Department of Chemistry and Nano Science, Ewha Womans University, Seoul, 03760, Korea.
Key Laboratory of Applied Surface and Colloid Chemistry, Xi'an Key Laboratory of Organometallic Material Chemistry, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, China.
Angew Chem Int Ed Engl. 2022 Aug 22;61(34):e202208143. doi: 10.1002/anie.202208143. Epub 2022 Jul 13.
A cobalt porphyrin complex with a pendant imidazole base ([(L )Co ]) is an efficient catalyst for the homogeneous catalytic two-electron reduction of dioxygen by 1,1'-dimethylferrocene (Me Fc) in the presence of triflic acid (HOTf), as compared with a cobalt porphyrin complex without a pendant imidazole base ([(L )Co ]). The pendant imidazole ligand plays a crucial role not only to provide an imidazolinium proton for proton-coupled electron transfer (PCET) from [(L )Co ] to O in the presence of HOTf but also to facilitate electron transfer (ET) from [(L )Co ] to O in the absence of HOTf. The kinetics analysis and the detection of intermediates in the stoichiometric and catalytic reduction of O have provided clues to clarify the crucial roles of the pendant imidazole ligand of [(L )Co ] for the first time.
具有悬垂咪唑基的钴卟啉配合物([(L)Co])是在三氟甲磺酸(HOTf)存在下，通过 1,1'-二甲基二茂铁(MeFc)将氧气进行均相催化两电子还原的有效催化剂，与没有悬垂咪唑基的钴卟啉配合物([(L)Co])相比。悬垂咪唑配体不仅对于在 HOTf 存在下从[(L)Co]到 O 的质子耦合电子转移(PCET)提供一个咪唑啉质子起到关键作用，而且在没有 HOTf 的情况下也有利于[(L)Co]到 O 的电子转移(ET)。在化学计量和催化还原 O 的动力学分析和中间体检测首次为阐明[(L)Co]的悬垂咪唑配体对 O 的还原的关键作用提供了线索。
