A summary of the thermodynamic and kinetic values of the reactions used in FD simulations are given in Table . Keq values are based on E 0 values and literature free energy data as described in the Supporting Information. With the exception of reaction 24, all rate constants listed in Table are obtained from prior measurements reported in the literature. The rate constant for the reduction of S2O8 2-by Ru(NH3)6 2+ , kf , was determined by cyclic voltammetry, and recently confirmed by steady-state microelectrode voltammetry and SECM. The rate of dissociation of S2O8 3•-, kf , was previously estimated from DFT to be > 5 x 10 12 s -1 ; however, the results of the FD simulations were found to be insensitive to values of kf 8 greater than 1 x 10 6 s - 1 . Values of kf and kf were independently obtained by separate specialized SECM measurements. Values of kf and kf where determined by flash photolysis experiments. With these literature values in hand, the rate constant for reaction 24 was determined by optimizing the fit of FD simulations to the experimental CV results, as described below.