Reversible helical polymerization of supramolecular toroidal objects

Reversible helical polymerization of toroids with rapid response to heating–cooling cycles and helicity control in the presence of a chiral regulator.

Light-triggered self-assembly of a cyanostilbene-conjugated glutamide from nanobelts to nanotoroids and inversion of circularly polarized luminescence

UV irradiation regulated transformation of chiral nanostructures and inversion of circularly polarized luminescence.

Formation of toroids by self-assembly of an α-α corner mimetic: supramolecular cyclization

An α-α corner mimetic self-assembles to form a rod-like supramolecular structure which bends and closes end-to-end like a cyclization reaction to form uniform toroids. Each peptide fragment containing l-leucine, α-aminoisobutyric acid (Aib) and l-tyrosine forms rigid 3₁₀ helical structures stabilized by multiple intramolecular N-HO hydrogen bonds. Two 3₁₀ helices are connected by the spacer 3-aminomethyl-benzylamine and maintain an angular distance of 120° and therefore mimic the α-α corner motif of a protein super secondary structure. The individual α-α corner subunits are themselves regularly interlinked through multiple water mediated intermolecular hydrogen-bonding interactions to form the rod-like supramolecular structure and toroids. The formation of the supramolecular structure has been proven with X-ray crystallography and other spectroscopic techniques. The cyclization of the supramolecular structure and toroid formation were studied by optical microscope, AFM and FE-SEM experiments. Despite other assignments such as exfoliation of graphene from graphite, the compound exhibits significant memory to finally produce the toroids.

Supramolecular Hydrogelators and Hydrogels: From Soft Matter to Molecular Biomaterials

In this review we intend to provide a relatively comprehensive summary of the work of supramolecular hydrogelators after 2004 and to put emphasis particularly on the applications of supramolecular hydrogels/hydrogelators as molecular biomaterials. After a brief introduction of methods for generating supramolecular hydrogels, we discuss supramolecular hydrogelators on the basis of their categories, such as small organic molecules, coordination complexes, peptides, nucleobases, and saccharides. Following molecular design, we focus on various potential applications of supramolecular hydrogels as molecular biomaterials, classified by their applications in cell cultures, tissue engineering, cell behavior, imaging, and unique applications of hydrogelators. Particularly, we discuss the applications of supramolecular hydrogelators after they form supramolecular assemblies but prior to reaching the critical gelation concentration because this subject is less explored but may hold equally great promise for helping address fundamental questions about the mechanisms or the consequences of the self-assembly of molecules, including low molecular weight ones. Finally, we provide a perspective on supramolecular hydrogelators. We hope that this review will serve as an updated introduction and reference for researchers who are interested in exploring supramolecular hydrogelators as molecular biomaterials for addressing the societal needs at various frontiers.

Assembly of twisted luminescent architectures based on acenaphtho[1,2-k]fluoranthene derivatives

Three DPAF derivatives DPAF-n (n = 8, 12, 16) with identical central aromatic cores and different lengths of flexible alkyl chains have been synthesized and employed as building blocks to fabricate luminescent twisted wires.