Organic materials with effective emission and multi-stimuli response are highly desirable for applications in optoelectronic devices, like displays or emissive diodes. In this context, the combination of fluorescence and liquid crystallinity yields a series of promising materials. A challenge on the design of such materials is fluorescence quenching due to higher ordered phases like liquid crystallinity or crystallinity. To overcome this quenching, chromophores with aggregation-induced emission can be used. Recently, we started to investigate fluorescent liquid crystalline materials obtained by two different approaches – a synthetic route and a supramolecular approach. The first route is based on AIE-active thioethers reported by Voskuhl and coworkers, which were decorated with alkyl-chains to promote liquid crystallinity. However, only one compound showed soft crystalline behavior with temperature-depending fluorescence. In contrast, the supramolecular approach yielded a series of hydrogen-bonded assemblies which showed temperature-depending fluorescence resulting from the order of the mesophase.

​ Figure 1: Molecular structures of the AIE-active compounds (A) and mesomorphic behavior under the POM (B, C) as well as the concept for hydrogen-bonded AIE-active mesogens (D) and their temperature-dependent fluorescence behavior (E).

Recent Publication

"Mesogens with Aggregation-Induced Emission Formed by Hydrogen Bonding" – M. Saccone, M. Blanke, C. G. Daniliuc, H. Rekola, J. Stelzer, A. Priimagi, J. Voskuhl,* M. Giese,* ACS Materials Lett. 2019, 1, 589-593.

"Structure–property relationships in aromatic thioethers featuring aggregation-induced emission: solid-state structures and theoretical analysis" – M. Saccone, S. Riebe, J. Stelzer, C. Wölper, C. G. Daniliuc, J. Voskuhl, M. Giese*, CrystEngComm 2019, 21, 3097-3105.

“Alkylated Aromatic Thioethers with Aggregation-Induced Emission Properties – Assembly and Photophysics” – S. Riebe, M. Saccone, J. Stelzer, A. Sowa, C. Wölper, K. Soloviova, C. Strassert, M. Giese,* J. Voskuhl,* Chem. Asian J. 2018, 14, 814-820.