The products of ultraviolet photolysis of N2O5 are NO3 and a wavelength dependent mixture of NO2, NO*2, and NO+O, where NO*2 represents one or more excited electronic states of nitrogen dioxide. This NO*2 emits the visible fluorescence spectrum of nitrogen dioxide (photolysis induced fluorescence, PIF), and this spectrum was compared with monochromatically excited NO2 fluorescence spectra (laser induced fluorescence, LIF). In a series of experiments, dispersed PIF and LIF spectra were measured where reactant pressure was 200 mTorr, delay time was 30 ns, and observation time was 600 ns. According to results obtained by Sugimoto and co‐workers, under these conditions the continuous spectrum, which reflects the overall internal energy of NO*2, had been little modified by collision, although there was degradation of fine structure. The continuous LIF spectra were fit to an empirical function, and the PIF spectra were shown to be well represented by a linear combination of these mono‐energetic excitation spectra. The coefficients of this linear combination plus other considerations were interpreted to give the almost nascent internal energy distribution of the electronically excited nitrogen dioxide molecules produced by N2O5 photolysis. This non‐Boltzmann internal energy distribution indicates that electronically excited nitrogen dioxide is produced in the 2B1 state when N2O5 is photolyzed.
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Research Article| December 15 1986
Nitrogen dioxide fluorescence from N2O5 photolysis
Daniel Oh, Wade Sisk, Anthony Young, Harold Johnston; Nitrogen dioxide fluorescence from N2O5 photolysis. J. Chem. Phys. 15 December 1986; 85 (12): 7146–7158. https://doi.org/10.1063/1.451348
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