Dicubane-like tetrameric cobalt(II)-pseudohalide ferromagnetic clusters.
Dicubane-like tetrameric cobalt(II)-pseudohalide ferromagnetic clusters.
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DOI：
10.1021/ic0013476
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发表时间：
2001-07
影响因子：
4.6
通讯作者：
Z. Serna;M. Urtiaga;M. Barandika;R. Cortés;Susana Martín;L. Lezama;M. I. Arriortua;T. Rojo
中科院分区：
文献类型：
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作者：
Z. Serna;M. Urtiaga;M. Barandika;R. Cortés;Susana Martín;L. Lezama;M. I. Arriortua;T. Rojo
三种四聚钴(II)-拟卤化物配合物已得到结构和磁性表征。化合物 1 和 2 是同晶的，并具有通式 [Co2(dpk-OH)(dpk-CH3O)(L)(H2O)]2A2-4H2O，其中 dpk = 二-2-吡啶基酮，1 时 L = N3(-) 和 A = BF4(-)，2 时 L = NCO(-) 和 A = ClO4(-)。 dpk-OH(-)和dpk-CH3O(-)分别是dpk在水和甲醇中的溶剂分解和进一步去质子化的结果。两种化合物均表现出由类二立方烷核心和两个缺失顶点组成的阳离子四聚体，其中 Co(II) 离子通过端接拟卤化物和氧桥连接。 3 也发现了类似的四核核，其分子式为[Co2(dpk-OH)(dpk-CH3O)(NCO)2]2。在这种情况下，四聚体是中性的，并显示出末端氰酸酯来代替1和2的配位水分子。2和3的四聚体单元代表了任何类型的具有氰酸酯桥的立方烷的第一个例子，以及通过这些假卤化物基团表现出金属间桥的第一个Co(II)化合物。磁化率测量表明这三种化合物中存在铁磁性 Co(II)-Co(II) 相互作用。
Three tetrameric cobalt(II)-pseudohalide complexes have been structurally and magnetically characterized. Compounds 1 and 2 are isomorphous and exhibit the general formula [Co2(dpk-OH)(dpk-CH3O)(L)(H2O)]2A2-4H2O where dpk = di-2-pyridyl ketone, L = N3(-) and A = BF4(-) for 1, and L = NCO(-) and A = ClO4(-) for 2. The ligands dpk-OH(-) and dpk-CH3O(-) result from solvolysis and ulterior deprotonation of dpk in water and methanol, respectively. Both compounds exhibit cationic tetramers consisting of a dicubane-like core with two missing vertexes where the Co(II) ions are connected through end-on pseudohalide and oxo-bridges. A similar tetranuclear core has been found for 3 whose formula is [Co2(dpk-OH)(dpk-CH3O)(NCO)2]2. In this case, the tetramers are neutral and exhibit a terminal cyanate in place of the coordinated molecule of water for 1 and 2. The tetrameric units for 2 and 3 represent the first examples of any kind of cubanes exhibiting cyanate bridges as well as the first Co(II) compounds exhibiting intermetallic bridges through these pseudohalide groups. Measurements of the magnetic susceptibility indicated the presence of ferromagnetic Co(II)-Co(II) interactions in the three compounds.