Coiled‐Coil Helical Nano‐Assemblies: Shape Persistent, Thixotropic, and Tunable Chiroptical Properties

Abstract

AbstractHere, we studied the self‐assembly and chiroptical properties of four C2‐symmetric molecules bearing terephthaloyl (TLF−C4 and TLF−C12) and benzene‐1,4‐dicarbonyl core (BLF−C4 and BLF−C12). β‐turn in the aggregates of TLF−C4 and TLF−C12 was found irrespective of the amount of water as anti‐solvent in methanol (MeOH). Interestingly, chiroptical properties can be switched from β‐turn to twisted β‐sheet secondary structure in BLF−C4 and BLF−C12 beyond a certain amount of water in MeOH. Detailed studies suggested lamellar arrangement of the TLF−C4 gelators with a β‐turn led to the formation of right‐handed coiled‐coil helical fibers. However, left‐handed coiled‐coil twisted fibers were formed by lamellar packing (twisted β‐sheet) of BLF−C4. In addition, TLF−C12 gel in methylcyclohexane (MCH) revealed shape persistent gelation. Rapid dynamic equilibrium between association and dissociation of non‐covalent interactions in BLF−C12 gel in MCH resulted in thixotropic and, in turn, injectable behavior.