Tripodal and/or picket porphyrins to mimic the cytochrome c oxidase activity

Abstract

The efficiency of different series of tris-(2-aminoethyl)amine TREN-capped porphyrins as catalysts for the electroreduction of dioxygen has been studied after adsorption of the molecules at the surface of a graphite electrode. The influence of two structural features have been explored: the relative position of the two metals in the iron-copper bimetallic complexes and the nature of the benzyl groups of the tripod itself. These compounds have also been compared with picket porphyrins bearing aromatic amino functions, e.g. quinoline. The conclusions obtained in the case of TRENcapped catalysts cannot be extended to those bearing aromatic pickets.

Molecular Catalysis of Electrochemical Reactions. Mechanistic Aspects

“…As the fruit of patient efforts, a series of molecules mimicking the heme-Cu arrangement were synthesized, able, under their reduced form, to achieve the four-electron reduction of dioxygen into water – (see Figure 14 in ref ). The most elaborated model involving the heme, the copper center and the tyrosine residue – is shown in Scheme and will be discussed later on.…”

“…Two electron relays, a copper complex and a heme, mediate electron transfer between cytochrome c and the heme-Cu catalytic site shown in Scheme 18, which contains besides a heme and a copper center, a tyrosine residue (Tyr, His is for histidine) able to transfer one proton and one electron in a coupled, or even simultaneous manner. [192][193][194][195][196][197] As the fruit of patient efforts, a series of molecules mimicking the heme-Cu arrangement were synthesized, able, under their reduced form, to achieve the four-electron reduction of dioxygen into water [198][199][200][201][202][203][204][205][206][207][208][209][210][211][212] (see Figure 14 in ref 213). The most elaborated model involving the heme, the copper center and the tyrosine residue [214][215][216] is shown in Scheme 19 and will be discussed later on.…”