Trismaleimide Dendrimers: Helix‐to‐Superhelix Supramolecular Transition Accompanied by White‐Light Emission

Abstract

Reported here are unprecedented fluorescent superhelices composed of primary, supramolecular polymers of the opposite helical twist. A new class of functional dendrimers was synthesized by amino‐ene click reactions, and they demonstrate an alternating OFF/ON fluorescence with generation growth. A peripherally alkyl‐modified dendrimer displays helix‐sense‐selective supramolecular polymerization, which predominantly forms right‐handed (or left‐handed) helical supramolecular polymers in the solution containing chiral solvents. With increasing the concentration, these primary helical supramolecular polymers spontaneously twist around themselves in the opposite direction to form superhelical structures. Atomic force microscopy and circular dichroism measurements were used to directly observe the helix‐to‐superhelix transition occurring with a reversal in the helical direction. Exceptional white‐light emission was observed during superhelix formation.

Active Regulation of Supramolecular Chirality through Integration of CdSe/CdS Nanorods for Strong and Tunable Circular Polarized Luminescence

“…Although it is well-known that chirality inversion takes place during the switching from helix to superhelix in the 1D supramolecular assembly, 42,43 to the best of our knowledge, the above result is the first instance of how the chirality inversion correlates to the helix-to-superhelix transition in a twodimensional (2D) supramolecular chiral assembly. This connection between folding−unfolding of the supramolecular nanosheet and chirality inversion could well explain how the interaction between the (R)-1 assemblies and NRs could efficiently inhibit the scrolling process during the shrinkage of the emulsion droplets.…”

Frank–Kasper phases in charge transfer complexes enable tunable photoelectronic properties

“…36 At 102 1C, a trident branch texture was observed, which eventually transformed into a dark field at 120 1C. 37,38 Fig. 3a shows the 1D WAXD of CTC TPE-TNF on heating.…”

Pathway complexity in fibre assembly: from liquid crystals to hyper-helical gelmorphs

“…2b). The bent molecular shape is facilitated by an intramolecular hydrogen bond forming a 9-membered ring, S (9). The structure also forms unusual R 2 2 (14) and R 2 2 (18) motifs.…”

“…7 Similarly, cooperative interactions between oligoalanine and non-chiral surfactants give rise to helical ribbons and tubules in the presence of antiparallel b sheets, while twisted ribbons result from parallel b-sheets or random coils. 8 Triggered or templated transitions to helical or superhelical structures are also currently topical, [9][10][11][12][13] and helical or superhelical structures can arise in inorganic materials and nanoparticle aggregates. 14,15 In the context of supramolecular gels, helicity and chiral induction play a signicant role in the nal materials properties.…”