Construction of novel spin-crossover systems by nano space control of assemblies

通过组件的纳米空间控制构建新型自旋交叉系统

基本信息

批准号：
18550055
负责人：
KAWATA Satoshi
金额：
$ 2.57万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18550055/
关键词：
Spin Crossover Binuclear Complex Iron(II)LIESST ヘリケート

项目摘要

Photomagnetic properties of a series of binuclear diiron(II) complexes belonging to the [{Fe(NCS)(py-X)}_2(bpypz)_2] family with bpypz = 3,5-bis (pyridine-2-yl)pyazolate and X = 4-Mepy (1), py (3), 3-Mepy (4), 3-Cipy (5) and 3-Brpy (6) have been investigated. The reflectivity T(LIESST) temperatures as well as the kinetic decays. All these complexes display a complete thermal spin transition centred between 100-150 K, and undergo the light-induced excited spin state trapping (LIESST) effect at low temperatures. The T(LIESST) relaxation temperature of the photoinduced high-spin state for each compound has been determined. For all of them the T(LIESST) curves at low temperature have been found close to antiferromagnetic response of the [{Fe (NCS)(3,5-Me_2py)}_2(bpypz)_2] (7) complex characterized by two iron(II) metal ions in HS electronic configuration, giving some evidences of a quantitative LS-LS → HS-HS photoconversion process. Depending on the nature of the cooperativity, kinetics have been treated with stretched exponential, simply exponential or sigmoidal model. Interestingly this series of dinuclear complexes follow a previously proposed linear relation between T(LIESST) and their thermal spin-transition temperatures T_<v2>: T(LIESST) = T_0-0.3 T1_<v2> To for these compounds is equal to 100 K. Based on that and by using the empirical linear relation found between the thermal spin transition and the Hammett constant, the HS-HS properties of complex 7 have been understood as a reflect of the physical impossibility that the T(LIESST) was higher than T_<v2>. The close vicinity of the thermal spin crossover phenomenon on 7 has been successively checked by applying hydrostatic pressure.

属于[{Fe(NCS)(py-X)}_2(bpypz)_2]家族的一系列双核二铁(II)络合物的光磁性质，其中bpypz = 3,5-双(吡啶-2-基)吡唑盐X = 4-Mepy (1)、py (3)、3-Mepy (4)、3-Cipy (5) 和 3-Brpy (6) 的反射率 T(LIESST) 温度以及动力学衰变都显示出以 100-150 K 为中心的完整热自旋跃迁，并经历光诱导的激发自旋态捕获 (LIESST)。已经确定了每种化合物的光诱导高自旋态的 T(LIEST) 弛豫温度，所有这些化合物在低温下的 T(LIEST) 曲线都接近。 [{Fe (NCS)(3,5-Me_2py)}_2(bpypz)_2] (7) 配合物的反铁磁响应，以 HS 电子构型中的两个铁 (II) 金属离子为特征，给出了定量 LS- 的一些证据LS → HS-HS 光转换过程根据协同性的性质，用拉伸指数、简单指数或 S 形模型来处理。配合物遵循先前提出的 T(LIESST) 与其热自旋跃迁温度 T_<v2> 之间的线性关系： T(LIESST) = T_0-0.3 T1_<v2> 这些化合物的 To 等于 100 K。通过使用热自旋跃迁和哈米特常数之间发现的经验线性关系，配合物 7 的 HS-HS 性质已被理解为 T(LIESST) 的物理不可能性的反映已经通过施加静水压连续检查了7上的热自旋交叉现象的附近。