Distorted MnIVMn3III cubane complexes as single-molecule magnets
Distorted MnIVMn3III cubane complexes as single-molecule magnets
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DOI：
10.1021/ja960970f
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发表时间：
1996-08-21
影响因子：
15
通讯作者：
Hendrickson, DN
中科院分区：
文献类型：
--
作者：
Aubin, SMJ;Wemple, MW;Hendrickson, DN
本文报道了六种畸变立方烷配合物[Mn（IV）Mn（3）（III）O（3）X]的交流磁化率数据。这些配合物都有一个孤立的S = 9/2的基态，在基态有零场分裂，轴向的零场分裂参数D在-0.27 ~-0.38cm（-1）之间。由于大自旋基态和明显的磁各向异性，一个异相交流磁化率信号被视为六个Mn-4复合物。异相交流磁化率信号反映了缓慢的磁化弛豫，这表明单个分子充当磁体。交流磁化率数据的Mn-4复合物之一的冷冻玻璃，以确认异相交流信号与孤立的分子。描述了影响一个给定的配合物是否可以作为单分子磁体的因素。上述Mn-4络合物仅代表第二种类型的分子，其表现出足够的磁各向异性以用作单分子磁体。
Alternating current (ac) magnetic susceptibility data are presented for six distorted cubane complexes of the composition [Mn(IV)Mn(3)(III)O(3)X]. Each of these complexes has a well isolated S = 9/2 ground state, There is zero-field splitting (ZFS) in the ground states where D, the axial ZFS parameter, is found to be in the range of -0.27 to -0.38 cm(-1). As a result of the big spin ground state and appreciable magnetic anisotropy, an out-of-phase ac magnetic susceptibility signal is seen for each of the six Mn-4 complexes. The out-of-phase ac susceptibility signal reflects slow magnetization relaxation which is taken to indicate that individual molecules are acting as magnets. Alternating current susceptibility data are presented for a frozen glass of one of the Mn-4 complexes to confirm that the out-of-phase ac signal is associated with isolated molecules. The factors that influence whether a given complex can function as a single-molecule magnet are described. The above Mn-4 complexes represent only the second type of molecules that exhibit enough magnetic anisotropy to function as single-molecule magnets.