Spin-crossover (SCO) materials with multiple spin states have attracted special interest for their potential applications in multi-switches and high-order data storage. Herein, an unprecedented asymmetric seven-/eight-step SCO behavior is revealed in a three-dimensional Hofmann-type metal–organic framework [Fe(4-abpt){Au(CN)₂}₂]·2DMF·EtOH (4-abpt = 4-amino-3,5-bis(4-pyridyl)-1,2,4-triazole), which represents the highest step in the SCO field. Moreover, the formation of a molecular alloy by mixing [Au(CN)₂]⁻ and [Ag(CN)₂]⁻ units is explored as a strategy towards multi-step SCO materials for the first time.

中文翻译：

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三维霍夫曼型金属有机框架中的不对称七步/八步自旋交越

具有多种自旋态的自旋交叉（SCO）材料因其在多开关和高阶数据存储中的潜在应用而引起了人们的特殊兴趣。在此，在三维霍夫曼型金属-有机骨架[Fe（4-abpt）{Au（CN）₂ } ₂ ]·2DMF·EtOH（4- ）中揭示了前所未有的不对称七步/八步SCO行为。abpt = 4-氨基-3,5-双（4-吡啶基）-1,2,4-三唑），代表SCO领域的最高步骤。此外，首次探索了通过混合[Au（CN）₂ ] ^-和[Ag（CN）₂ ] ^-单元来形成分子合金的方法，这是首次针对多步SCO材料的策略。