Vacuum ultraviolet spectrum of dinitrogen pentoxide

Absolute photoabsorption cross-sections at 195 +/- 3 K are reported for din itrogen pentoxide, N2O5, between 150 and 240 nm. The spectrum consists of a broad intense band with a maximum at 160 nm. The lack of sharp features in dicates that excitation of N2O5 results in dissociation over the whole of t he spectral range studied. At wavelengths above 200 nm, our results are up to 30% smaller than the current NASA recommendation, but are in generally g ood agreement with a more recent measurement. Below 200 nm, there are no re ported data with which to compare our work. (C) 1999 Elsevier Science Ltd. All rights reserved.