M. R. Montoya, J. R. Mellado, R. M. Galvín
Oct 25, 1990
Citations
0
Influential Citations
15
Citations
Journal
Journal of Electroanalytical Chemistry
Abstract
Abstract Nicotinamide N 1 -oxide was studied by dc and DP polarography and voltammetry from strongly acidic solutions (5 M H 2 SO 4 ) to solutions of pH 12. Tafel slopes and reaction orders were obtained at potentials corresponding to the foot of the polarographic waves. The effect of pH, reactant concentration, proton donors and drop time on the polarographic and kinetic parameters is studied. The results indicate that the protonated form of the N -oxide group is reduced in acidic media, whereas the unprotonated form is reduced at pH > 9. In both cases the reduction product is nicotinamide. At pH − group, this reaction being placed between the two one-electron transfers. At pH > 9, the protonation of the species formed after the first one-electron transfer is the rds. In the latter case, the proton donors present in the solution are involved in the reaction.