The IF B-X system: New high resolution L.I.F. spectrum and analysis

The technique of laser induced detection of chemical reaction products has been used to study the reaction: I 2 + F → IF + I. Using a single frequency dye laser and an accurate wavenumber measurement, the X 1 Σ + → B 3 Π(0 + ) excitation spectrum of the product IF molecules has been studied with high resolution over a large spectral range (700-789 nm and 837-873 nm). Due to the exoenergicity of the reaction very high rovibrational levels are populated in the X state up to ν″ = 20. Our measurements, together with those of previous authors, have allowed us to obtain an improved and extended spectroscopic representation of the X and B states of IF in terms of Dunham coefficients.