Fantastic supramolecular chiral self-assembly of POSS based dendrimers: From helical nano-fibers to nano-toroids and loofah-like superstructures

Abstract

Chiral dendrimers are ideal building blocks for assembled functional materials as their versatility and diverse assembly behaviors, however the assembled nanostructures still hardly be accurately predicted and flexibly controlled. Here, we reported a controllable fantastic supramolecular self-assembly of polyhedral oligomeric silsesquioxane (POSS) based chiral dendrimer (l-POSS), which could assemble into helical nano-fibers, nano-toroids and loofah-like superstructures as the regulated transfer and expression of chirality by solvents. Interestingly, the unique loofah-like network is constructed from the junction and loop of the helical nano-fibers as the advanced expressions of chirality, which have been proved by a designed disassembly process and a co-assembly with enantiomer d-POSS. After co-assembly with d-POSS, the transfer of chirality from dendrimer could be easily regulated by enantiomers with performed loofah-like structure or helical fibers disappeared and were replaced by the non-chiral nano-fibers as the assembly in a racemic state (l-POSS and d-POSS are in equimolar). These new insights into the transfer and expression of the chirality from chiral dendrimers could inspire the design, regulation and application of chiral architectures by taking advantage of the controllable multifarious self-assembly from dendritic building blocks.