Fractionation of 4N5N60 and 5N4N60 During Photolysis at 213 nm
نویسندگان
چکیده
Motivated by Yung and Miller's [199• suggestion that N20 is isotopically fractionated during UV photolysis in the stratosphere, we have studied the photolysis rates of the •4N•SN•60 and •SN•4N•60 structural isotopomers. In this study, we follow the concentrations of these compounds with FTIR spectroscopy during photolysis at 213 nm. When fitted to a Rayleigh fractionation model, the observations yield single-stage enrichment factors of e(•4N•SN•O / •4N•4N•O) = -73 q5 per mil and e(•SN•4N•O / •4N•4N•O) -41 q10 per mil. As predicted by Yung and Miller [199•, the photolysis rate of •SN•4N•60 is faster than •4N•SN•O at this wavelength. The magnitude of the observed fractionation, however, is significantly larger than predicted.
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