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Title: C–H activation and nucleophilic substitution in a photochemically generated high valent iron complex
Authors: Lim, Jia Hui
Engelmann, Xenia
Corby, Sacha
Ganguly, Rakesh
Ray, Kallol
Soo, Han Sen
Keywords: C–H Activation
Issue Date: 2018
Source: Lim, J. H., Engelmann, X., Corby, S., Ganguly, R., Ray, K., & Soo, H. S. (2018). C–H activation and nucleophilic substitution in a photochemically generated high valent iron complex. Chemical Science, 9(16), 3992-4002.
Series/Report no.: Chemical Science
Abstract: The photochemical oxidation of a (TAML)FeIII complex 1 using visible light generated Ru(bpy)33+ produces valence tautomers (TAML)FeIV (1+) and (TAML˙+)FeIII (1-TAML˙+), depending on the exogenous anions. The presence of labile Cl− or Br− results in a ligand-based oxidation and stabilisation of a radical-cationic (TAML˙+)FeIII complex, which subsequently leads to unprecedented C–H activation followed by nucleophilic substitution on the TAML aryl ring. In contrast, exogenous cyanide culminates in metal-based oxidation, yielding the first example of a crystallographically characterised S = 1 [(TAML)FeIV(CN)2]2− species. This is a rare report of an anion-dependent valence tautomerisation in photochemically accessed high valent (TAML)Fe systems with potential applications in the oxidation of pollutants, hydrocarbons, and water. Furthermore, the nucleophilic aromatic halogenation reaction mediated by (TAML˙+)FeIII represents a novel domain for high-valent metal reactivity and highlights the possible intramolecular ligand or substrate modification pathways under highly oxidising conditions. Our findings therefore shine light on high-valent metal oxidants based on TAMLs and other potential non-innocent ligands and open new avenues for oxidation catalyst design.
ISSN: 2041-6520
DOI: 10.1039/C7SC05378A
Rights: © 2018 The Author(s) (published by Royal Society of Chemistry) . Open Access Article. Published on 23 March 2018. Downloaded on 7/27/2018 6:22:43 AM. This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.
Fulltext Permission: open
Fulltext Availability: With Fulltext
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