New polynucleating ligands and their metal complexes with spin crossover activity

资助应允许在Jäger教授研究小组使用的配体体系基础上合成和表征新的多核配体及其配合物。在Freistaat th<e:1> ringen（1996 - 1999）建立的“磁性材料研究<e:1>、共通技术和传感基础分子配位”项目的框架下，大量的单核以及一些双核铁、铜和钴配合物被合成并进行了磁性表征。特别是一些单核铁配合物表现出有趣的磁性行为，如低温自发磁化、超磁性和各种自旋交叉现象。所获得的关于外围取代基对赤道配体和轴向配体对配体场强度的影响以及对金属中心磁性的影响的知识，为有目的地合成多核配体及其金属配合物提供了极好的资源。这种配合物提供了研究金属中心之间具有铁磁或铁磁相互作用以及耦合自旋交叉现象的系统的可能性。

The subsidies should allow the synthesis and characterisation of new polynucleating ligands and their complexes based on the ligand system used in the research group of Professor Jäger. In frame of the project "Magnetmaterialien für Kommunikationstechnik und Sensorik auf Basis molekularer Koordinationsverbindungen" founded by the Freistaat Thüringen (1996 - 1999), a large number of mononuclear as well as some dinuclear iron, copper and cobalt complexes have been synthesised and magnetically characterised. Especially some of the mononuclear iron complexes showed interesting magnetic behaviour as spontaneous magnetisation at low temperatures, metamagnetism and various spin crossover phenomena. The obtained knowledge about the influence of pheripheral substituends on the equatorial ligand as well as the axial ligand on the strength of the ligand field and therefore on the magnetic properties of the metal centre is an excellent pool for purposeful synthesis of polynucleating ligands and their metal complexes. This complexes offer the possibility to investigate systems with ferro- or ferrimagnetic interactions between the metal centres as well as coupled spin crossover phenomena.