Large intramolecular energy flow in vibrational overtone spectra of cyclohexene-3,3,6,6-d4

Abstract

The vibrational structure of CH stretching states in gas-phase cyclohexene-3,3,6,6-d 4 was studied using FTIR spectroscopy in the range 1200-11500 cm -1 and intracavity dye laser photoacoustic spectrometry in the range 12900-16000 cm -1 . The structure was modeled using an effective vibrational Hamiltonian which describes the Fermi resonance couplings of the CH stretching states with suitable low-frequency vibrations. Some conclusions are made on the possible ways of intramolecular vibrational redistribution of the energy (IVR) on the two methylenic groups for wavenumbers below 11 000 cm -1 in connection with the existence of near-infrared circular dichroism in monoterpenes