Figure 4: Voltammograms of complex 2; 10−3 M in CH3CN with TBAP 10−1 M obtained in presence of nitrogen base 10−2 M and benzoic anhydride 10−1 M under nitrogen and then oxygen atmosphere at scan rate 25 mV s−1. (a) 1-methylimidazole; (b) 2-methylimidazole, (full line: with pure benzoic anhydride; dotted line: with benzoic anhydride containing 2-3% of its acid).