Before proceeding to study the effect of quinone functionalisation on electrochemical CO 2 capture, we compared the computed and experimental CV redox potentials for selected AQ derivatives to evaluate the reliability of the DFT calculations. In all cases, E • 1 is more positive than E • 2 as it is easier to reduce Q than Q -. This is because (i) the gain of an electron is more favourable for neutral Q than for negatively charged Q -on electrostatic grounds and (ii) there is a greater contribution from solvation to the reduction driving force for the second than the first reduction (Figure ).