An S = ½ iron complex featuring N₂, thiolate, and hydride ligands: Reductive elimination of H₂ and relevant thermochemical Fe-H parameters
- Creators
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Gu, Nina X.
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Oyala, Paul H.
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Peters, Jonas C.
Abstract
Believed to accumulate on the Fe sites of the FeMo-cofactor (FeMoco) of MoFe-nitrogenase under turnover, strongly donating hydrides have been proposed to facilitate N₂ binding to Fe and may also participate in the hydrogen evolution process concomitant to nitrogen fixation. Here, we report the synthesis and characterization of a thiolate-coordinated Fe^(III)(H)(N₂) complex, which releases H₂ upon warming to yield an Fe^(II)–N₂–Fe^(II) complex. Bimolecular reductive elimination of H₂ from metal hydrides is pertinent to the hydrogen evolution processes of both enzymes and electrocatalysts, but well-defined examples are uncommon and usually observed from diamagnetic second- and third-row transition metals. Kinetic data obtained on the HER of this ferric hydride species are consistent with a bimolecular reductive elimination pathway, arising from cleavage of the Fe–H bond with a computationally determined BDFE of 55.6 kcal/mol.
Additional Information
© 2018 American Chemical Society. Received: March 7, 2018; Published: April 23, 2018. The authors are grateful to the NIH for support via Grant No. GM-070757 and to the National Science Foundation for support of the Caltech EPR Facility via Grant No. NSF-153194. N.X.G. acknowledges an NSF Graduate Research Fellowship. Dr. Gaël Ung provided technical assistance toward the synthesis of 2 and 3. Dr. Michael Takase and Larry Henling are thanked for providing crystallographic assistance. We thank Dr. Jay Winkler for helpful discussions. The authors declare no competing financial interest.Attached Files
Accepted Version - nihms-1036626.pdf
Supplemental Material - ja8b02603_si_001.pdf
Supplemental Material - ja8b02603_si_002.cif
Supplemental Material - ja8b02603_si_003.mol
Files
Additional details
- PMCID
- PMC6592702
- Eprint ID
- 86017
- Resolver ID
- CaltechAUTHORS:20180424-082955413
- NIH
- GM070757
- NSF
- 153194
- NSF Graduate Research Fellowship
- Created
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2018-04-25Created from EPrint's datestamp field
- Updated
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2022-03-10Created from EPrint's last_modified field