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Abstract Small molecule biomimetics inspired by the active site of the [FeFe]‐hydrogenase enzymes have shown promising electrocatalytic activity for hydrogen (H2) generation. However, most of the active‐site mimics based on [2Fe‐2S] clusters are not water‐soluble which limits the use of these electrocatalysts to organic media. Polymer‐supported [2Fe‐2S] systems, in particular, single‐site metallopolymer catalysts, have shown drastic improvements for electrocatalytic H2generation in aqueous milieu. [2Fe‐2S] complexes functionalized within well‐defined macromolecular supports via covalent bonding have demonstrated water solubility, enhanced site‐isolation, and improved chemical stability during catalysis. In this report, the synthesis of a new propanedithiolate (pdt)‐[2Fe‐2S] complex bearing a single α‐bromoester moiety for use in atom transfer radical polymerization (ATRP) is demonstrated as a novel metalloinitiator to prepare water‐soluble poly(2‐dimethylaminoethyl methacrylate) grafted (PDMAEMA‐g‐[2Fe‐2S]) metallopolymers. Using this approach, metallopolymers with controllable molecular weights (Mn= 5–40 kg mol−1) and low dispersity (Đ,Mw/Mn= 1.09–1.36) are prepared, which allows for the first time observation of the effect of the metallopolymers' chain length on the electrocatalytic activity. The ability to control the composition and molecular weight of these metallopolymers enables macromolecular engineering via ATRP of these materials to determine optimal structural features of metallopolymer catalysts for H2production.
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This content will become publicly available on May 20, 2026
Functionalization of Water-Soluble Metallopolymer Electrocatalysts for Water-Splitting Using Atom Transfer Radical Polymerization and Click Chemistry
ABSTRACT: The diverse functionalization of the polymeric support phase of diiron disulfide[2Fe–2S] metallopolymer elec-trocatalysts offers a route to enhanced generation of molecular hydrogen production via water-splitting. Click chemistry has been shown to be a useful tool in post-polymerization functionalization for a wide range of polymeric materials under mild conditions which is a requirement for [2Fe-2S] metallopolymers due to the presence of iron carbonyl (Fe-CO) bonds in the active site. In this study, we developed a new synthetic methodology to functionalize [2Fe–2S] metallopolymers using atom transfer radical polymerization (ATRP) and post-polymerization functionalization using azide-alkyne “click” cycloaddition. Azide functional [2Fe–2S] metallopolymers were prepared by the ATRP of 3-azidopropyl methacrylate (AzPMA) with either methyl methacrylate (MMA), or 2-(dimethylamino)ethyl methacrylate (DMAEMA), followed by copper-catalyzed “click” cycloaddition with functional terminal alkynes. Both families of PMMA and PDMAEMA functional [2Fe–2S] metallo-co-polymers were found to be retain Fe-CO bonds from the catalyst active site after the click chemistry reactions, and more importantly, exhibited high electrocatalytic activity for electrochemical water-splitting under pH neutral aqueous conditions.Not Available
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- PAR ID:
- 10652686
- Editor(s):
- Rowan, Stuart J
- Publisher / Repository:
- ACS Macro Letters
- Date Published:
- Journal Name:
- ACS Macro Letters
- Volume:
- 14
- Issue:
- 5
- ISSN:
- 2161-1653
- Page Range / eLocation ID:
- 582 to 588
- Subject(s) / Keyword(s):
- metallopolymers catalysis hydrogen production ATRP click chemistry
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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