高度异构的 (IV) 复合物:单核单分子磁铁的新例子
José Martínez-Lillo1, Teresa F Mastropietro, Elsa Lhotel
1Departament de Química Inorgànica/Instituto de Ciencia Molecular (ICMol), Universitat de València , C/Catedrático José Beltrán 2, 46980 Paterna (València), Spain.
Journal of the American Chemical Society
|August 21, 2013
概括
新的 (IV) 复合物 (NBu4) 2 [ReBr 4 ] 氧] 和 (NBu4) 2 [ReCl 4 ] 氧) 展示了单核单分子磁铁的特性. 这些化合物表现出缓慢的磁化放松和异型磁性中心,为先进的磁性材料铺平了道路.
科学领域:
- 无机化学 无机化学
- 材料科学 材料科学 材料科学
- 磁电化学 磁电化学 磁电化学
背景情况:
- (IV) 复合物因其磁性特性而引起人们的兴趣.
- 单核单分子磁铁 (SMM) 为高密度数据存储和量子计算提供了潜力.
研究的目的:
- 合成和描述 (IV) 复合物 (NBu4) 2[ReBr4(ox) ] (1) 的特征.
- 为了研究 (NBu4) 2[ReBr4(ox) ] (1) 和同结构 (NBu4) 2[ReCl4(ox) ] (2) 的磁性特性.
- 为了确定零场分裂张量参数,并了解磁性异构的起源.
主要方法:
- 用X射线衍射来确定晶体结构.
- 可变温度的dc和ac磁性易感度测量.
- 取决于场的磁化实验.
- 高频和电场电子偏磁共振 (EPR) 谱学.
- 计算方法包括完整的活性空间和密度函数理论 (DFT).
主要成果:
- (NBu4) 2[ReBr4(ox) ] (1) 的晶体结构显示了离散的[ReBr4(ox) ](2-) 离子和庞大的四-n-丁离子,具有最小的分子间相互作用.
- 这两种复合体都表现出单核单分子磁铁的特征,在低温下显示磁化缓慢放松.
- EPR研究确定了零场分裂张数的负符号,表明由于旋转轨道合和低分子对称性,显著的大小和罗姆比度 (E/D).
- 磁化测量和理论计算为D和E值提供了估计值.
结论:
- 合成的 (IV) 复合体是单核单分子磁铁的新例子.
- 磁性异构性源于强烈的旋转轨道合和中心的低分子对称性的结合.
- 这些发现有助于理解和设计具有可调节性质的新型磁性材料.
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