The effect of microhydration on the one-electron uptake of a prototypical disulfide is examined at the MP2/DZP++ level of theory. After systematic generation of low-lying conformers of dimethyldisulfide water clusters (DMDS: nH(2)O, n = 1-5), either neutral or anionic, it is found that their energy ranking is governed by the increasing strength of the three hydrogen bonds involved, namely, water-neutral DMDS bonds, intra-water bonds and water-anionic DMDS bonds. Their optimal values are respectively 3.5, 4.5 and 11.4 kcal/mol. The inclusion of a limited number of water molecules has a non-negligible impact on structure and UV Vis absorption of DMDS radical anion. Furthermore, its formation is favored by up to 1.04 eV when explicitly solvated by five water molecules. (C) 2009 Elsevier B.V. All rights reserved.