Synthesis of Metallopolymers via Atom Transfer Radical Polymerization from a [2Fe‐2S] Metalloinitiator: Molecular Weight Effects on Electrocatalytic Hydrogen Production
Synthesis of Metallopolymers via Atom Transfer Radical Polymerization from a [2Fe‐2S] Metalloinitiator: Molecular Weight Effects on Electrocatalytic Hydrogen Production
复制标题
[2Fe-2S] 金属引发剂通过原子转移自由基聚合合成金属聚合物：分子量对电催化产氢的影响
DOI：
10.1002/marc.201900424
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发表时间：
2019
影响因子：
4.6
通讯作者：
Pyun, Jeffrey
中科院分区：
文献类型：
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作者：
Karayilan, Metin;McCleary‐Petersen, Keelee Cathleen;Hamilton, Meghan O'Brien;Fu, Liye;Matyjaszewski, Krzysztof;Glass, Richard S.;Lichtenberger, Dennis L.;Pyun, Jeffrey
受[FeFe]-氢酶活性中心启发的小分子仿生学已显示出良好的电催化氢气生成活性。然而，大多数基于[2Fe-2S]团簇的活性中心模拟物是不溶于水的，这限制了这些电催化剂在有机介质中的应用。聚合物负载的[2Fe-2S]体系，特别是单位金属聚合物催化剂，在水环境中的电催化制氢性能有了很大的改善。[2Fe-2S]络合物通过共价键在定义良好的大分子载体中官能化，在催化过程中表现出水溶性，增强了位置隔离，并改善了化学稳定性。合成了一种用于原子转移自由基聚合的新型金属引发剂丙二硫酸酯-[2Fe-2S](α-g-[2Fe-2S])金属聚合物。用这种方法制备了相对分子质量可控(Mn=5~40kgmol−1)和低分散度(Đ，MW/Mn=1.0 9~1.3 6)的金属聚合物，首次观察了金属聚合物的链长对电催化活性的影响。能够控制这些金属聚合物的组成和相对分子质量的能力使得通过这些材料的ATRP进行大分子工程来确定用于制氢的金属聚合物催化剂的最佳结构特征。
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.