Recently, the research article: “Confining a Single Water Molecule Through Molecular Crystal Engineering for Water Oxidation” was published in " Angewandte Chemie International Edition ", and Jiangsu University is the first completion institution. Master student Pan Long is the first author, and Professor Yan Yan, Professor Guo Yongxian of Qilu University of Technology, and Professor Zhang Yifan of the Institute of Chemistry of the Chinese Academy of Sciences are the co-corresponding authors.

Abstract:

Hydrogen-bonded water clusters (H₂O)_n obscure the intrinsic reactivity of monomeric H₂O (n = 1) by restricting molecular reorientation. Elucidating the catalytic behavior of isolated water remains a key challenge in aqueous-phase chemistry. Here, we address this by designing a molecular crystal that uniformly confines single water molecules in identical tetrahedral cavities. This platform, CB-H₂O, exhibits exceptional activity for photocatalytic H₂O-to-H₂O₂ conversion, achieving 7.03 mmol g⁻¹ h⁻¹ with pure water, representing an 11.6-fold enhancement over cavity-deficient controls and being markedly superior to existing photocatalytic systems. This performance advantage is directly attributed to the crystallographically defined monomeric water, as verified by isotopic labelling and in-situ spectroscopy. Theoretical calculations further demonstrate that cavity confinement eliminates hydrogen-bond reorganization penalties, substantially lowering the activation barrier for water oxidation. Our work establishes monomeric-water catalysis as a distinct and efficient paradigm, showcasing molecular crystal engineering as a versatile approach to tailoring water-involved reactions for sustainable catalysis.

The Article Link: https://onlinelibrary.wiley.com/doi/10.1002/anie.202525362