英国伦敦帝国学院Andrew B. Cairns研究组的最新研究探讨了压力下缺陷、水化和组成对普鲁士蓝类似物的影响。 2021年2月25日，国际知名学术期刊《美国化学会杂志》发表了这一成果。

在这里，该研究组使用变压X射线和中子衍射来探索关键的结构特征，即缺陷、水化和组成，如何影响PBAs的压缩性和相行为。缺陷提高了灵活性，表现为一个非常低的批量模块(B₀≈6GPa)缺陷的PBAs。间隙水会增加B₀，并在有缺陷的系统中使压力引起的相变成为可能。相反，水合作用并没有改变化学计量MnPt(CN)₆的压缩性，而是改变了高压相变，表明在低能量扭曲之间存在相互作用。

由于八面体倾斜，AMnCo(CN)₆（AI = Rb，Cs）在压缩时从F43m转变为P4n2，并且可以通过A-位阳离子调节临界压力。在1GPa时，由于不正确的铁电机理，Rb_0.87Mn [Co(CN)₆]_0.91的对称性进一步降低到极性空间基团Pn。这些基本见解旨在促进应用于广泛领域的PBAs的理性设计。

据介绍，普鲁士蓝类似物(PBAs)的巨大组成空间，公式为A_xM[M '' (CN)₆]_y·nH2O，允许多种功能。然而，成分和物理性质之间的相互作用，尽管它与基础原理和工业界的相关性（很大），例如灵活性和相变的倾向-仍然很大程度上未知。

附：英文原文

Title: Probing the Influence of Defects, Hydration, and Composition on Prussian Blue Analogues with Pressure

Author: Hanna L. B. Bostrm, Ines E. Collings, Dominik Daisenberger, Christopher J. Ridley, Nicholas P. Funnell, Andrew B. Cairns

Issue&Volume: February 25, 2021

Abstract: The vast compositional space of Prussian blue analogues (PBAs), formula AxM[M′(CN)6]y·nH2O, allows for a diverse range of functionality. Yet, the interplay between composition and physical properties—e.g., flexibility and propensity for phase transitions—is still largely unknown, despite its fundamental and industrial relevance. Here we use variable-pressure X-ray and neutron diffraction to explore how key structural features, i.e., defects, hydration, and composition, influence the compressibility and phase behavior of PBAs. Defects enhance the flexibility, manifesting as a remarkably low bulk modulus (B0 ≈ 6GPa) for defective PBAs. Interstitial water increases B0 and enables a pressure-induced phase transition in defective systems. Conversely, hydration does not alter the compressibility of stoichiometric MnPt(CN)6, but changes the high-pressure phase transitions, suggesting an interplay between low-energy distortions. AMnCo(CN)6 (AI = Rb, Cs) transition from F43m to P4n2 upon compression due to octahedral tilting, and the critical pressure can be tuned by the A-site cation. At 1GPa, the symmetry of Rb0.87Mn[Co(CN)6]0.91 is further lowered to the polar space group Pn by an improper ferroelectric mechanism. These fundamental insights aim to facilitate the rational design of PBAs for applications within a wide range of fields.

DOI: 10.1021/jacs.0c13181

Source: https://pubs.acs.org/doi/10.1021/jacs.0c13181