Atmospheric Autoxidation Chemistry of Diethyl Ether

We report estimates of the rate coefficients for atmospheric autoxidation chemistry of diethyl ether (DE), a simple aliphatic ether, as a representative for the ether family, an important class of volatile chemical products (VCPs). We perform chamber experiments to estimate the rate coefficients of the H-shift reactions of peroxy radicals (RO₂) formed by hydroxyl radical (OH) oxidation of DE relative to the rate coefficients of their reaction with HO₂. We also estimate these rate coefficients for the fully deuterated version, diethyl ether-d₁₀ (DE-d10). Computational methods based on multi-conformer transition state theory are used to guide our interpretation of these rate coefficients. At ambient temperature (294 ± 1 K), H-shift rate coefficients of DE RO₂ are estimated to be ∼0.09 ± 0.06 s^–1, while those of DE-d10 RO₂ are ∼8–15 times smaller due primarily to reduction in quantum tunneling. Our estimates agree well with theoretical predictions. The RO₂ autoxidation rate coefficients are sufficiently fast to be competitive with their bimolecular reactions when NO levels are less than ∼1 ppb─common urban atmospheric conditions following the cont© 2025 American Chemical Societyrols of NO_x emissions, indicating efficient formation of highly oxygenated organic molecules (HOMs), which can be important secondary organic aerosol (SOA) contributors, from volatile ether compounds.