Hydrogen-bond induced chiral-nematic mesophases - A modular approach for systematic investigation of supramolecular liquid crystals and application potential thereof

• Applicant: Professor Michael Giese, Ph.D.
• Subject Area: Organic Molecular Chemistry - Synthesis and Characterisation
• Term: from 2017 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 349764126

A number of proof-of-principle studies on CLCs derived by the common approach to dope nematic liquid crystalline hosts with chiral dopants were already described and show their potential for applications. However, the synthesis of enantiopure, photo-switchable dopants is challenging and the manipulation of the photonic properties of the CLCs is rather by chance than by rational design. Herein, we describe a modular approach to supramolecular liquid crystals by direct incorporation of chirality into functional assemblies via hydrogen bonding. This allows us to prevent incompatibility issues as well as phase separation and helps to minimize the synthetic efforts for novel functional materials. The modular design enables systematic studies on the structure property relationships to get a detailed understanding of hydrogen bonded CLCs and deduce rational design criteria towards functional photonic materials with tailor-made properties. The first part of the present project investigates the efficiency of the chirality transfer by employing different chiral HB-acceptors. Determination of the HTP-values allows for the quantification of the chirality transfer (Phase 1). In the second part the chiral HB-acceptors will be combined with photo-switchable azopyridines to manipulate the photonic properties of the CLCs by light (Phase 2). Finally first proof-of-principle studies will be performed to investigate the application potential of the CLCs towards photonic data storage and sensors (Phase 3).

• DFG Programme: Research Grants