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在三角形金字塔铁的家族中缓慢的磁放松(II) 罗化物复合体
W Hill Harman1, T David Harris, Danna E Freedman
1Department of Chemistry, University of California, Berkeley, California 94720, USA.
Journal of the American Chemical Society
|December 15, 2010
概括
我们合成了具有可调节的连接体场的高旋转铁 (II) 复合体,观察了缓慢的磁放松. 综合体1展示了单核过渡金属综合体中迄今为止最高的自旋逆转障碍,为磁性行为提供了洞察力.
科学领域:
- 协调化学 协调化学
- 磁电化学 磁电化学 磁电化学
- 材料科学 材料科学 材料科学
背景情况:
- 三角形金字塔铁 (II) 复合体由于其磁性特性而引起人们的兴趣.
- 之前的研究发现了梅西衍生物 (复合物2) 中的缓慢磁放松.
研究的目的:
- 合成和表征一个同类系列的铁 (II) 复合体,具有不同的连接体.
- 为了研究联结体场强度对磁性行为的影响,特别是缓慢的磁性放松.
- 使用先进的光谱和磁性技术探测静态和动态磁性特性.
主要方法:
- 铁 (II) 复合物的合成与三 (pyrrolyl-α-methyl) 胺连接体.
- 用于结构确定的X射线晶体学.
- 莫斯巴乌尔光谱和高场EPR光谱检测电子结构和磁性.
- 磁化和交流磁性易感度测量以确定磁性异构和放松动态.
主要成果:
- 一系列的三角形金字塔铁 (II) 复合物[M (solv) (n) ][tpa (R)) 铁]被合成并进行了表征.
- 观察到大型单轴零场分裂参数 (D),随着联体场强度的扩展.
- 复合物1展示了单核过渡金属复合物的最高旋转逆转障碍 (Ueff = 65 cm-1),并确定了三种不同的放松过程.
- 莫斯巴乌尔光谱学证实了复合体1和4中的缓慢磁放松.
结论:
- 连接体场强度显著影响高旋铁 (II) 复合体的磁性异构和放松动态.
- 本系列为了解铁复合体中的单分子磁体行为提供了一个平台.
- 综合体1代表了基于单核过渡金属的缓慢磁放松的新基准.
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