 F 6 vapor have been recorded at several temperatures. Spectra at 77, 200, and 300 K were recorded using a Fourier transform spectrometer with unapodized resolutions of 0.0018 cm Ϫ1 (200 and 300 K) and 0.008 cm Ϫ1 (77 K). Spectra with rotational temperatures in the range 5-50 K were recorded in a supersonic jet using diode-laser absorption spectroscopy. The 6 band contains two clear sequences of hot-bands: one arises from the 4 torsional vibration at 67.5 cm Ϫ1 ; the other, shorter, weaker progression is built on the doubly degenerate 9 vibration at 220 cm Ϫ1 . They lie to high and low wavenumbers of the fundamental band, respectively. Eleven series were assigned and fitted to these hot bands. A perturbed series in the 4 sequence is considered, by analogy with the infrared spectrum of C 2 H 6 vapor, to be caused by an xy-Coriolis interaction either between 5 4 and 9 ϩ 2 4 in the ground state or, in the upper state, 6 ϩ 5 4 with 6 ϩ 9 ϩ 2 4 or 6 ϩ 5 4 with 2 8 . One further series resolved only in the jet spectrum and lying very close to the fundamental is almost certainly due to the 6 fundamental of the isotopomer 13 C 12 CF 6 .