The development of single-chain magnets with reversible and adjustable properties is of great significance for achieving high-density information storage and switching devices with multi-stimuli responsiveness, but it remains a challenging task. In this work, we synthesized a new cyano-bridged {Fe₂Co}-based coordination polymer, {[(^PzTp)Fe(CN)₃]₂Co(Ipi)₂}·2MeOH·0.5H₂O (1·solv; ^pzTp, tetra-kis(1-pyrazolyl)borate; Ipi, 1-(4-iodophenyl)-1H-imidazole). 1·solv displayed reversible metal-to-metal electron transfer (MMET) between Fe^III_LS(μ-CN)Co^II_HS(μ-NC)Fe^III_LS (LS, low spin; HS, high spin) and Fe^III_LS(μ-CN)Co^III_LS(μ-NC)Fe^II_LS states under alternating irradiations with 808 and 532 nm lasers, respectively, as verified by photomagnetic and in situ photo-monitored X-ray diffraction studies. The bidirectional light irradiations induced significant changes in magnetic anisotropy and intrachain exchange interactions, demonstrating the on/off switching of single-chain magnet (SCM) behavior by 808 and 532 nm light irradiations. 1·solv underwent a thermally induced single-crystal-to-single-crystal (SCSC) phase transition into a desolvated {[(^PzTp)Fe(CN)₃]₂Co(Ipi)₂} (1·desolv) phase, accompanying MMET. Magnetic susceptibility measurements indicated that 1·desolv exhibited thermally induced incomplete MMET behavior and field-induced nanomagnet behavior. 1·desolv also displayed a substantial dielectric anomaly during the electron transfer process, presenting a new case showing the synergetic switching of the dielectric and magnetic properties. Interestingly, 1·desolv can revert to the solvated phase 1·resolv after being soaked in mother liquor, whose SCM behavior was erased by the reversible SCSC transition. This study provides a new approach for the swift and reversible control of SCM behavior via both SCSC transition and light-induced MMET.

中文翻译：

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通过单晶到单晶转变和光诱导金属到金属电子转移实现单链磁体的可逆开关


开发具有可逆和可调特性的单链磁体对于实现具有多刺激响应性的高密度信息存储和开关器件具有重要意义，但这仍然是一项具有挑战性的任务。在这项工作中，我们合成了一种新的氰基桥联 {Fe₂Co} 配位聚合物 {[（^PzTp）Fe（CN）₃]₂Co（Ipi）₂}·2MeOH·0.5H₂O （1·solv;^pzTp，四-kis（1-吡唑基）硼酸盐;Ipi，1-（4-碘苯基）-1H-咪唑）。1·溶剂显示Fe^III_LS（μ-CN）Co^II_HS（μ-NC）Fe^III_LS（LS，低自旋;HS，高自旋）和 Fe^III_LS（μ-CN）Co^III_LS（μ-NC）Fe^II_LS 分别在 808 和 532 nm 激光器的交替照射下处于状态，通过光磁和原位光监控 X 射线衍射研究验证。双向光照射诱导了磁各向异性和链内交换相互作用的显着变化，证明了 808 nm 和 532 nm 光照射对单链磁体 （SCM） 行为的开/关切换。 1·溶剂化经历了热诱导的单晶到单晶 （SCSC） 相变，转化为脱溶剂化的 {[（^PzTp）Fe（CN）₃]₂Co（Ipi）₂}（1·溶剂化）相，伴随着 MMET。磁化率测量表明，1·desolv 表现出热诱导的不完全 MMET 行为和场诱导的纳米磁体行为。1·desolv 还在电子转移过程中表现出明显的介电异常，提出了一个显示介电和磁特性协同切换的新案例。有趣的是，1·desolv 在母液中浸泡后可以恢复到溶剂化相 1·resolv，其 SCM 行为被可逆 SCSC 转变所消除。本研究提供了一种通过 SCSC 过渡和光诱导 MMET 快速、可逆地控制 SCM 行为的新方法。