Hydration of DNA base cations in the gas phase

Hydration of the adenine and thymine cations was studied in the gas phase. Metastable fragmentation of the cluster ions was used to draw information on the relative strengths of the binding energy of each additional solvent molecule. Both cations of adenine and thymine exhibited a well-defined hydration shell structure, with the first hydration shell complete with four water molecules. On the other hand, the hydration shell structure for the cation dimer of adenine was less evident, but appeared to require seven or eight water molecules for the first hydration shell. An ab initio calculation was carried out at the Hartree-Fock level to address some of these issues.