Synthesis, structure and magnetic properties of oligonuclear polycyanometalates, encapsulated with transition metal bispidine complexes

在金属离子导向的模板反应中制备了一系列与铜（II）或镍（II）配位的单环、双环和三环大环配体。三铜（II）和三镍（II）配合物可以通过简单的反应得到，但产率相对较低，它们主要存在于两种可能接近简并的构象中，相互转化的激活障碍较低。在它们的半球形同步构象中，两个三核配合物可以结合成一个胶囊，该胶囊已被证明是角共享双八面体配合物的理想宿主。迄今为止未知的[(CN)5Fe(CN)Fe(CN)5]7-阴离子已经在六铜（II）配合物的腔内组装并稳定，基于两个三大环配体铜（II）阳离子；该Cu6Fe2簇在溶液中是稳定的，并进行了结构分析。该项目包括多种相似的基于寡聚大环的宿主分子的合成，主要基于双核氰基配合物的一系列主-客体组装的制备和表征，通过分子建模和核磁共振（镍（II））或EPR光谱（铜（II））研究宿主配合物的溶液结构，以及研究稳定的主-客体配合物的磁性。

A series of mono-, bis- and tris-macrocyclic ligands, coordinated to copper(II) or nickel(II) have been prepared in metal-ion-directed template reactions. The tricopper(II) and trinickel(II) complexes, obtainable by simple reactions but in relatively low yield, exist primarily in two probably nearly degenerate conformations with low activation barriers for their interconversion. In their hemispherical syn,syn conformation two of the trinuclear complexes may combine to a capsule which has been shown to be an ideal host for corner-shared bis-octahedral complexes. The so far unknown [(CN)5Fe(CN)Fe(CN)5]7- anion has been assembled in presence of, and stabilized inside the cavity of the hexakis-copper(II) complex, based on two of the tris-macrocyclic ligand copper(II) cations; this Cu6Fe2 cluster is stable in solution and has been structurally analyzed. The project involves the synthesis of a variety of similar oligo-macrocycle-based host molecules, the preparation and characterization of a range of host-guest assemblies, primarily based on dinuclear cyano complexes, the investigation of the solution structures of the host complexes by molecular modeling and NMR (nickel(II)) or EPR spectroscopy (copper(II)), and the investigation of the magnetic properties of the stable host-guest complexes.