Access to 2,4‐Disubstituted Pyrrole‐Based Polymer with Long‐Wavelength and Stimuli‐Responsive Properties via Copper‐Catalyzed [3+2] Polycycloaddition

Abstract

Pyrrole‐based polymers (PBPs), a type of fascinating functional polymers, play a crucial role in materials science. However, efficient synthetic strategies of pyrrole‐based polymers with diverse structures are mainly focus on conjugated polypyrroles and still remain challenging. Herein, we describe an atom and step economy protocol to access various 2,4‐disubstituted PBPs by in situ formation of pyrrole core structure via copper‐catalyzed [3+2] polycycloaddition of dialkynones and diisocyanoacetates. A series of PBPs is prepared with high molecular weight (Mw up to 18200 Da) and moderate to good yield (up to 87%), which possessed a fluorescent emission located in the green to yellow light region. Blending the PBPs with polyvinyl alcohol (PVA), the stretchable composite films exhibit a significant strengthening of the mechanical properties (tensile stress up to 59 MPa, elongation at break > 400%) and an unprecedented stress‐responsive luminescence enhancement that over fourfold fluorescent emission intensity is maintained upon stretching up to 100%. On the basis of computational studies, the unique photophysical and mechanical properties are attributed to the substitution of carbonyl chromophores on the pyrrole unit.This article is protected by copyright. All rights reserved