Kanižaj Lidija, Barišić Dario, Torić Filip, Pajić Damir, Molčanov Krešimir, Šantić Ana, Lončarić Ivor, Jurić Marijana
Division of Materials Chemistry, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia.
Department of Physics, Faculty of Science, University of Zagreb, Bijenička cesta 32, 10000 Zagreb, Croatia.
Inorg Chem. 2020 Dec 21;59(24):18078-18089. doi: 10.1021/acs.inorgchem.0c02548. Epub 2020 Dec 8.
The heterodimetallic [CuFe] compounds [Cu(terpy)Cl][Fe(CO)]·10HO (;terpy = 2,2':6',2''-terpyridine), [Cu(HO)(terpy)(CO)][CuFe(CHOH)(terpy)(CO)] (), and {[CuFe(HO)(terpy)(CO)]·6HO} () were obtained using building block approach, from reaction of aqueous solution of [Fe(CO)] and a methanol solution containing Cu ions and terpy by the layering technique. Interestingly, by changing only the anion of the starting salt of copper(II), Cu(NO)·3HO instead of CuCl·2HO, an unexpected change in the type of bridge, oxalate ( and ) versus chloride (), was achieved, thus affecting the overall structural architecture. Two polymorphs of 3D coordination polymer [CuFe(HO)(terpy)(CO)] (), crystallizing in the triclinic () and monoclinic () space groups, were formed hydrothermally, depending on whether CuCl·2HO or Cu(NO)·3HO was added to the water, besides K[Fe(CO)]·3HO and terpy, respectively. Under hydrothermal conditions iron(III) from initial building block is reduced to the divalent state, creating 2D honeycomb [Fe(CO)] layers, which are bridged by [Cu(HO)(terpy)] cations. Compounds were investigated by single-crystal X-ray diffraction, IR, and impedance spectroscopies, magnetization measurements, and density functional theory (DFT) calculations. In compounds and , 0D magnetism is observed, with having a ground-state spin of 1 due to different interactions through chloride bridges of Cu ions in tetramer [Cu(terpy)Cl] and showing strong antiferromagnetic coupling of Cu ions mediated by oxalate ligand in [Cu(HO)(terpy)(CO)] and weak ones between Cu and Fe ions through oxalate bridge in [CuFe(CHOH)(terpy)(CO)]. Polymer exhibits antiferromagnetic phase transition at 25 K: The [Fe(CO)] layers are antiferromagnetically ordered, and a small amount of interlayer interaction is transferred through [Cu(HO)(terpy)] cations via O-Cu-O bridges. Additionally, compounds and are electrical insulators, while and show proton conductivity.
通过构筑模块法，利用[Fe(CO)]水溶液与含有铜离子和2,2':6',2''-三联吡啶（terpy）的甲醇溶液，采用分层技术反应，得到了异双核[CuFe]化合物[Cu(terpy)Cl][Fe(CO)]·10H₂O（；terpy = 2,2':6',2''-三联吡啶）、[Cu(H₂O)(terpy)(CO)][CuFe(CH₃OH)(terpy)(CO)]（）和{[CuFe(H₂O)(terpy)(CO)]·6H₂O}（）。有趣的是，仅通过改变铜（II）起始盐的阴离子，用Cu(NO₃)·3H₂O代替CuCl₂·2H₂O，就实现了桥连类型的意外变化，从草酸盐（和）变为氯离子（），从而影响了整体结构架构。3D配位聚合物[CuFe(H₂O)(terpy)(CO)]（）的两种多晶型物，分别结晶于三斜（）和单斜（）空间群，是通过水热法形成的，这取决于除了K[Fe(CO)]·3H₂O和terpy之外，分别向水中加入的是CuCl₂·2H₂O还是Cu(NO₃)·3H₂O。在水热条件下，初始构筑模块中的铁（III）被还原为二价态，形成二维蜂窝状[Fe(CO)]层，这些层由[Cu(H₂O)(terpy)]阳离子桥连。通过单晶X射线衍射、红外光谱和阻抗光谱、磁化测量以及密度泛函理论（DFT）计算对这些化合物进行了研究。在化合物和中，观察到零维磁性，由于四聚体[Cu(terpy)Cl]中铜离子通过氯桥的不同相互作用，具有基态自旋为1，并且在[Cu(H₂O)(terpy)(CO)]中显示出由草酸盐配体介导的铜离子的强反铁磁耦合，以及在[CuFe(CH₃OH)(terpy)(CO)]中通过草酸盐桥连的铜和铁离子之间的弱反铁磁耦合。聚合物在25 K时表现出反铁磁相变：[Fe(CO)]层呈反铁磁有序排列，并且少量的层间相互作用通过[Cu(H₂O)(terpy)]阳离子经由O-Cu-O桥传递。此外，化合物和是电绝缘体，而和显示出质子传导性。
