Molecular design and physical properties of alkylamide-substituted 3-fold symmetric molecules

Abstract C 3-symmetric molecules incorporating alkylamide chains (−CONHCnH2n+1) form 1-dimensional (1D) columnar structures via intermolecular amide hydrogen bonding, exhibiting diverse physical properties. In these molecular systems, ferroelectricity based on amide group dipole inversion is observed, particularly pronounced in the discotic hexagonal columnar (Colh) liquid crystal phase. In systems incorporating chiral side alkyl chains, a pronounced chirality effect on molecular dynamics is observed. Cooperative dipole inversion, facilitated by unidirectional helical assembly structures, leads to the remarkable phenomenon of dramatically reduced coercive electric field. Furthermore, studies of ferroelectric–antiferroelectric mixed systems have revealed the correlation length required for ferroelectricity to emerge within 1D ferroelectric domains. This molecular design concept has been extended to various 3-fold symmetric frameworks, including triphenylamine, triphenylmethanol, triptycene, and hexadihydrotribenzo[12]annulene. Diverse assembly structure and physical property such as ferroelectricity, chirality effects, and glass formation have been discovered in these molecular systems. Alkylamide-substituted 3-fold symmetric molecules offer high design flexibility and are positioned as a molecular platform with great potential for self-assembly and property control.