Composition-Driven Structural Modulation and Guest-Induced Nanotemplate Effects of the Host-Guest Complexes Made by a Unimolecular Q-Clip

The composition of a self-assembly system has long been an essential factor that governs the resulting supramolecular structures. Nevertheless, due to the rigorous demands of structural compatibility in host-guest chemistry, the molar ratio of host-guest mixtures has not been applied as a significant factor in modulating the supramolecular structures of host-guest complexes. In this study,viausing a novel unimolecular quaternary clip (Q-clip) as the host molecule andpyreneas the guest molecule and a nanotemplating reagent, we discovered that the changes in the molar ratios of theQ-clip:pyrenemixtures resulted in the structural modulation of the host-guest complexes. Supramolecular lamellae made by the 1:4Q-clip:pyrenemixture and a hexagonal columnar phase (Col_h) made by the 1:8Q-clip:pyrenemixture were identified by the 1D powder and 2D fiber WAXS characterizations. Time-resolved synchrotron X-ray characterization and thermal analysis further showed that removing the easily sublimed guest molecules (pyrene)viathermal annealing simply hollowed out the supramolecular structures without damaging the supramolecular scaffolds made by theQ-clipsPyreneis thus a nanotemplating reagent that can be used to create the hollowed-out 2D lamellar and 1D cylindrical scaffolds ofQ-clips. The study thus gave a novel example of a host-guest mixture that is able to carry out composition-driven structural modulation and guest-induced nanotemplates. The finding broadens the horizon of host-guest chemistry and may inspire more nanoinnovation.