1. Spectroscopic Capture and Reactivity of a Low-Spin Cobalt(IV)-Oxo Complex Stabilized by Binding Redox-Inactive Metal Ions.
- Author
-
Hong, Seungwoo, Pfaff, Florian F., Kwon, Eunji, Wang, Yong, Seo, Mi‐Sook, Bill, Eckhard, Ray, Kallol, and Nam, Wonwoo
- Subjects
COBALT ,OXIDATION ,METAL ions ,SPECTROSCOPIC imaging ,OXYGEN - 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) Co
IV -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. [ABSTRACT FROM AUTHOR]- Published
- 2014
- Full Text
- View/download PDF