MULTIPLE-PHOTON EXCITATION OF DIFLUOROAMINO SULFUR PENTAFLUORIDE - STUDY OF ABSORPTION AND DISSOCIATION

Multiple-photon absorption and dissociation experiments with difluoroamino sulfur pentafluoride (SF5NF2) along with results of previous experiments with SF6 and S2F10 have led us to conclude that while the density of vibrational states of a polyatomic molecule influences the absorption process, the specific structure of an absorbing species is probably a more important factor. Absorption of intense infrared radiation by SF5NF2 occurs with virtually no decrease in the absorption cross section, up to a fluence of 0.03 J/cm 2. This fluence level is sufficient for isotopically selective cleavage of the weakest molecular bond (S-N). The reaction probability increases with about the third power of the laser energy fluence. The infrared absorption spectrum of SF5NF2 has three strong absorption bands between 850 and 1000 cm-1. Reaction probability is much greater for irradiation at frequencies within the center band than within the high frequency band. © 1979 American Institute of Physics.