Thomas Rauchfuss

Synthetic Models for the Hydrogenase Enzymes

In the hydrogenases, Nature employs organometallic reaction centers for production and oxidation of H₂. Synthetic models for the active sites show how these enzymes might function and provide powerful concepts for the inorganic chemist as well. Some themes to be discussed include:

• Proton relays in regulating formation and deprotonation of metal hydrides.
• Mixed valency in H₂ binding and release.
• M-H regiochemistry: terminal vs bridging hydrides, and in between.

Also discussed will be the mechanistic advantages for bimetallic centers and CO/CN- cofactors. These topics will be presented in the context of my research program that focuses on synthetic organometallic chemistry.

Leading references:

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. 2012, 134, 19260.

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. 2012, 134, 18843.

Manor, B. C.; Rauchfuss, T. B., “Hydrogen Activation by Biomimetic [NiFe]-Hydrogenase Model Containing Protected Cyanide Cofactors”, J. Am. Chem. Soc. 2013, 135, 11895.

Huynh, M. T.; Schilter, D.; Hammes-Schiffer, S.; Rauchfuss, T. B., “Protonation of Nickel–Iron Hydrogenase Models Proceeds after Isomerization at Nickel”, J. Am. Chem. Soc. 2014, 136, 12385.