Electrochemical Oxidation of Primary Amides in Water/AOT/Toluene Reverse Microemulsions

✍ Scribed by Edwin Garcı́a; John Texter

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 167 KB
• Volume: 162
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1994.1037

✦ Synopsis

Compartmentalization of chemistry in reverse micelles and microemulsions has resulted in novel chemistries ranging from organic synthesis through nanoparticle formation ( (1-3) ). Mechanisms of reactant transport in and out of swollen micelles (4) are key to understanding the control of these chemistries, and related questions ((5,6)) pertain to electron and chemical transport in membrane and cellular biology. The characterization of amide oxidation potentials has been motivated by questions concerning the stability, impact of ionizing radiation, and electronic conductivity of proteins and the peptide backbone ((7,8)). The direct observation of the electrochemical oxidation of the amide group has remained clusive, however. The present report appears to offer the first such direct voltammetric characterization. Our observation of compartmentalized amide oxidation in reverse (water-in-oil) microemulsions appears based on an autocatalytic mechanism comprising structuretransitions at the water/oil interface and potential window effects.

The water/AOT/tolucne microemulsion phase diagram has been well documented by Candau and her co-workers ( 9 ), and it has been shown that acrylamide functions as a cosurfactant in this system by expanding the isotropic (single phase) microemulsion region. We have found that primary amides behave similarly to acrylamide, and we have investigated the anodic oxidation of such microemulsions by square-wave voltammetry (SWV) (I0)