Hydrogen production through water splitting is one of the most promising solutions for the storage of renewable energy. [NiFe] hydrogenases are organometallic enzymes containing nickel and iron centres that catalyse hydrogen evolution with performances that rival those of platinum. These enzymes provide inspiration for the design of new molecular catalysts that do not require precious metals. However, all heterodinuclear NiFe models reported so far do not reproduce the Ni-centred reactivity found at the active site of [NiFe] hydrogenases. Here, we report a structural and functional NiFe mimic that displays reactivity at the Ni site. This is shown by the detection of two catalytic intermediates that reproduce structural and electronic features of the Ni-L and Ni-R states of the enzyme during catalytic turnover. Under electrocatalytic conditions, this mimic displays high rates for H2 evolution (second-order rate constant of 2.5 × 104 M−1 s−1; turnover frequency of 250 s−1 at 10 mM H+ concentration) from mildly acidic solutions.
This is a preview of subscription content, access via your institution
Subscribe to this journal
Receive 12 print issues and online access
$259.00 per year
only $21.58 per issue
Rent or buy this article
Get just this article for as long as you need it
Prices may be subject to local taxes which are calculated during checkout
Volbeda, A. et al. Crystal structure of the nickel–iron hydrogenase from Desulfovibrio gigas. Nature 373, 580–587 (1995).
Lubitz, W., Ogata, H., Rüdiger, O. & Reijerse, E. Hydrogenases. Chem. Rev. 114, 4081–4148 (2014).
Foerster, S. et al. Single crystal EPR studies of the reduced active site of [NiFe] hydrogenase from Desulfovibrio vulgaris miyazaki F. J. Am. Chem. Soc. 125, 83–93 (2003).
Brecht, M., van Gastel, M., Buhrke, T., Friedrich, B. & Lubitz, W. Direct detection of a hydrogen ligand in the [NiFe] center of the regulatory H2-sensing hydrogenase from Ralstonia eutropha in its reduced state by HYSCORE and ENDOR spectroscopy. J. Am. Chem. Soc. 125, 13075–13083 (2003).
George, S. J., Kurkin, S., Thorneley, R. N. F. & Albracht, S. P. J. Reactions of H2, CO, and O2 with active [NiFe]-hydrogenase from Allochromatium vinosum. A stopped-flow infrared study. Biochemistry 43, 6808–6819 (2004).
Ogata, H., Nishikawa, K. & Lubitz, W. Hydrogens detected by subatomic resolution protein crystallography in a [NiFe] hydrogenase. Nature 520, 571–574 (2015).
van der Zwaan, J. W., Albracht, S. P. J., Fontijn, R. D. & Slater, E. C. Monovalent nickel in hydrogenase from Chromatium vinosum: light sensitivity and evidence for direct interaction with hydrogen. FEBS Lett. 179, 271–277 (1985).
Murphy, B. J. et al. Discovery of dark pH-dependent H+ migration in a [NiFe]-hydrogenase and its mechanistic relevance: mobilizing the hydrido ligand of the Ni–C intermediate. J. Am. Chem. Soc. 137, 8484–8489 (2015).
Hidalgo, R., Ash, P. A., Healy, A. J. & Vincent, K. A. Infrared spectroscopy during electrocatalytic turnover reveals the Ni–L active site state during H2 oxidation by a NiFe hydrogenase. Angew. Chem. Int. Ed. 54, 7110–7113 (2015).
Tard, C. & Pickett, C. J. Structural and functional analogues of the active sites of the [Fe]-, [NiFe]-, and [FeFe]-hydrogenases. Chem. Rev. 109, 2245–2274 (2009).
Ohki, Y. & Tatsumi, K. Thiolate-bridged iron–nickel models for the active site of [NiFe] hydrogenase. Eur. J. Inorg. Chem. 2011, 973–985 (2011).
Simmons, T. R., Berggren, G., Bacchi, M., Fontecave, M. & Artero, V. Mimicking hydrogenases: from biomimetics to artificial enzymes. Coord. Chem. Rev. 270–271, 127–150 (2014).
Kaur-Ghumaan, S. & Stein, M. [NiFe] hydrogenases: how close do structural and functional mimics approach the active site? Dalton Trans. 43, 9392–9405 (2014).
Fourmond, V. et al. A nickel–manganese catalyst as a biomimic of the active site of NiFe hydrogenases: a combined electrocatalytical and DFT mechanistic study. Energy Environ. Sci. 4, 2417–2427 (2011).
Song, L.-C., Li, J.-P., Xie, Z.-J. & Song, H.-B. Synthesis, structural characterization, and electrochemical properties of dinuclear Ni/Mn model complexes for the active site of [NiFe]-hydrogenases. Inorg. Chem. 52, 11618–11626 (2013).
Ogo, S. et al. A dinuclear Ni(µ-H)Ru complex derived from H2 . Science 316, 585–587 (2007).
Canaguier, S., Fontecave, M. & Artero, V. Cp*-ruthenium-nickel-based H2-evolving electrocatalysts as bio-inspired models of NiFe hydrogenases. Eur. J. Inorg. Chem. 2011, 1094–1099 (2011).
Canaguier, S. et al. Catalytic hydrogen production by a Ni–Ru mimic of NiFe hydrogenases involves a proton-coupled electron transfer step. Chem. Commun. 49, 5004–5006 (2013).
Oudart, Y., Artero, V., Pécaut, J., Lebrun, C. & Fontecave, M. Dinuclear nickel–ruthenium complexes as functional bio-inspired models of NiFe hydrogenases. Eur. J. Inorg. Chem. 2007, 2613–2626 (2007).
Denny, J. A. & Darensbourg, M. Y. Metallodithiolates as ligands in coordination, bioinorganic, and organometallic chemistry. Chem. Rev. 115, 5248–5273 (2015).
Ogo, S. et al. A functional [NiFe] hydrogenase mimic that catalyzes electron and hydride transfer from H2 . Science 339, 682–684 (2013).
Barton, B. E. & Rauchfuss, T. B. Hydride-containing models for the active site of the nickel–iron hydrogenases. J. Am. Chem. Soc. 132, 14877–14885 (2010).
Barton, B. E., Whaley, C. M., Rauchfuss, T. B. & Gray, D. L. Nickel–iron dithiolato hydrides relevant to the [NiFe]-hydrogenase active site. J. Am. Chem. Soc. 131, 6942–6943 (2009).
Vaccaro, L., Artero, V., Canaguier, S., Fontecave, M. & Field, M. J. Mechanism of hydrogen evolution catalyzed by NiFe hydrogenases: insights from a Ni–Ru model compound. Dalton Trans. 39, 3043–3049 (2010).
Simmons, T. R. & Artero, V. Catalytic hydrogen oxidation: dawn of a new iron age. Angew. Chem. Int. Ed. 52, 6143–6145 (2013).
Chambers, G. M. et al. Models of the Ni–L and Ni–SIa states of the [NiFe]-hydrogenase active site. Inorg. Chem. 55, 419–431 (2016).
Gennari, M. et al. Influence of mixed thiolate/thioether versus dithiolate coordination on the accessibility of the uncommon +I and +III oxidation states for the nickel ion: an experimental and computational study. Inorg. Chem. 50, 3707–3716 (2011).
Gennari, M. et al. Reversible apical coordination of imidazole between the Ni(III) and Ni(II) oxidation states of a dithiolate complex: a process related to the Ni superoxide dismutase. Inorg. Chem. 49, 6399–6401 (2010).
Canaguier, S. et al. A structural and functional mimic of the active site of NiFe hydrogenases. Chem. Commun. 46, 5876–5878 (2010).
Zhu, W. et al. Modulation of the electronic structure and the Ni–Fe distance in heterobimetallic models for the active site in [NiFe] hydrogenase. Proc. Natl Acad. Sci. USA 102, 18280–18285 (2005).
Darensbourg, D. J., Reibenspies, J. H., Lai, C.-H., Lee, W.-Z. & Darensbourg, M. Y. Analysis of an organometallic iron site model for the heterodimetallic unit of [NiFe] hydrogenase. J. Am. Chem. Soc. 119, 7903–7904 (1997).
Pandelia, M.-E., Ogata, H. & Lubitz, W. Intermediates in the catalytic cycle of [NiFe] hydrogenase: functional spectroscopy of the active site. ChemPhysChem 11, 1127–1140 (2010).
Roncaroli, F. et al. Cofactor composition and function of a H2-sensing regulatory hydrogenase as revealed by Mossbauer and EPR spectroscopy. Chem. Sci. 6, 4495–4507 (2015).
Lubitz, W., Gastel, M. V. & Gärtner, W. in Nickel and its Surprising Impact in Nature (eds Sigel, A., Sigel, H. & Sigel, R. K. O.) 279–322 (Wiley, 2007).
Roy, S., Groy, T. L. & Jones, A. K. Biomimetic model for [FeFe]-hydrogenase: asymmetrically disubstituted diiron complex with a redox-active 2,2′-bipyridyl ligand. Dalton Trans. 42, 3843–3853 (2013).
Farmer, P. J., Reibenspies, J. H., Lindahl, P. A. & Darensbourg, M. Y. Effects of sulfur site modification on the redox potentials of derivatives of [N,N′-bis(2-mercaptoethyl)-1,5-diazacyclooctanato]nickel(II). J. Am. Chem. Soc. 115, 4665–4674 (1993).
Izutsu, K. Acid–Base Dissociation Constants in Dipolar Aprotic Solvents (Blackwell Scientific, 1990).
Costentin, C., Drouet, S., Robert, M. & Savéant, J.-M. Turnover numbers, turnover frequencies, and overpotential in molecular catalysis of electrochemical reactions. Cyclic voltammetry and preparative-scale electrolysis. J. Am. Chem. Soc. 134, 11235–11242 (2012).
Artero, V. & Savéant, J.-M. Toward the rational benchmarking of homogeneous H2-evolving catalysts. Energy Environ. Sci. 7, 3808–3814 (2014).
Costentin, C., Dridi, H. & Savéant, J.-M. Molecular catalysis of H2 evolution: diagnosing heterolytic versus homolytic pathways. J. Am. Chem. Soc. 136, 13727–13734 (2014).
Sampson, M. D. & Kubiak, C. P. Electrocatalytic dihydrogen production by an earth-abundant manganese bipyridine catalyst. Inorg. Chem. 54, 6674–6676 (2015).
Shaw, W. J., Helm, M. L. & DuBois, D. L. A modular, energy-based approach to the development of nickel containing molecular electrocatalysts for hydrogen production and oxidation. Biochim. Biophys. Acta Bioenerg. 1827, 1123–1139 (2013).
Van der Meer, M., Glais, E., Siewert, I. & Sarkar, B. Electrocatalytic dihydrogen production with a robust mesoionic pyridylcarbene cobalt catalyst. Angew. Chem. Int. Ed. 54, 13792–13795 (2015).
Kampa, M., Pandelia, M.-E., Lubitz, W., van Gastel, M. & Neese, F. A metal–metal bond in the light-induced state of [NiFe] hydrogenases with relevance to hydrogen evolution. J. Am. Chem. Soc. 135, 3915–3925 (2013).
Perotto, C. U. et al. A Ni(I)Fe(II) analogue of the Ni–L state of the active site of the [NiFe] hydrogenases. Chem. Commun. 51, 16988–16991 (2015).
Yoo, C., Oh, S., Kim, J. & Lee, Y. Transmethylation of a four-coordinate nickel(I) monocarbonyl species with methyl iodide. Chem. Sci. 5, 3853–3858 (2014).
Greene, B. L., Wu, C.-H., McTernan, P. M., Adams, M. W. W. & Dyer, R. B. Proton-coupled electron transfer dynamics in the catalytic mechanism of a [NiFe]-hydrogenase. J. Am. Chem. Soc. 137, 4558–4566 (2015).
Matson, E. M. et al. Nickel(II) pincer carbene complexes: oxidative addition of an aryl C–H bond to form a Ni(II) hydride. Organometallics 34, 399–407 (2015).
Breitenfeld, J., Scopelliti, R. & Hu, X. Synthesis, reactivity, and catalytic application of a nickel pincer hydride complex. Organometallics 31, 2128–2136 (2012).
Boro, B. J., Duesler, E. N., Goldberg, K. I. & Kemp, R. A. Synthesis, characterization, and reactivity of nickel hydride complexes containing 2,6-C6H3(CH2PR2)2 (R = tBu, cHex, and iPr) pincer ligands. Inorg. Chem. 48, 5081 (2009).
Peters, J. W. et al. [FeFe]- and [NiFe]-hydrogenase diversity, mechanism, and maturation. BBA Mol. Cell Res. 1853, 1350–1369 (2015).
Adamska, A. et al. Identification and characterization of the ‘super-reduced’ state of the H-cluster in FeFe hydrogenase: a new building block for the catalytic cycle? Angew. Chem. Int. Ed. 51, 11458–11462 (2012).
Chernev, P. et al. Hydride binding to the active site of [FeFe]-hydrogenase. Inorg. Chem. 53, 12164–12177 (2014).
Ezzaher, S. et al. Evidence for the formation of terminal hydrides by protonation of an asymmetric iron hydrogenase active site mimic. Inorg. Chem. 46, 3426–3428 (2007).
Mealli, C. & Rauchfuss, T. B. Models for the hydrogenases put the focus where it should be—hydrogen. Angew. Chem. Int. Ed. 46, 8942–8944 (2007).
Barton, B. E., Olsen, M. T. & Rauchfuss, T. B. Aza- and oxadithiolates are probable proton relays in functional models for the FeFe-hydrogenases. J. Am. Chem. Soc. 130, 16834–16835 (2008).
Olsen, M. T., Rauchfuss, T. B. & Wilson, S. R. Role of the azadithiolate cofactor in models for FeFe-hydrogenase: novel structures and catalytic implications. J. Am. Chem. Soc. 132, 17733–17740 (2010).
Carroll, M. E., Barton, B. E., Rauchfuss, T. B. & Carroll, P. J. Synthetic models for the active site of the FeFe-hydrogenase: catalytic proton reduction and the structure of the doubly protonated intermediate. J. Am. Chem. Soc. 134, 18843–18852 (2012).
Zaffaroni, R., Rauchfuss, T. B., Gray, D. L., De Gioia, L. & Zampella, G. Terminal vs bridging hydrides of diiron dithiolates: protonation of Fe2(dithiolate)(CO)2(PMe3)4 . J. Am. Chem. Soc. 134, 19260–19269 (2012).
Camara, J. M. & Rauchfuss, T. B. Combining acid–base, redox and substrate binding functionalities to give a complete model for the FeFe-hydrogenase. Nature Chem. 4, 26–30 (2012).
Reger, D. L. & Coleman, C. Preparation and reactions of the (dicarbonyl) (η5-cyclopentadienyl)(tetrahydrofuran)iron cation: a convenient route to (dicarbonyl)(η5-cyclopentadiemyl)(η2-olefin)iron cations and related complexes. J. Org. Chem. 131, 153–162 (1977).
Bhugun, I., Lexa, D. & Savéant, J.-M. Homogeneous catalysis of electrochemical hydrogen evolution by iron(0) porphyrins. J. Am. Chem. Soc. 118, 3982–3983 (1996).
Financial support for this work was provided by Labex arcane (ANR-11-LABX-003), the European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement no. 306398 and the COST Action CM1305 (EcostBio) including an STSM grant (COST-STSM-CM1305- 26539) to D.B.
The authors declare no competing financial interests.
Supplementary information (PDF 1202 kb)
Crystallographic data for compound LN2S2NiIIFeII. (CIF 1725 kb)
Rights and permissions
About this article
Cite this article
Brazzolotto, D., Gennari, M., Queyriaux, N. et al. Nickel-centred proton reduction catalysis in a model of [NiFe] hydrogenase. Nature Chem 8, 1054–1060 (2016). https://doi.org/10.1038/nchem.2575
This article is cited by
Effect of the NiN2S2 Metallothiolate Ligands on the Preparation, Structure, and Property of Dinickel Complexes Related to [NiFe]-Hydrogenases Active Site
Catalysis Letters (2022)
Immobilization of molecular catalysts on electrode surfaces using host–guest interactions
Nature Chemistry (2021)
Homogeneous catalysis: Synthetic models close in on enzymes
Nature Reviews Chemistry (2018)
Atomically dispersed Ni(i) as the active site for electrochemical CO2 reduction
Nature Energy (2018)
Natural inspirations for metal–ligand cooperative catalysis
Nature Reviews Chemistry (2017)