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Hu Y, Wang L, Kevlishvili I, Wang S, Chiou CY, Shieh P, Lin Y, Kulik HJ, Johnson JA, Craig SL. Self-Amplified HF Release and Polymer Deconstruction Cascades Triggered by Mechanical Force. J Am Chem Soc 2024; 146:10115-10123. [PMID: 38554100 DOI: 10.1021/jacs.4c01402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/01/2024]
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.
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Affiliation(s)
- Yixin Hu
- Department of Chemistry, Duke University, Durham, North Carolina 27705, United States
| | - Liqi Wang
- Department of Chemistry, Duke University, Durham, North Carolina 27705, United States
| | - Ilia Kevlishvili
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Shu Wang
- Department of Chemistry, Duke University, Durham, North Carolina 27705, United States
| | - Chun-Yu Chiou
- Department of Chemistry, Duke University, Durham, North Carolina 27705, United States
| | - Peyton Shieh
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Yangju Lin
- Department of Chemistry, Duke University, Durham, North Carolina 27705, United States
| | - Heather J Kulik
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Jeremiah A Johnson
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Stephen L Craig
- Department of Chemistry, Duke University, Durham, North Carolina 27705, United States
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Deng Z, Gillies ER. Emerging Trends in the Chemistry of End-to-End Depolymerization. JACS AU 2023; 3:2436-2450. [PMID: 37772181 PMCID: PMC10523501 DOI: 10.1021/jacsau.3c00345] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 08/09/2023] [Accepted: 08/16/2023] [Indexed: 09/30/2023]
Abstract
Over the past couple of decades, polymers that depolymerize end-to-end upon cleavage of their backbone or activation of a terminal functional group, sometimes referred to as "self-immolative" polymers, have been attracting increasing attention. They are of growing interest in the context of enhancing polymer degradability but also in polymer recycling as they allow monomers to be regenerated in a controlled manner under mild conditions. Furthermore, they are highly promising for applications as smart materials due to their ability to provide an amplified response to a specific signal, as a single sensing event is translated into the generation of many small molecules through a cascade of reactions. From a chemistry perspective, end-to-end depolymerization relies on the principles of self-immolative linkers and polymer ceiling temperature (Tc). In this article, we will introduce the key chemical concepts and foundations of the field and then provide our perspective on recent exciting developments. For example, over the past few years, new depolymerizable backbones, including polyacetals, polydisulfides, polyesters, polythioesters, and polyalkenamers, have been developed, while modern approaches to depolymerize conventional backbones such as polymethacrylates have also been introduced. Progress has also been made on the topological evolution of depolymerizable systems, including the introduction of fully depolymerizable block copolymers, hyperbranched polymers, and polymer networks. Furthermore, precision sequence-defined oligomers have been synthesized and studied for data storage and encryption. Finally, our perspectives on future opportunities and challenges in the field will be discussed.
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Affiliation(s)
- Zhengyu Deng
- Department
of Chemistry, The University of Western
Ontario, 1151 Richmond St., London, Ontario N6A 5B7, Canada
| | - Elizabeth R. Gillies
- Department
of Chemistry, The University of Western
Ontario, 1151 Richmond St., London, Ontario N6A 5B7, Canada
- Department
of Chemical and Biochemical Engineering, The University of Western Ontario, 1151 Richmond St., London, Ontario N6A 5B9, Canada
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Maschmeyer PG, Liang X, Hung A, Ahmadzai O, Kenny AL, Luong YC, Forder TN, Zeng H, Gillies ER, Roberts DA. Post-polymerization ‘click’ end-capping of polyglyoxylate self-immolative polymers. Polym Chem 2021. [DOI: 10.1039/d1py01169c] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Post-polymerization CuAAC reactions are used to ‘click’ stimuli-cleavable triazole end-caps onto self-immolative poly(ethyl glyoxylate).
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Affiliation(s)
- Peter G. Maschmeyer
- Key Centre for Polymers and Colloids, School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Xiaoli Liang
- Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research. The University of Western Ontario, 1151 Richmond St., London, Canada N6A 5B7
| | - Allison Hung
- Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research. The University of Western Ontario, 1151 Richmond St., London, Canada N6A 5B7
| | - Oksana Ahmadzai
- Key Centre for Polymers and Colloids, School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Annmaree L. Kenny
- Key Centre for Polymers and Colloids, School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Yuan C. Luong
- Key Centre for Polymers and Colloids, School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Timothy N. Forder
- Key Centre for Polymers and Colloids, School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Haoxiang Zeng
- Key Centre for Polymers and Colloids, School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - Elizabeth R. Gillies
- Department of Chemistry and the Centre for Advanced Materials and Biomaterials Research. The University of Western Ontario, 1151 Richmond St., London, Canada N6A 5B7
- Department of Chemical and Biochemical Engineering, The University of Western Ontario, 1151 Richmond St., London, Ontario, Canada N6A 5B9
| | - Derrick A. Roberts
- Key Centre for Polymers and Colloids, School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
- Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia
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