Sahu Swagat, Cheung Po Ling, Machan Charles W, Chabolla Steven A, Kubiak Clifford P, Gianneschi Nathan C
Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA.
Materials Science & Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA.
Chemistry. 2017 Jun 27;23(36):8619-8622. doi: 10.1002/chem.201701901. Epub 2017 Jun 5.
A series of polymeric frameworks with functional assemblies were designed to alter the catalytic activity of covalently bound Re electrocatalysts. Norbornenyl polymers containing positively charged quaternary ammonium salts, neutral phenyl, or negatively charged trifluoroborate groups were end-labelled with a Re fac-tricarbonyl bipyridine electrocatalyst via cross metathesis. Electrochemical studies in acetonitrile under an inert atmosphere and with saturated CO indicate that the quaternary ammonium polymers exhibit a significantly lower potential for CO reduction to CO (ca. 300 mV), while neutral polymers behave consistently with what has been reported for the free, molecular catalyst. In contrast, the trifluoroborate polymers displayed a negative shift in potential and catalytic activity was not observed. It is demonstrated that a single catalytically active complex can be installed onto a charged polymeric framework, thereby achieving environmentally tuned reduction potentials for CO reduction. These materials may be useful as polymer-based precursors for preparing catalytic and highly ordered structures such as thin films, porous catalytic membranes, or catalytic nanoparticles.
设计了一系列具有功能组件的聚合物框架，以改变共价键合的铼电催化剂的催化活性。含有带正电荷的季铵盐、中性苯基或带负电荷的三氟硼酸盐基团的降冰片烯基聚合物通过交叉复分解反应，用铼 fac-三羰基联吡啶电催化剂进行末端标记。在惰性气氛和饱和一氧化碳存在下于乙腈中进行的电化学研究表明，季铵聚合物将一氧化碳还原为一氧化碳的电位显著降低（约 300 mV），而中性聚合物的行为与已报道的游离分子催化剂一致。相比之下，三氟硼酸盐聚合物的电位出现负移，未观察到催化活性。结果表明，可以将单个催化活性配合物安装到带电的聚合物框架上，从而实现用于一氧化碳还原的环境调节还原电位。这些材料可用作基于聚合物的前体，用于制备催化和高度有序的结构，如薄膜、多孔催化膜或催化纳米颗粒。
