Laser-Photolysis Study of the External Magnetic Field Effect upon the Photochemical Processes of Carbonyl Compounds in Micelles

Article abstract of DOI:10.1021/j100213a023

The external magnetic field effects upon the primary photochemical processes of benzophenone and dibenzyl ketone in sodium dodecyl sulfate (SDS) and other micelles have been studied by nanosecond laser photolysis.The decay rate constants of the ketyl and benzyl radicals in the micelles were found to decrease in the presence of weak external magnetic fields and were determined for the ketyl radical in the SDS micelle as (2.82 +/- 0.05) x 10⁶s^-1 at zero field and (1.89 +/- 0.05 x 10⁶s^-1 at 700G.On the other hand, the amount of the escaping ketyl and benzyl radicals was found to increase in the presence of magnetic fields.Magnetic isotope effects were studied and the decay rate constants in SDS micelles at 700 G were determined as (2.16 +/- 0.05) x 10⁶s^-1 for (C6H5)2(13)COH and (1.86 +/- 0.05) x 10⁶s^-1 for (C6D5)2COH.The observed magnetic field and magnetic isotope effects were interpreted in terms of reductions in the triplet-singlet conversion rates of intermediate radical pairs in the presence of magnetic fields.