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Horch M, Schoknecht J, Wrathall SLD, Greetham GM, Lenz O, Hunt NT. Understanding the structure and dynamics of hydrogenases by ultrafast and two-dimensional infrared spectroscopy. Chem Sci 2019; 10:8981-8989. [PMID: 31762978 PMCID: PMC6857670 DOI: 10.1039/c9sc02851j] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 08/05/2019] [Indexed: 11/21/2022] Open
Abstract
Hydrogenases are valuable model enzymes for sustainable energy conversion approaches using H2, but rational utilization of these base-metal biocatalysts requires a detailed understanding of the structure and dynamics of their complex active sites. The intrinsic CO and CN- ligands of these metalloenzymes represent ideal chromophores for infrared (IR) spectroscopy, but structural and dynamic insight from conventional IR absorption experiments is limited. Here, we apply ultrafast and two-dimensional (2D) IR spectroscopic techniques, for the first time, to study hydrogenases in detail. Using an O2-tolerant [NiFe] hydrogenase as a model system, we demonstrate that IR pump-probe spectroscopy can explore catalytically relevant ligand bonding by accessing high-lying vibrational states. This ultrafast technique also shows that the protein matrix is influential in vibrational relaxation, which may be relevant for energy dissipation from the active site during fast reaction steps. Further insights into the relevance of the active site environment are provided by 2D-IR spectroscopy, which reveals equilibrium dynamics and structural constraints imposed on the H2-accepting intermediate of [NiFe] hydrogenases. Both techniques offer new strategies for uniquely identifying redox-structural states in complex catalytic mixtures via vibrational quantum beats and 2D-IR off-diagonal peaks. Together, these findings considerably expand the scope of IR spectroscopy in hydrogenase research, and new perspectives for the characterization of these enzymes and other (bio-)organometallic targets are presented.
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Affiliation(s)
- Marius Horch
- Department of Chemistry , York Biomedical Research Institute , University of York , Heslington , York , YO10 5DD , UK .
- Institut für Chemie , Technische Universität Berlin , Straße des 17. Juni 135 , Berlin , D-10623 , Germany
| | - Janna Schoknecht
- Institut für Chemie , Technische Universität Berlin , Straße des 17. Juni 135 , Berlin , D-10623 , Germany
| | - Solomon L D Wrathall
- Department of Chemistry , York Biomedical Research Institute , University of York , Heslington , York , YO10 5DD , UK .
| | - Gregory M Greetham
- STFC Central Laser Facility, Research Complex at Harwell , Rutherford Appleton Laboratory , Harwell Science and Innovation Campus , Didcot , Oxford , OX110PE , UK
| | - Oliver Lenz
- Institut für Chemie , Technische Universität Berlin , Straße des 17. Juni 135 , Berlin , D-10623 , Germany
| | - Neil T Hunt
- Department of Chemistry , York Biomedical Research Institute , University of York , Heslington , York , YO10 5DD , UK .
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2
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Kiefer LM, Kubarych KJ. Two-dimensional infrared spectroscopy of coordination complexes: From solvent dynamics to photocatalysis. Coord Chem Rev 2018. [DOI: 10.1016/j.ccr.2018.05.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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3
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Stromberg CJ, Heilweil EJ. Ultrafast Photodynamics of Cyano-Functionalized [FeFe] Hydrogenase Model Compounds. J Phys Chem A 2018; 122:4023-4030. [PMID: 29652502 PMCID: PMC6051340 DOI: 10.1021/acs.jpca.8b00661] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[FeFe] hydrogenases are efficient enzymes that produce hydrogen gas under mild conditions. Synthetic model compounds containing all CO or mixed CO/PMe3 ligands were previously studied by us and others with ultrafast ultraviolet or visible pump-infrared probe spectroscopy in an effort to better understand the function and interactions of the active site with light. Studies of anionic species containing cyano groups, which more closely match the biological active site, have been elusive. In this work, two model compounds dissolved in room-temperature acetonitrile solution were examined: [Fe2(μ-S2C3H6)(CO)4(CN)2]2- (1) and [Fe2(μ-S2C2H4)(CO)4(CN)2]2- (2). These species exhibit long-lived transient signals consistent with loss of one CO ligand with potential isomerization of newly formed ground electronic state photoproducts, as previously observed with all-CO and CO/PMe3-containing models. We find no evidence for fast (ca. 150 ps) relaxation seen in the all-CO and CO/PMe3 compounds because of the absence of the metal-to-metal charge transfer band in the cyano-functionalized models. These results indicate that incorporation of cyano ligands may significantly alter the electronic properties and photoproducts produced immediately after photoexcitation, which may influence the catalytic activity of model compounds when attached to photosensitizers.
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Affiliation(s)
- Christopher J. Stromberg
- Department of Chemistry and Physics, Hood College, 401 Rosemont Avenue, Frederick, Maryland 21701-8524, United States
| | - Edwin J. Heilweil
- Engineering Physics Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899-8443 United States
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4
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Wang S, Aster A, Mirmohades M, Lomoth R, Hammarström L. Structural and Kinetic Studies of Intermediates of a Biomimetic Diiron Proton-Reduction Catalyst. Inorg Chem 2018; 57:768-776. [PMID: 29297686 DOI: 10.1021/acs.inorgchem.7b02687] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
One-electron reduction and subsequent protonation of a biomimetic proton-reduction catalyst [FeFe(μ-pdt)(CO)6] (pdt = propanedithiolate), 1, were investigated by UV-vis and IR spectroscopy on a nano- to microsecond time scale. The study aimed to provide further insight into the proton-reduction cycle of this [FeFe]-hydrogenase model complex, which with its prototypical alkyldithiolate-bridged diiron core is widely employed as a molecular, precious metal-free catalyst for sustainable H2 generation. The one-electron-reduced catalyst was obtained transiently by electron transfer from photogenerated [Ru(dmb)3]+ in the absence of proton sources or in the presence of acids (dichloro- or trichloroacetic acid or tosylic acid). The reduced catalyst and its protonation product were observed in real time by UV-vis and IR spectroscopy, leading to their structural characterization and providing kinetic data on the electron and proton transfer reactions. 1 features an intact (μ2,κ2-pdt)(μ-H)Fe2 core in the reduced, 1-, and reduced-protonated states, 1H, in contrast to the Fe-S bond cleavage upon the reduction of [FeFe(bdt)(CO)6], 2, with a benzenedithiolate bridge. The driving-force dependence of the rate constants for the protonation of 1- (kpt = 7.0 × 105, 1.3 × 107, and 7.0 × 107 M-1 s-1 for the three acids used in this study) suggests a reorganization energy >1 eV and indicates that hydride complex 1H is formed by direct protonation of the Fe-Fe bond. The protonation of 1- is sufficiently fast even with the weaker acids, which excludes a rate-limiting role in light-driven H2 formation under typical conditions.
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Affiliation(s)
- Shihuai Wang
- Department of Chemistry-Ångström Laboratory, Uppsala University , Box 523, SE-751 20 Uppsala, Sweden
| | - Alexander Aster
- Department of Chemistry-Ångström Laboratory, Uppsala University , Box 523, SE-751 20 Uppsala, Sweden
| | - Mohammad Mirmohades
- Department of Chemistry-Ångström Laboratory, Uppsala University , Box 523, SE-751 20 Uppsala, Sweden
| | - Reiner Lomoth
- Department of Chemistry-Ångström Laboratory, Uppsala University , Box 523, SE-751 20 Uppsala, Sweden
| | - Leif Hammarström
- Department of Chemistry-Ångström Laboratory, Uppsala University , Box 523, SE-751 20 Uppsala, Sweden
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5
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Fukuzumi S, Lee YM, Nam W. Thermal and photocatalytic production of hydrogen with earth-abundant metal complexes. Coord Chem Rev 2018. [DOI: 10.1016/j.ccr.2017.07.014] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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6
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Ringenberg MR, Schwilk M, Wittkamp F, Apfel UP, Kaim W. Organometallic Fe-Fe Interactions: Beyond Common Metal-Metal Bonds and Inverse Mixed-Valent Charge Transfer. Chemistry 2017; 23:1770-1774. [DOI: 10.1002/chem.201605527] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Indexed: 12/20/2022]
Affiliation(s)
- Mark R. Ringenberg
- Institut für Anorganische Chemie; Universität Stuttgart; Pfaffenwaldring 55 70550 Stuttgart Germany
| | - Max Schwilk
- Institut für Theoretische Chemie; Universität Stuttgart; Pfaffenwaldring 55 70550 Stuttgart Germany
| | - Florian Wittkamp
- Lehrstuhl für Anorganische Chemie I; Ruhr-Universität Bochum; Universitätsstraße 150 44801 Bochum Germany
| | - Ulf-Peter Apfel
- Lehrstuhl für Anorganische Chemie I; Ruhr-Universität Bochum; Universitätsstraße 150 44801 Bochum Germany
| | - Wolfgang Kaim
- Institut für Anorganische Chemie; Universität Stuttgart; Pfaffenwaldring 55 70550 Stuttgart Germany
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7
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Eckert PA, Kubarych KJ. Dynamic Flexibility of Hydrogenase Active Site Models Studied with 2D-IR Spectroscopy. J Phys Chem A 2017; 121:608-615. [PMID: 28032999 DOI: 10.1021/acs.jpca.6b11962] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Hydrogenase enzymes enable organisms to use H2 as an energy source, having evolved extremely efficient biological catalysts for the reversible oxidation of molecular hydrogen. Small-molecule mimics of these enzymes provide both simplified models of the catalysis reactions and potential artificial catalysts that might be used to facilitate a hydrogen economy. We have studied two diiron hydrogenase mimics, μ-pdt-[Fe(CO)3]2 and μ-edt-[Fe(CO)3]2 (pdt = propanedithiolate, edt = ethanedithiolate), in a series of alkane solvents and have observed significant ultrafast spectral dynamics using two-dimensional infrared (2D-IR) spectroscopy. Since solvent fluctuations in nonpolar alkanes do not lead to substantial electrostatic modulations in a solute's vibrational mode frequencies, we attribute the spectral diffusion dynamics to intramolecular flexibility. The intramolecular origin is supported by the absence of any measurable solvent viscosity dependence, indicating that the frequency fluctuations are not coupled to the solvent motional dynamics. Quantum chemical calculations reveal a pronounced coupling between the low-frequency torsional rotation of the carbonyl ligands and the terminal CO stretching vibrations. The flexibility of the CO ligands has been proposed to play a central role in the catalytic reaction mechanism, and our results highlight that the CO ligands are highly flexible on a picosecond time scale.
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Affiliation(s)
- Peter A Eckert
- Department of Chemistry, University of Michigan , 930 N. University Ave., Ann Arbor, Michigan 48109, United States
| | - Kevin J Kubarych
- Department of Chemistry, University of Michigan , 930 N. University Ave., Ann Arbor, Michigan 48109, United States
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8
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Wright JA, Peck JNT, Cottrell SP, Jablonskytė A, Oganesyan VS, Pickett CJ, Jayasooriya UA. Muonium Chemistry at Diiron Subsite Analogues of [FeFe]-Hydrogenase. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201607109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Joseph A. Wright
- Energy Materials Laboratory; School of Chemistry; University of East Anglia; Norwich NR4 7TJ UK
| | - Jamie N. T. Peck
- Energy Materials Laboratory; School of Chemistry; University of East Anglia; Norwich NR4 7TJ UK
- Rutherford Appleton Laboratory; Harwell Oxford Didcot OX11 0QX UK
| | | | - Aušra Jablonskytė
- Energy Materials Laboratory; School of Chemistry; University of East Anglia; Norwich NR4 7TJ UK
| | - Vasily S. Oganesyan
- Energy Materials Laboratory; School of Chemistry; University of East Anglia; Norwich NR4 7TJ UK
| | - Christopher J. Pickett
- Energy Materials Laboratory; School of Chemistry; University of East Anglia; Norwich NR4 7TJ UK
| | - Upali A. Jayasooriya
- Energy Materials Laboratory; School of Chemistry; University of East Anglia; Norwich NR4 7TJ UK
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9
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Wright JA, Peck JNT, Cottrell SP, Jablonskytė A, Oganesyan VS, Pickett CJ, Jayasooriya UA. Muonium Chemistry at Diiron Subsite Analogues of [FeFe]-Hydrogenase. Angew Chem Int Ed Engl 2016; 55:14580-14583. [PMID: 27739628 PMCID: PMC5484327 DOI: 10.1002/anie.201607109] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Indexed: 11/29/2022]
Abstract
The chemistry of metal hydrides is implicated in a range of catalytic processes at metal centers. Gaining insight into the formation of such sites by protonation and/or electronation is therefore of significant value in fully exploiting the potential of such systems. Here, we show that the muonium radical (Mu.), used as a low isotopic mass analogue of hydrogen, can be exploited to probe the early stages of hydride formation at metal centers. Mu. undergoes the same chemical reactions as H. and can be directly observed due to its short lifetime (in the microseconds) and unique breakdown signature. By implanting Mu. into three models of the [FeFe]‐hydrogenase active site we have been able to detect key muoniated intermediates of direct relevance to the hydride chemistry of these systems.
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Affiliation(s)
- Joseph A Wright
- Energy Materials Laboratory, School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Jamie N T Peck
- Energy Materials Laboratory, School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK.,Rutherford Appleton Laboratory, Harwell Oxford, Didcot, OX11 0QX, UK
| | | | - Aušra Jablonskytė
- Energy Materials Laboratory, School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Vasily S Oganesyan
- Energy Materials Laboratory, School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Christopher J Pickett
- Energy Materials Laboratory, School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Upali A Jayasooriya
- Energy Materials Laboratory, School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK
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10
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Sensi M, Baffert C, Greco C, Caserta G, Gauquelin C, Saujet L, Fontecave M, Roy S, Artero V, Soucaille P, Meynial-Salles I, Bottin H, de Gioia L, Fourmond V, Léger C, Bertini L. Reactivity of the Excited States of the H-Cluster of FeFe Hydrogenases. J Am Chem Soc 2016; 138:13612-13618. [DOI: 10.1021/jacs.6b06603] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Matteo Sensi
- Aix Marseille Univ., CNRS, BIP UMR 7281, Marseille, France
- Department
of Biotechnologies and Biosciences, University of Milano-Bicocca, Piazza
della Scienza 2, 20126 Milan, Italy
| | - Carole Baffert
- Aix Marseille Univ., CNRS, BIP UMR 7281, Marseille, France
| | - Claudio Greco
- Department
of Earth and Environmental Sciences, Milano-Bicocca University, Piazza della
Scienza 1, 20126 Milan, Italy
| | - Giorgio Caserta
- Laboratoire
de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, Paris 75231 Cedex 05, France
| | - Charles Gauquelin
- Université de Toulouse, INSA, UPS, INP, LISBP, INRA:UMR792,135 CNRS:UMR 5504, avenue de Rangueil, 31077 Toulouse, France
| | - Laure Saujet
- Institut de Biologie et de Technologies de Saclay IBITECS, SB2SM/Institut de Biologie Intégrative de la Cellule I2BC, UMR 9198, CEA, CNRS, Université Paris Sud, F-91191 Gif sur Yvette, France
| | - Marc Fontecave
- Laboratoire
de Chimie des Processus Biologiques, UMR 8229 CNRS, Collège de France, Université Paris 6, 11 Place Marcelin Berthelot, Paris 75231 Cedex 05, France
| | - Souvik Roy
- Laboratoire
de Chimie et Biologie des Métaux, Université Grenoble Alpes, CNRS, CEA, 17 rue des Martyrs, 38054 Grenoble, France
| | - Vincent Artero
- Laboratoire
de Chimie et Biologie des Métaux, Université Grenoble Alpes, CNRS, CEA, 17 rue des Martyrs, 38054 Grenoble, France
| | - Philippe Soucaille
- Université de Toulouse, INSA, UPS, INP, LISBP, INRA:UMR792,135 CNRS:UMR 5504, avenue de Rangueil, 31077 Toulouse, France
| | - Isabelle Meynial-Salles
- Université de Toulouse, INSA, UPS, INP, LISBP, INRA:UMR792,135 CNRS:UMR 5504, avenue de Rangueil, 31077 Toulouse, France
| | - Hervé Bottin
- Institut de Biologie et de Technologies de Saclay IBITECS, SB2SM/Institut de Biologie Intégrative de la Cellule I2BC, UMR 9198, CEA, CNRS, Université Paris Sud, F-91191 Gif sur Yvette, France
| | - Luca de Gioia
- Department
of Biotechnologies and Biosciences, University of Milano-Bicocca, Piazza
della Scienza 2, 20126 Milan, Italy
| | | | | | - Luca Bertini
- Department
of Biotechnologies and Biosciences, University of Milano-Bicocca, Piazza
della Scienza 2, 20126 Milan, Italy
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11
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Blank JH, Moncho S, Lunsford AM, Brothers EN, Darensbourg MY, Bengali AA. Ligand Displacement Reaction Paths in a Diiron Hydrogenase Active Site Model Complex. Chemistry 2016; 22:12752-60. [PMID: 27482938 DOI: 10.1002/chem.201601677] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Indexed: 11/06/2022]
Abstract
The mechanism and energetics of CO, 1-hexene, and 1-hexyne substitution from the complexes (SBenz)2 [Fe2 (CO)6 ] (SBenz=SCH2 Ph) (1-CO), (SBenz)2 [Fe2 (CO)5 (η(2) -1-hexene)] (1-(η(2) -1-hexene)), and (SBenz)2 [Fe2 (CO)5 (η(2) -1-hexyne)] (1-(η(2) -1-hexyne)) were studied by using time-resolved infrared spectroscopy. Exchange of both CO and 1-hexyne by P(OEt)3 and pyridine, respectively, proceeds by a bimolecular mechanism. As similar activation enthalpies are obtained for both reactions, the rate-determining step in both cases is assumed to be the rotation of the Fe(CO)2 L (L=CO or 1-hexyne) unit to accommodate the incoming ligand. The kinetic profile for the displacement of 1-hexene is quite different than that for the alkyne and, in this case, both reaction channels, that is, dissociative (SN 1) and associative (SN 2), were found to be competitive. Because DFT calculations predict similar binding enthalpies of alkene and alkyne to the iron center, the results indicate that the bimolecular pathway in the case of the alkyne is lower in free energy than that of the alkene. In complexes of this type, subtle changes in the departing ligand characteristics and the nature of the mercapto bridge can influence the exchange mechanism, such that more than one reaction pathway is available for ligand substitution. The difference between this and the analogous study of (μ-pdt)[Fe(CO)3 ]2 (pdt=S(CH2 )3 S) underscores the unique characteristics of a three-atom S-S linker in the active site of diiron hydrogenases.
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Affiliation(s)
- Jan H Blank
- Department of Chemistry, Texas A&M University at Qatar, Doha, Qatar
| | - Salvador Moncho
- Department of Chemistry, Texas A&M University at Qatar, Doha, Qatar
| | - Allen M Lunsford
- Department of Chemistry, Texas A&M University, College Station, Texas, 77843, USA
| | | | | | - Ashfaq A Bengali
- Department of Chemistry, Texas A&M University at Qatar, Doha, Qatar.
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12
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Mirmohades M, Adamska-Venkatesh A, Sommer C, Reijerse E, Lomoth R, Lubitz W, Hammarström L. Following [FeFe] Hydrogenase Active Site Intermediates by Time-Resolved Mid-IR Spectroscopy. J Phys Chem Lett 2016; 7:3290-3293. [PMID: 27494400 DOI: 10.1021/acs.jpclett.6b01316] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Time-resolved nanosecond mid-infrared spectroscopy is for the first time employed to study the [FeFe] hydrogenase from Chlamydomonas reinhardtii and to investigate relevant intermediates of the enzyme active site. An actinic 355 nm, 10 ns laser flash triggered photodissociation of a carbonyl group from the CO-inhibited state Hox-CO to form the state Hox, which is an intermediate of the catalytic proton reduction cycle. Time-resolved infrared spectroscopy allowed us to directly follow the subsequent rebinding of the carbonyl, re-forming Hox-CO, and determine the reaction half-life to be t1/2 ≈ 13 ± 5 ms at room temperature. This gives direct information on the dynamics of CO inhibition of the enzyme.
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Affiliation(s)
- Mohammad Mirmohades
- Department of Chemistry - Ångström Laboratory, Uppsala University , Box 523, 751 20 Uppsala, Sweden
| | - Agnieszka Adamska-Venkatesh
- Max Planck Institute for Chemical Energy Conversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Constanze Sommer
- Max Planck Institute for Chemical Energy Conversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Edward Reijerse
- Max Planck Institute for Chemical Energy Conversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Reiner Lomoth
- Department of Chemistry - Ångström Laboratory, Uppsala University , Box 523, 751 20 Uppsala, Sweden
| | - Wolfgang Lubitz
- Max Planck Institute for Chemical Energy Conversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Leif Hammarström
- Department of Chemistry - Ångström Laboratory, Uppsala University , Box 523, 751 20 Uppsala, Sweden
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13
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Schilter D, Camara JM, Huynh MT, Hammes-Schiffer S, Rauchfuss TB. Hydrogenase Enzymes and Their Synthetic Models: The Role of Metal Hydrides. Chem Rev 2016; 116:8693-749. [PMID: 27353631 PMCID: PMC5026416 DOI: 10.1021/acs.chemrev.6b00180] [Citation(s) in RCA: 397] [Impact Index Per Article: 49.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hydrogenase enzymes efficiently process H2 and protons at organometallic FeFe, NiFe, or Fe active sites. Synthetic modeling of the many H2ase states has provided insight into H2ase structure and mechanism, as well as afforded catalysts for the H2 energy vector. Particularly important are hydride-bearing states, with synthetic hydride analogues now known for each hydrogenase class. These hydrides are typically prepared by protonation of low-valent cores. Examples of FeFe and NiFe hydrides derived from H2 have also been prepared. Such chemistry is more developed than mimicry of the redox-inactive monoFe enzyme, although functional models of the latter are now emerging. Advances in physical and theoretical characterization of H2ase enzymes and synthetic models have proven key to the study of hydrides in particular, and will guide modeling efforts toward more robust and active species optimized for practical applications.
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Affiliation(s)
- David Schilter
- Center for Multidimensional Carbon Materials, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - James M. Camara
- Department of Chemistry, Yeshiva University, 500 West 185th Street, New York, New York 10033, United States
| | - Mioy T. Huynh
- Department of Chemistry, University of Illinois at Urbana–Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Sharon Hammes-Schiffer
- Department of Chemistry, University of Illinois at Urbana–Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Thomas B. Rauchfuss
- Department of Chemistry, University of Illinois at Urbana–Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States
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14
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Fritzsch R, Brady O, Adair E, Wright JA, Pickett CJ, Hunt NT. Encapsulating Subsite Analogues of the [FeFe]-Hydrogenases in Micelles Enables Direct Water Interactions. J Phys Chem Lett 2016; 7:2838-2843. [PMID: 27396585 DOI: 10.1021/acs.jpclett.6b01338] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Encapsulation of subsite analogues of the [FeFe]-hydrogenase enzymes in supramolecular structures has been shown to dramatically increase their catalytic ability, but the molecular basis for this enhancement remains unclear. We report the results of experiments employing infrared absorption, ultrafast infrared pump-probe, and 2D-IR spectroscopy to investigate the molecular environment of Fe2(pdt)(CO)6 (pdt: propanedithiolate) [1] encapsulated in the dispersed alkane phase of a heptane-dodecyltrimethylammonium bromide-water microemulsion. It is demonstrated that 1 is partitioned between two molecular environments, one that closely resembles bulk heptane solution and a second that features direct hydrogen-bonding interactions with water molecules that penetrate the surfactant shell. Our results demonstrate that the extent of water access to the normally water-insoluble subsite analogue 1 can be tuned with micelle size, while IR spectroscopy provides a straightforward tool that can be used to measure and fine-tune the chemical environment of catalyst species in self-assembled structures.
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Affiliation(s)
- Robby Fritzsch
- Department of Physics, University of Strathclyde, SUPA , 107 Rottenrow East, Glasgow G4 0NG, United Kingdom
| | - Owen Brady
- Department of Physics, University of Strathclyde, SUPA , 107 Rottenrow East, Glasgow G4 0NG, United Kingdom
| | - Elaine Adair
- Department of Physics, University of Strathclyde, SUPA , 107 Rottenrow East, Glasgow G4 0NG, United Kingdom
| | - Joseph A Wright
- Energy Materials Laboratory, School of Chemistry, University of East Anglia , Norwich NR4 7TJ, United Kingdom
| | - Christopher J Pickett
- Energy Materials Laboratory, School of Chemistry, University of East Anglia , Norwich NR4 7TJ, United Kingdom
| | - Neil T Hunt
- Department of Physics, University of Strathclyde, SUPA , 107 Rottenrow East, Glasgow G4 0NG, United Kingdom
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15
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Darensbourg MY, Llobet A. Preface for Small Molecule Activation: From Biological Principles to Energy Applications. Part 3: Small Molecules Related to (Artificial) Photosynthesis. Inorg Chem 2016; 55:371-7. [PMID: 26782691 DOI: 10.1021/acs.inorgchem.5b02925] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Marcetta Y Darensbourg
- Department of Chemistry, Texas A&M University , College Station, Texas 77845, United States
| | - Antoni Llobet
- Departament de Quı́mica, Universitat Autònoma de Barcelona , Cerdanyola del Vallès, 08193 Barcelona, Spain
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