The photofragmentation of CO2-(H2O)(m), m = 3-20 at 355 nm yields two types of anionic products: O-(H2O)(m-k), 1 <= k <= 3, and CO2-(H2O)(m-k), 4 <= k <= 9, depending on the parent cluster size. The O-(H2O)(m-k) fragments, attributed to the dissociation of hydrated CO2-, are dominant for m = 3-7, while the water-evaporation products, CO2-(H2O)(m-k), take precedence for m = 8-20. The dissociation of CO2-is proposed to proceed via a hydration-stabilized excited state, originating from a low-lying CO2- resonance. In the evaporation channel, the suggested routes include cluster predissociation, CO2-photodissociation/recombination, and charge transfer to solvent. (c) 2006 Elsevier B.V. All rights reserved.