L. Henry

Self-, N2-, and O2-broadening parameters in the ν3 and ν1 + ν3 bands of 12C16O2

Abstract Self-broadening parameters at 296 K for lines in the ν 3 band of CO 2 and N 2 - and O 2 -broadening parameters at 296 and 198 K for lines in the ν 3 and ν 1 + ν 3 bands of the same molecule have been measured with a vacuum high-resolution grating spectrometer. The experimental results are compared with values calculated from a semiclassical model.

Inversion doubling in the ν2 vibration-rotation band of NH2D and ND2H

Abstract This paper is concerned with an analysis of both 14NH2D and 14ND2H spectra obtained in the 730- to 1080-cm−1 region with a long-path Fourier transform spectrometer. The assignment of the observed transitions together with a theoretical analysis of the vibration-inversion-rotation energy levels concerned with these transitions allows the first determination of the spectroscopic constants related to the symmetric and antisymmetric upper levels of the fundamental ν2 band.

Temperature dependence of the vibration-vibration transfer rates from CO2 and N2O excited in the (0001) vibrational level to 14N2 and 15N2 molecules

Abstract V-V transfer rates from CO 2 and N 2 O excited in the (00 0 1) vibrational level to 14 N 2 and 15 N 2 are determined from 150 to 1200 K using the laser fluorescence method, and compared with values calculated on the basis of dipole-quadrupole interactions.

Analysis of the ν2 and ν4 infrared bands of CD4

Abstract The infrared spectrum of totally deuterated methane CD 4 has been recorded between 930 cm −1 and 1180 cm −1 under high resolution (0.003 cm −1 ). The ν 2 and ν 4 bands of 12 CD 4 have been reanalyzed on the basis of a complete third-order Hamiltonian including all the coupling terms linking the upper states of the two bands. A set of only 16 self-consistent parameters have been adjusted to fit more than 1650 assigned transitions reaching a maximum upper state J value of 20. The obtained standard deviation is 0.0041 cm −1 . In addition, 171 lines of the ν 4 band of 13 CD 4 have been assigned. They have been analyzed, in the same dyad scheme, by adjusting 7 parameters of the ν 4 band together with the main ζ 24 Coriolis parameter. The obtained standard deviation is only 0.0012 cm −1 .

Vibrational energy transfer from the υ = 1 level of carbon monoxide to the υ = 1 level of the two isotopic species of nitrogen: 14N2 and 15N2

Abstract V-V transfer rates from CO (υ = 1) to 14 N 2 and 15 N 2 are determined from 100 to 700 K using the laser fluorescence method. The great effect of the energy level gap between the colliding partners is dramatically demonstrated. Theoretical considerations explain the observed difference.

High-resolution Fourier transform study of the ν14 band of benzene-d6

Abstract The perpendicular band of the E 1 u vibration ν 14 of benzene- d 6 was recorded in the region 790–830 cm −1 with the aid of a large Fourier transform spectrometer at the Universite Pierre et Marie Curie with resolution near the Doppler limit. Subbands with K Δ K ranging from −60 to +60 have been assigned in the ν 14 band. The r R K branches for K ∼ 17 to 30 are strongly affected by a perturbation which has been identified as a second-order rotational resonance with the infrared- and Raman-inactive fundamental ν 10 of symmetry B 2 u located near 823.7 cm −1 . Accurate spectroscopic constants are reported for the vibrational ground state of C 6 D 6 , for the ν 14 state, and analysis of the observed perturbation has also yielded constants for the elusive ν 10 state.

Self-broadening parameters in the ν3 band of 14N2 16O

Abstract Self-broadening parameters of lines belonging to the R branch of the N 2 O ν 3 band up to R (70) have been measured using a vacuum grating spectrometer. Line intensities were also deduced from the deconvoluted spectrum. Interpretation of the experimental results is achieved using two semiclassical models.

Analysis of the ν9ν10 band system of allene

Abstract The infrared spectrum of allene has been recorded with high resolution (0.002-0.004 cm −1 ) on a Fourier transform instrument in the region 730 to 1170 cm −1 containing the perpendicular bands, ν 9 and ν 10 . A total of 21 subbands with K Δ K ranging from −6 to +14 have been assigned in the ν 9 band, and 26 subbands with K Δ K = −10 to +15 have been assigned in the ν 10 band. The bands are affected by a combination of a J z -Coriolis and a quartic anharmonic interaction between their upper states ν 9 and ν 10 . In addition, several other more localized perturbations are found in the spectrum. The nature of the interactions responsible for these perturbations is discussed, and five of the strongest perturbations are quantitatively accounted for by constructing a Hamiltonian matrix which includes five different perturbing states and their Coriolis and anharmonic resonances with the ν 9 and ν 10 upper states. A set of spectroscopic constants for the ν 9 and ν 10 states and for some of the perturbing states is reported.

Vibrational energy transfers from the v=1 level of HBr to the v=1 level of CO, NO, N2, and O2, and to the 00° 1 level of CO2 and N2O

Rate constants for the vibrational energy transfer in HBr–M systems, with M=CO2, N2, N2O, CO, NO, O2, have been measured from 300 to 700 K using the laser‐induced fluorescence technique. The results are compared to the values calculated from Shin’s model and from Dillon–Stephenson method using, respectively, a Morse potential and a dipole–dipole potential. From the analysis of our results on the HBr–M systems and of the results obtained by other authors on many HX–M systems (X being an halogen atom) a discussion is given about the respective role played by the attractive multipolar forces and by the repulsive forces in the V–V transfers.

Vibrational relaxation in HCl–CO2 and HCl–N2O mixtures studied by the laser‐induced fluorescence method

Rate constants kM–HCl and kHCl–M for the energy transfer between the vibrational levels 0001 of M=CO2 or N2O and v=1 of HCl have been measured from 300 to about 900 K using the laser induced‐fluorescence method. The V–RT de‐excitation rates kHClM of M(0001) by HCl, and kMHC1 of HCl(v=1) by M have also been determined from measurements of the relaxation constants versus the molar fraction of M in the mixture. These rates are found to be on the same order of magnitude as the V–V transfer rates kM–HCl and kHCl–M, respectively. The V–V transfer and V–RT de‐excitation rates are evaluated from a method, developed by Shin, on the basis of a transfer of vibrational energy into rotational energy of HCl, and the calculated values are compared to the experimental results.