The photolysis of aqueous systems at 1849 A I. Solutions containing nitrous oxide

Yield-time curves have been obtained for the illumination with 1849 $^\overset{\circ}{\mathrm A}$ light of aqueous solutions of N$_2$O and the effect on these of added methanol has been measured. The results indicate that: (i) the oxygen atom produced by photolysis of N$_2$O is in a singlet state, $^1$S or $^1$D, and can insert into a water molecule forming hydrogen peroxide, a conclusion confirmed by use of N$_2^{18}$O; (ii) the H$_2$O$_2$ is attacked and decomposed to oxygen and water by II atoms and OH radicals produced in the photolysis of water; (iii) if ~$\phi$(N$_2$0 + hv $\rightarrow$~ N$_2$ + O) is unity, ~$\phi(\mathrm{H}_2\mathrm{O} \rightarrow \mathrm{H} + \mathrm{OH = 0.30\pm0.3$ and ~$\phi(mathrm{CH}_3\mathrm{OH} + hv \rightarrow \mathrm{CH}_2~O+H_2$ or $\mathrm{CH}_3O+H)$ = 0.46\pm0.05; (iv) if the linear extinction coefficient of H$_2$O for 1849 $^\overset{\circ}{\mathrm A}$ light is 1.8 cm$^{-1}$ that for D$_2$O is 0.14 cm$^{-1}$ and the molar extinction coefficient for N$_2$O is 60$\pm$+8 M$^{-1}$ cm$^{-1}$; and (v) when two CH$_2$OH radicals interact ca. 4% form CH$_2$~O + CH$_3$OH and 96 % form (CH$_2$OH)$_2$.