Revisiting H‑Bond <i>v</i>. PT: The Role of Precursor and Successor Complexes in Intermolecular, Stepwise Proton-Coupled Electron Transfer.

ABSTRACT: Multiple mechanisms have been proposed to explain the electrochemical proton-coupled electron transfer (PCET) of arylenediamines upon weak base addition in aprotic media. Similar to quinone electrochemistry, endergonic deprotonation to form freely diffusing products is a central criterion used to exclude proton transfer. However, the second oxidation wave of arylenediamines shows large, chemically reversible E _1/2 shiftsoften exceeding hundreds of millivoltsupon base addition. To explain these effects, proposed mechanisms invoke strong H-bonding or H-bonding followed by nonconcerted PCET. Here, we elucidate a new mechanism using cyclic voltammetry of a new arylenediamine series where the pK _a is varied via π-electron spacers. A thermochemical analysis,

SUBMITTER: Williams N 

PROVIDER: S-EPMC12593132 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature