When adding salicylic acid as a proton donor to a BTDF solution in THF, there was a clear shift to the CV where the reduction becomes irreversible with a shift to more positive potentials and with an increase in current. In the conditions of the acids at the first reduction potential, BTDF did not perform catalysis for proton reduction (Figure ). This can be explained by the high reductive potential that is probably required to reduce BTDF further which is the requirement for the proton reduction by BTDN on a glassy carbon electrode .