Formation of molecular iodine by photodissociation of CF2I2 at 193 nm

Difluorodiiodomethane CF2I2 has been studied by photofragment translational energy spectroscopy at 193 nm. The analysis of the TOF spectra revealed three decay pathways: a three-body decay CF2I2 + hv --> CF2 + I + I (75%) and two distinctly different molecular decays CF2I2 + hv --> CF2 + I-2 (21%) followed by a complete secondary decay of I-2 to I + I, and CF2I2 + hv --> CF2 + I-2 (4%) producing stable iodine molecules. The latter involves electronic product excitation consistent with CF, in its first excited singlet state. The measured anisotropic recoil distributions are in agreement with these processes and indicate absorption at 193 nm to prepare mainly an electronic state of A(1) symmetry. (C) 2000 Elsevier Science B.V. All rights reserved.