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Abstract The Fe protein of nitrogenase plays multiple roles in substrate reduction and cluster maturation via its redox‐active [Fe4S4] cluster. Here we report the synthesis and characterization of a water‐soluble [Fe4Se4] cluster that is used to substitute the [Fe4S4] cluster of theAzotobacter vinelandiiFe protein (AvNifH). Biochemical, EPR and XAS/EXAFS analyses demonstrate the ability of the [Fe4Se4] cluster to adopt the super‐reduced, all‐ferrous state upon its incorporation intoAvNifH. Moreover, these studies reveal that the [Fe4Se4] cluster inAvNifH already assumes a partial all‐ferrous state ([Fe4Se4]0) in the presence of dithionite, where its [Fe4S4] counterpart inAvNifH exists solely in the reduced state ([Fe4S4]1+). Such a discrepancy in the redox properties of theAvNifH‐associated [Fe4Se4] and [Fe4S4] clusters can be used to distinguish the differential redox requirements for the substrate reduction and cluster maturation of nitrogenase, pointing to the utility of chalcogen‐substituted FeS clusters in future mechanistic studies of nitrogenase catalysis and assembly.
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Synthesis and disassembly of an organometallic polymer comprising redox-active Co 4 S 4 clusters and Janus biscarbene linkers
Here, we show for the first time that main-chain organometallic polymers (MCOPs) can be prepared from Janus N-heterocyclic carbene (NHC) linkers and polynuclear cluster nodes. The crosslinked framework Co 4 S 4 -MCOP is synthesized via ligand displacement reactions and undergoes reversible electron transfer in the solid state. Discrete molecular cluster species can be excised from the framework by digesting the solid in solutions of excess monocarbene. Finally, we demonstrate a synthetic route to monodisperse framework particles via coordination modulation.
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- Award ID(s):
- 2045390
- PAR ID:
- 10392771
- Date Published:
- Journal Name:
- Chemical Communications
- Volume:
- 58
- Issue:
- 31
- ISSN:
- 1359-7345
- Page Range / eLocation ID:
- 4885 to 4888
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/d2cc00953f
