ABSTRACT
The diode laser spectrum of cis-1,2-CHF=CHF has been measured and analyzed in the nu4 fundamental region near 1016 cm(-1). This vibration of symmetry species A1 corresponds to the C-F symmetric stretching motion and gives rise to a strong b-type band. The rovibrational analysis, extended to the P, Q, and R branches, led to the identification of 2800 lines with J < or = 62, Ka < or = 18, Kc < or = 62. The assigned transitions free of major resonance contributions, fitted using Watson's A-reduction Hamiltonian in the Ir representation, yielded a set of spectroscopic parameters up to the quartic coefficients for the V4 = 1 state. Several perturbation effects occur throughout the band, mainly caused by the first-order c-type Coriolis interaction with the nu5 + nu11, vibrational state. Even though no transitions to the perturbing level were observed, the band orign and the rotational constants for the perturber were determined from a dyad model which includes the Coriolis interaction term.
Subject(s)
Ethylenes/chemistry , Spectrophotometry, Infrared/methods , Statistics as TopicABSTRACT
The two mid-infrared bands of the CF2&dbond;CHF molecule, nu5 centered at 1172.673 cm-1 and nu6 + nu9 at 1155.105 cm-1, were measured on a tunable diode laser spectrometer with a resolution near the Doppler limit. These vibrations of A' species give rise to a/b hybrid bands, even though our analysis has pointed out that the intensity of the a-type component is predominant. Most of the J and K structure has been resolved in different subbranches, and the rovibrational analysis led to the assignment of about 1400 (J
ABSTRACT
Diode laser spectra of CH2 F37 Cl (95% isotopically pure sample) have been recorded in the 9.4 µm region characterized by the nu4 fundamental. The spectral analysis allowed the assignment of more than 3700 transitions with J
ABSTRACT
The 2nu1 + nu2 + 2nu3 band of ozone, occurring in the 4780 cm-1 region, has been observed for the first time, using a Fourier transform spectrometer, at 0.008 cm-1 resolution and using a large path length pressure product. Assignments of vibration-rotational transitions have been made up to J = 48 and Ka = 9. As a few levels with Ka = 1 or 2 are perturbed, it has been necessary to take into account the Coriolis resonance between the (212) and (141) vibrational states. With the effective Hamiltonian explicitly accounting for the interaction between these two states, the fit on 165 energy levels leads to the rms deviation of 1.9 x 10(-3) cm-1, which is near the experimental accuracy. Line intensities of the 2nu1 + nu2 + 2nu3 band have been measured and calculated. The set of spectroscopic parameters for interacting bands, as well as transition moment constants, is given. A complete list of line positions and intensities, with a cutoff of 1 x 10(-26) cm-1/molecule.cm-2 at 296 K up to J = 65 and Ka = 15, has been generated, which leads to the integrated band intensity Sv (2nu1 + nu2 + 2nu3) = (5.1 +/- 2.0) x 10(-23) cm-1/molecule.cm-2. Copyright 1997Academic Press
