Noll Niklas, 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 Jan 4;27(1):444-450. doi: 10.1002/chem.202004486. Epub 2020 Nov 26.
A cyclic dinuclear ruthenium(bda) (bda: 2,2'-bipyridine-6,6'-dicarboxylate) complex equipped with oligo(ethylene glycol)-functionalized axial calix[4]arene ligands has been synthesized for homogenous catalytic water oxidation. This novel Ru(bda) macrocycle showed significantly increased catalytic activity in chemical and photocatalytic water oxidation compared to the archetype mononuclear reference [Ru(bda)(pic) ]. Kinetic investigations, including kinetic isotope effect studies, disclosed a unimolecular water nucleophilic attack mechanism of this novel dinuclear water oxidation catalyst (WOC) under the involvement of the second coordination sphere. Photocatalytic water oxidation with this cyclic dinuclear Ru complex using [Ru(bpy) ]Cl as a standard photosensitizer revealed a turnover frequency of 15.5 s and a turnover number of 460. This so far highest photocatalytic performance reported for a Ru(bda) complex underlines the potential of this water-soluble WOC for artificial photosynthesis.
一种配备有寡聚（乙二醇）功能化轴向杯[4]芳烃配体的环状双核钌（bda）（bda：2,2'-联吡啶-6,6'-二羧酸）配合物已被合成用于均相催化水氧化。与原型单核参考物[Ru(bda)(pic)]相比，这种新型Ru(bda)大环在化学和光催化水氧化中显示出显著提高的催化活性。动力学研究，包括动力学同位素效应研究，揭示了这种新型双核水氧化催化剂（WOC）在第二配位层参与下的单分子水亲核攻击机制。使用[Ru(bpy)]Cl作为标准光敏剂，用这种环状双核Ru配合物进行光催化水氧化，其周转频率为15.5 s，周转数为460。这种Ru(bda)配合物迄今报道的最高光催化性能突显了这种水溶性WOC在人工光合作用中的潜力。
