Outer‐Sphere Redox Reactions Leading to the Formation of Discrete Co^III/Fe^II Pyrazine‐Bridged Mixed‐Valence Compounds

Abstract

The kinetic and mechanistic study of the reaction of complexes [

Kineticomechanistic Study of the Redox pH Cycling Processes Occurring on a Robust Water-Soluble Cyanido-Bridged Mixed-Valence {CoIII/FeII}2 Square

“…The process involves a rate limiting outer-sphere redox reaction followed by a fast substitution/inner-sphere redox reaction sequence that had been studied by us for some time. [21][22][23][24][25][26][27][28] Although this compound did not show any evidence of complete intramolecular electron transfer phenomena, its striking stability in aqueous solution (stable across the full aqueous pH range, in deep contrast with that of other reported redox active metallomacrocycles), opens up the possibility of performing a thorough study of its participation in chemical processes, such as reversible oxidation, protonation, and OHassociation. With these facts in mind, we are here reporting a redox-reversible kinetico-mechanistic study of our tetrametallic {Fe II /Co II } 2 unit as a function of pH, oxidant concentration, temperature and pressure.…”

Redox‐Assisted Self‐Assembly of a Water‐Soluble Cyanido‐Bridged Mixed Valence {CoIII/FeII}2 Square

“…The preparation of aqueous solution (pH 1–12) resistant cyanido‐bridged Co III /Fe II complexes in a facile manner through a mechanistically designed process involving a rate‐limiting outer‐sphere redox followed by a fast substitution/inner‐sphere redox reaction sequence has been studied by us for some time . Although the possibilities for the use of such species in different environments due to their redox, structural, optical, and electronic properties have been explored, so far the unreactive character of these species have not allowed for its simple incorporation to supporting systems; only a few examples have allowed such functionalization .…”

“…The preparation of aqueouss olution( pH 1-12) resistant cyanido-bridged Co III /Fe II complexes in af acile manner through am echanistically designed process involving ar ate-limiting outer-sphere redox followedby af ast substitution/innersphere redox reactions equence has been studied by us for some time. [4,14,16,18,28,30,31,53,54] Althought he possibilities for the use of such species in different environments due to their redox,s tructural, optical, and electronic properties have been explored, [55][56][57][58] so far the unreactive charactero ft heses pecies have not allowed for its simple incorporation to supporting systems;o nly af ew examplesh ave allowed such functionalization. [17,18,58,59] In this respect, the use of tetradentated encapsulating Co III ligands should still leave asubstitutionally active position that allows the {Co III /Fe II }b imetallic fragment to act as ab uilding-block in self-assembly reactions; [38] the aim being that indicatedi nScheme 1.…”

Macrocyclic coordination chemistry

“…122 Macrocycle, L 76 , was used to form a discrete mixed valence bimetallic complex with cobalt and iron. 123 The cobalt(III) ion is encapsulated within the macrocycle and linked via a bridging pyrazine unit to an [Fe(CN) 5 ] 3À moiety. The mixed donor N 3 S 3 cryptand copper(II) complex, L 77 , has anion dependent coordination modes with the perchlorate complex hexadentate showing the metal ion bound to all six donor atoms.…”