Eric E. Bancroft

On the mechanism of the electrochemical reduction of N-methylpyridinium ion

The electrochemical reduction of N-methylpyridinium ion (NMP+) at concentrations <2 × 10−4 M in aqueous solution in the pH range of 5–11 has been shown to he a one-electron process which gives rise to 1-methyl-1,4-dihydropyridinyl radicals. These pyridinyl radicals undergo rapid dimerization for which the bimolecular rate constant has been shown to be in excess of 1 × 107 M−1 s−1. The formal potential for the reduction of NMP+ in aqueous 1.0 M KCl is found to be −1.372 V vs. NHE. The formation of the pyridinyl radical as a transient intermediate in the electroreduction of NMP+ has been established by spin trapping using α-phenyl-N-tert-butyl nitrone.

Derivative cyclic voltabsorptometry of cytochrome c.

Abstract The recently reported method of derivative cyclic voltabsorptometry has been applied to horse heart cytochrome c at fluoride doped tin oxide optically transparent electrodes. The advantages of the derivative cyclic voltabsorptometric method compared to voltammetric methods in analytical, kinetic and mechanistic studies are discussed.

Interfacial spin trapping in model membrane systems

Summary Spatially resolved spin trapping in ordered media has been demonstrated by using an amphiphilic nitrone derived spin trap co-assembled with other amphiphiles to form either micelles or vesicles. The ability of α-(4-dodecyloxyphenyl)-N- tert -butyl nitrone to trap transient phenyl radicals generated either in the bulk aqueous phase or in the hydrophobic region of the vesicle or micelle confirms its location and function at the “membrane”/solution interface. These results establish that reactions involving transient free radicals occurring at the interface of ordered systems can be studied using spatially resolved spin trapping.