Spectroelectrochemical study of the reversible adduct formation of Bis(phthalocyaninato)neodymate(III) complex with CO2 in a DMF solution

The reaction between CO2 and electrochemically reduced bis(phthalocyaninato)neodymate(III) complex in a dimethylformamide solution was investigated by cyclic voltammetry and in situ visible spectroscopy. The introduction of gaseous CO2 into the phthalocyanine solution caused a considerable increase in the first reduction peak current of the complex and a shift in the second reduction peak to more positive potentials. In addition, new anodic current peaks appeared in the reverse sweep at potentials different from those of the complex. These observations were explained in terms of the formation of a CO2-adduct. The formation and decomposition of the CO2-adducts occurred reversibly with the applied potential, which was confirmed by in situ visible spectroscopy.