Terminal Mo Carbide and Carbyne Reactivity: H₂ Cleavage, B–C Bond Activation, and C–C Coupling
- Creators
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Bailey, Gwendolyn A.
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Agapie, Theodor
Abstract
Transition-metal carbides have been posited as intermediates in the upgrading of C₁ feedstocks, including the Fischer–Tropsch synthesis of higher olefins from CO and H₂. Still, molecular examples remain rare, and their reactivity is poorly understood. In a molecular platform supported by a flexible terphenyl diphosphine ligand, the important C–C coupling step was previously demonstrated on the reaction of Mo carbide and carbene species with CO. Methylidyne and methylidene complexes were accessible on sequential treatment of the carbide with sources of H⁺ and H⁻, surrogates for heterolyzed H₂. Herein, we demonstrate that the terminal carbide complex is also capable of directly activating H₂, yielding a P–C-bonded ylide complex. The carbide moiety also inserts into the B–C bond of triphenylborane, yielding an unusual example of a borylcarbene with a direct Mo–B contact. C–C coupling from the terminal methylidyne, a potential intermediate formed on heterolytic H₂ cleavage and H⁺ transfer to the carbide, yields a Mo ketenyl complex, thus giving information for the first time on the relative rates of coupling from carbide, carbyne, and carbene species in the same molecular platform.
Additional Information
© 2021 American Chemical Society. Received 6 June 2021. Published online 12 August 2021. Published in issue 23 August 2021. We thank Lawrence Henling and Michael Takase for invaluable crystallographic assistance. G.A.B. is grateful to the NSERC of Canada and the Resnick Sustainability Institute at Caltech for fellowship support. We thank the the NSF (CHE-1800501), the Dow Next Generation Education Fund (instrumentation), and Caltech for funding. The authors declare no competing financial interest. CCDC 2000078–2000079 contain the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk/data_request/cif.Attached Files
Supplemental Material - om1c00336_si_001.xyz
Supplemental Material - om1c00336_si_002.pdf
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Additional details
- Alternative title
- Terminal Mo Carbide and Carbyne Reactivity: H2 Cleavage, B–C Bond Activation, and C–C Coupling
- Eprint ID
- 110627
- DOI
- 10.1021/acs.organomet.1c00336
- Resolver ID
- CaltechAUTHORS:20210830-230028871
- Natural Sciences and Engineering Research Council of Canada (NSERC)
- Resnick Sustainability Institute
- NSF
- CHE-1800501
- Dow Next Generation Educator Fund
- Caltech
- Created
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2021-08-31Created from EPrint's datestamp field
- Updated
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2021-08-31Created from EPrint's last_modified field
- Caltech groups
- Resnick Sustainability Institute