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Laboratoire d'Electrochimie Moleculaire, LEM, Paris

UMR CNRS - Université Paris Diderot - Paris France

   
 
Master Frontiers in Chemistry | UFR de Chimie - Université Paris Diderot - Paris 7 CNRS - Institut de chimie Université de Paris Master Chimie Sorbonne Paris Cité UFR de Chimie - Université Paris Diderot - Paris 7 CNRS - Institut de chimie
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Université Paris Diderot
Université de Paris CNRS, Centre National de la Recherche Scientifique
 
 


Le LEM - Publications: Abstracts

Publication 604

J. Am. Chem. Soc. , 128, 8726 -8727, 2006.
DOI: 10.1021/ja0621750
 
 

Carboxylates as Proton-Accepting Groups in Concerted Proton-Electron Transfers. Electrochemistry of the 2,5-Dicarboxylate 1,4-Hydrobenzoquinone/2,5-Dicarboxy 1,4-Benzoquinone Couple

Cyrille Costentin, Marc Robert, and Jean-Michel Savéant*

Contribution from the Laboratoire d'Electrochimie Moléculaire, Université de Paris 7-Denis Diderot, 2 place Jussieu,75251 Paris Cedex 05, France

 


Concerted proton and electron transfers (CPET) currently attract considerable theoretical and experimental attention, notably in view of their likely involvement in many enzymatic reactions. The role of carboxylate groups as proton-accepting sites in CPET reactions is explored by means of a cyclic voltammetric investigation of the 2,5-dicarboxy 1,4-benzoquinone/2,5-dicarboxylate 1,4-hydrobenzoquinone couple in a nonaqueous medium. The presence of carboxylate groups ortho to the phenol groups induces the removal of an electron to be coupled with the transfer of the phenolic proton to a carboxylate oxygen. The kinetics of the electrochemical reaction and the observation of a significant hydrogen/deuterium kinetic isotope effect unambiguously indicate that electron transfer and proton transfer are concerted, thus providing an additional demonstration of the role of carboxylate groups as proton-accepting sites in concerted proton-electron transfer reactions.
 
   
 
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