Water molecule enhances dipole-bound electron affinity of 1-methyl-cytosine

We investigate electron attachment to water complexes of 1-methyl-cytosine. In all the systems considered the excess electron is bonded to the dipole field of the complex. The calculations show that in the cases of the amino-oxo tautomer with a water molecule H-bonded to the amino group and with a water molecule H-bonded to the carbonyl group, enlargement of the dipole moment due to alignment of the dipoles of the water and base molecules leads to an almost four-fold increase of the electron affinity in comparison to the isolated 1-methyl-cytosine molecule.