In situ ESR spectroscopic evidence of the spin-trapped superoxide radical, O2−, electrochemically generated in DMSO at room temperature

Superoxide radical (O2−) was both electrochemically generated and detected at room temperature. In situ ESR spectroelectrochemistry with spin trapping was used for the radical detection. That is, the O2− radical was obtained in a DMSO solution under cyclic voltammetry conditions as soon as the potential of the dioxygen electroreduction was reached. This radical reacted then with a 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) spin-trap reagent present in solution to form the DMPO–OOH adduct. The hyperfine coupling constants determined for the adduct were aN = 1.285 mT, aHβ=1.042 mT and aHγ=0.142 mT in accord to those reported in literature.