Thomas and Will’s paper, ‘Proton-Coupled Electron Transfer Reactions with Photometric Bases Reveal Free Energy Relationships for Proton Transfer’ was just accepted for publication in the Journal of Physical Chemistry B. In this paper,the PCET oxidation of p-aminophenol in acetonitrile was studied. By using a series of 7-dimethylaminoquinoline proton acceptors, which provided an optical handle for proton transfer, a comprehensive picture of the PCET reactivity was obtained. Spectral analysis revealed a stepwise ET-PT reaction process. Proton transfer rate constants were found to correlate with the pKa of the conjugate acid of the proton acceptor, in agreement with anticipated free energy relationships for proton transfer processes in PCET reactions.
