Helicity-driven chiral self-sorting supramolecular polymerization with Ag: right- and left-helical aggregates.

The study of chiral self-sorting is extremely important for understanding biological systems and for developing applications for the biomedical field. In this study, we attempted unprecedented chiral self-sorting supramolecular polymerization accompanying helical inversion with Ag in one enantiomeric component. Bola-type terpyridine-based ligands (-L and -L) comprising - or -alanine analogs were synthesized. First, -L dissolved in DMSO/HO (1 : 1, v/v) forms right-handed helical fibers (aggregate I) supramolecular polymerization. However, after the addition of AgNO (0.2-1.1 equiv.) to the -L ligand, in particular, it was found that aggregate II with left-handed helicity is generated from the [-L(AgNO)] complex through the [-LAg] complex the dissociation of aggregate I by a multistep with an off pathway, thus demonstrating interesting self-sorting properties driven by helicity and shape discrimination. In addition, the [-L(AgNO)] complex, which acted as a building block to generate aggregate III with a spherical structure, existed as a metastable product during the formation of aggregate II in the presence of 1.2-1.5 equiv. of AgNO. Furthermore, the AFM and CD results of two samples prepared using aggregates I and III with different volume ratios were similar to those obtained upon the addition of AgNO to free -L. These findings suggest that homochiral self-sorting in a mixture system occurred by the generation of aggregate II composed of the [-LAg] complex the rearrangement of both, aggregates I and III. This is a unique example of helicity- and shape-driven chiral self-sorting supramolecular polymerization induced by Ag starting from one enantiomeric component. This research will improve understanding of homochirality in complex biological models and contribute to the development of new chiral materials and catalysts for asymmetric synthesis.