Articles you may be interested inFourier transform infrared and tunable diode laser spectra of the 13C12CH6 ν12 torsion-vibration-rotation band: Frequencies, intensities, and barriers to internal rotation Diode laser spectra of most of the Q branches of the v 9 band of ethane from R Q s j Q 15 have been recorded. The Q branches RQo_RQ 4 were deconvoluted to yield an effective resolution of (0.5-1.0) X IO~J cm~ 1 FWHM. Torsional spliuings were observed for most lines. In contrast to predictions based on first order theory, the spliUings which range from (2-53) X 1O~3 cm ~ 1, have a marked J and K dependence. A second order theory of torsion-vibration-rotation interaction between v 9 and 3v 4 is developed, which fits the spliuings with an rms error of 0.

Several groups have reported emission from the v 9 band of ethane at 12 ¡im in the spectra of Jupiter, Saturn, Neptune, and Titan. This paper reports the results of a laboratory study of v 9 using both high-resolution Fourier transform and diode laser absorption spectroscopy. Approximately 2000 transitions in this band have been subjected to an analysis that includes the normal rovibrational terms as well as the higher order effects of /-doubling, /-resonance, internal rotation, and a Coriolis resonance with the 3v 4 state. A model for this band capable of reproducing observed v 9 features to better than 0.001 cm" 1 is presented. High-precision values of the primary ground-state constants have also been determined: B 0 = 0-6630279(24) cm" 1 , Do 7 = 1.0324(23) x 10" 6 cm" 1 and D 0 JK = 2.651(88) x 10" 6 cm" 1 . A list of v 9 transitions occurring near 14 C02 laser lines that are good candidates for laser heterodyne searches has been compiled. An atlas is available from the authors that includes (1) plots of the observed and simulated v 9 spectra between 750 and 900 cm" 1 and (2) a list of over 8500 calculated transitions and intensities. Subject headings: line identifications -laboratory spectra -molecular processes 1984ApJ. . .280 . . 92ID 922DAUNT ET AL. Vol. 280

The infrared spectra of the ν3, ν4, and ν6 bands of formaldehyde in the region from 890 cm−1 to 1580 cm−1 have been obtained at high resolution using tunable diode laser (TDL) and Fourier transform-infrared (FT-IR) spectroscopy. The transition frequencies have been analyzed using a Hamiltonian including terms through sextic in centrifugal distortion and including five interstate vibration–rotation coupling terms. Excited state pure rotational transitions are also included in the data, and their frequencies are reproduced well. Individual measured line intensities are used to determine dipole derivatives and band strengths using the fully coupled, asymmetric top eigenvectors.

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