AI 中文总结
本文合成了三种水合层状亚硒酸铜，发现水合程度可调控其层间距与堆叠序列，该材料可用于水响应材料及低维磁耦合研究，也可作为合成Cu$_2$OSeO$_3$的可调前驱体。
AI 中文摘要
水合与脱水是调控层状无机材料结构的强大却未被充分探索的变量，因为嵌入的水可改变层间距、氢键网络及层堆叠方式。本文报道了一类新型水合层状亚硒酸铜的回流合成产物：(NH$_3$)$_2$Cu$_5$(SeO$_3$)$_2$(OH)$_6$(H$_2$O)$_{2+x}$（$x$ = 0、1和3）。通过电子衍射与单晶X射线衍射确定的晶体结构，推断三种化合物均具有由Cu(OH)$_4$正方形及Cu中心四方锥构成的扭曲类kagomé Cu$^{2+}$网络的相同层结构。该系列化合物的层内原子排列保持不变，而水合程度同时决定层间距与堆叠序列，因此为设计用于传感、离子传输、分离、致动及能源相关应用的水响应材料提供了罕见平台。水合状态下扭曲类kagomé Cu$^{2+}$层的保留，还暗示了研究层间水与堆叠序列如何影响低维磁耦合的潜在价值。在回流条件下，这些物相也被证实是Cu$_2$OSeO$_3$形成过程中的反应中间体，使其成为可调控的氧亚硒酸铜合成前驱体。
英文摘要
Hydration and dehydration are powerful yet underexplored variables for controlling the architecture of layered inorganic materials, because intercalated water can modify interlayer separation, hydrogen-bonding networks, and layer stacking. Here, we report the reflux synthesis of a new family of hydrated layered copper selenites, (NH$_3$)$_2$Cu$_5$(SeO$_3$)$_2$(OH)$_6$(H$_2$O)$_{2+x}$ ($x$ = 0, 1, and 3). From the crystal structures determined using electron diffraction and single crystal X-ray diffraction, we deduce that all three compounds share an identical layer built from Cu(OH)$_4$ squares and Cu-centered square pyramids forming distorted kagomé-like Cu$^{2+}$ network. While the intralayer atomic arrangement is preserved across the series, the degree of hydration governs both the interlayer separation and the stacking sequence. These compounds therefore provide a rare platform relevant to the design of hydration-responsive materials for sensing, ion transport, separations, actuation, and energy-related applications. The preservation of distorted kagomé-like Cu$^{2+}$ layers across hydration states further suggests potential interest for examining how interlayer water and stacking sequence affect low-dimensional magnetic coupling. Under reflux conditions, these phases are also shown to act as reactive intermediates in the formation of Cu$_2$OSeO$_3$, establishing them as tunable precursors for copper oxoselenite synthesis.
