A chiral molecule-based magnet [Mn^II (S-pnH) (H₂O)][Mn^III(CN)₆]·H₂O (S-pn = S-1,2-diaminopropane), 1S·2H₂O (P2₁2₁2₁), has been obtained, which has a two-dimensional (2D) square network of cyanide-bridged Mn^II–Mn^III ions. The crystallographic research on this coordination polymer indicates that it is robust enough to transform the single-crystal structure upon dehydration as well as rehydration. Meanwhile, the magnetic property changes are reversibly associated with the structural phase transitions. The complete reversibility upon dehydration/rehydration was demonstrated using in situ X-ray diffraction from the as-prepared 1S·2H₂O to the dehydrated [Mn^II (S-pnH)][Mn^III(CN)₆], 1S, then rehydrated to [Mn^II (S-pnH) (H₂O)][Mn^III(CN)₆]·H₂O, 1S-HP, and dehydrated again to [Mn^II (S-pnH)][Mn^III(CN)₆], 1S-DeHP. Neither the space groups nor the crystal axes changed during the dehydration/rehydration process. The dehydration is considered to be associated with a change in the coordination of the S-pnH from one 2D layer to the neighboring one involving a proton transfer and is accompanied by new cyanide bridging of Mn^II and Mn^III ions formed between the 2D sheet. Corresponding to the 2D to three-dimensional (3D) structural transition, the study of magnetic properties reveals that the Curie temperature of long-range magnetic ordering for 1S (T_C = 45 K) is more than double that for 1S·2H₂O (T_C = 21 K).

中文翻译：

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氰化物桥式手性结构磁体的可逆单晶到单晶转变和相关磁性


基于手性分子的磁体 [Mn^II （S-pnH） （H₂O）][Mn^III（CN）₆]·已获得 H₂O （S-pn = S-1,2-二氨基丙烷），1S·2H₂O （P2₁2₁2₁），它具有氰化物桥式 Mn^II–Mn^III 离子的二维 （2D） 方形网络。 对这种配位聚合物的晶体学研究表明，它足够坚固，可以在脱水和再水化时改变单晶结构。同时，磁性质的变化与结构相变可逆相关。使用原位 X 射线衍射证明脱水/再水化后的完全可逆性，从制备的 1S·2H₂O 到脱水的 [Mn^II （S-pnH）][Mn^III（CN）₆]，1 S，然后再水化至 [Mn^II （S-pnH） （H₂O）][Mn^III（CN）₆]·H₂ O，1S-HP，然后再次脱水为 [Mn^II （S-pnH）][Mn^III（CN）₆]，1S-DeHP。在脱水/再水化过程中，空间群和晶轴都没有改变。脱水被认为与 S-pnH 从一个 2D 层到相邻层的配位变化有关，涉及质子转移，并伴随着 Mn^II 和 Mn^III 离子在 2D 片之间形成的新氰化物桥。 对应于二维到三维 （3D） 结构转变，磁特性研究表明，1S （T_C = 45 K） 的长程磁排序居里温度是 1S·2H₂O （T_C = 21 K） 的两倍多。