Magnetic Field Effects on the Photolysis of p-Benzoquinone Derivatives in Sodium Dodecyl Sulfate Micelles

Article abstract of DOI:10.1021/j100243a036

Magnetic field effects on the photochemical reactions of p-benzoquinone derivatives were studied in sodium dodecyl sulfate (SDS) micellar solutions by steady-state and nanosecond laser flash photolysis.The relative quantum yield of the disappearance of quinones by steady irradiation decreases with increasing magnetic field up to 250-350 G and then reaches a constant value.In the leser flash photolysis, the decay of a transient due to the semiquinone radicals in micellar solution consists of "fast " and "slow" decay components (ca. 100 ns and 50-100 μs), the intensity ratio of which decreases by 20-40percent with a magnetic field of 400-1000 G.The triplet - singlet intersystem crossing (isc) of a 2,5-dimethyl-p-benzosemiquinone - dodecyl sulfate ion radical pair is 2.6*10⁶ and 1.0*10⁶ s^-1 at 0 and 950 G, respectively.The results are discussed in terms of the radical-pair model in which the triplet - singlet intersystem crossing of radical pairs is influenced by the external magnetic field.