Synthesis, magnetic and spectroscopic characterization of a new Fe7 cluster with a six-pointed star topology
Synthesis, magnetic and spectroscopic characterization of a new Fe7 cluster with a six-pointed star topology
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具有六角星形拓扑的新型 Fe7 团簇的合成、磁性和光谱表征
DOI：
10.1016/j.poly.2013.05.015
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发表时间：
2013
期刊：
影响因子：
2.6
通讯作者：
C. Lampropoulos
中科院分区：
文献类型：
--
作者：
C. Kizas;Constantina Papatriantafyllopoulou;M. Pissas;Y. Sanakis;A. Javed;A. Tasiopoulos;C. Lampropoulos
据报道，七核 FeIII7 团簇是由 [Fe3O(O2CPh)6(H2O)3]+ 与脂肪族氨基醇配体（即 apH（3-氨基-1-丙醇）和 hmpipH（2-羟甲基哌啶）的组合）反应制备的。 (aH2)[Fe7O3(OH)3(hmpip)6(O2CPh)7]配合物具有类似于金属中心非平面六角星形的金属核心。热重分析用于监测 1 的热稳定性，并显示该配合物在加热时质量逐步损失，而穆斯堡尔光谱用于评估 Fe 离子的化学环境。后者证实了簇中仅存在高自旋 FeIII 离子，X 射线晶体学也表明了这一点。对 1 的微晶样品测量了直流和交流磁化率，发现该簇的基态为 S= 21/2，具有低激发态。尝试使用两种不同的磁结构相关关系来合理化观察到的自旋，这两种关系先前是针对氧化物桥联的 FeIII 二聚体得出的，表明沿着外围六边形存在自旋受阻路径，这反过来又产生高自旋基态。使用该磁结构分析的结果，并假设 Si= 5/2 和中间 Si= 3/2 自旋投影的组合，最终合理化了观察到的 S= 21/2。该 Fe7 簇是第三个报道的具有这种拓扑结构的七核 Fe 簇的例子，其中心有一个四面体 Fe 离子，并加入了一个基于脂肪族配体 apH 和 hmpipH 的 Fe 簇小家族。
A heptanuclear FeIII7cluster is reported, prepared from the reaction of [Fe3O(O2CPh)6(H2O)3]+and a combination of aliphatic aminoalcohol ligands, namely apH (3-amino-1-propanol) and hmpipH (2-hydroxymethyl piperidine). The (apH2)[Fe7O3(OH)3(hmpip)6(O2CPh)7] complex possesses a metal core resembling a metal-centered non-planar six-pointed star. Thermogravimetric analysis was used to monitor the thermal stability of1, and shows stepwise loss of mass for this complex upon heating, while Mössbauer spectroscopy was used to evaluate the chemical environment of the Fe ions. The latter confirmed the existence of only high-spin FeIIIions in the cluster, as also suggested by X-ray crystallography. Dc and ac magnetic susceptibilities were measured on microcrystalline samples of1, and the ground state for this cluster was found to beS= 21/2, with low lying excited states. Attempts to rationalize the observed spin using two different magnetostructural correlation relationships, previously derived for oxide-bridged FeIIIdimers, suggested the presence of spin frustrated pathways along the peripheral hexagon, which in turn produce a high-spin ground state. The observedS= 21/2 was finally rationalized using the results of this magnetostructural analysis, and assuming a combination ofSi= 5/2 and intermediateSi= 3/2 spin projections. This Fe7cluster is the third reported example of a heptanuclear Fe cluster with this topology, featuring a tetrahedral Fe ion at the center, and joins a small family of Fe clusters based on the aliphatic ligands apH and hmpipH.
影响因子：
2.6
作者：
Yuan-Zhu Zhang;U. P. Mallik;R. Clérac;N. Rath;S. Holmes
通讯作者：
Yuan-Zhu Zhang;U. P. Mallik;R. Clérac;N. Rath;S. Holmes