Pulsed supersonic expansions of CF2 studied by diode laser spectroscopy

The vibration-rotation spectrum of the ν3 band of CF2 radical has been recorded in a supersonic expansion by tunable diode laser absorption spectroscopy near 1114 cm−1. The radical was prepared by pulse pyrolysis of hexafluoropropylene oxide, which decomposes at relatively low temperatures. The rotational temperature of CF2 has been evaluated to be 260 ± 15 K for a heating nozzle temperature of 1225 K. The average absolute number density of the radical at the nozzle exit in the jet has been obtained, and the efficiency of precursor conversion into CF2 is shown to be nearly unity at 1225 K.