Model of the Iron Hydrogenase Active Site Covalently Linked to a Ruthenium Photosensitizer: Synthesis and Photophysical Properties
| Autor: | Mikael Kritikos, Sascha Ott, Magnus Borgström, Leif Hammarström, Reiner Lomoth, Licheng Sun, Jonas Bergquist, Björn Åkermark |
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| Rok vydání: | 2004 |
| Předmět: |
Iron-Sulfur Proteins
Models Molecular Hydrogenase Heteroatom Molecular Conformation chemistry.chemical_element Ligands Supermolecule Photochemistry Ruthenium Inorganic Chemistry Structure-Activity Relationship chemistry.chemical_compound Polymer chemistry Electrochemistry Organometallic Compounds Physical and Theoretical Chemistry Binding Sites Photosensitizing Agents Molecular Structure Ligand Decarbonylation Phenylacetylene chemistry Terpyridine |
| Zdroj: | Inorganic Chemistry. 43:4683-4692 |
| ISSN: | 1520-510X 0020-1669 |
| DOI: | 10.1021/ic0303385 |
| Popis: | A model of the iron hydrogenase active site with the structure [(mu-ADT)Fe2(CO)6] (ADT = azadithiolate (S-CH2-NR-CH2-S), (2: R = 4-bromophenyl, 3: R = 4-iodophenyl)) has been assembled and covalently linked to a [Ru(terpy)2]2+ photosensitizer. This trinuclear complex 1 represents one synthetic step toward the realization of our concept of light-driven proton reduction. A rigid phenylacetylene tether has been incorporated as the linking unit in 1 in order to prolong the lifetime of the otherwise short-lived [Ru(terpy)2]2+ excited state. The success of this strategy is demonstrated by comparison of the photophysical properties of 1 and of two related ruthenium complexes bearing acetylenic terpyridine ligands, with those of [Ru(terpy)2]2+. IR and electrochemical studies reveal that the nitrogen heteroatom of the ADT bridge has a marked influence on the electronic properties of the [Fe2(CO)6] core. Using the Rehm-Weller equation, the driving force for an electron transfer from the photoexcited *[Ru(terpy)2]2+ to the diiron site in 1 was calculated to be uphill by 0.59 eV. During the construction of the trinuclear complex 1, n-propylamine has been identified as a decarbonylation agent on the [(mu-ADT)Fe2(CO)6] portion of the supermolecule. Following this procedure, the first azadithiolate-bridged dinuclear iron complex coordinated by a phosphine ligand [(mu-ADT)Fe2(CO)5PPh3] (4, R = 4-bromophenyl) was synthesized. |
| Databáze: | OpenAIRE |
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