Role of Proton‐Coupled Electron Transfer in O—O Bond Activation

Abstract

The selective reduction of oxygen to water requires four electrons and four protons. The design of catalysts that promote oxygen reduction therefore requires the management of both electron and proton inventories. Pacman and Hangman porphyrins provide a cleft for oxygen binding, a redox shuttle for oxygen reduction, and functionality for tuning the acid-base properties of bound oxygen and its intermediates. With proper control of the proton-coupled electron transfer events, O-O bond breaking of oxygen, and more generally oxygenated substrates, may be achieved with high efficiencies. The rule set developed for oxygen reduction may be applied to a variety of other small molecule activation reactions of consequence to energy conversion.

RETRACTED ARTICLE: Reduction of carbon dioxide to oxalate by a binuclear copper complex

“…Other researchers have used multifunctional ligands to control the spatial position of two metal centres. Some of the best known examples are the cofacial diporphyrins, which are capable of catalyzing multielectron redox processes [22][23][24] . Several research groups have prepared complexes from dipyridyltriazoles (though they lead to relatively short metal-metal distances) 25 ; other binucleating ligands have also been employed 26 .…”

Hydrogen adsorption engineering by intramolecular proton transfer on 2D nanosheets

“…Both of the organic self-assembled layers demonstrate a much higher reaction potential than the COOH-assembled and OH-assembled Au or even bare Au, which means that intramolecular proton transfer occurs in the COOH and OH functional groups during the HER. As a result, the electrochemistry of the HER in our system avoids energy-wasting reactions while coupling the proton-accepting or proton-donating groups in the MoS 2 catalyst 44 .…”

Ultrafast Photochemistry in Liquids

“…Once these pairs have reacted, the reaction occurs between pairs, which are increasingly more remote, and thus the rate decreases continuously until it becomes equal to the rate at which pairs are produced by diffusion, k ∞ . simultaneously or sequentially, have received considerable attention over the past three decades, from both experimental (119) and theoretical groups (120)(121)(122), owing to their importance in areas covering such diverse topics as photosynthesis (57), catalysis (123), and hydrogen production (124) or enzyme reactions (125). Here we emphasize only photoinduced PCET reactions, which are relevant for biological processes such as radiation-induced DNA damage (126) as well for the primary events in solar cells (127), and how nonequilibrium processes, triggered by the absorption of light, can affect them.…”