Studies in vacuum ultraviolet photochemistry IV. Diethyl ether

Diethyl ether has been photolysed at 147 and 123 nm in the gas phase at pressures of 2-200 Torr and conversions <0.5%. The most important primary process is that involving C-O fission [reaction (i)]. The majority of the Et-O-Et + hv ? Et + EtO (i) ethoxyl radicals decompose in an early vibration by loss of a methyl radical [reaction (ii)]. There is a small contribution from a second primary process [reaction (iii)] involving elimination of hydrogen. The ratio process (i): process EtO ? Me + HCHO (ii) Et-O-Et + hv ? EtOCH=CH₂ + H₂ (or 2H) (iii) (iii) is ca. 60. The overall photochemistry is interpreted in terms of these primary processes, and subsequent reaction of the radical products.