Mechanism of Photooxidation of Glyoxal and Formaldehyde in Solid O2 at 12-18 K

Article abstract of DOI:10.1021/j150667a005

The UV photoxidation of solid O2/trans-H2C2O2 samples at 12-18 K gives diformylperoxyl, 2, as the most important primary product (via facile intermediacy of HCO radicals) and *2CO as an important secondary photolysis product.Degradation of these products gives HC(O)OO*CO, HCOOH*CO^x, H2O2*2CO, H2O*CO2, CO, and CO3.A 30 K warm-up generates H2O2*2CO from 2*2CO by thermal decomposition.The photooxidation of the solid O2/H2C2O2 system is driven less to completion than the photooxidation of the solid O2/H2CO system; because the latter system has more free radical species through the H atom recoil in the H2CO photolysis, the H atoms escape from the photolysis cage and hence a significant change in the photolysis cage stoichiometry occurs.