Fig. 7. Difference in the first and second oxidation potential ΔE11/2 (orange) and ΔE21/2 (red) for (a) charged [2]rotaxane 1 and (b) non-charged [2]rotaxane 2 in comparison to the free macrocycle TTFC8. Half-wave potentials were obtained by CV measurements with a 1 mM analyte concentration, 0.1 M TBAX– electrolyte concentration and 100 mV s–1 scan rate referenced against Fe(Cp*)2 0/+. (c) Top view scheme to illustrate electrostatic forces in different redox states (CH2Cl2, TBABArF24) and resulting stabilisation and destabilisation energies between axle and macrocycle in [2]rotaxanes 1 (left) and 2 (right).
