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在单核Fe (II) 复合体中缓慢磁放松的状态外自旋轨道合的重要性
Po-Heng Lin1, Nathan C Smythe, Serge I Gorelsky
1Department of Chemistry, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada.
Journal of the American Chemical Society
|September 8, 2011
概括
研究了两个铁 (II) 复合体的磁性特性. 由于旋转轨道合,复合体1充当单分子磁体,而复合体2不表现出缓慢的磁放松.
科学领域:
- 无机化学 无机化学
- 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:
- 高旋转铁 (II) 复合物因其磁性特性而引起人们的兴趣.
- 旋转轨道合 (SOC) 显著影响磁放松动态.
- 了解影响慢磁放松的因素对于开发分子磁性材料至关重要.
研究的目的:
- 合成和描述两个具有不同几何形状的单核高旋转Fe (II) 复合体.
- 为了研究连接体场几何学对磁性和缓慢磁放松的影响.
- 阐明旋转轨道合在这些Fe(II) 复合物的磁性行为中的作用.
主要方法:
- 合成两种单核高旋转Fe(II) 复合物:[Fe(II) (((N(TMS) (((2)) (((2)) ((PCy ((3)))) (1) 和[Fe(II) (((N(TMS) ((2)) ((2)) ((深) (2) ] (2).
- 测量磁性特性,包括温度依赖的磁性易感性.
- 分析电子结构和旋转轨道合效应.
主要成果:
- 复合体1,具有三角平面几何,在600 Oe时呈现磁化缓慢放松,表现为场诱导的单分子磁体.
- 复合体2具有扭曲的四面体几何,不显示缓慢的磁放松.
- 复合体1中的低电子激发状态促进了SOC诱导的混合,将轨道角动量重新引入到基本状态.
结论:
- 连接体场的几何形状深刻地影响了激发状态的能量差距和SOC混合的程度.
- 综合体1展示了通过控制电子结构和SOC来设计单分子磁铁的原理.
- 综合体2强调了更大的能量差距如何抑制SOC效应,防止缓慢的磁放松.
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