The experiments detailed in Figure confirm that 3a is a substrate for the cyclic redox reaction network, that 3a undergoes multiple sequential cycles of oxidation and reduction under the standard operating conditions (i.e., [H3N•BD3]0 = 100 mM), and that the oxidation system remains viable over at least 96 hours. Directional rotation of the motor requires, in addition, the rate of enantiomerization of 4a to be greater than the rate of its reduction (i.e., renant > rred); if this condition is not met, the motor oscillates between the two redox states 3a and 4a but without accompanying rotation about the biaryl axis. Furthermore, effective motor operation requires that the rate of oxidation of 3a is the slowest of the three constituent steps (renant > rred > rox(Ra,Sa)) and that the oxidation of 3a proceeds stereoselectively, i.e., rox(Sa)/rox(Ra) ≠ 1. For the deracemization of 1a, the emergence of enantiomeric enrichment proved that these kinetic constraints were met. But directional rotation of 3a has no equivalent stereochemical consequence, so in order to confirm that the motor is operating, we evaluated these rates independently.