Volume 42, Issue 6 pp. 611-616
Concise Report

Impact of Polymer Matrix on Polymer Mechanochromism from Excited State Intramolecular Proton Transfer

Yu Wu

Yu Wu

Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing State Key Laboratory of Organic-Inorganic Composites, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029 China

Search for more papers by this author
Xin Cheng

Xin Cheng

Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing State Key Laboratory of Organic-Inorganic Composites, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029 China

Search for more papers by this author
Huan Hu

Huan Hu

Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing State Key Laboratory of Organic-Inorganic Composites, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029 China

Search for more papers by this author
Shui Hu

Shui Hu

Center of Advanced Elastomer Materials, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029 China

Search for more papers by this author
Zhimin Ma

Zhimin Ma

College of Engineering, Peking University, Beijing, 100871 China

Search for more papers by this author
Zhiyong Ma

Corresponding Author

Zhiyong Ma

Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing State Key Laboratory of Organic-Inorganic Composites, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing, 100029 China

E-mail: [email protected]Search for more papers by this author
First published: 13 November 2023
Citations: 2

Dedicated to the Special Issue of Emerging Themes in Polymer Science.

Comprehensive Summary

Mechanochromic polymers based on non-covalent changes have attracted much attention recently. Herein, we report the impact of inter/intramolecular hydrogen bonds on polymer mechanochromism from the excited state intramolecular proton transfer (ESIPT) process. PhMz-NH2-OH and PhMz=2A are designed and obtained by simple and high-yield synthesis, and are connected into polyurethane and poly(methyl acrylate-co-2-ethylhexyl acrylate), respectively. In the initial state, the PhMz-NH2-OH@PU sample shows blue fluorescence from the excited enol form (E*) excitons, owing to intermolecular hydrogen bonds that interrupt the ESIPT reactions but the PhMz=2A@PMA-2-EA sample expresses cyan fluorescence belonging to the excited keto form (K*) emission, implying that the intramolecular hydrogen bonds matter. Furthermore, under stretching, external force can tune the emission of the PhMz=2A@PMA-2-EA sample from K* to E* state. Though external force can putatively still promote a bond rotation, ESIPT reactions remain equivalently interrupted in both the relaxed and stressed states in a hydrogen-bond donating environment. DFT calculation confirms the force-induced increase in dihedral angle for the transition of ESIPT-on/off. Thus, PhMz-NH2-OH@PU and PhMz=2A@PMA-2-EA showed disparate initial ESIPT states and further different responses/sensitivity to force. This study reports a novel and efficient strategy for enriching mechanochromic investigation and extending the applications of ESIPT reactions.image

The full text of this article hosted at iucr.org is unavailable due to technical difficulties.