Chaotropic Polyoxometalates: From Fundamentals to Applications

• Applicants: Professor Ulrich Kortz, Ph.D.; Professor Dr. Werner Nau
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation ; Analytical Chemistry ; Organic Molecular Chemistry - Synthesis and Characterisation ; Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 505556509

Recent results published independently by the consortium have revealed that polyoxometalates (POMs) are widely used for various applications related to big societal challenges, such as energy conversion or storage, environmental science, and medicine. Some of these reports demonstrate that hydrated polyanions exhibit super-chaotropic behavior that drives remarkable properties when interacting with organic substances and gives rise to new perspectives in their manipulation at the supramolecular level. The goal of this CHAOPOM project is the evaluation of POM-based supramolecular interactions for a better understanding and quantification of their chaotropic character, and their use in the design of new materials for biological applications. Although the chaotropic nature of small classical inorganic anions such as perchlorate or thiocyanate has been known for a long time, this phenomenon has only recently been discovered for POMs. As a result, exciting new opportunities can be envisioned since primary driving forces originating from hydration properties of POMs will most likely be identified by the consortium. The study and consequences of the super-chaotropic effect that go beyond the historical Hofmeister scale will be unfolded in the proposed research project, which spans from fundamental aspects to applications. Our experimental work will be supported by theoretical calculations (molecular dynamics) in order to better understand the role of the POM hydration sphere in the aggregation processes.The objectives of the project are subdivided into four parts: (i) Investigation of supramolecular host-guest complexation phenomena: address the possibility of assembling POMs with functionally complementary compounds, similar to the interaction of boron clusters with organic macrocycles. (ii) Mastering the chaotropic effect from directed synthesis to the design of hierarchical supramolecular materials: by exploiting the super-chaotropic effect in inorganic polycondensation processes, the synthesis of conceptually novel molecular or extended POM-based materials becomes viable.(iii) POM-based systems for soft-matter engineering and bilayer materials: super-chaotropic POMs interact strongly with nonionic amphiphilic molecules giving opportunities for generating novel types of aggregates. (iv) Evaluation of bioactivity: investigate the interactions of POMs with potential drug targets in terms of their super-chaotropic properties.

• DFG Programme: Research Grants
• International Connection: France
• Partner Organisation: Agence Nationale de la Recherche / The French National Research Agency
• Cooperation Partners: Pierre Bauduin, Ph.D.; Professor Emmanuel Cadot, Ph.D.