Spin crossover — An unusual chemical equilibrium
Spin crossover — An unusual chemical equilibrium
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自旋交叉——一种不寻常的化学平衡
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
W. Linert
中科院分区：
文献类型：
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作者：
A. B. Koudriavtsev;W. Linert
本文综述了高自旋和低自旋过渡金属配合物之间的自旋交叉平衡的性质和理论模型。自旋交叉化合物是一种很有前途的信息存储和显示材料。在固态中，自旋交叉伴随着与相变有关的几种现象。提出了这些现象的解释理论模型的批判性分析。本文主要介绍了两种能充分描述大部分实验数据的模型，即类伊辛哈密顿量模型和分子统计模型。这两个模型产生的自旋交叉的描述是形式上相似，但不完全相同，它们是基于从根本上不同的概念的分子相互作用和排序，后者是起源的两步自旋交叉。类伊辛哈密顿模型是从晶格性质的角度来解释自旋交叉现象的，而分子统计模型则是从分子的角度来解释这一现象。后一种方法提供了在自旋交叉中观察到的合作现象的分子性质的阐明，这对于开发有前途的自旋交叉化合物的合成策略是重要的。
The nature and theoretical models of spin crossover equilibrium between high-spin and low-spin forms of transition metal complexes are reviewed. Spin crossover compounds are promising materials for information storage and display devices. In the solid state spin crossover is accompanied by several phenomena related to phase transitions. A critical analysis of theoretical models proposed for the explanation of these phenomena is given. The paper mainly focuses on two models that provide for adequate descriptions of the majority of experimental data, viz. the model of the Ising-like Hamiltonian and the molecular statistical model. Descriptions of spin crossover yielded by these two models are formally similar but not identical and they are based on fundamentally different concepts of molecular interactions and ordering, the latter being the origin of the two-step spin crossover. The Ising-like Hamiltonian model approaches spin crossover from the point of view of properties of lattices whereas the molecular statistical model explains this phenomenon starting from molecules. The latter approach provides for the elucidation of the molecular nature of cooperative phenomena observed in spin crossover which is important for developing the synthetic strategy of promising spin crossover compounds.