REMOTE SUBSTITUENT TUNING OF A FERMI RESONANCE INVOLVING METHYL TORSIONS

Abstract

Continuing our studies on the family of methylated stilbene analogs, we report here a perturbation between a 2e methyl torsional level and a weakly allowed methyl-phenyl-torsional combination band. Due to the remote substituent effects on the methyl barrier, we are able to fine tune the 2e level through the avoided crossing region. This work demonstrates unusual control of an internal perturbation in a system this size due to the fine control of methyl torsional barriers from remote substituents.