SPECTROSCOPY AND PHOTOABSORPTION CROSS-SECTIONS OF FNO

The spectroscopy and photoabsorption cross sections of nitrosyl fluoride are investigated in the spectral region 350-180 nm. Results for 350-250 nm are in good agreement with the initial measurements of Johnston and Bertin and later measurements from Solgadi and Flament and Huber et al. The spectrum is assigned to a series of vibrational progressions which arise from (0, 0, 0)″ and involve excitation of the ν′1 mode. Excitations to (n, 0, 0)′ and (n, 0, 1)′ make up the bulk of the spectrum, with promotions to (n, 1, 0)′, (n, 0, 2)′, and (n, 1, 2)′ becoming dominant at higher energies. Analysis of the spectrum results in values of ν′1 = 1096 cm-1, ν′2 = 480cm-1 and ν′3 = 349 cm-1 for the excited state FNO frequencies. The experimental basis for the assignment of ν′1 and ν′3 is distinctly stronger than that for ν′2. Below 250 nm, a broad, featureless continuum absorption is observed, which rises in intensity from σ = 1.77 × 10-20cm2 at 245 nm to 5.24 × 10-19cm2 at 180 nm. © 1993 Academic Press, Inc.