Molybdenum Catalyzed Ammonia Borane Dehydrogenation: Oxidation State Specific Mechanisms
Abstract
Though numerous catalysts for the dehydrogenation of ammonia borane (AB) are known, those that release >2 equiv of H_2 are uncommon. Herein, we report the synthesis of Mo complexes supported by a para-terphenyl diphosphine ligand, 1, displaying metal–arene interactions. Both a Mo^0 N_2 complex, 5, and a Mo^(II) bis(acetonitrile) complex, 4, exhibit high levels of AB dehydrogenation, releasing over 2.0 equiv of H_2. The reaction rate, extent of dehydrogenation, and reaction mechanism vary as a function of the precatalyst oxidation state. Several Mo hydrides (Mo^(II)(H)_2, [Mo^(II)(H)]^+, and [Mo^(IV)(H)_3]^+) relevant to AB chemistry were characterized.
Additional Information
© 2014 American Chemical Society. ACS AuthorChoice - This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes. Publication Date (Web): July 17, 2014. Received: June 15, 2014. We thank Lawrence M. Henling, Michael K. Takase, and Michael W. Day for crystallographic assistance, David VanderVelde for NMR expertise, and Aaron and Wes Sattler for helpful discussions. We are grateful to Caltech and the NSF (CHE- 1151918) for funding. T.A. is a Sloan, Cottrell, . BILRC is acknowledged for assistance with photochemistry. The NSF (CRIF:MU CHE0639094) and NIH (RR027690) are thanked for instrument grants to Caltech.Errata
Figures 2 and S32 incorrectly reported the units of time in seconds rather than minutes. These axis labels have been rectified in the attached versions of Figure 2 and the Supporting Information to match the (correct) time scales for H2 release reported in the text of the manuscript.Attached Files
Published - ja5059923.pdf
Supplemental Material - ja5059923_si_001.pdf
Supplemental Material - ja5059923_si_002.cif
Erratum - ja5132853.pdf
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Additional details
- PMCID
- PMC4140452
- Eprint ID
- 47888
- Resolver ID
- CaltechAUTHORS:20140804-112552589
- Caltech
- CHE-1151918
- NSF
- Cottrell Scholar of Research Corporation
- CHE-0639094
- NSF
- RR027690
- NIH
- Alfred P. Sloan Foundation
- Camille and Henry Dreyfus Foundation
- Created
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2014-08-04Created from EPrint's datestamp field
- Updated
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2023-06-01Created from EPrint's last_modified field