Theoretical studies on excited states of biorelated systems from gas phase to aqueous solution

Excited-state properties of molecules play a pivotal role in understanding their photophysical and photochemical behaviors. With the fast development of computational methodologies, the low-lying states of biorelated systems have been extensively investigated theoretically. Here, we review our recent works on the excited states of selected nucleobases and their related systems in the gas and condensed phases. The simulated electronic spectra of coumarin reproduce the band shape of experimental spectra and provide a basis to reasonably assign the observed bands. The absorption spectra and the excited-state dynamics of nucleic acid bases and their analogs in the gas phase and in aqueous solution have been explored by the combined quantum mechanics and molecular mechanics (QM/MM) calculations and QM/MM-based dynamics simulations with surface hopping. Based on extensive calculations and dynamics simulations, the solvent effects on the excited states and their dynamical behaviors have been discussed. V C 2015 Wiley Periodicals, Inc.