Polyoxotungstate Functionalization in the Context of Molecular Spintronics

基于分子的自旋电子学的发展，即利用与相关分子电荷和自旋状态相关的电荷传输现象，需要允许通用磁性功能化和可再现电接触模式的特定分子材料。在这种情况下，多钨酸盐的高核结构类型特别有前途，因为它们表现出高的热稳定性，许多W（VI）/W（V）基氧化还原过程几乎没有结构变化，和多齿配体功能，使复杂的杂金属为基础的自旋结构集成到多钨酸盐支架。这个项目的中心是新的合成策略的发展（后）磁性多钨酸盐的功能化，最终目的是允许与这些分子精确的电接触，例如在双结扫描隧道显微镜实验中。这将是第一次，使系统的自旋电子学特性的调查，这样的系统。该项目强调使用有机膦酸盐，特别是有机胂酸盐，最近已经显示出特别的承诺，实现和控制的关键方面，从电荷和溶解度，在溶液中的稳定性，化学吸附到金属基板和形成有序的单层，到新的杂金属子结构的整合和以前未知的簇结构的演变。在这里，有机胂酸盐的使用可以规避与其他已经建立的有机官能化技术相关的某些限制。此外，旁边的目标自旋电子学材料的性能，我们的初步结果还指出了一个巨大的潜力，迄今几乎未知的RAsO 3功能化的多钨酸盐作为一个通用的途径，以显着扩大其结构化学，实现前所未有的集群类型的前景。

The development of molecule-based spintronics, i.e. the exploitation of charge transport phenomena associated with the correlated molecular charge and spin states, requires particular molecular materials that allow for a versatile magnetic functionalization and reproducible electric contact modes. High-nuclearity structure types of polyoxotungstates are especially promising in this context, as they exhibit high thermal stability, a multitude of W(VI)/W(V)-based redox processes with virtually no structural changes, and multidentate ligand functionality that enables the integration of complex heterometal-based spin structures into the polyoxotungstate scaffolds.This project centers on the development of novel synthesis strategies for the (post-) functionalization of magnetic polyoxotungstates with the eventual aim to allow precise electrical contacts to such molecules, e.g. in two-junction scanning tunneling microscopy experiments. This would, for the first time, enable a systematic investigation of the spintronics characteristics of such systems. The project emphasizes the use of organophosphonates and especially organoarsonates, which recently have shown particular promise for achieving and controlling key aspects ranging from charge and solubility, stability in solution, chemisorption onto metal substrates and formation of ordered monolayers, to the integration of novel heterometal substructures and evolution of previously unknown cluster architectures. Here, the use of organoarsonates can circumvent certain limitations pertinent to other, already established organic functionalization techniques. Furthermore, next to the targeted spintronics materials properties, our preliminary results also point to a great potential of the hitherto nearly unknown RAsO3 functionalization of polyoxotungstates as a general pathway to significantly expand their structural chemistry, with the prospect of realizing unprecedented cluster types.