Abstract
High-valent cobalt-oxo intermediates are proposed as reactive intermediates in a number of cobalt-complex-mediated oxidation reactions. Herein we report the spectroscopic capture of low-spin (S=1/2) CoIV-oxo species in the presence of redox-inactive metal ions, such as Sc3+, Ce3+, Y3+, and Zn2+, and the investigation of their reactivity in C-H bond activation and sulfoxidation reactions. Theoretical calculations predict that the binding of Lewis acidic metal ions to the cobalt-oxo core increases the electrophilicity of the oxygen atom, resulting in the redox tautomerism of a highly unstable [(TAML)CoIII(O.)]2- species to a more stable [(TAML)CoIV(O)(Mn+)] core. The present report supports the proposed role of the redox-inactive metal ions in facilitating the formation of high-valent metal-oxo cores as a necessary step for oxygen evolution in chemistry and biology. What is the metal's role? Cobalt(IV)-oxo complexes binding redox-inactive metal ions, such as Sc3+, Ce3+, Y3+, and Zn2+, are investigated in oxygenation reactions. Theory predicts that the binding of metal ions to the cobalt-oxo core increases the electrophilicity of the oxygen atom. This result supports the role of redox-inactive metal ions in facilitating the formation of high-valent metal-oxo cores as a necessary step for oxygen evolution in chemistry and biology. CAN=cerium ammonium nitrate.
Original language | English |
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Pages (from-to) | 10403-10407 |
Number of pages | 5 |
Journal | Angewandte Chemie - International Edition |
Volume | 53 |
Issue number | 39 |
DOIs | |
State | Published - 14 Jul 2014 |
Bibliographical note
Publisher Copyright:© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Keywords
- Lewis acids
- cobalt
- oxo ligands
- oxygenation
- redox tautomerization