Photoelectron spectroscopy is combined with ab initio calculations to study the
microsolvation of the dicyanamide anion, N(CN)2-, allowing the electron
affinity of the N(CN)2 radical to be determined accurately as 4.135 . 0.010 eV. The electron
binding energies and the spectral width of the hydrated clusters are observed to increase with the
number of water molecules. The first five waters are observed to provide significant
stabilization to the solute, whereas the stabilization becomes weaker for n>5. The spectral
width, which carries information about the solvent reorganization upon electron detachment in
[N(CN)2-]H2O)n, levels off for n>6. Theoretical calculations reveal several close-lying
isomers for n = 1 and 2 due to the fact that the N(CN)2- anion possesses three almost equivalent
hydration sites. In all the hydrated clusters, the most stable structures consist of a water cluster
solvating one end of the N(CN)2- anion.