不同抗衡阴离子自旋交叉分子的制备与表征

Preparation and Characterization of Spin Crossover Molecules with Different Counter Anions

基于三氮唑(1,2,4-1H-triazole,Htrz)体系的Fe(Ⅱ)的配合物是一类非常重要的在室温附近发生自旋转变的自旋交叉分子,具有潜在的应用。本文报道了2种基于三氮唑体系的Fe(Ⅱ)的配合物的制备与表征,分别为[Fe(Htrz)_(2)(trz)](CF_(3)SO_(3))和[Fe(Htrz)_(2)(trz)](BF_(4)),并研究了抗衡阴离子对自旋转变行为的影响。自旋交叉分子的制备由2种前驱体简单混合反应而得,结构表征表明三氮唑参与反应,并且产物中的Fe元素基本为Fe(Ⅱ),磁性测试证实了这2种分子存在自旋转变特性,并且这种自旋转变具有温度磁滞效应。实验结果还表明抗衡阴离子对于自旋交叉分子的自旋转变行为有重要的影响。抗衡阴离子空间位阻越小、抗衡阴离子的电负性越强、结构越对称规整,则自旋转变温度越高。

The Fe(Ⅱ)spin crossover complex(SCO)based on 1,2,4-1H-triazole(Htrz)is an important molecule with the spin transition around room temperature,showing promising applications.The synthesis and characterizations of two Fe(Ⅱ)SCOs based on Htrz were reported,including[Fe(Htrz)_(2)(trz)](CF_(3)SO_(3))and[Fe(Htrz)_(2)(trz)](BF_(4)),and the effect of counter anions on spin transition is also investigated.SCO molecules were prepared by mixing two precursors.The structure characterizations indicate that the Htrz participates in the reaction as a ligand and the Fe is in the valence state of 2.The magnetic measurements confirm the spin transition with the temperature induced hysteresis in the two SOC molecules.The results further indicate that the counter anions have important effects on spin transition of SCO molecules.When the counter anion has smaller steric and stronger electronegativity,and the molecular structure is more symmetrical and regular,the SCO molecules demonstrate higher spin transition temperature.