Engineering the Dynamic Hydrogen Bonds in π-Stacked Supramolecular Assemblies for Hierarchical Nanocrystal Formation

Selectively engineering the dynamic bonds in supramolecular assemblies stabilized by cooperative weak interactions is challenging yet critical to modulate their spatial organizations and stimuli-responsive behaviors. This study presents a novel class of crystalline polyphenol assemblies hierarchically regulated by the interplay of π–π stacking and reconfigurable hydrogen bonds (H-bonds). Oriented structural reorganization of the crystalline assemblies to low-dimensional nanocrystals, accompanied by structural "self-correction", could be achieved by selectively engineering the dynamic H-bond interfaces. Specifically, 1D ultrafine nanofibers could be generated via a shear force-driven H-bond interface sliding, followed by the π-stacking directed "end-to-end" fusion of the supramolecular stacks. Meanwhile, 2D nanobelts could be obtained by introducing metal coordination to disintegrate the dynamic H-bond networks while unzipping the lamellar crystalline assemblies. In particular, the flexible 1D nanofibers and 2D nanobelts preserved molecular order with favorable electronic and band structures, exhibiting dimension-dependent fluorescence emission and metal cation-induced quenching. This study provided new insights into the structure–function relationship of polyphenol supramolecular assemblies that governs their spatial organization and dynamic response. Besides, the strategy to selectively engineer the dynamic H-bond interfaces for structural reorganization of crystalline supramolecular assemblies might be exploited as a "top-down" approach to fabricate flexible low-dimensional nanocrystals for multifunctional applications.