Piñeiro-López Lucı A, Valverde-Muñoz Francisco Javier, Seredyuk Maksym, Muñoz M Carmen, Haukka Matti, Real José Antonio
Institut de Ciència Molecular (ICMol), Departament de Química Inorgànica, Universitat de València , C/Catedrático José Beltrán Martínez, 2, 46980 Paterna (Valencia), Spain.
Taras Shevchenko National University , Department of Physical Chemistry, Volodymyrska Str. 64, Kyiv 01601, Ukraine.
Inorg Chem. 2017 Jun 19;56(12):7038-7047. doi: 10.1021/acs.inorgchem.7b00639. Epub 2017 May 30.
The synthesis, crystal structure, magnetic, calorimetric, and Mössbauer studies of a series of new Hofmann-type spin crossover (SCO) metal-organic frameworks (MOFs) is reported. The new SCO-MOFs arise from self-assembly of Fe, bis(4-pyridyl)butadiyne (bpb), and [Ag(CN)] or [M(CN)] (M = Ni, Pd). Interpenetration of four identical 3D networks with α-Po topology are obtained for {Fe(bpb)[Ag(CN)]} due to the length of the rod-like bismonodentate bpb and [Ag(CN)] ligands. The four networks are tightly packed and organized in two subsets orthogonally interpenetrated, while the networks in each subset display parallel interpenetration. This nonporous material undergoes a very incomplete SCO, which is rationalized from its intricate structure. In contrast, the single network Hofmann-type MOFs {Fe(bpb)[M(CN)]}·nGuest (M = Ni, Pd) feature enhanced porosity and display complete one-step or two-step cooperative SCO behaviors when the pores are filled with two molecules of nitrobenzene or naphthalene that interact strongly with the pyridyl and cyano moieties of the bpb ligands via π-π stacking. The lack of these guest molecules favors stabilization of the high-spin state in the whole range of temperatures. However, application of hydrostatic pressure induces one- and two-step SCO.
报道了一系列新型霍夫曼型自旋交叉（SCO）金属有机框架（MOF）的合成、晶体结构、磁性、量热和穆斯堡尔研究。新型SCO-MOF由铁、双（4-吡啶基）丁二炔（bpb）和[Ag(CN)]或[M(CN)]（M = Ni、Pd）自组装而成。由于棒状双单齿bpb和[Ag(CN)]配体的长度，{Fe(bpb)[Ag(CN)]}得到了具有α-Po拓扑结构的四个相同三维网络的互穿。这四个网络紧密堆积并组织成两个正交互穿的子集，而每个子集中的网络呈现平行互穿。这种无孔材料经历了非常不完全的SCO，这从其复杂结构得到了解释。相比之下，单网络霍夫曼型MOF {Fe(bpb)[M(CN)]}·n客体（M = Ni、Pd）具有增强的孔隙率，当孔中填充有通过π-π堆积与bpb配体的吡啶基和氰基部分强烈相互作用的两分子硝基苯或萘时，呈现出完全的一步或两步协同SCO行为。缺少这些客体分子有利于在整个温度范围内稳定高自旋态。然而，施加静水压力会诱导一步和两步SCO。
