Spectroelectrochemical study of N-hydroxyphthalimide and phthalimide-N-oxyl generated in an optically transparent thin-layer electrochemical voltammetry

Abstract

The combination of a sulfuric acid-acetonitrile mixed electrolyte solution and thin-layer spectroelectrochemical voltammetry enables the measurement of the potential-dependent spectrum of N-hydroxyphthalimide (NHPI) over the visible-ultraviolet-deep-ultraviolet wavelength region. The spectra change reversibly with the application of potential in the potential region where the reversible proton-coupled electron transfer of NHPI occurs. It was found that the absorption band supporting the formation of phthalimide-N-oxyl radical is generated in the deep-ultraviolet region by electro-oxidation.