Molecular eigenstate spectroscopy: Application to the intramolecular dynamics of some polyatomic molecules in the 3000 to 7000 cm(sup (minus)1) region. Progress report, September 1, 1990--January 31, 1993

摘要

This project uses high resolution infrared spectroscopy to probe the mechanism of intramolecular vibrational redistribution (IVR) in ultracold isolated polyatomic molecules. Single resonance spectra of 1-butyne and ethanol show that qualitatively different coupling mechanisms dominate in each case anharmonic and Coriolis coupling respectively. A random matrix method for simulation of these spectra has been implemented which allows estimation of the strength of the various mechanisms at each stage of the coupling process. A new infrared double resonance (IRDR) technique employing two high resolution F-center lasers has been developed. IRDR spectra of propyne in the 2v(sub 1) region explicitly reveal a two stage coupling mechanism involving anharmonic and z-type Coriolis interactions. The data span the range between traditional high resolution spectroscopy where all line positions can be fit precisely by an explicit Hamiltonian and the domain of statistical spectroscopy.