Static and Dynamic Nanosheets from Selective Assembly of Geometric Macrocycle Isomers

Abstract

In contrast to the significant advances that have been made in the construction of two-dimensional (2D) nanostructures, the rational modification from static to dynamic 2D sheets remains a great challenge. Static and dynamic sheets formed from selective self-assembly of geometric macrocycle isomers based on anthracene units are presented. The selfassembly of the cis isomer generates static planar sheets, whereas the trans isomer forms dynamic rolled sheets which are reversibly unrolled upon stimulation by a thermal signal. Furthermore, the mixed solution of the two isomers exhibits self-sorting behavior, generating the coexistence of the two independent self-assembled structures, the planar sheets and the folded scrolls. The self-sorted supramolecular objects with considerable shape and size differences are able to be readily separated, one isomer from the other.

Morphological Control of Coil–Rod–Coil Molecules Containing m-Terphenyl Group: Construction of Helical Fibers and Helical Nanorings in Aqueous Solution

“…Supramolecular architectures constructed by the self-assembly of organic molecular building blocks are of great interest owing to their electro-optical properties and potential applications for new discoveries in materials science. − Self-assembly of π-conjugated units holds high utility in the development of supramolecular structures with novel dimensionalities and morphologies. , The highly ordered π-conjugated units are crucial for further applications in areas such as molecular electronics, biomimetic chemistry, and drug delivery systems. − Rod–coil systems are proven to be one of the most promising candidates due to their considerable ability to spontaneously self-organize for the fabrication of various supramolecular nanostructures. − Lee and other research groups systematically investigated a variety of rod–coil molecules, including H-shaped, k-shaped, dumbbell-shaped, and macrocycle rod–coil molecules. − These molecules self-assembled into various well-defined nanoassemblies, including lamellar, columnar, and three-dimensional tetragonal and hexagonal structures in the bulk state, depending on the molecular shape, length of the coil or rod segments, external stimuli, and temperature of the system. Rod–coil molecules with poly­(ethylene oxide) (PEO) chains exhibit good solubility and biocompatibility in aqueous solution and facilitate the formation of various supramolecular aggregates with well-defined shapes and sizes, such as micelles, ribbons, planar networks, vesicles, helices, and tubules.…”