Single-molecule magnet materials owe their function to the presence of significant magnetic anisotropy, which arises from the interplay between the ligand field and spin-orbit coupling, and this is responsible for setting up an energy barrier for magnetic relaxation. Therefore, chemical control of magnetic anisotropy is a central challenge in the quest to synthesize new molecular nanomagnets with improved properties. There have been several reports of design principles targeting such control; however, these principles rely on idealized geometries, which are rarely obtained in crystal structures. Here, we present the results of high-pressure single-crystal diffraction on the single-ion magnet, Co(SPh)4(PPh4)2, in the pressure range of 0-9.2 GPa. Upon pressurization a sequence of small geometrical distortions of the central CoS4 moeity are observed, enabling a thorough analysis of the magneto-structural correlations. The magneto-structural correlations are investigated by theoretical analyses of the pressure-dependent experimental molecular structures. We observed a significant increase in the magnitude of the zero-field splitting parameter D, from -54.6 cm-1 to -89.7 cm-1, which was clearly explained from the reduction of the energy difference between the essential dxy and dx2-y2 orbitals, and structurally assigned to the change of an angle of compression of the CoS4 moeity.

中文翻译：

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高压结晶学作为单分子磁体设计的指南。

单分子磁体材料的功能是由于存在明显的磁各向异性，这是由配体场和自旋轨道耦合之间的相互作用引起的，这为磁弛豫建立了势垒。因此，磁各向异性的化学控制是合成具有改进性能的新型分子纳米磁体的主要挑战。已经有针对这种控制的设计原则的报告。但是，这些原理依赖于理想化的几何形状，而这种几何形状很少在晶体结构中获得。在这里，我们介绍了在0-9.2 GPa的压力范围内对单离子磁体Co（SPh）4（PPh4）2进行高压单晶衍射的结果。加压后，观察到一系列中心CoS4分子的小几何变形，能够对磁结构相关性进行全面分析。通过对压力依赖性实验分子结构的理论分析，研究了磁结构相关性。我们观察到零场分裂参数D的幅度显着增加，从-54.6 cm-1增至-89.7 cm-1，这可以通过减小基本dxy和dx2-y2轨道之间的能量差来清楚地解释。 ，并在结构上分配给CoS4分子压缩角的变化。