Optical Activity of Vibrational Transitions: A Coupled Oscillator Model

Abstract

The infrared optical activity arising entirely from molecular vibrational transitions is estimated by a coupled oscillator model for dimerlike molecules of high symmetry, such as diketopiperazines. Information on molecular geometry and experimental measurements of the absorption intensities of the monomer normal modes are sufficient to evaluate the rotational strengths. It is shown that rotational strengths of vibrational modes can be as large as 10−42 esu2 · cm2 (10−4 D ·μB).