Photodissociation dynamics of the triiodide anion (I-3(-))

The spectroscopy and dissociation dynamics of I-3(-) were investigated usin g fast beam photofragment translational spectroscopy. The photofragment yie ld of I-3(-) from 420 to 240 nm was measured, yielding two broadbands at th e same energies as in the absorption spectrum of I-3(-) in solution. Photod issociation dynamics measurements performed with two-particle time-and-posi tion sensitive detection revealed two product mass channels having photofra gment mass ratios of 1:2 and 1:1. Both channels were seen at all photolysis wavelengths. Translational energy distributions show that the 1:2 products are from a combination of I(P-2(3/2))+I-2(-) and I*(P-2(1/2))+I-2(-). The 1:1 mass channel is from symmetric three-body dissociation to I-+2I. (C) 20 00 American Institute of Physics. [S0021-9606(00)00730-3].