Infrared Spectra of Retarded Molecular Oscillator
A. Witkowski, O. Henri-Rousseau and P. Blaise
Centre d'Etudes Fondamentales, Université de Perpignan 52 av. de Villeneuve, 66860 Perpignan cedex, France
Received: July 17, 1996; revised version: November 6, 1996
Full Text PDF
Theoretical interpretation is proposed for the inhomogeneous broadening of the infrared line shapes of high harmonics of hydrogen containing modes observed by the optoacoustic and thermal lensing spectroscopy in the liquid phase of benzene and other organic transparent liquids. Attention is focused on the experimental fact that both line width and asymmetry factors of the harmonic series increase linearly with the harmonic number for which fact no satisfactory theoretical understanding was still available. This interpretation is based on recently proposed new approach to separation of electronic and nuclear movements accounting for the finite velocity of the π electronic cloud of vicinal molecules and its retardation in following the protonic motion. This retardation leads to the time dependence of molecular oscillator which may be viewed as anharmonic. The experimental results concerning the linear increase in the line width and the asymmetry factor with increasing order of the harmonic are well represented.
DOI: 10.12693/APhysPolA.91.495
PACS numbers: 33.70.Jg, 33.20.Ed