Published July 2014
| Published + Supplemental Material
Journal Article
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Efficient C-H Bond Activations O_2 Cleavage by a Dianionic Cobalt(II) Complex
Abstract
A dianionic, square planar cobalt(II) complex reacts with O_2 in the presence of acetonitrile to give a cyanomethylcobalt(III) complex formed by C-H bond cleavage. Interestingly, PhIO and -tolylazide react similarly to give the same cyanomethylcobalt(III) complex. Competition studies with various hydrocarbon substrates indicate that the rate of C-H bond cleavage greatly depends on the pK_a of the C-H bond, rather than on the C-H bond dissociation energy. Kinetic isotope experiments reveal a moderate KIE value of ca. 3.5 using either O_2 or PhIO. The possible involvement of a cobalt(IV) oxo species in this chemistry is discussed.
Additional Information
© 2014 The Author(s). This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. Received 10th January 2014. Accepted 7th May 2014. First published on 8th May 2014. This work was supported by the Director, Office of Science, Office of Basic Energy Sciences of the US Department of Energy under contract no. DE-AC02-05CH11231 and the National Institutes of Health (Grant GM 40392 to E.I.S.). R.G.H. acknowledges a Gerhard Casper Stanford Graduate Fellowship and the Achievement Rewards for College Scientist (ARCS) Foundation. The authors thank Dr Antonio Iavarone (QB3 Chemistry Mass Spectrometry Facility) for high-resolution ESI mass-spectrometry measurements, Apurva Pradhan for assistance with UV-vis measurements, and Dr John J. Curley for stimulating discussions.Attached Files
Published - c4sc00108g.pdf
Supplemental Material - c4sc00108g1.pdf
Supplemental Material - c4sc00108g2.cif
Files
c4sc00108g.pdf
Additional details
- Alternative title
- Efficient C-H Bond Activations O2 Cleavage by a Dianionic Cobalt(II) Complex.
- PMCID
- PMC4111274
- Eprint ID
- 87005
- Resolver ID
- CaltechAUTHORS:20180612-111659936
- DE-AC02-05CH11231
- Department of Energy (DOE)
- GM40392
- NIH
- Stanford University
- ARCS Foundation
- Created
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2018-06-12Created from EPrint's datestamp field
- Updated
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2023-06-01Created from EPrint's last_modified field