Facile analysis of EC cyclic voltammograms.
It has been found empirically that, for an E(rev)C(irrev) process, the forward/backward ratio of the peak height magnitudes in cyclic voltammetry equals 1 + ktau, where k is the rate constant of the chemical reaction and tau is the time required for the scan to travel between the half-wave and reversal potentials. The relationship is largely independent of the scan rate and the reversal potential, except insofar as these influence tau. Though not exact, the relationship is obeyed closely enough to provide accurate rate constants under favorable conditions. The utility of this simple formula in extracting homogeneous kinetic information is demonstrated using experimental data for the electron-transfer-induced isomerization of an octahedral manganese complex. An explanation of the relationship is presented, as is a more exact formula that reduces to 1 + ktau when k is small. A semiquantitative explanation of the relationship is provided.
Hogan
Conor F
CF
School of Chemistry, Monash University, Clayton, Melbourne, Victoria 3800, Australia. c.hogan@latrobe.edu.au
Bond
Alan M
AM
Myland
Jan C
JC
Oldham
Keith B
KB