ELECTROREDUCTION OF THE SCHIFF-BASE OF PYRIDOXAL-5'-PHOSPHATE AND HEXYLAMINE IN DIMETHYLFORMAMIDE AND METHANOL - EFFECT OF THE SELF-PROTONATION

The present paper reports an investigation of the electrochemical beha viour of the pyridoxal-5'-phosphate and hexylamine Schiff base in wate r, methanol and dimethylformamide using linear sweep voltammetry, abso rption spectroscopy and controlled-potential electrolysis. The global reduction corresponds to the formation of a secondary amine, hexyl-pyr idoxamine-5'-phosphate, by the uptake of two electrons and two protons in the electrode process. In the aprotic solvent, where the enolimine tautomer is favoured, evidence of a self-protonation effect on the el ectroreduction mechanism is obtained.