Photooxidation of acetone vapor

The photochemical reaction between acetone and oxygen has been studied at temperatures from 100 to 250 °C at several oxygen pressures with light of 3 130 Å. A study of the quantum yields of all the major products has shown the necessity of introducing the reaction to the generally accepted mechanism, with a rate constant about 80 times that of the reaction at 100 °C. Both this reaction and the reaction of acetyl radicals with oxygen appear to have low or negative activation energies, consistent with a rate-determining process involving combination of the radical with oxygen. The reaction of acetonyl radicals with oxygen to give carbon monoxide is not important at temperatures below 150 °C, but it becomes the most important reaction at temperatures above 250 °C.