Polarogmphic study of azo derivatives of 3-hydroxypyridine

Abstract

It was established that in most cases azo derivatives of 3-hydroxypyridine are reduced successively in two one-electron steps at more positive potentials than azobenzene on a dropping mercury electrode in anhydrous dimethylformamide (DMF) with a 0.05 N solution of tetraethylammonium perchlorate as the base electrolyte. However, one two-electron wave was observed for some compounds; this is evidently associated with self-protonation owing to the presence of the appropriate substituents. Some 3-hydroxypyridine derivatives exist in DMF in various tautomeric forms, as a result of which additional reduction waves appear. More pronounced reduction with respect to the azo group is observed only for three of the investigated compounds.