Enhancement and de-enhancement effects in vibrational resonance Raman optical activity

摘要

In this study, we investigate interference between several excited electronic states in resonanceenhanced vibrational Raman optical activity (RROA) spectra. A gradient Franck–Condon model forthe excited-state potential energy surface is applied in order to include vibronic effects in thedescription of the RROA intensities. Both sum-over-states and time-dependent expressions for theRROA intensities in case of close-lying excited states are given. As an example, we compare thecalculated RROA and resonance Raman spectra of (S)-(+)-naproxen-OCD_3to the experimentalones. Subsequently, we examine the excitation profiles of (S)-(+)-naproxen and study the vibrationat 1611 cm~(-1)in more detail order to demonstrate how the consideration of a second excitedelectronic state can lead to significant changes in the RROA intensities.