Biphasic Voltammetry of N,N,N′,N′-Tetraphenyl-para-phenylenediamine Microdroplets, Microparticles and Microparticle Suspensions



The aqueous biphasic voltammetry of the title compound is examined when it is immobilised on an electrode surface either when dissolved in an array of nitrobenzene droplets, in the form of solid microparticles, or when an electrode is immersed into a three-dimensional aqueous suspension of the solid. In each case, a different electrode reaction is observed to occur, even though the supporting electrolyte is unchanged, with either counter ion transfer across a liquid | liquid interface, or with electrochemical dissolution of the solid particles, or a suggested diffusive-type electron hopping between individual redox centres embedded within the solid crystals.