The bonding of copper ions to lattice oxygens dictates the activity and selectivity of copper exchanged zeolites. By ¹⁷O isotopic labelling of the zeolite framework, in conjunction with advanced EPR methodologies and DFT modelling, we determine the local structure of single site Cu^II species, we quantify the covalency of the metal-framework bond and we assess how this scenario is modified by the presence of solvating H₂¹⁶O or H₂¹⁷O molecules. This enables to follow the migration of Cu^II species as a function of hydration conditions, providing evidence for a reversible transfer pathway within the zeolite cage as a function of the water pressure. The results presented in this paper establish ¹⁷O EPR as a versatile tool for characterizing metal-oxide interactions in open-shell systems.

铜离子与晶格氧的结合决定了铜交换沸石的活性和选择性。通过沸石骨架的¹⁷ O同位素标记，结合先进的 EPR 方法和 DFT 建模，我们确定了单位点 Cu ^II物种的局部结构，我们量化了金属-骨架键的共价性，并评估了如何修改这种情况通过溶剂化 H ₂ ¹⁶ O 或 H ₂ ¹⁷ O 分子的存在。这使得能够跟踪 Cu ^II的迁移物种作为水合条件的函数，为沸石笼内作为水压函数的可逆转移途径提供了证据。本文中提出的结果将¹⁷ O EPR 作为表征开壳系统中金属-氧化物相互作用的通用工具。