Concerted proton-electron transfer in pyridylphenols: The importance of the hydrogen bond

Abstract

(Chemical Equation Presented) Slowed down by a break up: One-electron oxidation of intramolecularly hydrogen-bonded phenol-pyridine compounds 1 and 2 involves proton transfer coupled with electron transfer (see scheme; B = base). At the same driving force, 2 reacts substantially slower than 1. The methylene group between the phenol and pyridine groups in 2 breaks the conjugation between the rings, which has a marked effect on the hydrogen bond and is likely the origin of the difference in rate constants. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.