Poly[2]catenane Gels Based on Sequential Assembly of Small Molecules

Abstract

Polycatenane gels have attracted extensive attention due to their high degree of freedom and mobility. However, the syntheses of poly[2]catenane gels reported to date all rely on the polymer as the backbone. Herein, we prepared poly[2]catenane gels based on entirely sequential assembly of small molecules. Monomer M1 with two unclosed rings was first prepared, which self-assembled to form supramolecular polymers (SPs) via hydrogen bonding and π-π interactions. Upon adding small molecule monomers M2 and M3 with aldehyde groups, ring closing of SPs occurred because the amino groups in the SPs reacted with M2 to form imine bonds. In addition, M3, which had twice the number of aldehyde groups as M2, enabled SPs to ring-close, causing the proceeding of crosslinking process at the same time. Thus linear SPs were transformed into poly[2]catenane gel networks. Due to the presence of hydrogen bonds in the poly[2]catenane gel, the gel also possessed stimulus responsiveness and self-healing properties.

Keywords

Poly[2]catenane / Gel / Dynamic covalent bond / Non-covalent bond / Self-assembly / Stimuli-responsiveness / Supramolecular chemistry / Networks / Hydrogen bonding

RIGHTS & PERMISSIONS

2024 SIOC, CAS, Shanghai, & WILEY-VCH GmbH