Electrocatalytic O 2 Activation by Fe Tetrakis(pentafluorophenyl)porphyrin in Acidic Organic Media. Evidence of High-Valent Fe Oxo Species

Nikolaos Kostopoulos (1) , Ceĺia Achaibou (1) , Jean-Marc Noel (2) , Fredeŕic Kanoufi (2) , Marc Robert (1) , Claire Fave (1) , Elodie Anxolabéhère-Mallart (1)

1 LEM (UMR_7591) - Laboratoire d'Electrochimie Moléculaire
2 ITODYS (UMR_7086) - Interfaces, Traitements, Organisation et Dynamique des Systèmes

O2 activation under mild conditions remains a weighty challenge for chemists. Herein we report a study of electrochemical O2 reductive activation catalyzed by Fe III (F20 TPP)Cl, by means of cyclic voltammetry and UV−vis spectroelectrochemistry in acidic solutions of N,N-dimethylformamide. Two parallel catalytic pathways have been evidenced occurring at different overpotentials. At high overpotential a classical electron−proton (EPT) pathway where protonation of Fe peroxo ultimately leads to the formation of high-valent Fe oxo species dominates. At low overpotential a proton−electron (PET) pathway involving a hydrosuperoxo species has been identified.

Keywords: reductive O2 activation; iron porphyrin; molecular electrochemistry

Domains: Chemical Sciences; Other; Chemical Sciences; Catalysis; Chemical Sciences; Inorganic chemistry

Nikolaos Kostopoulos, Ceĺia Achaibou, Jean-Marc Noel, Fredeŕic Kanoufi, Marc Robert, et al.. Electrocatalytic O 2 Activation by Fe Tetrakis(pentafluorophenyl)porphyrin in Acidic Organic Media. Evidence of High-Valent Fe Oxo Species. Inorganic Chemistry, 2020, 59 (16), pp.11577-11583. ⟨10.1021/acs.inorgchem.0c01379⟩. ⟨hal-02951618⟩