Boroxines are significant structures in the production of covalent organic frameworks, anion receptors, self-healing materials, and others. However, their utilization in aqueous media is a formidable task due to hydrolytic instability. Here we report a water-stable boroxine structure discovered from 2-hydroxyphenylboronic acid. We find that, under ambient environments, 2-hydroxyphenylboronic acid undergoes spontaneous dehydration to form a dimer with dynamic covalent bonds and aggregation-induced enhanced emission activity. Intriguingly, upon exposure to water, the dimer rapidly transforms into a boroxine structure with excellent pH stability and water-compatible dynamic covalent bonds. Building upon these discoveries, we report the strong binding capacity of boroxines toward fluoride ions in aqueous media, and develop a boroxine-based hydrogel with high acid–base stability and reversible gel–sol transition. This discovery of the water-stable boroxine structure breaks the constraint of boroxines not being applicable in aqueous environments, opening a new era of researches in boroxine chemistry.

环硼氧烷是生产共价有机框架、阴离子受体、自修复材料等的重要结构。然而，由于水解不稳定性，它们在水介质中的利用是一项艰巨的任务。在这里，我们报告了从 2-羟基苯基硼酸中发现的水稳定性环硼氧烷结构。我们发现，在周围环境下，2-羟基苯基硼酸会自发脱水形成具有动态共价键和聚集诱导增强的发射活性的二聚体。有趣的是，接触水后，二聚体迅速转化为环硼氧烷结构，具有优异的 pH 稳定性和与水相容的动态共价键。基于这些发现，我们报告了环硼氧烷对水介质中氟离子的强大结合能力，并开发了一种具有高酸碱稳定性和可逆凝胶-溶胶转变的环硼氧烷基水凝胶。水稳定性环硼氧烷结构的发现，打破了环硼氧烷不适用于水环境的限制，开启了环硼氧烷化学研究的新纪元。