分子基自旋交叉材料的设计合成与强磁场EPR研究

Knowing the changing modes and rules of the magnetic properties of spin crossover materials is the basis of designing and synthesizing the spin crossover materials suitable for the real applications. This project will synthesize a serial of mono- and multi-nuclear Fe based spin crossover compounds with the ligands containing terminal N, phenoxy, and Schiff's base units. The high field EPR is used as core characterizing technique to trace the spin crossover process in hope of studying the link between local environments of spin centers and magnetic properties during the spin transition, which is expected to develop the knowledge about the functional properties and the physical nature. We hope to study the synthesis of molecule based spin crossover materials and spin crossover process thoroughly, evolve the rules of synthesis and spin crossover, and finally be able to provide theoretical basis and examples for designing and selecting the he spin crossover materials suitable for the real applications.

掌握自旋交叉材料的磁性质在外场扰动下的变化方式和变化规律是设计合成实用型自旋交叉材料的基础。本项目将定向合成含有端基氮、酚氧和希夫碱基团的系列单核或多核的铁基自旋交叉化合物，以强磁场EPR为核心分析手段，对自旋转变的过程进行跟踪研究，理清自旋中心的局域环境与磁性质的对应关系，深化对该类材料的功能特性和物理本质的认识。本项目希望通过对分子基自旋交叉材料合成和自旋转变过程的跟踪研究，总结出合成和自旋转变的规律，为设计筛选实用型分子基自旋交叉材料提供部分理论基础和研究实例。

本项目主要研究自旋交叉材料的合成和自旋转变的规律。我们定向合成了一系列自旋交叉材料和相关分子基磁性材料，包括第一例表现出单分子磁性和自旋交叉行为并存的单核钴化合物，系列基于喹啉基多羧酸配体的低维分子磁体，一例可用紫外光控制的双稳态分子，一例N-供电子配体的单核Co(II)化合物。我们以强磁场EPR为核心手段，并结合利用磁学、光学、理论计算等手段，系统地研究了自旋交叉材料的合成策略、分子对称性和晶格振动对自旋弛豫机理和动力学变化的影响，为合成更高性能的分子基自旋材料提出了建议。