Excited-State Dynamics of Pyrimidine DNA Bases Revealed by Ultrafast Vibrational Spectroscopy

Abstract

To better understand the link between light absorption and deleterious DNA photoproducts, the photophysics of DNA bases was investigate with femtosecond mid-IR transient absorption spectroscopy. Markers band for two excited states, a dark singlet state and a triplet state, were found. These marker bands provide insight into the nature and dynamics of the states. The results confirm a model for pyrimidine bases previous proposed based on UV-visible transient absorption measurements. This study provides an important foundation for future investigations of the role of these states in DNA.