Ba. Coles et al., Non-aqueous electrochemical studies at a high temperature channel flow cell heated by radio frequency radiation, J ELEC CHEM, 513(2), 2001, pp. 87-93
The effect of applied temperature was studied on various non-aqueous one- a
nd two-electron systems of ferrocene, tris(4-bromophenyl)amine and N,N,N',N
'-tetramethyl-1,4-phenylenediamine in acetonitrile solvent at both radio fr
equency channel cell (RFCC) and microdisk electrode apparatus. Experimental
ly obtained diffusion coefficients (D-c) and activation energies (E-A) for
both RFCC and microelectrode experiments are in excellent agreement with ea
ch other and published data. Analysis of the data in terms of the Stokes-Ei
nstein equation is also presented. This expands on previous work done in th
is area to incorporate not only solvent-based systems in addition to simple
aqueous electrochemistry, but also more mechanistically complex electrode
processes with coupled homogeneous kinetics such as ECE reactions. The appl
ication of the RFCC as a tool for mechanistic studies is discussed with the
investigation of the well characterised ECE reaction of in-iodo-nitrobenze
ne in acetonitrile, giving a value of 80 +/- 5 kJ mol (- 1) for the activat
ion energy of the rate constant for the decomposition of the m-iodo-nitrobe
nzene radical anion. This represents, to the authors' knowledge, the first
example of a quantitative, fully modelled investigation of a mechanisticall
y complex electrochemical process at a locally heated electrode. (C) 2001 E
lsevier Science B.V. All rights reserved.