Manipulation of Liquid Crystalline Properties by Dynamic Covalent Chemistry─En Route to Adaptive Materials
Meik Blanke, Leona Postulka, Isabelle Ciara, Francesco D’Acierno, Marcus Hildebrandt, Jochen S. Gutmann, Ronald Y. Dong, Carl A. Michal, Michael Giese
Abstract
Dynamic covalent bonds bear great potential for the development of adaptive and self-healing materials. Herein, we introduce a versatile concept not only for the design of low-molecular-weight liquid crystals but also for their in situ postsynthetic modification by using the dynamic covalent nature of imine bonds. The methodology allows systematic investigations of structure–property relationships as well as the manipulation of the materials’ behavior (liquid crystallinity) and the introduction of additional properties (here, fluorescence) by a solvent-free method. For the first time, the transamination reaction is followed by variable-temperature 19F solid-state NMR in the mesophase, providing insights into the reaction dynamics in a liquid crystalline material. Finally, the application potential for the design of liquid crystalline materials with adaptive properties is demonstrated by a sequential combination of these reactions.