New Instrumental Approaches to Fast Electro-Chemistry at Ultramicroelectrodes

Abstract

The advent of ultramicroelectrodes has opened up the possibility of performing electrochemical kinetic measurements conveniently on timescales of nanoseconds. Thus, it should become possible to resolve fast kinetic events in electrode processes that could only be surmised on the basis of conventional measurements in the millisecond or high microsecond domains. The fast kinetic methods used in homogeneous chemistry, such as pulse radiolysis and flash photolysis, have already demonstrated that many chemical steps proceed in the picosecond, nanosecond, and low microsecond regimes. Among them are examples of certain importance to electrochemistry, including electron transfers, proton transfers, ejections of leaving groups, ligand exchanges, and isomerizations. By and large, electrochemistry has been blind to chemistry on these timescales and has suffered from a relative inability to define the mechanisms of electrode processes as a consequence.