Translational spectroscopy studies of the photodissociation dynamics of O-4(-)

An investigation of the photodissociation dynamics of the dimer anion O-4(-) at 523.6, 349.0, and 261.8 nm is reported. Product translational energy and angular distributions have been obtained using photofragment translational spectroscopy in a fast ion beam. At all wavelengths photodissociation (O-4(-)+h nu-->O-2+O-2(-)) is observed to proceed via a rapid parallel electronic transition, with the photofragment angular distribution strongly peaked along the laser electric vector. The lowest energy photodissociation channel produces O-2(a(1) Delta(g)) and ground state O-2(-)(X(2) Pi(g)), indicating that O-4(-) is a doublet anion. The partitioning of energy in the dissociation reveals a complicated wavelength dependence. (C) 1996 American Institute of Physics.