Hydrogenases models

PHOTOPRODUCTION OF HYDROGEN BY INORGANIC SEMICONDUCTOR Ti02 - HYDROGENASE MODEL SYSTEM... 

Figure 1. H2 photoproduction by Ti02 - hydrogenase model system.

Fontecilla-Camps, J. C. (1996) The active site of Ni-Fe hydrogenases Model chemistry and crystallographic results. J. Biol. Inorg. Chem., 1, 91-8. 

Figure 3.4.11 Synthetic molecular catalysts for hydrogen conversion. (A) [FeFe] hydrogenase model with functionalities for substrate binding (H2) and management of redox and proton equivalents (adapted from [162]). (B) Synthetic mononuclear Ni electrocatalyst with pending amines that function as proton relays proposed transition state for heterolytic H2 splitting and formation (adapted from [165]).

The individual steps of the mechanism in Scheme 39 are analogous to those discussed above for the hydrogenase model complexes. After the heterolysis step yielding D+ and D, an intramolecular and probably very rapid exchange between thiol deuterons and diazene protons has to take place in order to explain the experimental findings. 

Biomimetic Efficiency A Structural and Electronic Investigation of Rotational Barriers Found in DFT-inspired Fe-hydrogenase Models... 

Fig. 2.4 Hydrogenase model by Schwartz (2009). As compared to the natural cyanide, tiimethyl phosphine hgands in the model complex will increase redox potentials of the Fe(ll) centers while reducing M-H acidity of hydride (cp. Franzle 1992). This diminishes...

Akabori S., Sakurai S., Izumi Y. and Fujii Y. (1957) An asymmetric catalyst - a hydrogenase model, Biochimia 22,154-156. 

Synthetic, structural, and reactivity studies of iron-only hydrogenase model compounds 05CCR(249)1641. 

Diiron hydrogenase has deeply inspired researchers in the development of new systems for the photocatalytic evolution of hydrogen from water. However, the construction of hydrogenase models with high photocatalytic activity and efficiency is still a great challenge. Dendritic... 

Huynh MT, Schilter D, Hammes-Schiffer S, Rauchfuss TB (2014) Protonation of nickel-iron hydrogenase models proceeds after isomerization at nickel. J Am Chem Soc 136 (35) 12385-12395. doi 10.1021/ja505783z... 

Darensbourg MY, Lyon EJ, Zhao X, Georgakaki IP (2003) The organometallic active site of [Fe]-hydrogenase models and entatic states. Proc Natl Acad Sci USA 100(7) 3683-3688. doi 10.1073/pnas.0536955100... 

Singleton ML, Bhuvanesh N, Reibenspies JH, Darensbourg MY (2008) Synthetic support of de novo design sterically bulky [FeFe]-hydrogenase models. Angew Chem Int Ed 47 (49) 9492-9495. doi 10.1002/anie.200803939... 

Sano Y, Onoda A, Hayashi T (2011) A hydrogenase model system based on the sequence of cytochrome c photochemical hydrogen evolution in aqueous media. Chem Conunun 47 (29) 8229-8231. doi 10.1039/cIcc 11157d... 

Sano Y, Onoda A, Hayashi T (2012) Photocatalytic hydrogen evolution by a diiron hydrogenase model based on a peptide fragment of cytochrome C555 with an attached diiron carbonyl cluster and an attached ruthenium photosensitizer. J Inorg Biochem 108 159-162. doi 10.1016/j.jinorgbio.2011.07.010... 

Poddutoori P, Co DT, Samuel APS, Kim CH, Vagnini MT, Wasielewski MR (2011) Photoinitiated multistep charge separation in ferrocene-zinc porph5oin-diiron hydrogenase model complex triads. Energ Environ Sci 4(7) 2441-2450... 

Darensbourg, M. Y. Lyon, E. J. Zhao, X. Georgakaki, I. P. Bioinorganic chemistry special feature The organometallic active site of [Fe]hydrogenase Models and entatic states. Proc. Natl. Acad. Sci. U. S. A. 2003,100, 3683-3688. 

Mejia-Rodriguez, R. Chong, D. Reibenspies, J. H., Soriaga, M. P. Darensbourg, M. Y. The hydrophilic phosphatriazaadamantane ligand in the development of h2 production electrocatalysts Iron hydrogenase model complexes. J. Am. Chem. Soc. 2004,126, 12004-12014. 

Barton BE, Rauchfuss TB. Terminal hydride in [FeFe]-hydrogenase model has lower potential for H2 production than the isomeric bridging hydride. Inorg Chem 2008 47 2261-2263. 

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