Effect of pressure and light on spin crossover and molecular magnetic interactions

这个方案的主要目标之一是研究新合成的铁(II)与三唑和四唑配体的自旋交叉配合物以及由氢键和/或p-p-堆积引起的一维、二维和三维晶格结构中的协同相互作用。为了定量地解释，所谓的弹性相互作用的美因茨模型将在金属稀释的混晶系列上进行测试，并在压力的影响下进行。这个模型已经被开发并成功地用于单核(即零维)铁(II)自旋交叉化合物。将进行LIESST效应研究，以了解驰豫动力学是否与晶格维度相关。-另一个目标是研究压力对具有磁交换相互作用的选定分子系统的影响。要研究的一类是普鲁士蓝型化合物。初步实验表明，加压可以在自旋态转换发生之前诱导电子转移。另一类要在压力下研究的系统是关于反铁磁耦合和热和压力诱导的自旋交叉的相互作用的双、三和寡核铁(II)化合物。将采用一种直接监测金属对形成中的自旋状态的方法。结果有望为关联和短程相互作用的存在提供支持。

One the main goals of this proposal is the study of the cooperative interactions in newly synthesized iron(II) spin crossover complexes with triazole and tetrazole ligands and 1-D, 2-D, and 3-D lattice structures brought about by hydrogen bonding and/or p-p-stacking. For a quantitative interpretation, the so-called "Mainz model" of elastic interactions will be tested on metal-diluted mixed crystal series and under the influence of pressure. This model has been developed and successfully tested for mononuclear (i.e. zero-dimensional) iron(II) spin crossover compounds. LIESST effect studies will be performed in order to learn whether the relaxation kinetics correlates with the lattice dimensionality. - Another goal is the investigation of the effect of pressure on selected molecular systems with magnetic exchange interactions. One class to be studied are the Prussian Blue type compounds. Preliminary experiments show that applying pressure induces electron transfer before the spin state switching occurs. Another class of systems to be studied under pressure are di-, tri- and oligonuclear iron(II) compounds regarding the interplay of antiferromagnetic coupling and thermal and pressure-induced spin crossover. A method for direct monitoring the spin state in metal-pair formations will be employed.The results are expected to lend support for the existence of correlations and short range interactions.