Self-Amplified HF Release and Polymer Deconstruction Cascades Triggered by Mechanical Force
Name
10504962.pdf
Description
Accepted version
Size
2.19 MB
Format
Adobe PDF
Checksum (MD5)
b68d865f58da485bc9ce38b99caebc68
Author(s)
Hu, Yixin
Wang, Liqi
Kevlishvili, Ilia
Wang, Shu
Chiou, Chun-Yu
Shieh, Peyton
Lin, Yangju
Kulik, Heather J
Johnson, Jeremiah A
Craig, Stephen L
Date Issued
March 30, 2024
Journal
Journal of the American Chemical Society
Publisher
American Chemical Society
Citation
Self-Amplified HF Release and Polymer Deconstruction Cascades Triggered by Mechanical Force. Yixin Hu, Liqi Wang, Ilia Kevlishvili, Shu Wang, Chun-Yu Chiou, Peyton Shieh, Yangju Lin, Heather J. Kulik, Jeremiah A. Johnson, and Stephen L. Craig. Journal of the American Chemical Society 2024 146 (14), 10115-10123
Version
Author's final manuscript
Abstract
Hydrogen fluoride (HF) is a versatile reagent for material transformation, with applications in self-immolative polymers, remodeled siloxanes, and degradable polymers. The responsive in situ generation of HF in materials therefore holds promise for new classes of adaptive material systems. Here, we report the mechanochemically coupled generation of HF from alkoxy-gem-difluorocyclopropane (gDFC) mechanophores derived from the addition of difluorocarbene to enol ethers. Production of HF involves an initial mechanochemically assisted rearrangement of gDFC mechanophore to α-fluoro allyl ether whose regiochemistry involves preferential migration of fluoride to the alkoxy-substituted carbon, and ab initio steered molecular dynamics simulations reproduce the observed selectivity and offer insights into the mechanism. When the alkoxy gDFC mechanophore is derived from poly(dihydrofuran), the α-fluoro allyl ether undergoes subsequent hydrolysis to generate 1 equiv of HF and cleave the polymer chain. The hydrolysis is accelerated via acid catalysis, leading to self-amplifying HF generation and concomitant polymer degradation. The mechanically generated HF can be used in combination with fluoride indicators to generate an optical response and to degrade polybutadiene with embedded HF-cleavable silyl ethers (11 mol %). The alkoxy-gDFC mechanophore thus provides a mechanically coupled mechanism of releasing HF for polymer remodeling pathways that complements previous thermally driven mechanisms.
MIT Department
Massachusetts Institute of Technology. Department of Chemical Engineering
Massachusetts Institute of Technology. Department of Chemistry
Terms of Use
Creative Commons Attribution-Noncommercial-ShareAlike
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1021/jacs.4c01402
