Photodissociation dynamics of the triiodide anion (I3−)

The spectroscopy and dissociation dynamics of I3− were investigated using fast beam photofragment translational spectroscopy. The photofragment yield of I3− from 420 to 240 nm was measured, yielding two broadbands at the same energies as in the absorption spectrum of I3− in solution. Photodissociation dynamics measurements performed with two-particle time-and-position sensitive detection revealed two product mass channels having photofragment 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(2P3/2)+I2− and I*(2P1/2)+I2−. The 1:1 mass channel is from symmetric three-body dissociation to I−+2I.