Abstract Upon irradiation in 2-propanol, p-nitroacetophenone 1 was reduced via the triplet state to p-hydroxyaminoacetophenone 5 which was further reduced to p- aminoacelophenone 2 and 4, 4′-diacetylazobenzene 4. Similar irradiation of 5 also gave 2 and 4, and its oxidation by oxygen gave 4, 4′-diacetylazoxybenzene 3. Photolysis of monomeric p-nitrosoacetophenone 6 afforded acetophenone and 3 that were not ...