Controllable synthesis, crystal structure and magnetic properties of Monoer-Dimer Cocrystallized Mn III Salen-type composite material
Controllable synthesis, crystal structure and magnetic properties of Monoer-Dimer Cocrystallized Mn III Salen-type composite material
复制标题
单二聚体共晶Mn III Salen型复合材料的可控合成、晶体结构及磁性能
DOI：
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发表时间：
2018
影响因子：
3.8
通讯作者：
Baoling Wang
中科院分区：
文献类型：
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作者：
Qiong Wu;Wei Wu;Yongmei Wu;Weili Li;Yongfeng Qiao;Ying Wang;Baoling Wang
通过锰-席夫碱配合物与五阴离子Anderson异多阴离子的反应，分离出了一种新的超分子结构[Mn 2 (Salen) 2 (h2o) 2][Mn(Salen)(h2o) 2] 2na [IMo 6 O 24]$8H 2o (1) (Salen¼N， n0 -乙烯-双（水杨酸酯）]。化合物1通过单晶x射线衍射、元素、红外和热重分析进行了表征。结构分析表明，该单体胞中同时含有Mn III -Salen二聚体和单体阳离子片段，anderson型多阴离子为其反阴离子。在填料排列中，所有的锰二聚体都被多金属氧酸单元很好地分离，并与锰三单体形成三级结构。有趣的是，与之前的工作不同的是，在完全相同的反应条件下，我们能够通过改变聚阴离子的电荷状态来模板Mn III -Salen配合物成不同的构型。此外，还利用超导量子干涉器件的直流和交流磁场对1的磁性进行了检测。最重要的是，我们将实验数据拟合到heisenberg型自旋模型中，结果表明二聚体中Mn III上的自旋（S¼2）之间存在~5 K的铁磁交换相互作用，而Mn III上的自旋（S¼2）之间存在反铁磁相互作用。单体和二聚体（~2 K）。这种超磁态在低温下会引起轻微的自旋受挫，从而影响磁性行为。此外，我们对磁化率的交流场测量显示了单分子磁铁的典型特征。
By the reaction of manganese-Schiff-base complexes with penta-anionic Anderson heteropolyanion, a new supramolecular architecture [Mn 2 (Salen) 2 (H 2 O) 2 ][Mn(Salen)(H 2 O) 2 ] 2 Na[IMo 6 O 24 ]$8H 2 O (1) (salen ¼ N,N 0 -ethylene-bis (salicylideneiminate) has been isolated. Compound 1 was characterized by the single-crystal X-ray diffraction, elemental, IR and thermal gravimetric analyses. Structural analysis reveals that the unit cell simultaneously contains Mn III -Salen dimer and monomer cation fragments, for which the Anderson-type polyanions serve as counter anions. In the packing arrangement, all the Mn III dimers are well separated by polyoxometalate units and form tertiary structure together with Mn III monomers. Interestingly, different from the previous work, in the exact same reaction conditions, we are able to template Mn III -Salen complexes into different configurations by varying the charge state of polyanions. Besides, the magnetic properties of 1 were also examined by using both dc and ac magnetic field of the superconducting quantum interference devices. Most importantly, our fitting of the experimental data to a Heisenberg-type spin model shows that there exists a ferromagnetic exchange interaction ~5 K between the spins (S ¼2) on Mn III in the dimer, while antiferromagnetic ones exist among.monomers and dimer (~2 K). This meta-magnetic state could induce a slight spin frustration at low temperature, which would in turn affect the magnetic behavior. In addition, our ac field measurement of the susceptibilities suggests a typical signature for a single-molecule magnet.