Protonation of [FeFe]-hydrogenase sub-site analogues: revealing mechanism using FTIR stopped-flow techniques
| Autor: | Lee R. Webster, Pei Meng Woi, Joseph A. Wright, Christopher J. Pickett, Aušra Jablonskytė, Saad K. Ibrahim |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Iron-Sulfur Proteins
Models Molecular Hydrogenase Hydride Stereochemistry Chemistry Kinetics Protonation Activation energy Stopped flow Metal Crystallography visual_art Spectroscopy Fourier Transform Infrared visual_art.visual_art_medium Protons Physical and Theoretical Chemistry Fourier transform infrared spectroscopy |
| Zdroj: | Faraday Discuss.. 148:359-371 |
| ISSN: | 1364-5498 1359-6640 |
| Popis: | The formation of transient metal hydride(s) at the metallo-sulfur active sites of [FeFe]-hydrogenase is implicated in both hydrogen evolution and uptake reactions. Stopped-flow spectroscopic techniques can provide insight into the reactivity patterns of model {2Fe2S} sub-sites towards protons, and this information contributes to understanding the nature of the biological systems. In this study we have focussed on the influence of the nature of the bridging dithiolate ligand in influencing the kinetics and activation energy parameters for protonation in synthetic sub-sites including Fe2{micro-[S(CH2)(n)S]}(CO)4(PMe3)2 [n = 2, ethane-1,2-dithiolate (edt) or n = 3, propane-1,3-dithiolate (pdt)], Fe2[(micro-SCH2)2NH](CO)4(PMe3)2 and (NEt4)2{Fe2[(micro-SCH2)2NH](CO)4(CN)2}. Notably we find that (i) the presence of a nitrogen in the dithiolate bridge does not accelerate metal-metal bond protonation, and that (ii) immobilisation of (NEt4)2[Fe2(micro-pdt)(CO)4(CN)2] in a polymer matrix stabilises otherwise short-lifetime protonation products. |
| Databáze: | OpenAIRE |
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