Estimation of the pKa for various Brønsted acids in polar aprotic media using electrochemical measurements of chromium (III) with picolinic acid

The electrochemical reduction of Crpic and the effect of various proton-donors in DMF were investigated in this work. Measurements showed important electrochemical changes in the presence of proton-donors such as ascorbic acid, benzoic acid and acetic acid. Dissociation constants and acid strength are estimated using the Nernstian behavior of the chromium (III) complex and the proportional relation between ΔEp vs pKa are assistance to estimate the dissociation constants and the acid strength.