Tris(triazolyl)borate (Ttz) is a proton responsive ligand, and the redox potential of Ttz complexes can be altered by protonation. Protonation events can therefore alter the thermodynamics of reduction of copper complexes, and this is relevant to nitrite reduction mediated by copper complexes wherein Cu(II) reduction to Cu(I) is the first step. The electrochemical behavior of tris(triazolyl)borate and the corresponding copper complexes, Ttz(tBu,Me)CuCI (1) and Ttz(tBu,Me)CuNO(2) (2), was investigated under both neutral and acidic conditions. Upon protonation, reduction of 1 is shifted more positive (Delta E-pc = 290 mV) upon addition of 1.0 equiv. of acid. This result indicates that ligand protonation facilitates the reduction process, which is also evident from the UV-Vis spectral data. In contrast, with the Ttz(tBu,Me)CuNO(2) (2) analog, the reduction peak shifted towards a more negative potential while UV Vis spectra shows no significant changes as acid is added. This suggests that the protons may not be involved in assisting the redox process but rather lead to decomposition events at reducing potentials. Other electrochemical control studies on a series of compounds, namely (Ttz(tBu,Me))ZnCI (3), (Ttz(tBu,Me))K (4), H(Ttz(tBu,Me)) (5), and Htz(tBu,Me) (6), were also conducted with and without acid present. These studies have shown that triazole rings, by themselves and in metal complexes, are not redox active under the conditions we have used. We therefore conclude that the Ttz ligand (including in 1 and 2) is not a site for reduction in our studies. (C) 2017 Elsevier B.V. All rights reserved.