A computational and experimental study of the cyclic voltammetry response of partially blocked electrodes, part III:: interfacial liquid-liquid kinetics of aqueous vitamin B12s with random arrays of femtolitre microdroplets of dibromocyclohexane

The cyclic voltammetric response of electrodes modified with catalytically reactive microdroplets is modelled using finite difference simulations and a method is presented for the determination of kinetic parameters for the coupled heterogeneous reaction. The method is first applied to investigate the liquid-liquid reaction between pure trans-1,2-dibromocyclohexane (DBCH) microdroplets, deposited on the Surface of a basal plane pyrolytic graphite electrode, and vitamin B 12, in aqueous solution. Second, cyclic voltammetry on electrodes modified with micro-droplets of DBCH diluted in dodecane is employed to determine the apparent bimolecular interfacial rate constant for the initial step in the DBCH(oil)B-12s (aq) reaction. The results are compared and contrasted with a previous SECM/ITIES study of a similar reaction. (C) 2003 Elsevier B.V. All rights reserved.