Allosteric Spin Crossover Induced by Ligand-Based Molecular Alloying
Allosteric Spin Crossover Induced by Ligand-Based Molecular Alloying
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DOI：
10.1021/acs.inorgchem.0c01061
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发表时间：
2020-09-08
影响因子：
4.6
通讯作者：
Aromi, Guillem
中科院分区：
文献类型：
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作者：
Bartual-Murgui, Carlos;Perez-Padilla, Cristian;Aromi, Guillem
自旋交叉（SCO）现象代表了分子水平上的不稳定性的来源，并且稀释到非活性主体中最初是理解其合作性质和在固态下控制它的参数的关键。在这里，我们设计了一种分子合金化的方法，其中所有的组件是SCO活性，但具有显着不同的特征温度。因此，分子材料[Fe（Mebpp）2]（Cl 〇 4）2（2）已经掺杂有增加量的配体Me 2bpp（Mebpp和Me 2bpp = 1个甲基取代的和双甲基取代的双吡唑基吡啶配体），产生具有式[Fe（Mebpp）2 - 2x（Me 2bpp）_]（Cl 〇 4）2（4x; 0.05 < x < 0.5）的分子合金。通过单晶X射线衍射（SCXRD）、差示扫描量热仪（DSC）和磁谱仪研究了组成对SCO过程的影响。虽然分子间相互作用的衰减被证明对SCO协同性有很强的影响，自旋转换被发现发生在中间温度下，并在一个唯一的步骤中的合金的所有组分，从而揭示了一个前所未有的变构SCO过程。这种效应又提供了在42 K范围内调节SCO温度的手段。
The spin crossover (SCO) phenomenon represents a source of inultistabilitc,r at the molecular level, and dilution into a nonactive host was originally key to understand its cooperative nature and the parameters goveining it in the solid state. Here, we devise a olecular alloying approach in which all components are SCO-active, but with significantly different characteristic temperatures. Thus, the molecular material [Fe(Mebpp)2] (C104)2 (2) has been doped with increasing amounts of the ligand Me2bpp (Mebpp and Me2bpp = 1 methyl- and bis-methyl-substituted bis-pyrazolylpyridine ligands), yielding molecular alloys with the formula;[Fe(Mebpp)2_2x(Me2bpp)_] (CI04)2 (4x; 0.05 < x < 0.5). The effect of the composition on >the SCO process is studied through single crystal X-ray diffi-action (SCXRD), inagnetometry, and differential scanning calorimetry (DSC). While the attenuation of intermolecular interactions is shown to have a strong effect on the SCO cooperativity, the spin conversion was found to occur at intermediate temperatures and in one sole step for all components of the alloys, thus unveiling an unprecedented allosteric SCO process. This effect provides in turn a means of tuning the SCO temperature within a range of 42 K.