Pulsating Tubules from Noncovalent Macrocycles

Abstract

Despite recent advances in synthetic nanometer-scale tubular assembly, conferral of dynamic response characteristics to the tubules remains a challenge. Here, we report on supramolecular nanotubules that undergo a reversible contraction-expansion motion accompanied by an inversion of helical chirality. Bent-shaped aromatic amphiphiles self-assemble into hexameric macrocycles in aqueous solution, forming chiral tubules by spontaneous one-dimensional stacking with a mutual rotation in the same direction. The adjacent aromatic segments within the hexameric macrocycles reversibly slide along one another in response to external triggers, resulting in pulsating motions of the tubules accompanied by a chiral inversion. The aromatic interior of the self-assembled tubules encapsulates hydrophobic guests such as carbon-60 (C(60)). Using a thermal trigger, we could regulate the C(60)-C(60) interactions through the pulsating motion of the tubules.

Nanorings and rods interconnected by self-assembly mimicking an artificial network of neurons

“…This type of geometric arrangement in similar wedge-like aromatic subunits has previously demonstrated to have high effectiveness in stabilizing toroidal and nanotubular assemblies. 17 Interestingly, full rings simulated from bent multichain assemblies (rim thickness of several layers of molecules) did not change their arrangement once the ring structure was formed because their total kinetic and potential energies already fluctuated around equilibrium values ( Supplementary Fig. S16).…”

“…The tailored formation of self-assembled supramolecular nanotubules based on stacked, oligomeric toroids making use of a wedge-like geometry of a polyaromatic molecular synthon aggregated through p-interactions has been reported 17 . Similarly, interconnected pairs of rings (although not in a network fashion) have been constructed using the complementarities of nucleic acid bases in DNA strand-based rotaxanes, taking advantage of the axle rotational flexibility of the chain 18 .…”

Uniform patchy and hollow rectangular platelet micelles from crystallizable polymer blends

“…Although self-assembled hollow structures such as nanotubes (23), toroids (24), dynamic tubules (25), and nanocapsules (26) are of intense interest, well-defined and monodisperse rectangular 2D structures are unknown. Based on the triblock platelet comicelle structure we envisaged that crosslinking of the P2VP coronas followed by the addition of a good solvent for the PFS core and coronas should lead to disassembly to generate a perforated architecture.…”

A dynamic supramolecular polymer with stimuli-responsive handedness for in situ probing of enzymatic ATP hydrolysis

“…Typical designs of helical assemblies consist of optically active monomers, which bias the handedness during the (supramolecular) polymerization process [8][9][10][11][12][13][14][15][16][17][18][19] . In this respect, helicity induction in racemic or achiral assemblies constructed from achiral monomers through non-covalent interactions with the chiral guest molecules is an alternative, synthetic strategy [20][21][22][23][24][25][26] .…”