Light-Atom Influences on the Electronic Structures of Iron–Sulfur Clusters
- 19 February 2014
- journal article
- research article
- Published by American Chemical Society (ACS) in Inorganic Chemistry
- Vol. 53 (5) , 2591-2597
Abstract
Ligand K-edge X-ray absorption spectroscopy was used to study dimeric and tetrameric Cl-terminated Fe–S clusters with variable numbers of S2– substituted by NtBu2– (NtBu2– = tertbutylimido) ligands to gain insights into the functional role of the interstitial light atom in the iron–molybdenum cofactor (FeMoco) of nitrogenase. These studies are complemented by time-dependent density functional theory analysis to quantify the relative effects on Fe–S and Fe–Cl bonding. The results show that NtBu2– substitution dramatically affects the electronic structure of dimeric clusters, while the impact on tetrameric clusters is small. Strong agreement between experiment and theory merited extension of this analysis to hypothetical clusters with S2– substituted by N and C-atom donor ligands as well as FeMoco itself. These results show that very strong electron donors are required to appreciably modulate the electronic structure of tetrameric (or larger) iron sulfur clusters, pointing to a possible role of the central C4– in FeMoco.Keywords
This publication has 33 references indexed in Scilit:
- Evidence for Interstitial Carbon in Nitrogenase FeMo CofactorScience, 2011
- Comparative Assessment of the Composition and Charge State of Nitrogenase FeMo-CofactorInorganic Chemistry, 2011
- Decoding the Nitrogenase Mechanism: The Homologue ApproachAccounts of Chemical Research, 2009
- Sulfur K-Edge X-ray Absorption Spectroscopy as a Probe of Ligand−Metal Bond Covalency: Metal vs Ligand Oxidation in Copper and Nickel Dithiolene ComplexesJournal of the American Chemical Society, 2007
- UCSF Chimera—A visualization system for exploratory research and analysisJournal of Computational Chemistry, 2004
- Ligand K-Edge X-ray Absorption Spectroscopy of [Fe4S4]1+,2+,3+ Clusters: Changes in Bonding and Electronic Relaxation upon RedoxJournal of the American Chemical Society, 2004
- Structural, Spectroscopic, and Redox Consequences of a Central Ligand in the FeMoco of Nitrogenase: A Density Functional Theoretical StudyJournal of the American Chemical Society, 2003
- A Stable Terminal Imide on IronJournal of the American Chemical Society, 2000
- New structural insights into the iron-molybdenum cofactor from Azotobacter vinelandii nitrogenase through sulfur K and molybdenum L x-ray absorption edge studiesJournal of the American Chemical Society, 1988
- Improved syntheses of tetrachlorodi-.mu.-sulfidodiferrate(2-) ([Fe2S2Cl4]2-) and hexachloro-.mu.-oxodiferrate(2-) ([Fe2OCl6]2-) and oxo/sulfido ligand substitution by use of silylsulfide reagentsInorganic Chemistry, 1983