The production of organic nitrates from atmospheric oxidation of ethers and glycol ethers

The production of organic nitrates from OH reaction (in the presence of NO) with methoxy propane, 1-methoxy-2-propanol, ethoxy butane, and 2-butoxyethanol was studied, The measured total organic nitrate yields were 1.8 (±0.4)%, 0.98 (±0.2)%, 7.7 (±2)%, and 9.6 (±1)%, respectively. The total organic nitrate yield for methoxypropane is 26% of that (7.0%) for n-butane. The organic nitrate yield for ethoxy butane is 55% of that (14%) for n-hexane. The peroxy radicals produced from OH reaction with the methylene groups α to the ether linkage have an organic nitrate branching ratio (k _3b/k ₃) value ∼50% of those in analogous n-alkanes. On the other hand, k _3b/k ₃ values for peroxy radical functional groups not adjacent to the ether linkage (in γ and δ positions) are on average 1.7 times greater than for the analogous n-alkyl peroxy radicals. The organic nitrate formation yield for 1-methoxy-2-propanol is almost half that of methoxy propane, while for 2-butoxyethanol it is 21% greater than that of butoxyethane. Our data lead us to the conclusion that the ether linkage imparts an inductive effect that decreases the value of k _3b/k ₃ for peroxy radicals adjacent to it, yet has a stabilizing effect, from the additional vibrational modes for those peroxy radicals not adjacent to it, increasing their k _3b/k ₃ values, The effect of both the -O- and OH groups in these molecules and the importance of their position relative to the peroxy group are discussed in this paper.