Lifetime of singlet oxygen

Moan J, Berg K (1991) The photodegradation of porphyrins in cells can be used to estimate the lifetime of singlet oxygen. Photochem Photobiol 53 549-553. 

The change of p with solvents may be due to either a change of the lifetime of singlet oxygen (1 /kB) or a change of the reactivity of the substrate toward singlet oxygen (kg), or both. Systematic studies of solvent effects are, therefore, very much needed. 

Nonpolar solvents, e.g., halogenated or fluorinated hydrocarbons, suppress electron-transfer reactions and increase the lifetime of singlet oxygen. Polar reactions, such as [2 + 2] cycloadditions, are also considerably reduced in nonpolar solvents. 

Young RH, Brewer D, Keller RA. The determination of rate constants of reaction and lifetimes of singlet oxygen in solution by a flash photolysis technique. J Am Chem Soc 1973 95 375-379. 

Hatz, S., Lambert, J. D. C., Ogilby, P. R., Measuring the Lifetime of Singlet Oxygen in a Single Cell Addressing the Issue of Cell Viability, Photochem. Photobiol. Sci. 2007, 6, 1106 1116. 

RELATIVE LIFETIME OF SINGLET OXYGEN IN AROMATIC SOLVENTS[690]... 

The variability in chemiluminescence from the photooxidation of solid polymer films prevented measurements of /3-values in solid media, where the results would be most pertinent to the general question of polymer stability. We might expect a close correspondence of /3-values to those determined in solution in this work, since the lifetimes of singlet oxygen in benzene and cyclohexane, which should bracket the properties of the polymers in this study, are nearly identical (22). 

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