Chiral Assemblies from an Achiral Pyridinium‐Tailored Anthracene

Abstract

Chiral helical structures have attracted increasing attention in the field of supramolecular assembly because of their critical roles in life and material sciences. In this research, the achiral amphiphile 1-[11-(2-anthracenylmethoxy)-11-oxoundecyl]pyridinium bromide (2-APB), in which the hydrophobic anthracene and the hydrophilic pyridinium units are linked by alkyl chains, was found to form chiral supramolecular assemblies in a cooperative manner in the presence of iodide anion. Moreover, these assemblies show left (L)- or right (R)-handedness randomly, independent of the assembly conditions. By using the same method, 2-APB could assemble together with other pseudo-halogen anions (OCN , SCN , SeCN ) that have similar anionic radius as iodide to form chiral structures. This work illustrates a simple and rational design that can be used to fabricate supramolecular chiral structures from achiral molecules.

Evaluation of a Peptide-Based Coassembled Nanofibrous and Thixotropic Hydrogel for Dermal Wound Healing

“…8,26,29,31 The circular dichroism spectra of hydrogel 1 show positive cotton at 340−390 nm owing to the π−π* transition of the anthracene ring (Figure 3c). 8,68 However, the circular dichroism spectra of hydrogel 4 show a very weak negative cotton effect at 350−385 nm, which suggest different orientations of noncovalent interactions between peptide 1 and CD (Figure 3d). 8,68 Additionally, the prominent π−π* transitions due to the aromatic moieties are observed between 230 and 270 nm for hydrogels 1 and 4 (Figure 3c,d).…”

Сhiral and Racemic Fields Concept for Understanding of the Homochirality Origin, Asymmetric Catalysis, Chiral Superstructure Formation from Achiral Molecules, and B-Z DNA Conformational Transition

“…Another strange feature of crystallization of achiral molecules in the LC phase was found during crystallization of pyridinum-tailored antracene 44 [181] in the presence of iodine and other Similar effects were observed in the ongoing formation of other chiral superstructures from achiral molecules [57,[177][178][179][180]. The dependence of chiral nanostructures from various mesophase temperatures of LC (maximal order) suggests that this regularity is of general nature.…”

“…Another strange feature of crystallization of achiral molecules in the LC phase was found during crystallization of pyridinum-tailored antracene 44 [181] in the presence of iodine and other pseudo-halogen anions with a similar anionic radius. Another strange feature of crystallization of achiral molecules in the LC phase was found during crystallization of pyridinum-tailored antracene 44 [181] in the presence of iodine and other pseudo-halogen anions with a similar anionic radius.…”

“…Another strange feature of crystallization of achiral molecules in the LC phase was found during crystallization of pyridinum-tailored antracene 44 [181] in the presence of iodine and other pseudo-halogen anions with a similar anionic radius.…”

Chiroptical properties of dithia[3.3]cyclophanes composed of anthracene and pyridine/pyridinium moieties: A combined experimental and theoretical study

“…Naturally, a strong DA interaction, which is electrostatic in nature, is expected to occur between the anthracene and pyridinium moieties in 1‐H + . Recently, supramolecular helical assemblies were constructed by utilizing anthracene‐pyridinium conjugates . Consequently, we examined the strength of DA (or cation‐π) interaction between anthracene and pyridinium units fixed in a rigid cyclophane framework, and the influence of the DA interaction on the (chir)optical properties of 1‐H + was quantitatively investigated and the results were compared with those for relevant protonated [3.3]‐ and [2.2]pyridinophanes ( 2‐H + and 3‐H + ).…”