Spin-crossover behavior in cyanide-bridged iron(II)-silver(I) bimetallic 2D Hofmann-like metal-organic frameworks.
Spin-crossover behavior in cyanide-bridged iron(II)-silver(I) bimetallic 2D Hofmann-like metal-organic frameworks.
复制标题
氰化物桥联铁(II)-银(I)双金属二维霍夫曼金属有机骨架中的自旋交叉行为。
DOI：
10.1021/ic700607x
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发表时间：
2007
影响因子：
4.6
通讯作者：
J. Real
中科院分区：
文献类型：
--
作者：
M. Muñoz;A. Gaspar;Ana Galet;J. Real
两个新系列化合物组成{Fe(3- xpyridine)2[Ag(CN)2]2} (X = F (1), Cl (2), Br （3)， I(4)）和{Fe(3- xpyridine)2[Ag(CN)2][Ag(3- xpyridine)(CN)2]}。合成并表征了3-Xpy (X = Br （5)， I(6)）。这六种化合物由由共享{Fe4[Ag(CN)2]4}n基序定义的微波纹二维配位聚合物堆叠而成。这两个家庭的堆叠方式不同。在化合物1-4中，层是成对排列的，显示出亲银相互作用；Ag)……Ag距离在3.0 ~ 3.3 A之间，Ag…不同对的两个连续层之间的银分离约为6 A。化合物5和6是同结构的，具有晶体填塞，由几乎均匀分布的层分开约8.3 a(指Fe…Fe层间距离)。层间包含一个不配位的3-Xpyridine分子。另一个3-Xpyridine分子保持在{Fe4[Ag(CN)2]4}n窗口所定义的平面上，与一个银原子配位。这两个系列显示出完全不同的特性；在300 K时，1-4呈淡黄色，显示出与铁（II）离子在高自旋状态下相似的畸变[FeN6]八面体核。1和2分别经历了两步(T（1)1/2 = 96 K和T(2)1/2 = 162 K）和50%的自旋跃迁（T1/2 = 106 K）。化合物3和4在环境压力下是高自旋化合物。5和6在300 K时呈深红色，并分别在T1/2 = 306和261 K的高温下发生自旋交叉行为。
Two new series of compounds formulated {Fe(3-Xpyridine)2[Ag(CN)2]2} (X = F (1), Cl (2), Br (3), I (4)) and {Fe(3-Xpyridine)2[Ag(CN)2][Ag(3-Xpyridine)(CN)2]}.3-Xpy (X = Br (5), I (6)) have been synthesized and characterized. The six compounds are made up of stacking of slightly corrugated two-dimensional coordination polymers defined by sharing {Fe4[Ag(CN)2]4}n motifs. The stacking is different for the two families. In compounds 1-4 the layers are organized by pairs displaying argentophilic interactions; the Ag...Ag distance was found to be in the interval 3.0-3.3 A, while the Ag...Ag separation between two consecutive layers belonging to different pairs was found to be around 6 A. Compounds 5 and 6 are isostructural with a crystal packing defined by an almost homogeneous distribution of layers separated by around 8.3 A (referred to the Fe...Fe interlayer distance). Between the layers an uncoordinated 3-Xpyridine molecule is included. Another 3-Xpyridine molecule, which remains in the plane defined by the {Fe4[Ag(CN)2]4}n windows, coordinates one silver atom. Both series display quite different properties; at 300 K, 1-4 are pale-yellow and display similar distorted [FeN6] octahedron cores characteristic of the iron(II) ion in the high-spin state. 1 and 2 undergo a two-step (T(1)1/2 = 96 K and T(2)1/2 = 162 K) and a 50% spin transition (T1/2 = 106 K), respectively. Compounds 3 and 4 are high-spin compounds at ambient pressure. 5 and 6 are deep red in color at 300 K and undergo spin-crossover behavior at significantly higher temperatures T1/2 = 306 and 261 K, respectively.