Electrochemical Characterization of Stable Nitroxyl Radicals, Intermediaries in the Synthesis of 3-Methacryloylamin-PROXYL

摘要

Nitroxyl radicals have suited into materials used as anodes in lithium secondary batteries due to their stability and reversibility during the redox process. In the literature there is a wide range of such compounds, where changes in the size of the molecule and the substituent, provide variation of the redox E°. This paper presents the electrochemical characterization of three compounds obtained during the synthesis of 3-methacryloylamin-PROXYL, 4-oxo-TEMPO (2), 3-bromo-4-oxo-TEMPO (4) and 3-carbamoyl-PROXYL (5). Cyclic voltammetry and direct and double pulse chronoamperometry were used, with a glassy carbon electrode in a 0.1M Bu_4NPF_6 solution in acetonitrile. The oxidation of these radicals is a quasireversible process in which the species involved are stable. The E_(1/2) and diffusion coefficients (D) for the three free radical species were evaluated.