The intricate hydrogen-bonded network of water gives rise to various structures with anomalous properties at different thermodynamic conditions. Nanoconfinement can further modify the water structure and properties, and induce specific water motifs, which are instrumental for technological applications such as atmospheric water harvesting. However, so far, a causal relationship between nanoconfinement and the presence of specific hydrophilic adsorption sites is lacking, hampering the further design of nanostructured materials for water templating. Therefore, this work investigates the organisation of water in zirconium-based metal-organic frameworks (MOFs) with varying topologies, pore sizes, and chemical composition, to extract design rules to shape water. The highly tuneable pores and hydrophilicity of MOFs makes them ideally suited for this purpose. We find that small nanopores favour orderly water clusters that nucleate at hydrophilic adsorption sites. Favourably positioning the secondary adsorption sites, hydrogen-bonded to the primary adsorption sites, allows larger clusters to form at moderate adsorption conditions. To disentangle the importance of nanoconfinement and hydrophilic nucleation sites in this process, we introduce an analytical model with precise control of the adsorption sites. This sheds a new light on design parameters to induce specific water clusters and hydrogen-bonded networks, thus rationalising the application space of water in nanoconfinement.

水错综复杂的氢键网络在不同的热力学条件下产生了具有异常性质的各种结构。纳米约束可以进一步改变水的结构和特性，并诱导特定的水基序，这有助于大气水收集等技术应用。然而，到目前为止，纳米约束与特定亲水吸附位点的存在之间缺乏因果关系，阻碍了用于水模板的纳米结构材料的进一步设计。因此，这项工作研究了具有不同拓扑结构、孔径和化学成分的锆基金属有机框架 （MOF） 中的水组织，以提取塑造水的设计规则。MOF 的高度可调孔隙和亲水性使其非常适合此目的。我们发现小纳米孔有利于在亲水吸附位点成核的有序水簇。将次级吸附位点与初级吸附位点氢键相接，从而在中等吸附条件下形成更大的团簇。为了理清纳米约束和亲水成核位点在此过程中的重要性，我们引入了一个精确控制吸附位点的分析模型。这为诱导特定水团簇和氢键网络的设计参数提供了新的思路，从而合理化了水在纳米约束中的应用空间。