Dynamic Dance of Chirality and Morphology: Interplay of Solvent-Sensitive Self-Assembly in Topological Evolution and Chirality Amplification

ACS Appl Mater Interfaces. 2024 Nov 13;16(45):62988-62998. doi: 10.1021/acsami.4c13524. Epub 2024 Oct 31.

Abstract

The building block Pyra-Chol has been designed and synthesized, which exhibits different achiral morphologies in good solvents, forming nanospheres in THF and nanoflowers in 1,4-dioxane. In the presence of water as a poor cosolvent, Pyra-Chol demonstrates an agnostic behavior, generating left-handed superhelices in the water:THF (80:20) solvent system. However, when the good solvent is switched to 1,4-dioxane, a change in chirality is observed in the water:1,4-dioxane (30:70) solvent system, resulting in the formation of fused nanospheres. Interestingly, when the poor cosolvent is changed from water to MCH in THF, the chiral pattern remains unchanged, but the morphology changes completely. Supported by the collective spectroscopic and microscopic analysis, the present study efficaciously demonstrates the remarkable control of hydrophobic building block over the chiral sense and also highlights the fascinating influence of good as well as poor cosolvent in supporting the distinct molecular packing.

Keywords: hydrophobic effect; noncovalent interaction; self-assembly; superhelix; supramolecular chirality.