Studies of a Nickel‐Based Single‐Molecule Magnet
Studies of a Nickel‐Based Single‐Molecule Magnet
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DOI：
10.1002/1521-3765(20021104)8:21
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发表时间：
2002-11
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影响因子：
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通讯作者：
H. Andres;R. Basler;A. Blake;C. Cadiou;G. Chaboussant;C. M. Grant;H. Güdel;M. Murrie;S. Parsons;C. Paulsen;Fabrizzio Semadini;V. Villar;W. Wernsdorfer;R. Winpenny
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文献类型：
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作者：
H. Andres;R. Basler;A. Blake;C. Cadiou;G. Chaboussant;C. M. Grant;H. Güdel;M. Murrie;S. Parsons;C. Paulsen;Fabrizzio Semadini;V. Villar;W. Wernsdorfer;R. Winpenny
合成并研究了环状配合物[Ni12(chp)12(O2CMe)12(thf)6(H2O)6] (1) (chp=6-氯-2-吡啶酮酸酯)。配合物 1 在 S=1 中心之间表现出铁磁交换，给出 S=12 自旋基态。详细研究表明，它是一种单分子磁体，具有大约 10 K 的能垒，可用于磁化强度的重新定向。还观察到共振量子隧道效应。共振之间的场可以精确测量 D，即 0.067 K。非弹性中子散射研究可以准确导出交换参数，而仅从磁化率数据中这是不可能的。需要三种交换相互作用：两个大约 11 和 2 cm−1 的铁磁最近邻相互作用和一个 -0.9 cm−1 的反铁磁次近邻相互作用。
A cyclic complex [Ni12(chp)12(O2CMe)12(thf)6(H2O)6] (1) has been synthesised and studied (chp=6-chloro-2-pyridonate). Complex 1 exhibits ferromagnetic exchange between the S=1 centres, giving an S=12 spin ground state. Detailed studies demonstrate that it is a single-molecule magnet with an energy barrier of approximately 10 K for reorientation of magnetisation. Resonant quantum tunnelling is also observed. The field between resonances allows accurate measurement of D, which is 0.067 K. Inelastic neutron scattering studies have allowed exchange parameters to be derived accurately, which was impossible from susceptibility data alone. Three exchange interactions are required: two ferromagnetic nearest neighbour interactions of approximately 11 and 2 cm−1 and an anti-ferromagnetic next nearest neighbour interaction of −0.9 cm−1.