Supramolecular Helical Columns from the Self‐Assembly of Chiral Rods

Abstract

Chiral-bridged rod molecules (CBRs) that consisted of bis(penta-p-phenylene) conjugated to an opened or closed chiral bridging group as a rigid segment and oligoether dendrons as flexible segments were synthesized and characterized. In the bulk state, both molecules self-assemble into a hexagonal columnar structure, as confirmed by X-ray scatterings and transmission electron microscopy (TEM) observations. Interestingly, these structures display opposite Cotton effects in the chromophore of the aromatic unit in spite of the same chirality (R,R) of the chiral bridging groups. The molecules were observed to self-assemble into cylindrical micellar aggregates in aqueous solution, as confirmed by light scattering and TEM investigations, and exhibit intense signals in the circular dichroism (CD) spectra, which are indicative of one-handed helical conformations. The CD spectra of each molecule showed opposite signals to each other, which were similar to those in the bulk. Notably, when the opened CBR was added to a solution of closed CBRs up to a certain concentration, the CD signal of the closed CBR was amplified. This implies that both molecules co-assemble into a one-handed helical structure because the opened chiral bridge is conformationally flexible, which is inverted to co-assemble with the closed CBR. These results demonstrate that small structural modifications of the chiral moiety can transfer the chiral information to a supramolecular assembly in the opposite way.

Chiral V‐shaped Pyrenes: Hexagonal Packing, Superhelix, and Amplified Chiroptical Performance

“…It is worthy to note that the peak of 1/√3 was extraordinary strong, which evidenced that the primary fibres in the hexagonal packing cell of the superhelix were also hexagonal. Such chiral hexagonal superhelix is unprecedented, in which the chiral V‐shaped molecular conformation would guide six molecules helically packed in a hexagonal manner with perfect shape match [15a, 20] . Consequently, the intermolecular π‐π stacking became predominant.…”

Poly(aryl ether) Dendrons with Monopyrrolotetrathiafulvalene Unit‐Based Organogels exhibiting Gel‐Induced Enhanced Emission (GIEE)

“…On the basis on these results, we assumedt hat the molecule might favor packing in ap arallel fashion to maximize p-stacking, hydrogen-bonding, and S···Si nteractions. [36] The packing model of the rectangularc olumnar phase is shown in Figure 6. Chem.…”

Design and Construction of a Brain-Like Computer: A New Class of Frequency-Fractal Computing Using Wireless Communication in a Supramolecular Organic, Inorganic System

“…Once we synthesize the basic neuron structure, we need different versions of synthetic neurons. Modified versions of neuron are used only for self-assembling them in the form of a wire, spiral, glia like spherical, or semicircular assemblies [91]. These basic assemblies are essential for the mid brain structures.…”