Electrode reaction schemes and standard potential of solvated electron electrode in methylamine

Abstract

Potential-sweep and cyclic voltammetric studies on solutions of LiCl, NaI, KI and CsI in methylamine indicate that the cathodic reaction is the dissolution of electrons from the electrode metal into the solution and/or the deposition of alkali metal M on to the electrode, depending on the solubility of M. On the basis of these findings, the electrode reaction schemes for the respective salt solutions are written in terms of the solvated electron species: free solvated electron e s − , ion pair (M + ·e s − ) and alkali anion M − . These species involved in the prevailing reaction paths agree with those proposed by pulse radiolysis studies on alkali metal methylamide solutions in methylamine. The formal standard potential of the metal/e s − electrode found is −2.90±0.02 V vs. Ag/AgNO 3 (0.02 M ) at −50°C. From this value the chemical solvation energy for e s − is evaluated as −1.26 eV.