Model calculations of the electron affinities and ionization potentials of DNA

We have studied the electron affinities and ionization potentials for models of DNA. We conclude that removing an electron is most favorable on the PO4− groups; whereas, addition of an electron is most favorable on a nucleic acid. The computed electron affinities are 1.9, 4.8, 5.7, and 7.9 kcal/mol for adenine, cytosine, guanine, and thymine, respectively. Our best estimate of the IP for hydrated DNA is 4.5 eV and for hydrated DNA plus Na+ counter ions is 5.6 eV.