Semiquinone of 5,6-dihydroxyindole

Indeed, with pulse radiolysis doses of approximately 20 Gy, the semiquinone of 5,6-dihydroxyindole 1 decays predominantly by second-order kinetics, consistent with disproportionation. The rate constant is dependent upon pH, with values at pH... 

There appear to be at least three separate possible pathways for decay of the semiquinone of 5,6-dihydroxyindole 1. These are (i) disproportionation, resulting in the formation of indolequinone 6, which may rapidly rearrange into the... 

In the case of pathway (i), it has been argued (91JCS(P2)1941) on the basis of the similarity of the metastable product spectra (with peaks in the 430 nm region) found after the decay of the semiquinones of 5,6-dihydroxyindole 1 and 5-methoxy-6-hydroxyindole 22 (90JPC6666) that the initial product observed after... 

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