Dey Bijoy, Chandrasekhar Vadapalli
Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad - 500046, Telangana, India.
Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur-208016, India.
Dalton Trans. 2022 Sep 26;51(37):13995-14021. doi: 10.1039/d2dt01967a.
Spin crossover (SCO) is one of the most studied magnetic bistable phenomena because of its application in the field of multifunctional magnetic materials. Fe complexes in a N coordination environment have been the most well-studied in terms of their SCO behaviour. Other coordination environments, notably the NO coordination environment, has also been quite effective in inducing SCO behaviour in the corresponding Fe complexes. This review deals with such systems. The three ligand families that are discussed are: Jager type ligands, hydrazone based ligands and tridentate ligands having salicylaldehyde derivatives. These ligands allow the assembly of both mononuclear and multinuclear complexes that exhibit cooperative spin transitions. Also, Fe complexes obtained from some of these ligands are multifunctional and exhibit a coupling of optical and magnetic properties. Most of the Fe complexes obtained from these families of ligands are charge neutral which allows easy surface deposition. Further, modulation of these ligand families allows a fine tuning of the ligand field strength which results in varying SCO behavior. In addition some of the Fe complexes derived from these ligands exhibit a light induced excited spin state trapping (LIESST) effect. All of the above aspects are reviewed in this review.
自旋交叉（SCO）是研究最多的磁双稳现象之一，因其在多功能磁性材料领域的应用。就其SCO行为而言，处于N配位环境中的铁配合物研究最为深入。其他配位环境，尤其是NO配位环境，在相应的铁配合物中诱导SCO行为方面也相当有效。本综述涉及此类体系。所讨论的三个配体家族为：雅格型配体、腙基配体和具有水杨醛衍生物的三齿配体。这些配体能够组装出表现出协同自旋转变的单核和多核配合物。此外，从其中一些配体得到的铁配合物具有多功能性，表现出光学和磁性的耦合。从这些配体家族得到的大多数铁配合物是电荷中性的，这便于进行表面沉积。此外，对这些配体家族的调控能够微调配体场强度，从而导致不同的SCO行为。另外，从这些配体衍生出的一些铁配合物表现出光诱导激发自旋态捕获（LIESST）效应。本综述对上述所有方面进行了评述。
