To investigate the key electron transfer steps in the electrochemical system, cyclic voltammetry (CV) was performed (Figure ). To simplify the experimental setup, the L7•Cr III complex was independently synthesized by treatment of L7 with NaH (1.0 equiv) in THF followed by direct addition of solid CrCl3•3THF to give a purple-green solid. 17a L7•Cr III exhibited quasireversible behavior with a large peak-to-peak separation (1.84V) and a cathodic peak potential of -1.53V at 100 mV/s (compared to ~-1.42V for the unligated CrCl3•3THF complex) (Figure ). Both CrCl3 and L7•Cr III exhibited scan-rate dependent shifts in the cathodic peak potential with large half-peak to peak separation, suggesting that reduction at the cathode is kinetically slow. When compared to CrCl3, the cathodic peak current of the L7•Cr III catalyst is approximately 110 mV more negative, with an onset potential that is 150 mV more cathodic, suggesting the ligand increases the reduction potential of the complex or that it imposes an increased overpotential. Finite element simulation of the CV supported sluggish kinetics for the direct reduction of L7•Cr III , as the voltammetry was best fit with low heterogeneous electron transfer rate constant of 1x10 -5 cm s -1 (for comparison, fast reversible redox couples typically exhibit rate constants near 0.1 cm s -1 ). RAE 2 has a peak potential of -1.63V vs Fc/Fc + under the same CV conditions (Figure 5c, iii). This value lies close to the peak potential of L7•Cr III (-1.53V), which could result in direct reduction of 2 at the cathode competing with reduction of L7•Cr III given the challenging nature of the direct reduction of the Cr III species. Thus, TDAE-mediated reduction of L7•Cr III could allow the reaction to proceed more rapidly and at less-negative potentials, which could then avoid possible deleterious direct reduction of RAE 2.