A cyclic voltammogram (CV) for the direct reduction of 4-BrBN at a GC electrode in dry DMF is shown by the black trace in Figure where the first reduction wave at ~ -2.4 V corresponds to the irreversible 2e -reduction of 4-BrBN to generate BN. This irreversible reduction is followed by the reversible reduction of BN (BN + e -⇄ BN •-, E 0' = -2.74 V). All CV studies used a three-electrode cell consisting of a GC working electrode, Pt wire counter electrode, and Ag/AgxO quasi-reference electrode (QRE) that was calibrated vs the Fc/Fc + redox couple.