Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489, Berlin, Germany.
Faculty of Chemistry and Biochemistry, Ruhr-Universität Bochum, Universitätsstraße 150, 44780, Bochum, Germany.
Angew Chem Int Ed Engl. 2023 Feb 1;62(6):e202214074. doi: 10.1002/anie.202214074. Epub 2022 Dec 29.
In many metalloenzymes, sulfur-containing ligands participate in catalytic processes, mainly via the involvement in electron transfer reactions. In a biomimetic approach, we now demonstrate the implication of S-ligation in cobalt mediated oxygen reduction reactions (ORR). A comparative study between the catalytic ORR capabilities of the four-nitrogen bound [Co(cyclam)] (1; cyclam=1,5,8,11-tetraaza-cyclotetradecane) and the S-containing analog [Co(S N -cyclam)] (2; S N -cyclam=1,8-dithia-5,11-diaza-cyclotetradecane) reveals improved catalytic performance once the chalcogen is introduced in the Co coordination sphere. Trapping and characterization of the intermediates formed upon dioxygen activation at the Co centers in 1 and 2 point to the involvement of sulfur in the O reduction process as the key for the improved catalytic ORR capabilities of 2.
在许多金属酶中，含硫配体参与催化过程，主要通过参与电子转移反应。在仿生方法中，我们现在证明了 S 配体在钴介导的氧还原反应 (ORR) 中的作用。对四氮配位的 [Co(cyclam)] (1；cyclam=1,5,8,11-四氮杂环十四烷) 和含硫类似物 [Co(S N -cyclam)] (2；S N -cyclam=1,8-二硫代-5,11-二氮杂环十四烷) 的催化 ORR 能力进行了比较研究，结果表明，一旦将硫引入钴配位球，就会提高催化性能。在 1 和 2 中，对氧在 Co 中心活化形成的中间体进行捕获和表征，表明硫在 O 还原过程中的参与是提高 2 的催化 ORR 能力的关键。
