Reactive species triplet oxygen atom

Riboflavin or vitamin makes a prosthetic group of flavin enzymes where it can be reversibly reduced by hydrogen atoms (formula [38]). When exposed to light, riboflavin absorbs energy and reacts, via a triplet exited state, with other molecules such as protonated substrates or molecular oxygen, generating reactive species. In the type I photodynamic reaction, energy is transferred from a triplet sensi-tiser to O2 with the formation of O2. 

Homogeneous gas phase reactions with the reactive hydroxyl species (OH), triplet atomic oxygen (O P) and ozone (O3) together with photol)d ic decomposition were found to be the most important breakdown mechanisms. These are typical reactions of hydrocarbon compounds in the atmosphere. The rates of the various removal processes are highly dependent upon environmental variables such as the intensity of sunlight and the concentrations of other pollutants which act as sources or sinks of the above reactive species. A summary of the breakdown rate predictions appears in Table 2.10. 

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