Spin transition in three-dimensional bridged coordination polymers of iron (II)-urea-triazoles
Spin transition in three-dimensional bridged coordination polymers of iron (II)-urea-triazoles
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DOI：
10.1016/j.ica.2008.03.070
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发表时间：
2008-09-01
影响因子：
2.8
通讯作者：
von Malotki, Christian
中科院分区：
文献类型：
--
作者：
Rentschler, Eva;von Malotki, Christian
[Fe-2(n-Rdubtrz)(3)](X)(4)中心点NH(2)O(n-R=(CH2)(Y)，y=4，6，8，12；Du=二脲；btrz=双三唑；X=BF4-，ClO4-，三氟酸盐，对甲苯磺酸盐)与铁盐(FeX2)反应，合成了[Fe-2(n-Rdubtrz)(n-Rdubtrz)]配位聚合物的三维自旋交叉(SCO)网络。对一维化合物[Fe(Rtrzu)(3)](X)(2)(R=正丙基，叔丁基；trzu=尿素三唑)的研究支持了对其性质的研究。用红外光谱、元素分析、热重分析和原子吸收光谱对其进行了表征。通过磁化率测量和Fe-57穆斯堡尔谱考察了所有络合物的SCO行为。虽然聚合物网络中的SCO对反离子表现出强烈的依赖性，但在不同的亚甲基桥联长度下，络合物中没有观察到明显的变化。确定了[Fe(Rtrzu)(3)](X)(2)化合物的磁滞效应。(C)2008爱思唯尔B.V.保留所有权利。
Three-dimensional spin-crossover (SCO) networks of [Fe-2(n-Rdubtrz)(3)](X)(4) center dot nH(2)O (n-R = (CH2)(y), y = 4, 6, 8, 12; du = diurea; btrz = bis-triazole; X = BF4-, ClO4-, triflate, tosylate) coordination polymers are prepared by reaction of bridging aliphatic bis-urea triazoles (n-Rdubtrz) with the iron-salts (FeX2). Investigations of the properties are supported by studies of one-dimensional compounds of [Fe(Rtrzu)(3)](X)(2) (R = n-propyl, t-butyl; trzu = urea triazole). Characterization of the complexes is carried out with IR-spectroscopy, elemental analysis, TGA and atomic absorption spectroscopy. SCO-behaviour of all complexes is inspected by magnetic susceptibility measurements and Fe-57 Mossbauer. While the SCO in the polymeric networks shows strong dependency on the counter ions, in the complexes no pronounced change is observed for different methylene bridging lengths. For [Fe(Rtrzu)(3)](X)(2) compounds hysteresis effects are ascertained. (c) 2008 Elsevier B.V. All rights reserved.