1. Reaction free energy and direction of rotation. It is relatively trivial to construct an equation (see ESI) for the ratchetting constant, r0, of catenane 6, 13g which describes the direction of rotationif r0 > 1 it cycles in one direction at non-equilibrium steady state, if it is < 1 it cycles in the other. Based on the form of eq. 3 motor 6 can turn in either direction depending on the concentrations of FmocCl, Et3N, CO2 and Et3NHCl (see ESI). Indeed, superficially we might draw the conclusion that since eq. 3 does not contain an explicit free energy term, the energetic properties of the coupled reaction do not matter. However, this would be disingenuous because 𝐾 rxn = 𝑒 -∆G rxn 𝑅𝑇 , which we can substitute to generate eq. 3a. ] (eq 3a)