Concerted proton-coupled electron transfer from a metal-hydride complex

Area of Science:

• Catalysis
• Organometallic Chemistry
• Electrochemistry

Background:

• Metal hydrides are crucial in catalytic processes like proton and CO2 reduction, and H2 oxidation.
• These reactions involve proton-coupled electron transfer (PCET), often interpreted as stepwise electron and proton transfers.
• A concerted transfer mechanism could offer lower reaction barriers and higher catalytic rates.

Purpose of the Study:

• To investigate the feasibility of concerted, bidirectional PCET in metal hydrides.
• To experimentally establish the mechanism of oxidation-deprotonation reactions in a tungsten hydride complex.

Main Methods:

• Studied the oxidation-deprotonation reactions of a tungsten hydride complex.
• Analyzed the rate dependence on the driving force for both electron and proton transfer.
• Utilized various oxidants and bases to probe the reaction mechanism.

Main Results:

• Provided experimental evidence for concerted, bidirectional PCET in a metal-hydride species.
• Demonstrated that a concerted pathway can be feasible for these reactions.
• Identified factors influencing the reaction mechanism.

Conclusions:

• The findings support the occurrence of concerted PCET in metal hydrides.
• This mechanistic insight can guide the design of more efficient catalysts.
• Future catalyst development should consider concerted PCET pathways for improved performance.