The photodissociation of I-2(-) embedded in mass-selected I-2(-)(Ar)(n) clusters (n = 6-20) was studied using femtosecond photoelectron spectroscopy. The (A) over tilde'<--(X) over tilde transition in the I-2(-) chromophore was excited using a femtosecond pump pulse, and the subsequent dynamics were followed by photodetachment with a femtosecond probe pulse and measurement of the resulting photoelectron spectrum. In all clusters, dissociation of the I-2(-) is complete by 300 fs. From 300 fs to 1 ps, the spectra yield the number of Ar atoms interacting with the I- fragment. At later times, recombination of I-2(-) occurs in I-2(-)(Ar)(n greater than or equal to 12) on both the (X) over tilde and (A) over tilde states. Analysis of the spectra yields the time scale for (X) over tilde state vibrational relaxation and solvent evaporation. In I-2(-)(Ar)(20), energy transfer from I-2(-) to Ar atoms through vibrational relaxation is slightly faster than energy loss from the cluster through Ar evaporation, indicating the temporary storage of energy within Ar cluster modes.