化学
催化作用
钴
氧化还原
光化学
电子转移
部分
催化循环
分子内力
配体(生物化学)
质子耦合电子转移
速率决定步骤
反应机理
无机化学
立体化学
有机化学
生物化学
受体
作者
Yingying Li,Rong‐Zhen Liao
标识
DOI:10.1002/cssc.202400123
摘要
Water oxidation is a crucial reaction in the artificial photosynthesis system. In the present work, density functional calculations were employed to decipher the mechanism of water oxidation catalyzed by a binuclear cobalt complex, which was disclosed to be a homogeneous water oxidation catalyst in pH=7 phosphate buffer. The calculations showed that the catalytic cycle starts from the CoIII,III‐OH2 species. Then, a proton‐coupled electron transfer followed by a one‐electron transfer process leads to the generation of the formal CoIV,IV‐OH intermediate. The subsequent PCET produces the active species, namely the formal CoIV,V=O intermediate (4). The oxidation processes mainly occur on the ligand moiety, including the coordinated water moiety, implying a redox non‐innocent behavior. Two cobalt centers keep their oxidation states and provide one catalytic center for water activation during the oxidation process. 4 triggers the O‐O bond formation via the water nucleophilic attack pathway, in which the phosphate buffer ion functions as the proton acceptor. The O‐O bond formation is the rate‐limiting step with a calculated total barrier of 17.7 kcal/mol. The last electron oxidation process coupled with an intramolecular electron transfer results in the generation of O2.
科研通智能强力驱动
Strongly Powered by AbleSci AI