Radiation chemistry of ethers. Part VI. Photolysis at 254 nm of the diethyl ether–oxygen charge transfer complex

Abstract

Oxygen-saturated diethyl ether exhibits a charge transfer absorption band (λ_max. 215 nm) with considerable absorption at 254 nm. Photolysis was carried out with a low pressure mercury arc. Photolysis of products was avoided by keeping conversion low, and chain reactions were minimized by working at –30°. The major products(quantum yields) were: H₂O₂(0·24), 1-ethoxyethyl hydroperoxide (0·04), ethyl acetate (0·26), acetaldehyde (0·18), ethanol (0·18), ethyl formate (0·04), methanol (0·035), formaldehyde (0·005), and ethyl vinyl ether (0·013). A satisfactory material balance was obtained. The products formed are consistent with a primary photoprocess involving transfer of an electron to the O₂ to give O₂^–. Further, deprotonation of the ether radical cation in the presence of O₂ leads to the 1-ethoxyethylperoxyl radical. With the exception of 1-ethoxyethyl hydroperoxide all major products are believed to arise from disproportionation reactions of these two radicals.