The electrochemistry of BTDN without any other reactants has been previously described and shows two reversible reductions at -1.06 and -1.89 V vs Fc 0/+ in MeCN. When the solution is saturated with CO2 there is a clear change in the current response (Figures and). The first reduction varies slightly, less reversibility is seen at slow scan rates (Figure ). At the second reduction, there is clear evidence of a chemical reaction occurring (Figure ). The reduction peak becomes almost fully irreversible, there is a slight anodic shift of the peak potential and an increase in current is seen (Figure ). This is the typical behaviour of an EC (electrochemical step followed by a chemical step) , indicating that the doubly reduced species interacts with the dissolved CO2 in the solution. The increase in current also shows that more electrons are transferred in this reaction which is indicative of an ECE or disproportionation (DISP) reaction. A new feature that arises under the CO2 atmosphere is a third reduction wave with an onset point around -2.1 V vs Fc 0/+ reaching a plateau around -2.5 V vs Fc 0/+ . The current of this wave is about twice that of the first and second reduction waves of BTDN, the peak current ratio decreases at faster scan rates (Figure and Table ). The difference in peak current ratios between the scan rates shows that the reactions are quite slow or limited by mass transport of CO2. The comparatively large reductive current at the third reduction and the observation of only one oxidation peak show that multiple electrons have irreversibly been transferred to the presumptive BTDN-CO2 adduct. The first reduction looks unperturbed when compared to the CV in inert Ar atmosphere, this reduction is known to be a one-electron reduction. Using the first reduction at slow scan rate as benchmark and comparing the reduction currents (Table ), it can be seen that ∼2 electrons are transferred during the third reduction process at slow scan rates. The transfer of these electrons is not seen in the oxidative scan and hint at an irreversible reductive process taking place in the third reduction wave. At higher scan rates this ratio becomes much smaller, demonstrating that these reactions are limited either by the kinetics of the reaction or by mass transport.