The photochemical reaction of chrysene under UVA light irradiation in acetonitrile/water yields 1,4- and 5,6-chrysenequinones and one lactone, H-benzo[d]naphtha[1,2-b]pyran-6-one. Solvent-dissolved oxygen is necessary for the photolysis. The presence of TiO2, Al2O3, La2O3, KI, or I2 decreased the photolysis rate. The free radical scavenger, Na2S2O3, greatly suppressed the chrysene photolysis, indicating that a free radical process was involved. Also, a self-catalysis phenomenon for chrysene photolysis was observed and investigated.
