Breaking Parallel Orientation of Rods via a Dendritic Architecture toward Diverse Supramolecular Structures. Issue 34 (15th July 2019) - Zhang, Ruimeng
Abstract: Self‐assembled nanostructures of rod‐like molecules are commonly limited to nematic or layered smectic structures dominated by the parallel arrangement of the rod‐like components. Distinct self‐assembly behavior of four categories of dendritic rods constructed by placing a tri(hydroxy) group at the apex of dendritic oligo‐fluorenes is observed. Designed hydrogen bonding and dendritic architecture break the parallel arrangement of the rods, resulting in molecules with specific (fan‐like or cone‐like) shapes. While the fan‐shaped molecules tend to form hexagonal packing cylindrical phases, the cone‐shaped molecules could form spherical motifs to pack into various ordered structures, including the Frank–Kasper A15 phase and dodecagonal quasicrystal. This study provides a model system to engineer diverse supramolecular structures by rod‐like molecules and sheds new light into the mechanisms of the formation of unconventional spherical packing structures in soft matter. Abstract : The preferred parallel orientation of rod‐like molecules is successfully broken by synergistic effects of hydrogen bonding interaction and dendritic architecture. The resulting molecular shape (fan‐like shape and cone‐like shape) with balanced enthalpy and entropy regulates the formation of diverse supramolecular structures with the curved interface.