Catalysis of the electroreduction of dioxygen and hydrogen peroxide by an anthracene-linked dimeric cobalt porphyrin

Synthesis, Characterization, and Electrochemical Study of Tetradentate Ruthenium‐Schiff Base Complexes: Dioxygen Activation with a Cytochrome P450 Model Using 1‐ or 2‐Methylimidazole as Axial Bases

“…There are few reports in the literature on these reactions with molecular oxygen, reduced to hydrogen peroxide or water via a two-or four-electron transfer on chemically modified electrodes. The main papers were published by Horwitz et al [21] and Taqui Khan et al [47], Anson et al [64][65][66], and Chang et al [67][68][69]. Here, we have determined the number of electrons for our ruthenium complexes using coulometry after electrolysis under oxygen atmosphere.…”

Cobalt(IV) corroles as catalysts for the electroreduction of O2: Reactions of heterobimetallic dyads containing a face-to-face linked Fe(III) or Mn(III) porphyrin

“…Examples of one set of molecular catalysts are given by linked dicobalt bisporphyrins which efficiently electrocatalyze the direct four-electron reduction of O 2 to H 2 O in acidic solutions when adsorbed on the surface of a graphite electrode [18][19][20][21][22][23]. This contrasts with monocobalt porphyrins which can act as four-electron reduction catalysts only through self-assembly on the electrode surface [16,[24][25][26][27][28].…”

The four-electron reduction of oxygen to water on a planar cobalt chelate

“…This indeed is observed experimentally. 2b Finally, we discuss a striking result of Liu et al , 5 namely the fact that the anthracene-linked diporphyrin (5), containing only one cobalt atom, was also able to reduce O2 to H 2 0 , but at lower rates than the corresponding dicobalt complex. Although the second porphyrin ring does not contain a Co ion, the potential of the remaining Co has shifted to 0.6 V vs. R.H.E.5 Nevertheless, the formation of an intramolecular adduct seems unlikely since the molecule contains only one catalytic centre.…”