This suggests that (CN)2 release is an electrochemical over-oxidation process rather than a potential-independent reductive coupling process. We propose that at high potentials Fe 3+ is oxidised triggering the release of a CN ligand according to Eq. 9, which in turn can either recombine forming (CN)2 (Eq. 10) or attack EC forming CO2 and HCN (Eq. 11). Since we see no evidence for HCN (m/z=27) it is therefore likely it is further oxidised according to Eq. 12,