By saturating a DMF solution with CO2, C2O4 2-is expected to exist almost exclusively as C2O4 2-•CO2, eq 8. In this way, the voltammetric behavior of C2O4 2-•CO2 can be examined independent of free C2O4 2-in solution. Addition of DiMeFc to a CO2-saturated solution containing C2O4 2-can then be used to determine whether eq 14 occurs. Furthermore, successful oxidative reduction of 4-BrBN in a saturated CO2 solution can provide evidence that CO2 •-is generated through the course of C2O4 2-•CO2 oxidation.