Work

Stimuli‐Responsive Supramolecular Polymers of Mono‐ and Bis‐triazolylphenylazoaniline‐Functionalized Copillar[5]Arenes: With Distinctive Binding Modes

Year: 2025

Type: article

Abstract: Mono‐ and bis‐triazolylphenylazoaniline‐functionalized copillar[5]arenes 1 and 2 were synthesized forming linear supramolecular polymers with dual pH and photo responsiveness. Upon acidification, copillar[5]arene 1 undergoes protonation, converting its aniline group into a primary ammonium ion ( 1‐H ), which significantly enhances its supramolecular polymerization compared to 1 . Designed as an AB‐type supramolecular polymer, 1‐H exhibits distinct polymerization behavior in contrast to neutral copillar[5]arene 2 , which forms a 1:1 supramolecular polymer with dimethoxypillar[5]arene ( DMP5 ). Copillar[5]arene 2 is believed to bind DMP5 through its cavity, linking two aniline groups from separate molecules to form a two component supramolecular polymer. The degree of polymerization of 1‐H and the 1:1 ratio of 2 and DMP5 can be controlled by adjusting the pH, as confirmed by pH‐ and concentration‐dependent 1 H‐NMR and diffusion‐ordered spectroscopy (DOSY) experiments. UV–vis spectroscopy and FE‐SEM were further used to examine the effects of photoirradiation on polymer morphology and absorption at varying concentrations.

Source: Chemistry - An Asian Journal

DOI: 10.1002/asia.202500601