Polyoxotungstate Functionalization in the Context of Molecular Spintronics

点击翻译按钮获取中文摘要

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.