Can One Measure Resonance Raman Optical Activity?

Abstract

AbstractResonance Raman optical activity (RROA) is commonly measured as the difference in intensity of Raman scattered right and left circularly polarized light, IR−IL, when a randomly polarized light is in resonance with a chiral molecule. Strong and sometimes mono‐signate experimental RROA spectra of several chiral solutes were reported previously, although their signs and relative intensities could not be reproduced theoretically. By examining multiple light‐matter interaction events which can occur simultaneously under resonance, we show that a new form of chiral Raman spectroscopy, eCP‐Raman, a combination of electronic circular dichroism and circularly polarized Raman, prevails. By incorporating the finite‐lifetime approach for resonance, the experimental patterns of the model chiral solutes are captured theoretically by eCP‐Raman, without any RROA contribution. The results open opportunity for applications of eCP‐Raman spectroscopy and for extracting true RROA experimentally.