Abstract

The torsional level structure of a molecule containing a methyl group can be influenced by the presence of a second methyl group. In addition to this torsional-torsional coupling, the system of interacting rotors can couple to the overall rotation of the molecule. We have examined such effects in the high resolution S1S0 spectra of two different molecules, 2,3-dimethylnaphthalene and 4-dimethylaminobenzonitrile (DMABN). We will present a complete analysis of these spectra and discuss the ways in which these couplings may be related to the local electronic structure and to the dynamical process known as intramolecular vibration relaxation. We also will show how the results for DMABN relate to the presumed twisted intramolecular charge transfer character of its first electronically excited state.

© 1990 Optical Society of America