Excitation and ionization energies of unnatural nucleic acid bases: a computational approach

The nucleic acid bases in DNA and RNA are the basic units that encode all of genetic information. Researchers have tried to increase the number of possible bases, by adding functional groups as well as synthesizing entirely new molecules that can be stabilized in the helical structure. Most of the conditions of success of these unnatural nucleic acid bases, therefore, rely on ground state stability and as well as biological functionality. However, for its use to encode information safely, one needs to also consider their photo-stability, i.e., stability in the excited states. In this work, we study the excited and ionized states of a few of the unnatural bases to understand their photo-stability.