INERTIAL CONTRIBUTION TO VIBRATIONAL OPTICAL-ACTIVITY IN METHYL TORSION MODES

Simple expressions are obtained for the Raman and infrared optical activity generated by the oscillations in space of a chiral molecular frame that accompany a methyl torsion vibration in the molecule. Substitution of methyl groups at different points permits the structure of chiral molecules to be probed about different torsion axes. The theory is most straightforward when the torsion axis is a principal axis of inertia of the molecule, and is applied to oscillations of a bridged biphenyl about its twofold proper rotation axis. © 1979, American Chemical Society. All rights reserved.