Molecular Design of POSS–Oligosaccharide Hybrid Materials for Stabilizing Soft-Matter Quasicrystals and Frank–Kasper Phases

Block copolymers (BCPs) are known for their ability to self-assemble into diverse nanostructures. BCP-like hybrid materials combining oligosaccharides and polyhedral oligomeric silsesquioxane (POSS) have been reported to form unique spherical packings. Previous work demonstrated that AB-type sugar–POSS architectures could produce noncanonical spherical structures, including Frank–Kasper (FK) phases. Achieving more stable and complex morphologies, however, requires enhanced molecular conformational asymmetry. Here, we designed and synthesized sugar–(POSS)2 hybrid materials with increased conformational asymmetry by systematically tuning oligosaccharide length, glycosidic bonding patterns, and POSS alkyl substituents. The materials were prepared via a thiol–yne reaction. As a result, stable FK A15 and σ phases, as well as dodecagonal quasicrystals (DDQC), were obtained. This work extends the molecular design principles of sugar–(POSS)2 molecules and establishes a versatile platform for the rational design of complex spherical packings in soft matter, thereby opening new avenues for advanced materials development.