Nitrous oxide absorption spectrum

Selwyn, G., J. Podolske, and H. S. Johnston, Nitrous Oxide Ultraviolet Absorption Spectrum at Stratospheric Temperatures, Geophys. Res. Lett., 4, 427-430 (1977). 

The carbonyl sulfide calculations were not as straightforward as the 2D nitrous oxide work. One issue is that the transition involves three transition dipoles to various states, whereas in nitrous oxide the absorption is dominated by a single transition. The calculation for OCS only considered a single transition. In addition the quality of the potential energy surfaces was not as high, and the 2D approximation not as good, for OCS relative to NNO. An illustration of this is that the predicted OCS spectrum has a maximum at 214 nm while the experimental spectrum has a maximum at 223 nm. In comparison the difference in peak location for NNO was only 3 nm. 

In very rare cases in which photoionization is the only photoprocess, the absorption observed in a nitrous oxide-saturated solution will be that of the cation radical. However, generally, other processes such as intersystem crossing also occur in parallel. In the presence of oxygen, the hydrated electron and the triplet will be scavenged at diffusion-controlled rates, and the absorption observed in the oxygenated solution will be due to the cation radical. Under these conditions, the cation radical spectrum is easily determined. The molar absorption coefficient of the cation radical can also be calculated using the hydrated electron as an internal standard. The molar absorption coefficient for sulphacetamide cation radical was determined in this manner (Land et al 1982) and later confirmed by pulse radiolysis (see Section 12.2.2.6). 

A transient with an excited state absorption AD maximum at 720 nm was detected In dilute natural waters (adjusted to a pH of 7) Irradiated with 266 nm laser light. The AD spectrum plotted 400-450 ns after the laser flash resembled that of the solvated electron in water (21). Nitrous oxide Is known to react specifically with the equated electron. Reaction 1. 

Figure 6.1 Enlarged spectrum of the Rydberg levels and ionization limit of aluminum in the range 206.5 nm to 212.0 nm measured in absorption with a nitrous oxide / acetylene flame (sample 5 g/L Al reference deionized H2O)...

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