Spin-State Effects on the Thermal Dihydrogen Release from Solid-State [MH(η^2‑H_2)dppe_2]^+ (M = Fe, Ru, Os) Organometallic Complexes for Hydrogen Storage Applications
Abstract
Mössbauer spectroscopy, experimental thermodynamic measurements, and computational studies were performed to investigate the properties of molecular hydrogen binding to the organometallic fragments [MHdppe_2]^+ (M = Fe, Ru, Os; dppe =1,2-bis(diphenylphosphino)ethane) to form the dihydrogen complex fragments [MH(η^2-H_2)dppe_2]^+. Mössbauer spectroscopy showed that the dehydrogenated complex [FeHdppe_2]^+ adopts a geometry consistent with the triplet spin state, transitioning to a singlet state complex upon addition of the dihydrogen molecule in a manner similar to the previously studied dinitrogen complexes. From simulations, this spin transition behavior was found to be responsible for the strong binding behavior experimentally observed in the iron complex. Spin-singlet to spin-singlet transitions were found to exhibit thermodynamics consistent with the 5d > 3d > 4d binding trend observed for other transition metal dihydrogen complexes. Finally, the method for distinguishing between dihydrogen and dihydride complexes based on partial quadrupole splittings observed in Mössbauer spectra was confirmed, providing a tool for further characterization of these unique species for Mössbauer active compounds.
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. Received: September 30, 2013. Revised: January 2, 2014. Publication Date (Web): January 7, 2014. The authors wish to thank David Vandervelde of Caltech's liquid NMR facility for his assistance with NMR experiments and Joseph Reiter and Jason Zan at the Jet Propulsion Laboratory in Pasadena, CA for their assistance in planning thermodynamic measurements. Sieverts instrument work was performed at the Jet Propulsion Laboratory, which is operated by the California Institute of Technology under contract with NASA. The Caltech NMR facility is partially supported by the National Institutes of Health through Grant NIH RR027690. ROHF calculations were performed using computational facilities located at the National Energy Research Scientific Computing (NERSC) Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. We wish to express gratitude to the Resnick Sustainability Institute for financial support of the project. This work was supported as part of EFree, an Energy Frontier Research Center, under Award No. DE-SG0001057. The authors declare no competing financial interest.Attached Files
Published - jp409739b.pdf
Supplemental Material - jp409739b_si_001.pdf
Files
| Name | Size | Download all |
|---|---|---|
|
md5:9bd852b18b0e2b613e1889f0601a3d70
|
1.2 MB | Preview Download |
|
md5:7da5db8811cc28d2479178d98856b2de
|
807.5 kB | Preview Download |
Additional details
- Alternative title
- Spin-State Effects on the Thermal Dihydrogen Release from Solid-State [MH(η2‑H2)dppe_2]+ (M = Fe, Ru, Os) Organometallic Complexes for Hydrogen Storage Applications
- PMCID
- PMC3983317
- Eprint ID
- 43550
- Resolver ID
- CaltechAUTHORS:20140129-130314711
- NASA/JPL/Caltech
- RR027690
- NIH
- DE-AC02-05CH11231
- Department of Energy (DOE)
- Resnick Sustainability Institute
- DE-SG0001057
- Department of Energy (DOE)
- Created
-
2014-01-29Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Resnick Sustainability Institute