Department of Chemistry, School of Engineering Sciences in Chemistry Biotechnology and Health, KTH Royal Institute of Technology, 10044 Stockholm, Sweden.
Department of Chemistry-BMC, Uppsala University, BMC Box 576, S-751 23 Uppsala, Sweden.
J Am Chem Soc. 2023 May 31;145(21):11818-11828. doi: 10.1021/jacs.3c03415. Epub 2023 May 17.
Many enzymes use adaptive frameworks to preorganize substrates, accommodate various structural and electronic demands of intermediates, and accelerate related catalysis. Inspired by biological systems, a Ru-based molecular water oxidation catalyst containing a configurationally labile ligand [2,2':6',2″-terpyridine]-6,6″-disulfonate was designed to mimic enzymatic framework, in which the sulfonate coordination is highly flexible and functions as both an electron donor to stabilize high-valent Ru and a proton acceptor to accelerate water dissociation, thus boosting the catalytic water oxidation performance thermodynamically and kinetically. The combination of single-crystal X-ray analysis, various temperature NMR, electrochemical techniques, and DFT calculations was utilized to investigate the fundamental role of the self-adaptive ligand, demonstrating that the on-demand configurational changes give rise to fast catalytic kinetics with a turnover frequency (TOF) over 2000 s, which is compared to oxygen-evolving complex (OEC) in natural photosynthesis.
许多酶利用自适应框架来预组织底物，适应中间产物的各种结构和电子需求，并加速相关催化。受生物系统的启发，设计了一种基于 Ru 的分子水氧化催化剂，其中含有构象不稳定的配体[2,2':6',2″-三联吡啶]-6,6″-二磺酸盐，以模拟酶的框架，其中磺酸盐配位非常灵活，既可以作为电子供体来稳定高价 Ru，也可以作为质子受体来加速水的离解，从而在热力学和动力学上增强催化水氧化性能。利用单晶 X 射线分析、各种温度 NMR、电化学技术和 DFT 计算相结合的方法，研究了自适应性配体的基本作用，表明按需构象变化导致快速催化动力学，周转频率（TOF）超过 2000 s-1，与天然光合作用中的氧析出复合物（OEC）相当。
