Overtone spectroscopy of methyl C-H stretch vibration in CH 3 CF 2 Cl and CH 3 CFCl 2 Academic Article uri icon


  • Photoacoustic spectra of the second (3ν CH), third (4ν CH), and fourth (5ν CH) overtones of the methyl C–H stretches in CH 3 CF 2 Cl and CH 3 CFCl 2 were measured. The spectra are characterized by a multiple peak structure of partially resolved triplets and quartets with an anomalous linewidth decrease in the 4ν CH region. The results are interpreted in terms of a simplified local mode model for C–H stretching vibrations, including also the stretch- deformation Fermi resonances. The model accounts for most spectral features and allows determination of the time scale for vibrational redistribution.

publication date

  • March 1, 2000