Schindler Dorothee, Meza-Chincha Ana-Lucia, Roth Maximilian, Würthner Frank
Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
Center for Nanosystems Chemistry (CNC), Universität Würzburg, Theodor-Boveri-Weg, 97074, Würzburg, Germany.
Chemistry. 2021 Dec 6;27(68):16938-16946. doi: 10.1002/chem.202100549. Epub 2021 May 27.
Two di- and tetranuclear Ru(bda) (bda: 2,2'-bipyridine-6,6'-dicarboxylate) macrocyclic complexes were synthesized and their catalytic activities in chemical and photochemical water oxidation investigated in a comparative manner to our previously reported trinuclear congener. Our studies have shown that the catalytic activities of this homologous series of multinuclear Ru(bda) macrocycles in homogeneous water oxidation are dependent on their size, exhibiting highest efficiencies for the largest tetranuclear catalyst. The turnover frequencies (TOFs) have increased from di- to tetranuclear macrocycles not only per catalyst molecule but more importantly also per Ru unit with TOF of 6 s to 8.7 s and 10.5 s in chemical and 0.6 s to 3.3 s and 5.8 s in photochemical water oxidation per Ru unit, respectively. Thus, for the first time, a clear structure-activity relationship could be established for this novel class of macrocyclic water oxidation catalysts.
合成了两种双核和四核的Ru(bda)（bda：2,2'-联吡啶-6,6'-二羧酸）大环配合物，并以比较的方式研究了它们在化学和光化学水氧化中的催化活性，与我们之前报道的三核同系物进行对比。我们的研究表明，这一同源系列多核Ru(bda)大环在均相水氧化中的催化活性取决于其尺寸，最大的四核催化剂表现出最高的效率。周转频率（TOF）不仅从双核大环到四核大环每个催化剂分子有所增加，更重要的是每个Ru单元也有所增加，在化学水氧化中每个Ru单元的TOF分别从6 s增加到8.7 s和10.5 s，在光化学水氧化中从0.6 s增加到3.3 s和5.8 s。因此，首次为这类新型大环水氧化催化剂建立了明确的构效关系。
