Wang Meng, Shanmugam Muralidharan, McInnes Eric J L, Shaver Michael P
Department of Materials, School of Natural Sciences, University of Manchester, Manchester M13 9PL, U.K.
Sustainable Materials Innovation Hub, Henry Royce Institute, University of Manchester, Manchester M13 9PL, U.K.
J Am Chem Soc. 2023 Nov 8;145(44):24294-24301. doi: 10.1021/jacs.3c09075. Epub 2023 Oct 27.
Polymeric frustrated Lewis pairs, or poly(FLP)s, have served to bridge the gap between functional polymer science and main group catalysis, pairing the uniqueness of sterically frustrated Lewis acids and bases with a polymer scaffold to create self-healing gels and recyclable catalysts. However, their utilization in radical chemistry is unprecedented. In this paper, we disclose the synthesis of polymeric frustrated radical pairs, or poly(FRP)s, by in situ photoinduction of FLP moieties, where their Lewis acidic and basic centers are tuned to promote single electron transfer (SET). Through systematic manipulation of the chemical structure, we demonstrate that inclusion of ortho-methyl groups on phosphine monomers is crucial to enable SET. The generation of radicals is evidenced by monitoring the stable polymeric phosphine radical cations via UV/vis and EPR spectroscopy. These new poly(FRP)s enable both catalytic hydrogenation and radical-mediated photocatalytic perfluoroalkylations. These polymeric radical systems open new avenues to design novel functional polymers for catalysis and photoelectrical chemistry.
聚合物受阻路易斯酸碱对，即聚（FLP），在功能聚合物科学和主族催化之间架起了桥梁，将空间位阻受阻路易斯酸和碱的独特性与聚合物支架相结合，以制备自修复凝胶和可回收催化剂。然而，它们在自由基化学中的应用尚无先例。在本文中，我们通过原位光诱导FLP部分，揭示了聚合物受阻自由基对，即聚（FRP）的合成方法，其中它们的路易斯酸和碱中心经过调节以促进单电子转移（SET）。通过对化学结构的系统调控，我们证明在膦单体上引入邻甲基对于实现单电子转移至关重要。通过紫外/可见光谱和电子顺磁共振光谱监测稳定的聚合物膦自由基阳离子，证实了自由基的产生。这些新型聚（FRP）能够实现催化氢化和自由基介导的光催化全氟烷基化反应。这些聚合物自由基体系为设计用于催化和光电化学的新型功能聚合物开辟了新途径。
