High-spin wheel of a heptanuclear mixed-valent Fe(II,III) complex.
High-spin wheel of a heptanuclear mixed-valent Fe(II,III) complex.
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DOI：
10.1002/anie.200390084
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发表时间：
2003-01
影响因子：
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通讯作者：
H. Oshio;Norihisa Hoshino;Tasuku Ito;M. Nakano;F. Renz;P. Gütlich
中科院分区：
文献类型：
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作者：
H. Oshio;Norihisa Hoshino;Tasuku Ito;M. Nakano;F. Renz;P. Gütlich
以氧原子作为桥联配体的铁和锰簇具有多种结构，目前在材料和生物无机化学中引起人们的兴趣。例如，具有高自旋基态的纳米分子可提供单畴磁体，[1] 可以表现出磁滞、[2] 慢磁弛豫、[3] 和纯分子起源的自旋量子隧道特性。 [4]储铁蛋白铁蛋白和锰簇分别作为无机系统中的生物原型[5]和光系统II中水氧化复合物的模型[6]进行了广泛的研究。金属簇合物合成路线的发展在自旋化学和生物化学领域取得了显着的成就。在有机桥联配体中，烷氧基因其多种桥联模式（μ2和μ3）而被广泛用于构建金属簇。反应条件的微妙变化导致了意想不到的美丽结构的形成，例如环状多金属簇。 [7]之前，我们描述了一种烷氧桥联铁(ii)立方体，[Fe4 (sae) 4 (MeOH) 4](H2sae ¼ 2-水杨基氨基-1-乙醇)，其在1.1 K的阻断温度下表现出超顺磁行为。[7g]在探索希夫碱配体的多功能性的过程中，我们发现具有更高自旋多重性的配合物可以通过涉及铁(ii或iii)氯化物和三齿席夫碱配体3-甲氧基-2-水杨基氨基-1-乙醇(H2L)。具有[FeII 核心结构的烷氧基桥连簇分子
Iron and manganese clusters with oxygen atoms acting as bridging ligands possess a variety of structures and are of current interest in materials and bioinorganic chemistry. For example, nanosized molecules with a high-spin ground state afford single-domain magnets,[1] which may display hysteresis,[2] slow magnetic relaxation,[3] and spin-quantum tunneling characteristics of a purely molecular origin.[4] The ironstorage protein ferritin and manganese clusters have been extensively studied as a biological prototype in the inorganic systems,[5] and as models of the water-oxidizing complex in photosystem II,[6] respectively. The development of synthetic routes to metal clusters has resulted in remarkable achievements in spin chemistry and biochemistry. Among organic bridging ligands, alkoxo groups have been employed extensively for constructing metal clusters because of their versatile bridging modes (μ2 and μ3). Subtle changes in reaction conditions have resulted in the formation of unexpected and beautiful structures, such as cyclic polymetallic clusters.[7] Previously, we have described an alkoxo-bridged iron (ii) cube,[Fe4 (sae) 4 (MeOH) 4](H2sae ¼ 2-salicylideneamino-1-ethanol), which exhibited superparamagnetic behavior with a blocking temperature of 1.1 K.[7g] In the course of exploring the versatility of Schiff base ligands, we found that complexes with higher spin multiplicities could be synthesized from reactions involving iron (ii or iii) chloride and the tridentate Schiff base ligand 3-methoxy-2-salicylideneamino-1-ethanol (H2L). Alkoxo-bridged cluster molecules with core structures of [FeII