Cyanated macrocycles for electron and ion transport

The project entitled Cyanated macrocycles for electron and ion transport aims at improved materials for batteries and related applications. Materials for batteries must fulfil two important tasks; they have to transport and accumulate electricity and ions, for example lithium ions. However, these materials often contain rare metals from non-renewable sources. Replacing these materials by more sustainable and less toxic organic molecules is an important target to develop next generation batteries, which are essential for solving the environmental challenges that we are facing. Consequently, the target materials for this project are based on organic molecules. Similar to the parts of a power line or a water pipe, there should be no disruptions or leaks within the materials for efficient transport, so the molecules must be well connected. The materials also need to be porous to leave space for the accumulation of ions. For the accumulation of electricity, the so-called redox properties of the molecules are important. They describe how good the molecules can take up electricity (and release it again). Despite significant efforts in recent years, achieving excellent properties for organic molecules remains challenging. New ideas and design concepts are introduced for this project to obtain target molecules with excellent performance. The molecules are cyclic so they can form pipes when connected to one another; and they are large enough to leave space for the accumulation of ions. Hence, these molecules are called macrocycles. Different to power lines or water pipes, the macrocycles will be able to transport both electricity and ions at the same time, if they are well connected. Therefore, macrocycles with different connections (certain segments of the macrocycles) will be tested. These connections are also important for the assembly of the pipes close to each other. For good redox properties, the macrocycles will feature so-called cyano groups. Cyano groups are known to improve the take-up and release of electricity. In a first step, the reactions for the preparation of the macrocycles will be developed using model compounds. The macrocycles will then be prepared using the newly developed reactions. Subsequently, their assembly and redox properties will be investigated. The transport of electricity and ions will be studied using transistors based on the new materials. After these initial investigations, the materials will be tested in batteries. However, the macrocycles are also expected to be useful for various applications beyond batteries. For example, the expected material properties are promising for medical applications, such as sensors and ion pumps, as well as for electronic devices, such as smart windows and electronic paper. The scope of the materials will be further investigated together with collaborators in the United Kingdom and in Austria.