Ling Jianheng, Vonder Haar Amy L, Colley Kiser Z, Kim Juno, Musser Andrew J, Milner Phillip J
Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, United States.
Res Sq. 2024 Nov 26:rs.3.rs-5428587. doi: 10.21203/rs.3.rs-5428587/v1.
The reductive functionalization of inert substrates like chloroarenes is a critical yet challenging transformation relevant to both environmental remediation and organic synthesis. Combining electricity and light is an emerging approach to access the deeply reducing potentials required for single electron transfer to chloroarenes, yet this approach is held back by the poor stability and mechanistic ambiguity of current homogeneous systems. Incorporating redox-active moieties into insoluble organic materials represents a promising strategy to unlock new heterogeneous catalytic activity while improving catalyst stability. Herein, we demonstrate the first example of heterogeneous electrophotocatalysis using redox-active rylene diimide polymers for the reduction of chloroarenes. In particular, we find that the electrophotocatalytic activity varies significantly not just as a function of the rylene diimide but also of the redox-inactive polymer backbone. In particular, , a flexible, non-conjugated perylenediimide polymer, outperforms all other tested materials as an electrophotocatalyst. Using transient absorption spectroscopy, we reveal that precomplexation between the closed-shell and the haloarene substrate is key to productive catalysis. Overall, our work represents the first example of heterogeneous electrophotocatalysis using an insoluble redox-active organic material and provides critical insights into how polymer structure dictates electrophotocatalytic activity in the solid state, guiding the development of next-generation heterogeneous (electro)photocatalysts for sustainable synthesis.
氯代芳烃等惰性底物的还原官能团化是一种与环境修复和有机合成相关的关键但具有挑战性的转化反应。将电和光结合是一种新兴方法，可获得单电子转移至氯代芳烃所需的深度还原电位，但这种方法因当前均相体系稳定性差和机理不明确而受到阻碍。将氧化还原活性部分引入不溶性有机材料中是一种有前景的策略，既能释放新的非均相催化活性，又能提高催化剂稳定性。在此，我们展示了首个使用氧化还原活性苝二酰亚胺聚合物进行氯代芳烃还原的非均相光电催化实例。特别地，我们发现光电催化活性不仅显著取决于苝二酰亚胺，还取决于氧化还原惰性的聚合物主链。具体而言，一种柔性、非共轭的苝二酰亚胺聚合物作为光电催化剂的性能优于所有其他测试材料。通过瞬态吸收光谱，我们揭示了闭壳层[具体物质]与卤代芳烃底物之间的预络合是有效催化的关键。总体而言，我们的工作代表了首个使用不溶性氧化还原活性有机材料的非均相光电催化实例，并为聚合物结构如何决定固态中的光电催化活性提供了关键见解，为可持续合成的下一代非均相（电）光催化剂的开发提供了指导。
