Oxidation and Reduction of Porphyrins

An ambipolar PEDOT-perfluorinated porphyrin electropolymer: application as an active material in energy storage systems

“… 75,76 Superimposed in this broad oxidation might be also involved the oxidation of the porphyrin macrocycle. 70,73 A similar electrochemical response has been reported for a film obtained after electropolymerization of a EDOT-trimer mono substituted porphyrin monomer. 78 The peak currents for the redox systems present a linear relationship with the scan rate ( Fig.…”

“…This is a consequence of the electron-withdrawing effects characteristic of the perfluorinated benzene rings. 69,70 On the other hand, EDOT-TPPF 16 exhibits similar quasireversible reductions but only one irreversible oxidation peak at around 1.25 V (cyan voltammogram in Fig. 1a), with a peak current value around four times higher than the first reduction peak.…”

“…These results are typical for free base porphyrins, which usually show two well-dened reversible single-electron macrocycle oxidations and reductions in nonbinding solvents, 69 related to the formation of the corresponding radical cation and dication, and radical anion and dianion, respectively. [70][71][72] However, it is known that peripheral substitution in tetraphenyl porphyrins has a strong effect in modulating their electron donor-acceptor capabilities. In the present case, we observed that the TPPF 20 oxidation occurs at more positive (anodic) and the reduction at less negative (cathodic) potentials compared to the values reported for tetraphenyl porphyrins without substituents.…”

“…The two redox systems at negative potentials can be associated with the reductions of the porphyrin macrocycle, generating the corresponding radical anion and dianion. [69][70][71][72] The broad oxidation can be due to the oxidation of new EDOT dimer, trimer, or long chains which were formed by the coupling of EDOT radical cations, generated during continuous cycling. 75,76 Superimposed in this broad oxidation might be also involved the oxidation of the porphyrin macrocycle.…”