1
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O'Neill RT, Boulatov R. Mechanochemical Approaches to Fundamental Studies in Soft-Matter Physics. Angew Chem Int Ed Engl 2024; 63:e202402442. [PMID: 38404161 DOI: 10.1002/anie.202402442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 02/24/2024] [Accepted: 02/25/2024] [Indexed: 02/27/2024]
Abstract
Stretching a segment of a polymer beyond its contour length makes its (primarily backbone) bonds more dissociatively labile, which enables polymer mechanochemistry. Integrating some backbone bonds into suitably designed molecular moieties yields mechanistically and kinetically diverse chemistry, which is becoming increasingly exploitable. Examples include, most prominently, attempts to improve mechanical properties of bulk polymers, as well as prospective applications in drug delivery and synthesis. This review aims to highlight an emerging effort to apply the concepts and experimental tools of mechanochemistry to fundamental physical questions in soft matter. A succinct summary of the state-of-the-knowledge of the field, with emphasis on foundational concepts and generalizable observations, is followed by analysis of 3 recent examples of mechanochemistry yielding molecular-level details of elastomer failure, macromolecular chain dynamics in elongational flows and kinetic allostery. We conclude with reasons to assume that the highlighted approaches are generalizable to a broader range of physical problems than considered to date.
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Affiliation(s)
- Robert T O'Neill
- Department of Chemistry, University of Liverpool, University of Liverpool, Department of Chemistry, Grove Street, Liverpool, L69 7ZD
| | - Roman Boulatov
- Department of Chemistry, University of Liverpool, University of Liverpool, Department of Chemistry, Grove Street, Liverpool, L69 7ZD
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2
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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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3
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Lin Y, Kouznetsova TB, Foret AG, Craig SL. Solvent Polarity Effects on the Mechanochemistry of Spiropyran Ring Opening. J Am Chem Soc 2024; 146:3920-3925. [PMID: 38308653 DOI: 10.1021/jacs.3c11621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2024]
Abstract
The spiropyran mechanophore (SP) is employed as a reporter of molecular tension in a wide range of polymer matrices, but the influence of surrounding environment on the force-coupled kinetics of its ring opening has not been quantified. Here, we report single-molecule force spectroscopy studies of SP ring opening in five solvents that span normalized Reichardt solvent polarity factors (ETN) of 0.1-0.59. Individual multimechanophore polymers were activated under increasing tension at constant 300 nm s-1 displacement in an atomic force microscope. The extension results in a plateau in the force-extension curve, whose midpoint occurs at a transition force f* that corresponds to the force required to increase the rate constant of SP activation to approximately 30 s-1. More polar solvents lead to mechanochemical reactions that are easier to trigger; f* decreases across the series of solvents, from a high of 415 ± 13 pN in toluene to a low of 234 ± 9 pN in n-butanol. The trend in mechanochemical reactivity is consistent with the developing zwitterionic character on going from SP to the ring-opened merocyanine product. The force dependence of the rate constant (Δx‡) was calculated for all solvent cases and found to increase with ETN, which is interpreted to reflect a shift in the transition state to a later and more productlike position. The inferred shift in the transition state position is consistent with a double-well (two-step) reaction potential energy surface, in which the second step is rate determining, and the intermediate is more polar than the product.
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Affiliation(s)
- Yangju Lin
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Tatiana B Kouznetsova
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Alex G Foret
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Stephen L Craig
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
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4
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Horst M, Meisner J, Yang J, Kouznetsova TB, Craig SL, Martínez TJ, Xia Y. Mechanochemistry of Pterodactylane. J Am Chem Soc 2024; 146:884-891. [PMID: 38131266 DOI: 10.1021/jacs.3c11293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
Pterodactylane is a [4]-ladderane with substituents on the central rung. Comparing the mechanochemistry of the [4]-ladderane structure when pulled from the central rung versus the end rung revealed a striking difference in the threshold force of mechanoactivation: the threshold force is dramatically lowered from 1.9 nN when pulled on the end rung to 0.7 nN when pulled on the central rung. We investigated the bicyclic products formed from the mechanochemical activation of pterodactylane experimentally and computationally, which are distinct from the mechanochemical products of ladderanes being activated from the end rung. We compared the products of pterodactylane's mechanochemical and thermal activation to reveal differences and similarities in the mechanochemical and thermal pathways of pterodactylane transformation. Interestingly, we also discovered the presence of elementary steps that are accelerated or suppressed by force within the same mechanochemical reaction of pterodactylane, suggesting rich mechanochemical manifolds of multicyclic structures. We rationalized the greatly enhanced mechanochemical reactivity of the central rung of pterodactylane and discovered force-free ground state bond length to be a good low-cost predictor of the threshold force for cyclobutane-based mechanophores. These findings advance our understanding of mechanochemical reactivities and pathways, and they will guide future designs of mechanophores with low threshold forces to facilitate their applications in force-responsive materials.
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Affiliation(s)
- Matías Horst
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Jan Meisner
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
- Institute for Physical Chemistry, Department of Chemistry, Heinrich-Heine-Universität Düsseldorf, Düsseldorf D-40225, Germany
| | - Jinghui Yang
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Tatiana B Kouznetsova
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Stephen L Craig
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Todd J Martínez
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Yan Xia
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
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5
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Alonso M, Bettens T, Eeckhoudt J, Geerlings P, De Proft F. Wandering through quantum-mechanochemistry: from concepts to reactivity and switches. Phys Chem Chem Phys 2023; 26:21-35. [PMID: 38086672 DOI: 10.1039/d3cp04907h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
Mechanochemistry has experienced a renaissance in recent years witnessing, at the molecular level, a remarkable interplay between theory and experiment. Molecular mechanochemistry has welcomed a broad spectrum of quantum-chemical methods to evaluate the influence of an external mechanical force on molecular properties. In this contribution, an overview is given on recent work on quantum mechanochemistry in the Brussels Quantum Chemistry group (ALGC). The effect of an external force was scrutinized both in fundamental topics, like reactivity descriptors in Conceptual DFT, and in applied topics, such as designing molecular force probes and tuning the stereoselectivity of certain types of reactions. In the conceptual part, a brief overview of the techniques introducing mechanical forces into a quantum-mechanical description of a molecule is followed by an introduction to conceptual DFT. The evolution of the electronic chemical potential (or electronegativity), chemical hardness and electrophilicity are investigated when a chemical bond in a series of diatomics is put under mechanical stress. Its counterpart, the influence of mechanical stress on bond angles, is analyzed by varying the strain present in alkyne triple bonds by applying a bending force, taking the strain promoted alkyne-azide coupling cycloaddition as an example. The increase of reactivity of the alkyne upon bending is probed by Fukui functions and the local softness. In the applied part, a new molecular force probe is presented based on an intramolecular 6π-electrocyclization in constrained polyenes operating under thermal conditions. A cyclic process is conceived where ring opening and closure are triggered by applying or removing an external pulling force. The efficiency of mechanical activation strongly depends on the magnitude of the applied force and the distance between the pulling points. The idea of pulling point distances as a tool to identify new mechanochemical processes is then tested in [28]hexaphyrins with an intricate equilibrium between Möbius aromatic and Hückel antiaromatic topologies. A mechanical force is shown to trigger the interconversion between the two topologies, using the distance matrix as a guide to select appropriate pulling points. In a final application, the Felkin-Anh model for the addition of nucleophiles to chiral carbonyls under the presence of an external mechanical force is scrutinized. By applying a force for restricting the conformational freedom of the chiral ketone, otherwise inaccessible reaction pathways are promoted on the force-modified potential energy surfaces resulting in a diastereoselectivity different from the force-free reaction.
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Affiliation(s)
- Mercedes Alonso
- Eenheid Algemene Chemie (ALGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium.
| | - Tom Bettens
- Eenheid Algemene Chemie (ALGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium.
| | - Jochen Eeckhoudt
- Eenheid Algemene Chemie (ALGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium.
| | - Paul Geerlings
- Eenheid Algemene Chemie (ALGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium.
| | - Frank De Proft
- Eenheid Algemene Chemie (ALGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium.
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6
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Suga K, Yamakado T, Saito S. Dual Ratiometric Fluorescence Monitoring of Mechanical Polymer Chain Stretching and Subsequent Strain-Induced Crystallization. J Am Chem Soc 2023. [PMID: 38051032 DOI: 10.1021/jacs.3c09175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
Tracking the behavior of mechanochromic molecules provides valuable insights into force transmission and associated microstructural changes in soft materials under load. Herein, we report a dual ratiometric fluorescence (FL) analysis for monitoring both mechanical polymer chain stretching and strain-induced crystallization (SIC) of polymers. SIC has recently attracted renewed attention as an effective mechanism for improving the mechanical properties of polymers. A polyurethane (PU) film incorporating a trace of a dual-emissive flapping force probe (N-FLAP, 0.008 wt %) exhibited a blue-to-green FL spectral change in a low-stress region (<20 MPa), resulting from conformational planarization of the probe in mechanically stretched polymer chains. More importantly, at higher probe concentrations (∼0.65 wt %), the PU film showed a second spectral change from green to yellow during the SIC growth (20-65 MPa) due to self-absorption of scattered FL in a short wavelength region. The reversibility of these spectral changes was demonstrated by load-unload cycles. With these results in hand, the degrees of the polymer chain stretching and the SIC were quantitatively mapped and monitored by dual ratiometric imaging based on different FL ratios (I525/I470 and I525/I600). Simultaneous analysis of these two mappings revealed a spatiotemporal gap in the distribution of the polymer chain stretching and the SIC. The combinational use of the dual-emissive force probe and the ratiometric FL imaging is a universal approach for the development of soft matter physics.
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Affiliation(s)
- Kensuke Suga
- Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Takuya Yamakado
- Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Shohei Saito
- Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
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7
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Buche MR, Rimsza JM. Modeling single-molecule stretching experiments using statistical thermodynamics. Phys Rev E 2023; 108:064503. [PMID: 38243517 DOI: 10.1103/physreve.108.064503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 11/30/2023] [Indexed: 01/21/2024]
Abstract
Single-molecule stretching experiments are widely utilized within the fields of physics and chemistry to characterize the mechanics of individual bonds or molecules, as well as chemical reactions. Analytic relations describing these experiments are valuable, and these relations can be obtained through the statistical thermodynamics of idealized model systems representing the experiments. Since the specific thermodynamic ensembles manifested by the experiments affect the outcome, primarily for small molecules, the stretching device must be included in the idealized model system. Though the model for the stretched molecule might be exactly solvable, including the device in the model often prevents analytic solutions. In the limit of large or small device stiffness, the isometric or isotensional ensembles can provide effective approximations, but the device effects are missing. Here a dual set of asymptotically correct statistical thermodynamic theories are applied to develop accurate approximations for the full model system that includes both the molecule and the device. The asymptotic theories are first demonstrated to be accurate using the freely jointed chain model and then using molecular dynamics calculations of a single polyethylene chain.
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Affiliation(s)
- Michael R Buche
- Computational Solid Mechanics and Structural Dynamics, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - Jessica M Rimsza
- Geochemistry, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
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8
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Clerc M, Sandlass S, Rifaie-Graham O, Peterson JA, Bruns N, Read de Alaniz J, Boesel LF. Visible light-responsive materials: the (photo)chemistry and applications of donor-acceptor Stenhouse adducts in polymer science. Chem Soc Rev 2023; 52:8245-8294. [PMID: 37905554 PMCID: PMC10680135 DOI: 10.1039/d3cs00508a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Indexed: 11/02/2023]
Abstract
Donor-acceptor Stenhouse adduct (DASA) photoswitches have gained a lot of attention since their discovery in 2014. Their negative photochromism, visible light absorbance, synthetic tunability, and the large property changes between their photoisomers make them attractive candidates over other commonly used photoswitches for use in materials with responsive or adaptive properties. The development of such materials and their translation into advanced technologies continues to widely impact forefront materials research, and DASAs have thus attracted considerable interest in the field of visible-light responsive molecular switches and dynamic materials. Despite this interest, there have been challenges in understanding their complex behavior in the context of both small molecule studies and materials. Moreover, incorporation of DASAs into polymers can be challenging due to their incompatibility with the conditions for most common polymerization techniques. In this review, therefore, we examine and critically discuss the recent developments and challenges in the field of DASA-containing polymers, aiming at providing a better understanding of the interplay between the properties of both constituents (matrix and photoswitch). The first part summarizes current understanding of DASA design and switching properties. The second section discusses strategies of incorporation of DASAs into polymers, properties of DASA-containing materials, and methods for studying switching of DASAs in materials. We also discuss emerging applications for DASA photoswitches in polymeric materials, ranging from light-responsive drug delivery systems, to photothermal actuators, sensors and photoswitchable surfaces. Last, we summarize the current challenges in the field and venture on the steps required to explore novel systems and expand both the functional properties and the application opportunities of DASA-containing polymers.
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Affiliation(s)
- Michèle Clerc
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biomimetic Membranes and Textiles, 9014 St. Gallen, Switzerland.
- University of Fribourg, Department of Chemistry, 1700 Fribourg, Switzerland
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, UK
- Swiss National Center of Competence in Research Bio-Inspired Materials, Switzerland
| | - Sara Sandlass
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA
| | - Omar Rifaie-Graham
- Department of Chemistry, School of Physical and Chemical Sciences, Queen Mary University of London, London E1 4NS, UK
| | - Julie A Peterson
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, USA.
| | - Nico Bruns
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, UK
- Swiss National Center of Competence in Research Bio-Inspired Materials, Switzerland
- Department of Chemistry, Technical University of Darmstadt, 64287 Darmstadt, Germany.
| | - Javier Read de Alaniz
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, USA.
| | - Luciano F Boesel
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Biomimetic Membranes and Textiles, 9014 St. Gallen, Switzerland.
- Swiss National Center of Competence in Research Bio-Inspired Materials, Switzerland
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9
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Ritter VC, McDonald SM, Dobrynin AV, Craig SL, Becker ML. Mechanochromism and Strain-Induced Crystallization in Thiol-yne-Derived Stereoelastomers. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2302163. [PMID: 37399511 DOI: 10.1002/adma.202302163] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 06/19/2023] [Accepted: 06/30/2023] [Indexed: 07/05/2023]
Abstract
Most elastomers undergo strain-induced crystallization (SIC) under tension; as individual chains are held rigidly in a fixed position by an applied strain, their alignment along the strain field results in a shift from strain-hardening (SH) to SIC. A similar degree of stretching is associated with the tension necessary to accelerate mechanically coupled, covalent chemical responses of mechanophores in overstretched chains, raising the possibility of an interplay between the macroscopic response of SIC and the molecular response of mechanophore activation. Here, thiol-yne-derived stereoelastomers doped covalently with a dipropiolate-derivatized spiropyran (SP) mechanophore (0.25-0.38 mol%) are reported. The material properties of SP-containing films are consistent with undoped controls, indicating that the SP is a reporter of the mechanical state of the polymer. Uniaxial tensile tests reveal correlations between mechanochromism and SIC, which are strain-rate-dependent. When mechanochromic films are stretched slowly to the point of mechanophore activation, the covalently tethered mechanophore remains trapped in a force-activated state, even after the applied stress is removed. Mechanophore reversion kinetics correlate with the applied strain rate, resulting in highly tunable decoloration rates. Because these polymers are not covalently crosslinked, they are recyclable by melt-pressing into new films, increasing their potential range of strain-sensing, morphology-sensing, and shape-memory applications.
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Affiliation(s)
| | | | - Andrey V Dobrynin
- Department of Chemistry, University of North Carolina, Chapel Hill, NC, 27514, USA
| | - Stephen L Craig
- Department of Chemistry, Duke University, Durham, NC, 27708, USA
| | - Matthew L Becker
- Department of Chemistry, Duke University, Durham, NC, 27708, USA
- Thomas Lord Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC, 27708, USA
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10
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Ditzler RAJ, King AJ, Towell SE, Ratushnyy M, Zhukhovitskiy AV. Editing of polymer backbones. Nat Rev Chem 2023; 7:600-615. [PMID: 37542179 DOI: 10.1038/s41570-023-00514-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/12/2023] [Indexed: 08/06/2023]
Abstract
Polymers are at the epicentre of modern technological progress and the associated environmental pollution. Considerations of both polymer functionality and lifecycle are crucial in these contexts, and the polymer backbone - the core of a polymer - is at the root of these considerations. Just as the meaning of a sentence can be altered by editing its words, the function and sustainability of a polymer can also be transformed via the chemical modification of its backbone. Yet, polymer modification has primarily been focused on the polymer periphery. In this Review, we focus on the transformations of the polymer backbone by defining some concepts fundamental to this topic (for example, 'polymer backbone' and 'backbone editing') and by collecting and categorizing examples of backbone editing scattered throughout a century's worth of chemical literature, and outline critical directions for further research. In so doing, we lay the foundation for the field of polymer backbone editing and hope to accelerate its development.
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Affiliation(s)
- Rachael A J Ditzler
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Andrew J King
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Sydney E Towell
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Maxim Ratushnyy
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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11
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Zhang S, Xue Y, Wu Y, Zhang YX, Tan T, Niu Z. PET recycling under mild conditions via substituent-modulated intramolecular hydrolysis. Chem Sci 2023; 14:6558-6563. [PMID: 37350822 PMCID: PMC10283487 DOI: 10.1039/d3sc01161e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 05/24/2023] [Indexed: 06/24/2023] Open
Abstract
Catalytic depolymerization represents a promising approach for the closed-loop recycling of plastic wastes. Here, we report a knowledge-driven catalyst development for poly(ethylene terephthalate) (PET) recycling, which not only achieves more than 23-fold enhancement in specific activity but also reduces the alkali concentration by an order of magnitude compared with the conventional hydrolysis. Substituted binuclear zinc catalysts are developed to regulate biomimetic intramolecular PET hydrolysis. Hammett studies and density functional theory (DFT) calculations indicate that the substituents modify the charge densities of the active centers, and an optimal substituent should slightly increase the electron richness of the zinc sites to facilitate the formation of a six-membered ring intermediate. The understanding of the structure-activity relationship leads to an advanced catalyst with a specific activity of 778 ± 40 gPET h-1 gcatal-1 in 0.1 M NaOH, far outcompeting the conventional hydrolysis using caustic bases (<33.3 gPET h-1 gcatal-1 in 1-5 M NaOH). This work opens new avenues for environmentally benign PET recycling.
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Affiliation(s)
- Shengbo Zhang
- Department State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University Beijing 100084 China
| | - Yingying Xue
- Laboratory of Theoretical and Computational Nanoscience, CAS Key Laboratory of Nanophotonic Materials and Devices, National Center for Nanoscience and Technology, Chinese Academy of Sciences Beijing 100190 China
| | - Yanfen Wu
- Department State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University Beijing 100084 China
| | - Yu-Xiao Zhang
- Department State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University Beijing 100084 China
| | - Ting Tan
- Laboratory of Theoretical and Computational Nanoscience, CAS Key Laboratory of Nanophotonic Materials and Devices, National Center for Nanoscience and Technology, Chinese Academy of Sciences Beijing 100190 China
| | - Zhiqiang Niu
- Department State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University Beijing 100084 China
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12
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McFadden ME, Overholts AC, Osler SK, Robb MJ. Validation of an Accurate and Expedient Initial Rates Method for Characterizing Mechanophore Reactivity. ACS Macro Lett 2023; 12:440-445. [PMID: 36944217 DOI: 10.1021/acsmacrolett.3c00054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
Understanding structure-mechanochemical reactivity relationships is important for informing the rational design of new stimuli-responsive polymers. To this end, establishing accurate reaction kinetics for mechanophore activation is a key objective. Here, we validate an initial rates method that enables the accurate and rapid determination of rate constants for ultrasound-induced mechanochemical transformations. Experimental reaction profiles are well-aligned with theoretical models, which support that the initial rates method effectively deconvolutes the kinetics of specific mechanophore activation from the competitive process of nonspecific chain scission.
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Affiliation(s)
- Molly E McFadden
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Anna C Overholts
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Skylar K Osler
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Maxwell J Robb
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
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13
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Metze F, Sant S, Meng Z, Klok HA, Kaur K. Swelling-Activated, Soft Mechanochemistry in Polymer Materials. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:3546-3557. [PMID: 36848262 PMCID: PMC10018775 DOI: 10.1021/acs.langmuir.2c02801] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 01/26/2023] [Indexed: 06/12/2023]
Abstract
Swelling in polymer materials is a ubiquitous phenomenon. At a molecular level, swelling is dictated by solvent-polymer interactions, and has been thoroughly studied both theoretically and experimentally. Favorable solvent-polymer interactions result in the solvation of polymer chains. For polymers in confined geometries, such as those that are tethered to surfaces, or for polymer networks, solvation can lead to swelling-induced tensions. These tensions act on polymer chains and can lead to stretching, bending, or deformation of the material both at the micro- and macroscopic scale. This Invited Feature Article sheds light on such swelling-induced mechanochemical phenomena in polymer materials across dimensions, and discusses approaches to visualize and characterize these effects.
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14
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Walter M, Linsler D, König T, Gäbert C, Reinicke S, Moseler M, Mayrhofer L. Mechanochemical Activation of Anthracene [4+4] Cycloadducts. J Phys Chem Lett 2023; 14:1445-1451. [PMID: 36734822 DOI: 10.1021/acs.jpclett.2c03493] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Controlled formation and breaking of weak chemical bonds is a versatile method for modifying the properties of materials. Anthracene [4+4] cycloadducts are a prime example that can be formed by light and opened by external forces. We address the theoretical description of mechanochemistry of these cycloadducts, where the standard constraint geometry simulates forces approach fails due to the lack of consideration of temperature. Explicit inclusion of external forces reveals the corresponding transition barriers that are clearly dominated by rupture of the [4+4] inter-anthracene bonds. Other bonds come into play at extremely large forces only, which cannot be expected to be reached under ambient conditions. The theoretical results are in line with the experimental rheology of [4+4]-linked anthracene polymers, which indicates reversible re-formation of [4+4] cycloaddition bonds with ultraviolet light after mechanochemical bond breaking due to applied shear stress.
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Affiliation(s)
- Michael Walter
- Fraunhofer IWM, MikroTribologie Centrum μTC, 76131Karlsruhe, Germany
- FIT Freiburg Centre for Interactive Materials and Bioinspired Technologies, University of Freiburg, 79085Freiburg, Germany
- Cluster of Excellence livMatS@FIT, 79110Freiburg, Germany
| | - Dominic Linsler
- Fraunhofer IWM, MikroTribologie Centrum μTC, 76131Karlsruhe, Germany
| | - Tobias König
- Fraunhofer IWM, MikroTribologie Centrum μTC, 76131Karlsruhe, Germany
| | | | | | - Michael Moseler
- Fraunhofer IWM, MikroTribologie Centrum μTC, 76131Karlsruhe, Germany
- Cluster of Excellence livMatS@FIT, 79110Freiburg, Germany
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15
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Vugrin L, Carta M, Delogu F, Halasz I. Extending the Hammett correlation to mechanochemical reactions. Chem Commun (Camb) 2023; 59:1629-1632. [PMID: 36662170 DOI: 10.1039/d2cc06487a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Using Raman in situ monitoring and mechanochemistry-specific kinetic analysis, we find a correlation between the reaction probability and the Hammett constants in a model mechanochemical reaction of imine formation, indicating that the body of knowledge developed in physical-organic chemistry could be transferable to ball milling reactions in the solid state.
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Affiliation(s)
- Leonarda Vugrin
- Ruđer Bošković Institute, Bijenička c. 54, Zagreb 10000, Croatia.
| | - Maria Carta
- Department of Mechanical, Chemical and Materials Engineering, University of Cagliari, via Marengo 2, Cagliari 09123, Italy.
| | - Francesco Delogu
- Department of Mechanical, Chemical and Materials Engineering, University of Cagliari, via Marengo 2, Cagliari 09123, Italy.
| | - Ivan Halasz
- Ruđer Bošković Institute, Bijenička c. 54, Zagreb 10000, Croatia.
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16
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Cao N, Cai W, Qian L, Nie Z, Mao C, Cui S. Emulating Titin by a Multidomain DNA Structure. ACS Macro Lett 2023; 12:59-64. [PMID: 36573670 DOI: 10.1021/acsmacrolett.2c00585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Titin, a giant protein containing multiple tandem domains, is essential in maintaining the superior mechanical performance of muscle. The consecutive and reversible unfolding and refolding of the domains are crucial for titin to serve as a modular spring. Since the discovery of the mechanical features of a single titin molecule, the exploration of biomimetic materials with titin-emulating modular structures has been an active field. However, it remains a challenge to prepare these modular polymers on a large scale due to the complex synthesis process. In this study, we propose modular DNA with multiple hairpins (MH-DNA) as the fundamental block for the bottom-up design of advanced materials. By analyzing the unfolding and refolding dynamics of modular hairpins by atomic force microscopy (AFM)-based single-molecule force spectroscopy (SMFS), we find that MH-DNA shows comparable stability to those of polyproteins like titin. The unique low hysteresis of modular hairpin makes it an ideal molecular spring with remarkable mechanical efficiency. On the basis of the well-established DNA synthesis techniques, we anticipate that MH-DNA can be used as a promising building block for advanced materials with a combination of superior structural stability, considerable extensibility, and high mechanical efficiency.
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Affiliation(s)
- Nanpu Cao
- College of Chemistry, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
| | - Wanhao Cai
- College of Chemistry, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
| | - Lu Qian
- College of Chemistry, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
| | - Zhou Nie
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Chengde Mao
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Shuxun Cui
- College of Chemistry, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
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17
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Kozlenko AS, Ozhogin IV, Pugachev AD, Lukyanova MB, El-Sewify IM, Lukyanov BS. A Modern Look at Spiropyrans: From Single Molecules to Smart Materials. Top Curr Chem (Cham) 2023; 381:8. [PMID: 36624333 DOI: 10.1007/s41061-022-00417-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 11/30/2022] [Indexed: 01/11/2023]
Abstract
Photochromic compounds of the spiropyran family have two main isomers capable of inter-switching with UV or visible light. In the current review, we discuss recent advances in the synthesis, investigation of properties, and applications of spiropyran derivatives. Spiropyrans of the indoline series are in focus as the most promising representatives of multi-sensitive spirocyclic compounds, which can be switched by a number of external stimuli, including light, temperature, pH, presence of metal ions, and mechanical stress. Particular attention is paid to the structural features of molecules, their influence on photochromic properties, and the reactions taking place during isomerization, as the understanding of the structure-property relationships will rationalize the synthesis of compounds with predetermined characteristics. The main prospects for applications of spiropyrans in such fields as smart material production, molecular electronics and nanomachinery, sensing of environmental and biological molecules, and photopharmacology are also discussed.
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Affiliation(s)
- Anastasia S Kozlenko
- Institute of Physical and Organic Chemistry, Southern Federal University, Stachki Prosp., 194/2, Rostov-On-Don, 344090, Russia.
| | - Ilya V Ozhogin
- Institute of Physical and Organic Chemistry, Southern Federal University, Stachki Prosp., 194/2, Rostov-On-Don, 344090, Russia
| | - Artem D Pugachev
- Institute of Physical and Organic Chemistry, Southern Federal University, Stachki Prosp., 194/2, Rostov-On-Don, 344090, Russia
| | - Maria B Lukyanova
- Institute of Physical and Organic Chemistry, Southern Federal University, Stachki Prosp., 194/2, Rostov-On-Don, 344090, Russia
| | - Islam M El-Sewify
- Institute of Physical and Organic Chemistry, Southern Federal University, Stachki Prosp., 194/2, Rostov-On-Don, 344090, Russia.,Department of Chemistry, Faculty of Science, Ain Shams University, Cairo, Egypt
| | - Boris S Lukyanov
- Institute of Physical and Organic Chemistry, Southern Federal University, Stachki Prosp., 194/2, Rostov-On-Don, 344090, Russia
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18
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Craig SL. Concluding remarks: Fundamentals, applications and future of mechanochemistry. Faraday Discuss 2023; 241:485-491. [PMID: 36472143 DOI: 10.1039/d2fd00141a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This paper provides a summary of the Faraday Discussions meeting on "Mechanochemistry: fundamentals, applications, and future" in the context of broad themes whose exploration might contribute to a unified framework of mechanochemical phenomena.
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Affiliation(s)
- Stephen L Craig
- Department of Chemistry, Duke University, Durham, NC 27708-0346, USA.
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19
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Wang L, Zheng X, Kouznetsova TB, Yen T, Ouchi T, Brown CL, Craig SL. Mechanochemistry of Cubane. J Am Chem Soc 2022; 144:22865-22869. [DOI: 10.1021/jacs.2c10878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Liqi Wang
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Xujun Zheng
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | | | - Tiffany Yen
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Tetsu Ouchi
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Cameron L. Brown
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Stephen L. Craig
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
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20
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Yu Y, Zheng X, Duan C, Craig SL, Widenhoefer RA. Force-Modulated Selectivity of the Rhodium-Catalyzed Hydroformylation of 1-Alkenes. ACS Catal 2022. [DOI: 10.1021/acscatal.2c04534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yichen Yu
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Xujun Zheng
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Chenghao Duan
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Stephen L. Craig
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Ross A. Widenhoefer
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
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21
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Yett A, Rablen PR. A G4 approach to computing the Hammett substituent constants
σ
p
,
σ
m
,
σ
−
,
σ
+
, and
σ
+
m. J PHYS ORG CHEM 2022. [DOI: 10.1002/poc.4436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Ariana Yett
- Department of Chemistry and Biochemistry Swarthmore College Swarthmore Pennsylvania USA
| | - Paul R. Rablen
- Department of Chemistry and Biochemistry Swarthmore College Swarthmore Pennsylvania USA
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22
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Baumann C, Willis‐Fox N, Campagna D, Rognin E, Marten P, Daly R, Göstl R. Regiochemical effects for the mechanochemical activation of
9‐π‐extended anthracene‐maleimide Diels–Alder
adducts. JOURNAL OF POLYMER SCIENCE 2022. [DOI: 10.1002/pol.20220342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Christoph Baumann
- DWI – Leibniz Institute for Interactive Materials Aachen Germany
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University Aachen Germany
| | - Niamh Willis‐Fox
- Department of Engineering, Institute for Manufacturing University of Cambridge Cambridge UK
| | - Davide Campagna
- DWI – Leibniz Institute for Interactive Materials Aachen Germany
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University Aachen Germany
| | - Etienne Rognin
- Department of Engineering, Institute for Manufacturing University of Cambridge Cambridge UK
| | - Paul Marten
- DWI – Leibniz Institute for Interactive Materials Aachen Germany
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University Aachen Germany
| | - Ronan Daly
- Department of Engineering, Institute for Manufacturing University of Cambridge Cambridge UK
| | - Robert Göstl
- DWI – Leibniz Institute for Interactive Materials Aachen Germany
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23
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Keyvan Rad J, Balzade Z, Mahdavian AR. Spiropyran-based advanced photoswitchable materials: A fascinating pathway to the future stimuli-responsive devices. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C: PHOTOCHEMISTRY REVIEWS 2022. [DOI: 10.1016/j.jphotochemrev.2022.100487] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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24
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Fenwick NW, Telford R, Martin WHC, Bowen RD. Hammett Correlation in Competing Fragmentations of Ionized 2‐Substituted Benzanilides. European J Org Chem 2022. [DOI: 10.1002/ejoc.202200416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Nathan W. Fenwick
- University of Bradford Faculty of Life Sciences School of Chemistry and Biosciences Richmond Road BD7 1DP Bradford UNITED KINGDOM
| | - Richard Telford
- University of Bradford Faculty of Life Sciences School of Chemistry and Biosciences Richmond Road BD7 1DP Bradford UNITED KINGDOM
| | - William H C Martin
- University of Bradford Faculty of Life Sciences School of Chemistry and Biosciences Richmond Road BD7 1DP Bradford UNITED KINGDOM
| | - Richard D Bowen
- University of Bradford Faculty of Life Sciences School of Chemistry and Biosciences Richmond Road BD7 1DP Bradford UNITED KINGDOM
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25
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Abstract
Polymer chains, if long enough, are known to undergo bond scission when mechanically stressed. While the mechanochemical response of random coils is well understood, biopolymers and some key synthetic chains adopt well-defined secondary structures such as helices. To understand covalent mechanochemistry in such structures, poly(γ-benzyl glutamates) are prepared while regulating the feed-monomer chirality, producing chains with similar molecular weights and backbone chemistry but different helicities. Such chains are stressed in solution and their mechanochemistry rates compared by following molecular weight change and using a rhodamine mechanochromophore. Results reveal that while helicity itself is not affected by the covalent bond scissions, chains with higher helicity undergo faster mechanochemistry. Considering that the polymers tested differ only in conformation, these results indicate that helix-induced chain rigidity improves the efficiency of mechanical energy transduction.
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Affiliation(s)
- Hang Zhang
- Schulich Faculty of ChemistryTechnion—Israel Institute of TechnologyHaifa3200008Israel
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26
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Qiu W, Scofield JMP, Gurr PA, Qiao GG. Mechanochromophore-linked Polymeric Materials with Visible Color Changes. Macromol Rapid Commun 2022; 43:e2100866. [PMID: 35338794 DOI: 10.1002/marc.202100866] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/19/2022] [Indexed: 11/07/2022]
Abstract
Mechanical force as a type of stimuli for smart materials has obtained much attention in the past decade. Color-changing materials in response to mechanical stimuli have shown great potential in the applications such as sensors and displays. Mechanochromophore-linked polymeric materials, which are a growing sub-class of these materials, are discussed in detail in this review. Two main types of mechanochromophores which exhibit visible color change, summarized herein, involve either isomerization or radical generation mechanisms. This review focuses on their synthesis and incorporation into polymer matrices, the type of mechanical force used, factors affecting the mechanochromic properties, and their applications. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Wenlian Qiu
- Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Joel M P Scofield
- Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Paul A Gurr
- Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Greg G Qiao
- Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria, 3010, Australia
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27
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Yamakado T, Saito S. Ratiometric Flapping Force Probe That Works in Polymer Gels. J Am Chem Soc 2022; 144:2804-2815. [PMID: 35108003 DOI: 10.1021/jacs.1c12955] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Polymer gels have recently attracted attention for their application in flexible devices, where mechanically robust gels are required. While there are many strategies to produce tough gels by suppressing nanoscale stress concentration on specific polymer chains, it is still challenging to directly verify the toughening mechanism at the molecular level. To solve this problem, the use of the flapping molecular force probe (FLAP) is promising because it can evaluate the nanoscale forces transmitted in the polymer chain network by ratiometric analysis of a stress-dependent dual fluorescence. A flexible conformational change of FLAP enables real-time and reversible responses to the nanoscale forces at the low force threshold, which is suitable for quantifying the percentage of the stressed polymer chains before structural damage. However, the previously reported FLAP only showed a negligible response in solvated environments because undesirable spontaneous planarization occurs in the excited state, even without mechanical force. Here, we have developed a new ratiometric force probe that functions in common organogels. Replacement of the anthraceneimide units in the flapping wings with pyreneimide units largely suppresses the excited-state planarization, leading to the force probe function under wet conditions. The FLAP-doped polyurethane organogel reversibly shows a dual-fluorescence response under sub-MPa compression. Moreover, the structurally modified FLAP is also advantageous in the wide dynamic range of its fluorescence response in solvent-free elastomers, enabling clearer ratiometric fluorescence imaging of the molecular-level stress concentration during crack growth in a stretched polyurethane film.
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Affiliation(s)
- Takuya Yamakado
- Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Shohei Saito
- Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
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28
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Diesendruck C, Zhang H. Accelerated Mechanochemistry in Helical Polymers. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202115325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Charles Diesendruck
- Technion - Israel Institute of Technology Schulich Faculty of Chemistry Kiryat Hatechnion 3200008 Haifa ISRAEL
| | - Hang Zhang
- Technion Israel Institute of Technology Schulich Faculty of Chemistry Haifa ISRAEL
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29
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Kotani R, Yokoyama S, Nobusue S, Yamaguchi S, Osuka A, Yabu H, Saito S. Bridging pico-to-nanonewtons with a ratiometric force probe for monitoring nanoscale polymer physics before damage. Nat Commun 2022; 13:303. [PMID: 35027559 PMCID: PMC8758707 DOI: 10.1038/s41467-022-27972-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 12/15/2021] [Indexed: 02/07/2023] Open
Abstract
Understanding the transmission of nanoscale forces in the pico-to-nanonewton range is important in polymer physics. While physical approaches have limitations in analyzing the local force distribution in condensed environments, chemical analysis using force probes is promising. However, there are stringent requirements for probing the local forces generated before structural damage. The magnitude of those forces corresponds to the range below covalent bond scission (from 200 pN to several nN) and above thermal fluctuation (several pN). Here, we report a conformationally flexible dual-fluorescence force probe with a theoretically estimated threshold of approximately 100 pN. This probe enables ratiometric analysis of the distribution of local forces in a stretched polymer chain network. Without changing the intrinsic properties of the polymer, the force distribution was reversibly monitored in real time. Chemical control of the probe location demonstrated that the local stress concentration is twice as biased at crosslinkers than at main chains, particularly in a strain-hardening region. Due to the high sensitivity, the percentage of the stressed force probes was estimated to be more than 1000 times higher than the activation rate of a conventional mechanophore.
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Affiliation(s)
- Ryota Kotani
- Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan
| | - Soichi Yokoyama
- Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan
| | - Shunpei Nobusue
- Institute of Advanced Energy, Kyoto University, Uji, 611-0011, Japan
| | | | - Atsuhiro Osuka
- Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan
| | - Hiroshi Yabu
- WPI-Advanced Institute for Materials Research (AIMR), Tohoku University, Sendai, 980-8577, Japan.
| | - Shohei Saito
- Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan.
- PRESTO, Japan Science and Technology Agency, Kyoto, 606-8502, Japan.
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30
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Nijem S, Song Y, Schwarz R, Diesendruck CE. Flex-activated CO mechanochemical production for mechanical damage detection. Polym Chem 2022. [DOI: 10.1039/d2py00503d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
New flex-activated mechanophore allows for mechanical damage in polymers using a simple household CO detectors, in addition to the formation of an extended and fluorescent π system.
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Affiliation(s)
- Sally Nijem
- Schulich Faculty of Chemistry and Grand Technion Energy Program, Technion – Israel Institute of Technology, 320003, Haifa, Israel
| | - Ying Song
- Schulich Faculty of Chemistry and Grand Technion Energy Program, Technion – Israel Institute of Technology, 320003, Haifa, Israel
- Department of Chemistry, Nanning Normal University, 530001, Nanning, Guangxi, China
| | - Rony Schwarz
- Schulich Faculty of Chemistry and Grand Technion Energy Program, Technion – Israel Institute of Technology, 320003, Haifa, Israel
| | - Charles E. Diesendruck
- Schulich Faculty of Chemistry and Grand Technion Energy Program, Technion – Israel Institute of Technology, 320003, Haifa, Israel
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31
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Versaw BA, Zeng T, Hu X, Robb MJ. Harnessing the Power of Force: Development of Mechanophores for Molecular Release. J Am Chem Soc 2021; 143:21461-21473. [PMID: 34927426 DOI: 10.1021/jacs.1c11868] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Polymers that release small molecules in response to mechanical force are promising materials for a variety of applications ranging from sensing and catalysis to targeted drug delivery. Within the rapidly growing field of polymer mechanochemistry, stress-sensitive molecules known as mechanophores are particularly attractive for enabling the release of covalently bound payloads with excellent selectivity and control. Here, we review recent progress in the development of mechanophore-based molecular release platforms and provide an optimistic, yet critical perspective on the fundamental and technological advancements that are still required for this promising research area to achieve significant impact.
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Affiliation(s)
- Brooke A Versaw
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Tian Zeng
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Xiaoran Hu
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Maxwell J Robb
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
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32
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Overholts AC, McFadden ME, Robb MJ. Quantifying Activation Rates of Scissile Mechanophores and the Influence of Dispersity. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c02232] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Anna C. Overholts
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Molly E. McFadden
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Maxwell J. Robb
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
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33
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O’Neill RT, Boulatov R. The Contributions of Model Studies for Fundamental Understanding of Polymer Mechanochemistry. Synlett 2021. [DOI: 10.1055/a-1710-5656] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
AbstractThe exciting field of polymer mechanochemistry has made great empirical progress in discovering reactions in which a stretching force accelerates scission of strained bonds using single molecule force spectroscopy and ultrasonication experiments. Understanding why these reactions happen, i.e., the fundamental physical processes that govern coupling of macroscopic motion to chemical reactions, as well as discovering other patterns of mechanochemical reactivity require complementary techniques, which permit a much more detailed characterization of reaction mechanisms and the distribution of force in reacting molecules than are achievable in SMFS or ultrasonication. A molecular force probe allows the specific pattern of molecular strain that is responsible for localized reactions in stretched polymers to be reproduced accurately in non-polymeric substrates using molecular design rather than atomistically intractable collective motions of millions of atoms comprising macroscopic motion. In this review, we highlight the necessary features of a useful molecular force probe and describe their realization in stiff stilbene macrocycles. We describe how studying these macrocycles using classical tools of physical organic chemistry has allowed detailed characterizations of mechanochemical reactivity, explain some of the most unexpected insights enabled by these probes, and speculate how they may guide the next stage of mechanochemistry.
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Affiliation(s)
| | - Roman Boulatov
- Department of Chemistry, University of Liverpool
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University
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34
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Abstract
AbstractThis Account covers the recent progress made on heterocyclic mechanophores in the field of polymer mechanochemistry. In particular, the types of such mechanophores as well as the mechanisms and applications of their force-induced structural transformations are discussed and related perspectives and future challenges proposed.1 Introduction2 Types of Mechanophores3 Methods to Incorporate Heterocycle Mechanophores into Polymer Systems4 Mechanochemical Reactions of Heterocyclic Mechanophores4.1 Three-Membered-Ring Mechanophores4.2 Four-Membered-Ring Mechanophores4.3 Six-Membered-Ring Mechanophores4.4 Bicyclic Mechanophores5 Applications5.1 Cross-Linking of Polymer5.2 Degradable Polymer5.3 Mechanochromic Polymer6 Concluding Remarks and Outlook
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35
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He S, Stratigaki M, Centeno SP, Dreuw A, Göstl R. Tailoring the Properties of Optical Force Probes for Polymer Mechanochemistry. Chemistry 2021; 27:15889-15897. [PMID: 34582082 PMCID: PMC9292383 DOI: 10.1002/chem.202102938] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Indexed: 02/05/2023]
Abstract
The correlation of mechanical properties of polymer materials with those of their molecular constituents is the foundation for their holistic comprehension and eventually for improved material designs and syntheses. Over the last decade, optical force probes (OFPs) were developed, shedding light on various unique mechanical behaviors of materials. The properties of polymers are diverse, ranging from soft hydrogels to ultra‐tough composites, from purely elastic rubbers to viscous colloidal solutions, and from transparent glasses to super black dyed coatings. Only very recently, researchers started to develop tailored OFP solutions that account for such material requirements in energy (both light and force), in time, and in their spatially detectable resolution. We here highlight notable recent examples and identify future challenges in this emergent field.
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Affiliation(s)
- Siyang He
- DWI - Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52056, Aachen, Germany.,Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany
| | - Maria Stratigaki
- DWI - Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52056, Aachen, Germany
| | - Silvia P Centeno
- DWI - Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52056, Aachen, Germany
| | - Andreas Dreuw
- Interdisciplinary Center for Scientific Computing, Heidelberg University, Im Neuenheimer Feld 205, 69120, Heidelberg, Germany
| | - Robert Göstl
- DWI - Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52056, Aachen, Germany
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36
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Hemmer JR, Rader C, Wilts BD, Weder C, Berrocal JA. Heterolytic Bond Cleavage in a Scissile Triarylmethane Mechanophore. J Am Chem Soc 2021; 143:18859-18863. [PMID: 34735137 DOI: 10.1021/jacs.1c10004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Covalent mechanophores display the cleavage of a weak covalent bond when a sufficiently high mechanical force is applied. Three different covalent bond breaking mechanisms have been documented thus far, including concerted, homolytic, and heterolytic scission. Motifs that display heterolytic cleavage typically separate according to non-scissile reaction pathways that afford zwitterions. Here, we report a new mechanochromic triarylmethane mechanophore, which dissociates according to a scissile heterolytic pathway and displays a pronounced mechanochromic response. The mechanophore was equipped with two styrenylic handles that allowed its incorporation as a cross-linker into poly(N,N-dimethylacrylamide) and poly(methyl acrylate-co-2-hydroxyethyl acrylate) networks. These materials are originally colorless, but compression or tensile deformation renders the materials colored. By combining tensile testing and in situ transmittance measurements, we show that this effect is related to scissile cleavage leading to colored triarylmethane carbocations.
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Affiliation(s)
- James R Hemmer
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Chris Rader
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Bodo D Wilts
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland.,Department of Chemistry and Physics of Materials, University of Salzburg, Jakob-Haringer-Str. 2a, 5020 Salzburg, Austria
| | - Christoph Weder
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - José Augusto Berrocal
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
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37
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Gu F, Jiang T, Ma X. Visually Monitoring the Compactness of Polymer Matrixes Coded by Disparate Luminescence. ACS APPLIED MATERIALS & INTERFACES 2021; 13:43473-43479. [PMID: 34488339 DOI: 10.1021/acsami.1c15299] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The intrinsic property disclosure of polymer systems by visual monitoring of photoluminescence behaviors is of great value in fundamental interest and promising applications. Three novel polymer films were obtained by simply doping methyl 9,14-diphenyl-9,14-dihydrodibenzo[a,c]phenazine-11-carboxylate (DPC) with three polymer materials. The photoluminescence behaviors of these films represented diverse fluorescence emissions from light orange to blue, especially room-temperature phosphorescence (RTP) emissions with ultralong lifetime, attributing to various configurations of DPC molecules provided by distinct microscopic environments in three polymer systems. The rigidity and regularity of polymer systems would be visually reflexed by luminescence regulation and temperature responses. In addition, irregular distribution of distinct polymer systems could be specifically monitored by both fluorescence and phosphorescence behaviors when doping different polymer materials into one blend film.
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Affiliation(s)
- Fan Gu
- Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Meilong Road 130, Shanghai 200237, China
| | - Tao Jiang
- Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Meilong Road 130, Shanghai 200237, China
| | - Xiang Ma
- Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Meilong Road 130, Shanghai 200237, China
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38
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Horst M, Yang J, Meisner J, Kouznetsova TB, Martínez TJ, Craig SL, Xia Y. Understanding the Mechanochemistry of Ladder-Type Cyclobutane Mechanophores by Single Molecule Force Spectroscopy. J Am Chem Soc 2021; 143:12328-12334. [PMID: 34310875 DOI: 10.1021/jacs.1c05857] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We have recently reported a series of ladder-type cyclobutane mechanophores, polymers of which can transform from nonconjugated structures to conjugated structures and change many properties at once. These multicyclic mechanophores, namely, exo-ladderane/ene, endo-benzoladderene, and exo-bicyclohexene-peri-naphthalene, have different ring structures fused to the first cyclobutane, significantly different free energy changes for ring-opening, and different stereochemistry. To better understand their mechanochemistry, we used single molecule force spectroscopy (SMFS) to characterize their force-extension behavior and measure the threshold forces. The threshold forces correlate with the activation energy of the first bond, but not with the strain of the fused rings distal to the polymer main chain, suggesting that the activation of these ladder-type mechanophores occurs with similar early transition states, which is supported by force-modified potential energy surface calculations. We further determined the stereochemistry of the mechanically generated dienes and observed significant and variable contour length elongation for these mechanophores both experimentally and computationally. The fundamental understanding of ladder-type mechanophores will facilitate future design of multicyclic mechanophores with amplified force-response and their applications as mechanically responsive materials.
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Affiliation(s)
- Matías Horst
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Jinghui Yang
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Jan Meisner
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Tatiana B Kouznetsova
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Todd J Martínez
- Department of Chemistry, Stanford University, Stanford, California 94305, United States.,SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Stephen L Craig
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Yan Xia
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
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39
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Muramatsu T, Okado Y, Traeger H, Schrettl S, Tamaoki N, Weder C, Sagara Y. Rotaxane-Based Dual Function Mechanophores Exhibiting Reversible and Irreversible Responses. J Am Chem Soc 2021; 143:9884-9892. [PMID: 34162206 DOI: 10.1021/jacs.1c03790] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Mechanochromic mechanophores permit the design of polymers that indicate mechanical events through optical signals. Here we report rotaxane-based supramolecular mechanophores that display both reversible and irreversible fluorescence changes. These responses are triggered by different forces and are achieved by exploiting the molecular shuttling function and force-induced dethreading of rotaxanes. The new rotaxane mechanophores are composed of a ring featuring a luminophore, which is threaded onto an axle with a matching quencher and two stoppers. In the stress-free state, the luminophore is preferentially located in the proximity of the quencher, and the emission is quenched. The luminophore slides away from the quencher when a force is applied and the fluorescence is switched on. This effect is reversible, unless the force is so high that the luminophore-carrying ring slips past the stopper and dethreading occurs. We show that the combination of judiciously selected ring and stopper moieties is crucial to attain interlocked structures that display such a dual response. PU elastomers that contain such doubly responsive rotaxanes exhibit reversible fluorescence changes over multiple loading-unloading cycles due to the shuttling function, whereas permanent changes are observed upon repeated deformations to high strains due to breakage of the mechanical bond upon dethreading of the ring from the axle. This response allows one, at least conceptually, to monitor the actual deformation of polymer materials and examine mechanical damage that was inflicted in the past on the basis of an optical signal.
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Affiliation(s)
- Tatsuya Muramatsu
- Department of Materials Science and Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| | - Yuji Okado
- Research Institute for Electronic Science, Hokkaido University, N20, W10, Kita-ku, Sapporo, Hokkaido 001-0020, Japan
| | - Hanna Traeger
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg, Switzerland
| | - Stephen Schrettl
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg, Switzerland
| | - Nobuyuki Tamaoki
- Research Institute for Electronic Science, Hokkaido University, N20, W10, Kita-ku, Sapporo, Hokkaido 001-0020, Japan
| | - Christoph Weder
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg, Switzerland
| | - Yoshimitsu Sagara
- Department of Materials Science and Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552, Japan.,JST-PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
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40
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Bowser BH, Wang S, Kouznetsova TB, Beech HK, Olsen BD, Rubinstein M, Craig SL. Single-Event Spectroscopy and Unravelling Kinetics of Covalent Domains Based on Cyclobutane Mechanophores. J Am Chem Soc 2021; 143:5269-5276. [PMID: 33783187 DOI: 10.1021/jacs.1c02149] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mechanochemical reactions that lead to an increase in polymer contour length have the potential to serve as covalent synthetic mimics of the mechanical unfolding of noncovalent "stored length" domains in structural proteins. Here we report the force-dependent kinetics of stored length release in a family of covalent domain polymers based on cis-1,2-substituted cyclobutane mechanophores. The stored length is determined by the size (n) of a fused ring in an [n.2.0] bicyclic architecture, and it can be made sufficiently large (>3 nm per event) that individual unravelling events are resolved in both constant-velocity and constant-force single-molecule force spectroscopy (SMFS) experiments. Replacing a methylene in the pulling attachment with a phenyl group drops the force necessary to achieve rate constants of 1 s-1 from ca. 1970 pN (dialkyl handles) to 630 pN (diaryl handles), and the substituent effect is attributed to a combination of electronic stabilization and mechanical leverage effects. In contrast, the kinetics are negligibly perturbed by changes in the amount of stored length. The independent control of unravelling force and extension holds promise as a probe of molecular behavior in polymer networks and for optimizing the behaviors of materials made from covalent domain polymers.
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Affiliation(s)
- Brandon H Bowser
- NSF Center for the Chemistry of Molecularly Optimized Networks, Duke University, Durham, North Carolina 27708, United States.,Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Shu Wang
- NSF Center for the Chemistry of Molecularly Optimized Networks, Duke University, Durham, North Carolina 27708, United States.,Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Tatiana B Kouznetsova
- NSF Center for the Chemistry of Molecularly Optimized Networks, Duke University, Durham, North Carolina 27708, United States.,Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Haley K Beech
- NSF Center for the Chemistry of Molecularly Optimized Networks, Duke University, Durham, North Carolina 27708, United States.,Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Bradley D Olsen
- NSF Center for the Chemistry of Molecularly Optimized Networks, Duke University, Durham, North Carolina 27708, United States.,Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Michael Rubinstein
- NSF Center for the Chemistry of Molecularly Optimized Networks, Duke University, Durham, North Carolina 27708, United States.,Department of Chemistry, Duke University, Durham, North Carolina 27708, United States.,Departments of Physics, Mechanical Engineering and Materials Science, and Biomedical Engineering, Duke University, Durham, North Carolina 27708, United States.,World Premier Institute for Chemical Reaction Design and Discovery, Hokkaido University, Sapporo, Japan
| | - Stephen L Craig
- NSF Center for the Chemistry of Molecularly Optimized Networks, Duke University, Durham, North Carolina 27708, United States.,Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
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41
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Sagara Y, Traeger H, Li J, Okado Y, Schrettl S, Tamaoki N, Weder C. Mechanically Responsive Luminescent Polymers Based on Supramolecular Cyclophane Mechanophores. J Am Chem Soc 2021; 143:5519-5525. [DOI: 10.1021/jacs.1c01328] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Yoshimitsu Sagara
- Department of Materials Science and Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552, Japan
- JST-PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Hanna Traeger
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg, Switzerland
| | - Jie Li
- Research Institute for Electronic Science, Hokkaido University, N20, W10, Kita-Ku, Sapporo, Hokkaido 001-0020, Japan
| | - Yuji Okado
- Research Institute for Electronic Science, Hokkaido University, N20, W10, Kita-Ku, Sapporo, Hokkaido 001-0020, Japan
| | - Stephen Schrettl
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg, Switzerland
| | - Nobuyuki Tamaoki
- Research Institute for Electronic Science, Hokkaido University, N20, W10, Kita-Ku, Sapporo, Hokkaido 001-0020, Japan
| | - Christoph Weder
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg, Switzerland
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42
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Abstract
In mechanochemistry, molecules under tension can react in unexpected ways. The reactivity of mechanophores (mechanosensitive molecules) can be controlled using various geometric or electronic factors. Often these factors affect the rate of mechanical activation but sometimes give rise to alternative reaction pathways. Here we show that a simple isotope substitution (H to D) leads to a reversal of selectivity in the activation of a mechanophore. Remarkably this isotope effect is not kinetic in nature but emerges from dynamic effects in which deuteration reduces the ability of the reactant to follow a post-transition-state concerted trajectory on the bifurcated force-modified potential energy surface. These results give a new insight into the reactivity of molecules under tension.
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Affiliation(s)
- Robert Nixon
- Department of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
| | - Guillaume De Bo
- Department of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
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43
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Bettens T, Hoffmann M, Alonso M, Geerlings P, Dreuw A, De Proft F. Mechanochemically Triggered Topology Changes in Expanded Porphyrins. Chemistry 2021; 27:3397-3406. [PMID: 33170967 PMCID: PMC7898923 DOI: 10.1002/chem.202003869] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Indexed: 12/16/2022]
Abstract
A hitherto unexplored class of molecules for molecular force probe applications are expanded porphyrins. This work proves that mechanical force is an effective stimulus to trigger the interconversion between Hückel and Möbius topologies in [28]hexaphyrin, making these expanded porphyrins suitable to act as conformational mechanophores operating at mild (sub-1 nN) force conditions. A straightforward approach based on distance matrices is proposed for the selection of pulling scenarios that promote either the planar Hückel topology or the three lowest lying Möbius topologies. This approach is supported by quantum mechanochemical calculations. Force distribution analyses reveal that [28]hexaphyrin selectively allocates the external mechanical energy to molecular regions that trigger Hückel-Möbius interconversions, explaining why certain pulling scenarios favor the Hückel two-sided topology and others favor Möbius single-sided topologies. The meso-substitution pattern on [28]hexaphyrin determines whether the energy difference between the different topologies can be overcome by mechanical activation.
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Affiliation(s)
- Tom Bettens
- Eenheid Algemene Chemie (ALGC)Vrije Universiteit Brussel (VUB)Pleinlaan 21050BrusselsBelgium
| | - Marvin Hoffmann
- Interdisciplinary Center for Scientific ComputingRuprecht-Karls UniversityIm Neuenheimer Feld 205A69120HeidelbergGermany
| | - Mercedes Alonso
- Eenheid Algemene Chemie (ALGC)Vrije Universiteit Brussel (VUB)Pleinlaan 21050BrusselsBelgium
| | - Paul Geerlings
- Eenheid Algemene Chemie (ALGC)Vrije Universiteit Brussel (VUB)Pleinlaan 21050BrusselsBelgium
| | - Andreas Dreuw
- Interdisciplinary Center for Scientific ComputingRuprecht-Karls UniversityIm Neuenheimer Feld 205A69120HeidelbergGermany
| | - Frank De Proft
- Eenheid Algemene Chemie (ALGC)Vrije Universiteit Brussel (VUB)Pleinlaan 21050BrusselsBelgium
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44
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O’Neill RT, Boulatov R. The many flavours of mechanochemistry and its plausible conceptual underpinnings. Nat Rev Chem 2021; 5:148-167. [PMID: 37117533 DOI: 10.1038/s41570-020-00249-y] [Citation(s) in RCA: 131] [Impact Index Per Article: 43.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/23/2020] [Indexed: 12/12/2022]
Abstract
Mechanochemistry describes diverse phenomena in which mechanical load affects chemical reactivity. The fuzziness of this definition means that it includes processes as seemingly disparate as motor protein function, organic synthesis in a ball mill, reactions at a propagating crack, chemical actuation, and polymer fragmentation in fast solvent flows and in mastication. In chemistry, the rate of a reaction in a flask does not depend on how fast the flask moves in space. In mechanochemistry, the rate at which a material is deformed affects which and how many bonds break. In other words, in some manifestations of mechanochemistry, macroscopic motion powers otherwise endergonic reactions. In others, spontaneous chemical reactions drive mechanical motion. Neither requires thermal or electrostatic gradients. Distinct manifestations of mechanochemistry are conventionally treated as being conceptually independent, which slows the field in its transformation from being a collection of observations to a rigorous discipline. In this Review, we highlight observations suggesting that the unifying feature of mechanochemical phenomena may be the coupling between inertial motion at the microscale to macroscale and changes in chemical bonding enabled by transient build-up and relaxation of strains, from macroscopic to molecular. This dynamic coupling across multiple length scales and timescales also greatly complicates the conceptual understanding of mechanochemistry.
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45
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Razgoniaev AO, Glasstetter LM, Kouznetsova TB, Hall KC, Horst M, Craig SL, Franz KJ. Single-Molecule Activation and Quantification of Mechanically Triggered Palladium-Carbene Bond Dissociation. J Am Chem Soc 2021; 143:1784-1789. [PMID: 33480680 DOI: 10.1021/jacs.0c13219] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Metal-complexed N-heterocyclic carbene (NHC) mechanophores are latent reactants and catalysts for a range of mechanically driven chemical responses, but mechanochemical scission of the metal-NHC bond has not been experimentally characterized. Here we report the single-molecule force spectroscopy of ligand dissociation from a pincer NHC-pyridine-NHC Pd(II) complex. The force-coupled rate constant for ligand dissociation reaches 50 s-1 at forces of approximately 930 pN. Experimental and computational observations support a dissociative, rather than associative, mechanism of ligand displacement, with rate-limiting scission of the Pd-NHC bond followed by rapid dissociation of the pyridine moiety from Pd.
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Affiliation(s)
- Anton O Razgoniaev
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Logan M Glasstetter
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Tatiana B Kouznetsova
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Kacey C Hall
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Matias Horst
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Stephen L Craig
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Katherine J Franz
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
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46
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De Chavez D, Kobayashi H, Fukuoka A, Hasegawa JY. On the Electronic Structure Origin of Mechanochemically Induced Selectivity in Acid-Catalyzed Chitin Hydrolysis. J Phys Chem A 2021; 125:187-197. [PMID: 33382273 DOI: 10.1021/acs.jpca.0c09030] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Recently, mechanical ball milling was applied to chitin depolymerization. The mechanical activation afforded higher selectivity toward glycosidic bond cleavage over amide bond breakage. Hence, the bioactive N-acetylglucosamine (GlcNAc) monomer was preferentially produced over glucosamine. In this regard, the force-dependent mechanochemical activation-deactivation process in the relaxed and pulled GlcNAc dimer undergoing deacetylation and depolymerization reactions was studied. For the relaxed case, the activation energies of the rate-determining steps (RDS) proved that the two reactions could occur simultaneously. Mechanical forces associated with ball milling were approximated with linear pulling and were introduced explicitly in the RDS of both reactions through force-modified potential energy surface (FMPES) formalism. In general, as the applied pulling force increases, the activation energy of the RDS of deacetylation shows no meaningful change, while that of depolymerization decreases. This result is consistent with the selectivity exhibited in the experiment. Energy and structural analyses for the depolymerization showed that the activation can be attributed to a significant change in the glycosidic dihedral at the reactant state. A lone pair of the neighboring pyranose ring O adopts a syn-periplanar conformation relative to the glycosidic bond. This promotes electron donation to the σ*-orbital of the glycosidic bond, leading to activation. Consequently, the Brønsted-Lowry basicity of the glycosidic oxygen also increases, which can facilitate acid catalysis.
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Affiliation(s)
- Danjo De Chavez
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, N13W8, Kita-Ku, Sapporo 060-0810, Japan
| | - Hirokazu Kobayashi
- Institute for Catalysis, Hokkaido University, N21W10, Kita-Ku, Sapporo 001-0021, Japan
| | - Atsushi Fukuoka
- Institute for Catalysis, Hokkaido University, N21W10, Kita-Ku, Sapporo 001-0021, Japan
| | - Jun-Ya Hasegawa
- Institute for Catalysis, Hokkaido University, N21W10, Kita-Ku, Sapporo 001-0021, Japan
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47
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Synthesis, optical properties and in vitro cell viability of novel spiropyrans and their photostationary states. Tetrahedron 2021. [DOI: 10.1016/j.tet.2020.131854] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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48
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Chen Y, Mellot G, van Luijk D, Creton C, Sijbesma RP. Mechanochemical tools for polymer materials. Chem Soc Rev 2021; 50:4100-4140. [DOI: 10.1039/d0cs00940g] [Citation(s) in RCA: 112] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This review aims to provide a field guide for the implementation of mechanochemistry in synthetic polymers by summarizing the molecules, materials, and methods that have been developed in this field.
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Affiliation(s)
- Yinjun Chen
- Department of Chemical Engineering & Chemistry and Institute for Complex Molecular Systems
- Eindhoven University of Technology
- 5600 MB Eindhoven
- The Netherlands
| | - Gaëlle Mellot
- Laboratoire Sciences et Ingénierie de la Matière Molle
- ESPCI Paris
- PSL University
- Sorbonne Université
- CNRS
| | - Diederik van Luijk
- Department of Chemical Engineering & Chemistry and Institute for Complex Molecular Systems
- Eindhoven University of Technology
- 5600 MB Eindhoven
- The Netherlands
| | - Costantino Creton
- Laboratoire Sciences et Ingénierie de la Matière Molle
- ESPCI Paris
- PSL University
- Sorbonne Université
- CNRS
| | - Rint P. Sijbesma
- Department of Chemical Engineering & Chemistry and Institute for Complex Molecular Systems
- Eindhoven University of Technology
- 5600 MB Eindhoven
- The Netherlands
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49
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Martínez‐Tong DE, Pomposo JA, Verde‐Sesto E. Triggering Forces at the Nanoscale: Technologies for Single‐Chain Mechanical Activation and Manipulation. Macromol Rapid Commun 2020; 42:e2000654. [DOI: 10.1002/marc.202000654] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 11/14/2020] [Indexed: 01/05/2023]
Affiliation(s)
- Daniel E. Martínez‐Tong
- Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología University of the Basque Country (UPV/EHU) P. Manuel Lardizábal 3 Donostia‐San Sebastián 20018 Spain
- Centro de Física de Materiales (UPV/EHU‐CSIC) P. Manuel Lardizábal 5 San Sebastián 20018 Spain
| | - José A. Pomposo
- Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología University of the Basque Country (UPV/EHU) P. Manuel Lardizábal 3 Donostia‐San Sebastián 20018 Spain
- Centro de Física de Materiales (CFM) (CSIC‐UPV/EHU)—Materials Physics Center (MPC) Paseo Manuel de Lardizábal 5 Donostia‐San Sebastián 20018 Spain
- IKERBASQUE—Basque Foundation for Science Plaza Euskadi 5 Bilbao 48009 Spain
| | - Ester Verde‐Sesto
- Centro de Física de Materiales (CFM) (CSIC‐UPV/EHU)—Materials Physics Center (MPC) Paseo Manuel de Lardizábal 5 Donostia‐San Sebastián 20018 Spain
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Sommer M. Substituent Effects Control Spiropyran-Merocyanine Equilibria and Mechanochromic Utility. Macromol Rapid Commun 2020; 42:e2000597. [PMID: 33270317 DOI: 10.1002/marc.202000597] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/11/2020] [Indexed: 11/12/2022]
Abstract
Spiropyran (SP) derivatives can be converted into the colored merocyanine (MC) form using a variety of triggers. Optical switching by light for memories and dynamic systems is long known. Recently, mechanical force has been reported as an additional stimulus that converts SP into MC. SP-based mechanochromic systems are especially interesting for polymer scientists, as the covalent attachment of polymer chains is ideal to transduce force to the SP level. Whether such materials are investigated to better understand fundamental processes or long standing questions in polymer science, to design force sensors or to self-report damage, or simply pose fascinating materials which turn colored upon deformation, they have intrigued polymer scientists for more than a decade. With the chemistry of SPs being feasible and SP functionalization important to modulate SP/MC equilibria, a significant amount of work on SP structure- mechanochromic function relations has accumulated. SPs can be used as bifunctional initiators, cross-linkers, monomers, or be synthesized during polymerization. This feature article provides an overview of how the chemistry used sets the boundaries within which the mechanochromic response of SP containing polymers can be modulated.
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Affiliation(s)
- Michael Sommer
- Chemnitz University of Technology, Straße der Nationen 62, 09111, Chemnitz, Germany
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