1
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Asai D, Tahara K. Synthesis and Reactivity of an X-Shaped Molecule: Reversible Formation and Cleavage of a Four-Membered Ring in Response to External Stimuli. Org Lett 2024; 26:4898-4903. [PMID: 38836760 DOI: 10.1021/acs.orglett.4c01392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
We herein report the synthesis and reactivity of an X-shaped molecule featuring three four-membered rings (4MRs) arranged in a ladder configuration. This molecule exhibits a reversible opening and closure of the central 4MR upon exposure to light irradiation and thermal treatment. The central 4MR of this molecule is also cleaved via electrochemical and chemical reductions. The stimuli-responsiveness of the X-shaped molecule is attributed to the small energy gap difference between its open and closed states, stemming from the antiaromatic character of its precursor.
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Affiliation(s)
- Daisuke Asai
- Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571, Japan
| | - Kazukuni Tahara
- Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571, Japan
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2
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Kurokawa K, Ogawa N, Kuroda Y, Yamaoka Y, Takikawa H, Tsubaki K, Takasu K. Chromic properties of dibenzo[ j, l]fluoranthenes exhibiting different resonance contributions. Org Biomol Chem 2024. [PMID: 38812407 DOI: 10.1039/d4ob00750f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
Chromic molecules change colour in response to external stimuli and are utilized in applications such as food additive detection, light dimmers, and biological probes. One of the common design strategies for organic chromic molecules is based on changes in the π-conjugation. We have hypothesized that non-alternant polyaromatic hydrocarbon (PAH) skeletons can be used as backbones for chromic molecules. Herein, we synthesized hydroxy-substituted dibenzo[j,l]fluoranthenes, a class of non-alternant PAHs, as novel chromic compounds and evaluated their halochromic properties by UV-vis and fluorescence spectroscopy. Under basic conditions, the 1-hydroxy derivatives show a hyperchromic shift, whereas the 9-hydroxy derivatives show a bathochromic shift and fluorescence although the skeleton of the chromophore is the same. Density functional theory calculations indicated that the different chromic properties are attributed to the differences in their resonance structures.
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Affiliation(s)
- Kazuma Kurokawa
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan.
| | - Naoki Ogawa
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan.
| | - Yusuke Kuroda
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan.
| | - Yousuke Yamaoka
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan.
| | - Hiroshi Takikawa
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan.
| | - Kazunori Tsubaki
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Shimogamo, Sakyo-ku, Kyoto 606-8522, Japan
| | - Kiyosei Takasu
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan.
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3
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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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4
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Ding S, Wang W, Germann A, Wei Y, Du T, Meisner J, Zhu R, Liu Y. Bicyclo[2.2.0]hexene: A Multicyclic Mechanophore with Reactivity Diversified by External Forces. J Am Chem Soc 2024; 146:6104-6113. [PMID: 38377579 DOI: 10.1021/jacs.3c13589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Polymer mechanochemistry has been established as an enabling tool in accessing chemical reactivity and reaction pathways that are distinctive from their thermal counterparts. However, eliciting diversified reaction pathways by activating different constituent chemical bonds from the same mechanophore structure remains challenging. Here, we report the design of a bicyclo[2.2.0]hexene (BCH) mechanophore to leverage its structural simplicity and relatively low molecular symmetry to demonstrate this idea of multimodal activation. Upon changing the attachment points of pendant polymer chains, three different C-C bonds in bicyclo[2.2.0]hexene are specifically activated via externally applied force by sonication. Experimental characterization confirms that in different scenarios of polymer attachment, the regioisomers of BCH undergo different activation reactions, entailing retro-[2+2] cycloreversion, 1,3-allylic migration, and retro-4π ring-opening reactions, respectively. Control experiments with small-molecule analogues reveal that the observed diversified reactivity of BCH regioisomers is possible only with mechanical force. Theoretical studies further elucidate that the differences in the positions of substitution between regioisomers have a minimal impact on the potential energy surface of the parent BCH scaffold. The mechanochemical selectivity between different C-C bonds in each constitutional isomer is a result of selective and effective coupling of force to the aligned C-C bond in each case.
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Affiliation(s)
- Shihao Ding
- Beijing National Laboratory for Molecular Sciences, Center for Soft Matter Science and Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, and College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Wenkai Wang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, and College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Anne Germann
- Institute for Physical Chemistry, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany
| | - Yiting Wei
- Beijing National Laboratory for Molecular Sciences, Center for Soft Matter Science and Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, and College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Tianyi Du
- Beijing National Laboratory for Molecular Sciences, Center for Soft Matter Science and Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, and College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Jan Meisner
- Institute for Physical Chemistry, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany
| | - Rong Zhu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, and College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Yun Liu
- Beijing National Laboratory for Molecular Sciences, Center for Soft Matter Science and Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, and College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
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5
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He X, Tian Y, O’Neill RT, Xu Y, Lin Y, Weng W, Boulatov R. Coumarin Dimer Is an Effective Photomechanochemical AND Gate for Small-Molecule Release. J Am Chem Soc 2023; 145:23214-23226. [PMID: 37821455 PMCID: PMC10603814 DOI: 10.1021/jacs.3c07883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Indexed: 10/13/2023]
Abstract
Stimulus-responsive gating of chemical reactions is of considerable practical and conceptual interest. For example, photocleavable protective groups and gating mechanophores allow the kinetics of purely thermally activated reactions to be controlled optically or by mechanical load by inducing the release of small-molecule reactants. Such release only in response to a sequential application of both stimuli (photomechanochemical gating) has not been demonstrated despite its unique expected benefits. Here, we describe computational and experimental evidence that coumarin dimers are highly promising moieties for realizing photomechanochemical control of small-molecule release. Such dimers are transparent and photochemically inert at wavelengths >300 nm but can be made to dissociate rapidly under tensile force. The resulting coumarins are mechanochemically and thermally stable, but rapidly release their payload upon irradiation. Our DFT calculations reveal that both strain-free and mechanochemical kinetics of dimer dissociation are highly tunable over an unusually broad range of rates by simple substitution. In head-to-head dimers, the phenyl groups act as molecular levers to allow systematic and predictable variation in the force sensitivity of the dissociation barriers by choice of the pulling axis. As a proof-of-concept, we synthesized and characterized the reactivity of one such dimer for photomechanochemically controlled release of aniline and its application for controlling bulk gelation.
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Affiliation(s)
- Xiaojun He
- Department
of Chemistry, College of Chemistry and Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Yancong Tian
- Department
of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, U.K.
| | - Robert T. O’Neill
- Department
of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, U.K.
| | - Yuanze Xu
- Department
of Chemistry, College of Chemistry and Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Yangju Lin
- Department
of Chemistry, College of Chemistry and Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Wengui Weng
- Department
of Chemistry, College of Chemistry and Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Roman Boulatov
- Department
of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, U.K.
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6
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Li Z, Wang Z, Wang C, Li W, Fan W, Zhao R, Feng H, Peng D, Huang W. Mechanoluminescent Materials Enable Mechanochemically Controlled Atom Transfer Radical Polymerization and Polymer Mechanotransduction. RESEARCH (WASHINGTON, D.C.) 2023; 6:0243. [PMID: 37795336 PMCID: PMC10546606 DOI: 10.34133/research.0243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 09/13/2023] [Indexed: 10/06/2023]
Abstract
Organic mechanophores have been widely adopted for polymer mechanotransduction. However, most examples of polymer mechanotransduction inevitably experience macromolecular chain rupture, and few of them mimic mussel's mechanochemical regeneration, a mechanically mediated process from functional units to functional materials in a controlled manner. In this paper, inorganic mechanoluminescent (ML) materials composed of CaZnOS-ZnS-SrZnOS: Mn2+ were used as a mechanotransducer since it features both piezoelectricity and mechanolunimescence. The utilization of ML materials in polymerization enables both mechanochemically controlled radical polymerization and the synthesis of ML polymer composites. This procedure features a mechanochemically controlled manner for the design and synthesis of diverse mechanoresponsive polymer composites.
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Affiliation(s)
- Zexuan Li
- Frontiers Science Center for Flexible Electronics, Institute of Flexible Electronics, Northwestern Polytechnical University, Xi’an 710072, China
| | - Zhenhua Wang
- Frontiers Science Center for Flexible Electronics, Institute of Flexible Electronics, Northwestern Polytechnical University, Xi’an 710072, China
| | - Chen Wang
- Frontiers Science Center for Flexible Electronics, Institute of Flexible Electronics, Northwestern Polytechnical University, Xi’an 710072, China
| | - Wenxi Li
- School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, China
| | - Wenru Fan
- Frontiers Science Center for Flexible Electronics, Institute of Flexible Electronics, Northwestern Polytechnical University, Xi’an 710072, China
| | - Ruoqing Zhao
- Frontiers Science Center for Flexible Electronics, Institute of Flexible Electronics, Northwestern Polytechnical University, Xi’an 710072, China
| | - Haoyang Feng
- Frontiers Science Center for Flexible Electronics, Institute of Flexible Electronics, Northwestern Polytechnical University, Xi’an 710072, China
| | - Dengfeng Peng
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Wei Huang
- Frontiers Science Center for Flexible Electronics, Institute of Flexible Electronics, Northwestern Polytechnical University, Xi’an 710072, China
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7
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McFadden ME, Barber RW, Overholts AC, Robb MJ. Naphthopyran molecular switches and their emergent mechanochemical reactivity. Chem Sci 2023; 14:10041-10067. [PMID: 37772118 PMCID: PMC10530568 DOI: 10.1039/d3sc03729k] [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: 07/19/2023] [Accepted: 08/23/2023] [Indexed: 09/30/2023] Open
Abstract
Naphthopyran molecular switches undergo a ring-opening reaction upon external stimulation to generate intensely colored merocyanine dyes. Their unique modularity and synthetic accessibility afford exceptional control over their properties and stimuli-responsive behavior. Commercial applications of naphthopyrans as photoswitches in photochromic ophthalmic lenses have spurred an extensive body of work exploring naphthopyran-merocyanine structure-property relationships. The recently discovered mechanochromic behavior of naphthopyrans has led to their emergent application in the field of polymer mechanochemistry, enabling advances in the design of force-responsive materials as well as fundamental insights into mechanochemical reactivity. The structure-property relationships established in the photochemical literature serve as a convenient blueprint for the design of naphthopyran molecular force probes with precisely tuned properties. On the other hand, the mechanochemical reactivity of naphthopyran diverges in many cases from the conventional photochemical pathways, resulting in unexpected properties and opportunities for deeper understanding and innovation in polymer mechanochemistry. Here, we highlight the features of the naphthopyran scaffold that render it a powerful platform for the design of mechanochromic materials and review recent advances in naphthopyran mechanochemistry.
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Affiliation(s)
- Molly E McFadden
- Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena California 91125 USA
| | - Ross W Barber
- Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena California 91125 USA
| | - Anna C Overholts
- Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena California 91125 USA
| | - Maxwell J Robb
- Division of Chemistry and Chemical Engineering, California Institute of Technology Pasadena California 91125 USA
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8
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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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9
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O'Neill RT, Boulatov R. Experimental quantitation of molecular conditions responsible for flow-induced polymer mechanochemistry. Nat Chem 2023; 15:1214-1223. [PMID: 37430105 DOI: 10.1038/s41557-023-01266-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 06/05/2023] [Indexed: 07/12/2023]
Abstract
Fragmentation of macromolecular solutes in rapid flows is of considerable fundamental and practical importance. The sequence of molecular events preceding chain fracture is poorly understood, because such events cannot be visualized directly but must be inferred from changes in the bulk composition of the flowing solution. Here we describe how analysis of same-chain competition between fracture of a polystyrene chain and isomerization of a chromophore embedded in its backbone yields detailed characterization of the distribution of molecular geometries of mechanochemically reacting chains in sonicated solutions. In our experiments the overstretched (mechanically loaded) chain segment grew and drifted along the backbone on the same timescale as, and in competition with, the mechanochemical reactions. Consequently, only <30% of the backbone of a fragmenting chain is overstretched, with both the maximum force and the maximum reaction probabilities located away from the chain centre. We argue that quantifying intrachain competition is likely to be mechanistically informative for any flow fast enough to fracture polymer chains.
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Affiliation(s)
| | - Roman Boulatov
- Department of Chemistry, University of Liverpool, Liverpool, UK.
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10
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Reza AI, Iwai K, Nishiwaki N. A Study of the Correlation between the Bulkiness of peri-Substituents and the Distortion of a Naphthalene Ring. Molecules 2023; 28:5343. [PMID: 37513214 PMCID: PMC10386483 DOI: 10.3390/molecules28145343] [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: 06/13/2023] [Revised: 07/03/2023] [Accepted: 07/10/2023] [Indexed: 07/30/2023] Open
Abstract
A systematic study on the distortion of a naphthalene ring was performed using steric repulsion between peri-substituents at the 1- and 8-positions. The introduction of bromo groups into the methyl groups of the 1,8-dimethylnaphthalene enhanced the steric repulsion to distort the naphthalene ring. X-ray crystallography revealed that 1,8-bis(bromomethyl)naphthalene had a vertical distortion with a 11.0° dihedral angle (α) between peri-substituents which disturbed the coplanarity of the naphthalene ring. On the other hand, the dihedral angle of 1,8-bis(dibromomethyl)naphthalene was smaller (α = 8.3°) despite the bulkier substituents. In this case, horizontal distortion of the naphthalene ring increased. These distortions should non-electronically activate the naphthalene framework. In order to evaluate their reactivity, nitration and hydrogenation were carried out; however, the 1,8-bis(dibromomethyl)naphthalene was intact under the employed conditions. A DFT calculation suggested that the inertness of the 1,8-bis(dibromomethyl)naphthalene is presumably due to the negative hyperconjugation of the (dibromo)methyl group.
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Affiliation(s)
- Annisa Indah Reza
- School of Engineering Science, Kochi University of Technology, Tosayamada, Kami, Kochi 782-8502, Japan
| | - Kento Iwai
- School of Engineering Science, Kochi University of Technology, Tosayamada, Kami, Kochi 782-8502, Japan
- Research Center for Molecular Design, Kochi University of Technology, Tosayamada, Kami, Kochi 782-8502, Japan
| | - Nagatoshi Nishiwaki
- School of Engineering Science, Kochi University of Technology, Tosayamada, Kami, Kochi 782-8502, Japan
- Research Center for Molecular Design, Kochi University of Technology, Tosayamada, Kami, Kochi 782-8502, Japan
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11
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Boswell BR, Mansson CMF, Cabrera GE, Hansen CR, Oliver AG, Burns NZ. A Metal-Free Cyclobutadiene Reagent for Intermolecular [4 + 2] Cycloadditions. J Am Chem Soc 2023; 145:5631-5636. [PMID: 36856576 DOI: 10.1021/jacs.3c01591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Cyclobutadiene is a highly reactive antiaromatic hydrocarbon that has fascinated chemists for over 60 years. However, its preparation and uses in chemical synthesis are sparing, in part due to its lengthy synthesis that generates hazardous byproducts including excess heavy metals. Herein, we report a scalable, metal-free cyclobutadiene reagent, diethyldiazabicyclohexene dicarboxylate, and explore its intermolecular [4 + 2] cycloaddition with various electron-deficient alkenes. We also demonstrate its utility in a three-step synthesis of dipiperamide G and a diverse array of product derivatizations including bromocyclobutadiene.
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Affiliation(s)
- Benjamin R Boswell
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Carl M F Mansson
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Gabrielle E Cabrera
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Calvin R Hansen
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Allen G Oliver
- Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, Indiana 46545, United States
| | - Noah Z Burns
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
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12
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Willis-Fox N, Watchorn-Rokutan E, Rognin E, Daly R. Technology pull: scale-up of polymeric mechanochemical force sensors. TRENDS IN CHEMISTRY 2023. [DOI: 10.1016/j.trechm.2023.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
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13
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Mandal I, Kilbinger AFM. Practical Route for Catalytic Ring-Opening Metathesis Polymerization. JACS AU 2022; 2:2800-2808. [PMID: 36590270 PMCID: PMC9795566 DOI: 10.1021/jacsau.2c00566] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/21/2022] [Accepted: 11/23/2022] [Indexed: 06/17/2023]
Abstract
Norbornene derivatives are typical monomers for ring-opening metathesis polymerization (ROMP) for synthesizing highly functional polymers. However, the lack of catalytic methods, that is, the lack of readily available chain transfer agents (CTAs) for these monomers has been a significant cost limitation when large-scale syntheses are required. Here, we report commercially available styrene and its derivatives as efficient regioselective CTAs for the catalytic synthesis of metathesis polymers requiring up to 1000 times less ruthenium than in classical ROMP experiments. The molecular weight of the synthesized polymers was controlled by the monomer-to-CTA ratio. Low molecular weight ROMP polymers known for their antimicrobial properties were also synthesized on a gram scale in this report. Polymers were characterized by SEC, 1H NMR spectroscopy, and isotopically resolved MALDI-TOF MS. This approach describes a greener, more cost-effective, and eco-friendly methodology for the preparation of metathesis-based materials on the multigram scale.
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14
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Double-Layer Hydrogels with Tunable Mechanofluorochromic Response for Smart Display. CHINESE JOURNAL OF POLYMER SCIENCE 2022. [DOI: 10.1007/s10118-022-2885-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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15
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Tan M, Wang X, Xie T, Zhang Z, Shi Y, Li Y, Chen Y. Fluorogenic Mechanophore Based on Dithiomaleimide with Dual Responsiveness. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c01077] [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)
- Min Tan
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Sun Yat-Sen University, Guangzhou 510006, China
| | - Xiaoying Wang
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Sun Yat-Sen University, Guangzhou 510006, China
| | - Tong Xie
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Sun Yat-Sen University, Guangzhou 510006, China
| | - Zhen Zhang
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Sun Yat-Sen University, Guangzhou 510006, China
| | - Yi Shi
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Sun Yat-Sen University, Guangzhou 510006, China
| | - Yuanchao Li
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Sun Yat-Sen University, Guangzhou 510006, China
| | - Yongming Chen
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Sun Yat-Sen University, Guangzhou 510006, China
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16
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Ultrasound triggered organic mechanoluminescence materials. Adv Drug Deliv Rev 2022; 186:114343. [PMID: 35580814 DOI: 10.1016/j.addr.2022.114343] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 04/05/2022] [Accepted: 05/09/2022] [Indexed: 11/23/2022]
Abstract
Ultrasound induced organic mechanoluminescence materials have become one of the focal topics in wireless light sources since they exhibit high spatiotemporal resolution, biocompatibility and excellent tissue penetration depth. These properties promote great potential in ultrahigh sensitive bioimaging with no background noise and noninvasive nanodevices. Recent advances in chemistry, nanotechnology and biomedical research are revolutionizing ultrasound induced organic mechanoluminescence. Herein, we try to summarize some recent researches in ultrasound induced mechanoluminescence that use various materials design strategies based on the molecular conformational changes and cycloreversion reaction. Practical applications, like noninvasive bioimaging and noninvasive optogenetics, are also presented and prospected.
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17
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Xuan M, Schumacher C, Bolm C, Göstl R, Herrmann A. The Mechanochemical Synthesis and Activation of Carbon-Rich π-Conjugated Materials. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2105497. [PMID: 35048569 PMCID: PMC9259731 DOI: 10.1002/advs.202105497] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 12/21/2021] [Indexed: 05/14/2023]
Abstract
Mechanochemistry uses mechanical force to break, form, and manipulate chemical bonds to achieve functional transformations and syntheses. Over the last years, many innovative applications of mechanochemistry have been developed. Specifically for the synthesis and activation of carbon-rich π-conjugated materials, mechanochemistry offers reaction pathways that either are inaccessible with other stimuli, such as light and heat, or improve reaction yields, energy consumption, and substrate scope. Therefore, this review summarizes the recent advances in this research field combining the viewpoints of polymer and trituration mechanochemistry. The highlighted mechanochemical transformations include π-conjugated materials as optical force probes, the force-induced release of small dye molecules, and the mechanochemical synthesis of polyacetylene, carbon allotropes, and other π-conjugated materials.
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Affiliation(s)
- Mingjun Xuan
- DWI – Leibniz Institute for Interactive MaterialsForckenbeckstr. 50Aachen52056Germany
- Institute of Technical and Macromolecular ChemistryRWTH Aachen UniversityWorringerweg 1Aachen52074Germany
| | - Christian Schumacher
- Institute of Organic ChemistryRWTH Aachen UniversityLandoltweg 1Aachen52074Germany
| | - Carsten Bolm
- Institute of Organic ChemistryRWTH Aachen UniversityLandoltweg 1Aachen52074Germany
| | - Robert Göstl
- DWI – Leibniz Institute for Interactive MaterialsForckenbeckstr. 50Aachen52056Germany
| | - Andreas Herrmann
- DWI – Leibniz Institute for Interactive MaterialsForckenbeckstr. 50Aachen52056Germany
- Institute of Technical and Macromolecular ChemistryRWTH Aachen UniversityWorringerweg 1Aachen52074Germany
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18
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Wang K, Yan S, Han T, Wu Q, Yan N, Kang M, Ge J, Wang D, Tang BZ. Cascade C-H-Activated Polyannulations toward Ring-Fused Heteroaromatic Polymers for Intracellular pH Mapping and Cancer Cell Killing. J Am Chem Soc 2022; 144:11788-11801. [PMID: 35736562 DOI: 10.1021/jacs.2c04032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The development of straightforward and efficient synthetic methods toward ring-fused heteroaromatic polymers with attractive functionalities has great significance in both chemistry and materials science. Herein, we develop a facile cascade C-H-activated polyannulation route that can in situ generate multiple ring-fused aza-heteroaromatic polymers from readily available monomers in an atom-economical manner. A series of complex polybenzimidazole derivatives with high absolute molecular weights of up to 24 000 are efficiently produced in high yields within 2 h. Benefiting from their unique imidazole-containing ring-fused structures with multiple aryl pendants, the obtained polymers show excellent thermal and morphological stability, good solution processability, high refractive index, small chromic dispersion, as well as remarkable acid-base-responsive fluorescence. Taking advantage of the ratiometric fluorescence response of the triphenylamine-substituted heteroaromatic polymer to pH variations, we successfully apply it as a sensitive fluorescence probe for the mapping and quantitative analysis of intracellular pH in live cells. Furthermore, through the simple N-methylation reaction of the ring-fused polybenzimidazoles, diverse azonia-containing polyelectrolytes are readily produced, which can efficiently kill cancer cells via the synergistic effects of dark toxicity and phototoxicity.
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Affiliation(s)
- Kang Wang
- Center for AIE Research, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China.,College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Saisai Yan
- Center for AIE Research, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China.,College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Ting Han
- Center for AIE Research, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
| | - Qian Wu
- Center for AIE Research, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China.,Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China
| | - Neng Yan
- Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong 999077, China
| | - Miaomiao Kang
- Center for AIE Research, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
| | - Jinyin Ge
- Center for AIE Research, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China.,College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Dong Wang
- Center for AIE Research, Shenzhen Key Laboratory of Polymer Science and Technology, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
| | - Ben Zhong Tang
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China.,Shenzhen Institute of Aggregate Science and Technology, School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China
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19
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Hu H, Cheng X, Ma Z, Sijbesma RP, Ma Z. Polymer Mechanochromism from Force-Tuned Excited-State Intramolecular Proton Transfer. J Am Chem Soc 2022; 144:9971-9979. [PMID: 35617457 DOI: 10.1021/jacs.2c03056] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Real-time monitoring of strain/stress in polymers is a big challenge to date. Herein, we for the first time report an ESIPT (excited-state intramolecular proton transfer)-based mechanochromic mechanophore (MM). The synthesis of target MM PhMz-4OH [(2-hydroxyphenyl)benzimidazole with four aliphatic hydroxyls] is quite facile. PhMz-4OH possesses characteristic dual emissions, and its ESIPT activity is greatly affected by steric hindrance. Then, PhMz-4OH was covalently linked into polyurethane chains (PhMz-4OH@PU). Upon stretching, the PhMz-4OH@PU films showed fluorescence color change and spectral variation with the increase in enol emission and blueshift of keto emission due to the force-induced torsion of the dihedral angle between the proton donor and the proton acceptor. The PhMz-4OH@PU films with high mechanophore concentrations (>0.36 mol %) might undergo a two-stage force-responsive process, including torsion of the dihedral angle via force-induced disaggregation and direct chain-transduced force-induced torsion of the dihedral angle. The intensity ratio of enol emission to keto emission (IE/IK) shows a quantitative correlation with elongation, and real-time strain sensing is achieved. PhMz-4OH is a successful type II MM (without covalent bond scission) and displays high sensitivity and excellent reversibility to stress. Two control structures PhMz-NH2 and PhMz-2OH were also embedded into PU but no spectral or color changes were detected, further confirming that mechanochromism of PhMz-4OH@PU films arises from the chain-transduced force. Density function theory (DFT) calculation was performed to study the force-tuned ESIPT process theoretically and rationalize the experimental results. This study might lay the foundation for real-time stress/strain sensing in practical applications.
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Affiliation(s)
- Huan Hu
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Organic-Inorganic Composites, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Xin Cheng
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Organic-Inorganic Composites, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Zhimin Ma
- College of Engineering, Peking University, Beijing 100871, China
| | - Rint P Sijbesma
- Department of Chemical Engineering & Chemistry and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, Eindhoven 5600 MB, The Netherlands
| | - Zhiyong Ma
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Organic-Inorganic Composites, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China.,State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai 200438, China
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20
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Wang X, Cao Y, Peng Y, Wang L, Hou W, Zhou Y, Shi Y, Huang H, Chen Y, Li Y. Concurrent and Mechanochemical Activation of Two Distinct and Latent Fluorophores via Retro-Diels-Alder Reaction of an Anthracene-Aminomaleimide Adduct. ACS Macro Lett 2022; 11:310-316. [PMID: 35575364 DOI: 10.1021/acsmacrolett.2c00036] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Generally, a typical mechanochromophore produces color change through chemical transformation into one or two identical new chromophores/fluorophores under applied mechanical force. Herein, we introduce a novel mechanophore based on an anthracene-aminomaleimide Diels-Alder (DA) adduct featuring two distinct and latent fluorophores. This nonfluorescent mechanophore undergoes retro-DA reaction upon mechanochemical activation in solution and the solid state, generating the respective anthracene and aminomaleimide fragments simultaneously, both of which are highly emissive with different fluorescent colors. In addition, the aminomaleimide fluorophore exhibits sensitive fluorescence on-off response to protic solvents or polar solvents, which enables dual-color mechanochromism from this single mechanophore.
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Affiliation(s)
- Xiaoying Wang
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, Sun Yat-Sen University, Guangzhou 510006, China
| | - Yifeng Cao
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, Sun Yat-Sen University, Guangzhou 510006, China
| | - Yanling Peng
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, Sun Yat-Sen University, Guangzhou 510006, China
| | - Lewen Wang
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, Sun Yat-Sen University, Guangzhou 510006, China
| | - Wangmeng Hou
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, Sun Yat-Sen University, Guangzhou 510006, China
| | - Yecheng Zhou
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, Sun Yat-Sen University, Guangzhou 510006, China
| | - Yi Shi
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, Sun Yat-Sen University, Guangzhou 510006, China
| | - Huahua Huang
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, Sun Yat-Sen University, Guangzhou 510006, China
| | - Yongming Chen
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, Sun Yat-Sen University, Guangzhou 510006, China
| | - Yuanchao Li
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, Sun Yat-Sen University, Guangzhou 510006, China
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21
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Yin G, Huang J, Liu D, Li R, Wei S, Si M, Ni F, Zheng Y, Yang Q, Zhou R, Le X, Lu W, Chen T. Mechanochemical transformation of fluorescent hydrogel based on dynamic lanthanide-terpyridine coordination. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2022.03.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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22
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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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23
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Ditzler RAJ, Zhukhovitskiy AV. Sigmatropic Rearrangements of Polymer Backbones: Vinyl Polymers from Polyesters in One Step. J Am Chem Soc 2021; 143:20326-20331. [PMID: 34809424 DOI: 10.1021/jacs.1c09657] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Polymer modification is a fundamental scientific challenge, as a means of both upcycling plastics and extracting a stimulus response from them. To date, the overwhelming majority of polymer modifications has focused on the polymer periphery. Herein, we demonstrate nearly quantitative, scission-free modification of polymer backbones, namely, a metamorphosis of polyesters into vinyl polymers resembling commodity materials via the Ireland-Claisen sigmatropic rearrangement. The glass transition temperature (Tg) and thermal stability of the polyesters undergo dramatic changes post-transformation. Beyond polymer modification, our work advances the application of retrosynthetic analysis in polymer synthesis; the nontraditional production of vinyl polymers from lactones opens the door to a slew of previously inaccessible materials.
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Affiliation(s)
- Rachael A J Ditzler
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Aleksandr V Zhukhovitskiy
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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24
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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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25
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Wang T, Wang H, Shen L, Zhang N. Force-induced strengthening of a mechanochromic polymer based on a naphthalene-fused cyclobutane mechanophore. Chem Commun (Camb) 2021; 57:12675-12678. [PMID: 34779466 DOI: 10.1039/d1cc05305a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We discovered a force-induced strengthening of a mechanochromic polymer based on a naphthalene-fused cyclobutane mechanophore (NCD). Our results revealed that mechanically induced retro-cycloaddition of the NCD and subsequent crosslinking reactions between CC bonds were responsible for this peculiar strenghthening, and demonstrated the good possibility that the NCD can be applied in smart materials fields.
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Affiliation(s)
- Taisheng Wang
- School of Materials Science and Engineering, Nanjing Institute of Technology, Nanjing, 211167, P. R. China. .,Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology, Nanjing, 211167, P. R. China
| | - Haoxiang Wang
- School of Materials Science and Engineering, Nanjing Institute of Technology, Nanjing, 211167, P. R. China.
| | - Lei Shen
- School of Materials Science and Engineering, Nanjing Institute of Technology, Nanjing, 211167, P. R. China.
| | - Na Zhang
- School of Materials Science and Engineering, Nanjing Institute of Technology, Nanjing, 211167, P. R. China. .,Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology, Nanjing, 211167, P. R. China
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26
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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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27
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Tan M, Hu Z, Dai Y, Peng Y, Zhou Y, Shi Y, Li Y, Chen Y. A Simple Mechanochromic Mechanophore Based on Aminothiomaleimide. ACS Macro Lett 2021; 10:1423-1428. [PMID: 35549011 DOI: 10.1021/acsmacrolett.1c00543] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mechanochromic mechanophores have promising applications in stress sensing and damage detection. Here we report a simple mechanofluorochromic mechanophore based on aminothiomaleimide (ATM). Poly(methyl acrylate) containing this mechanophore (ATM-PMA) was synthesized by atom transfer radical polymerization (ATRP) using an ATM-derived difunctional initiator. To investigate its mechanofluorochromism, the solution of ATM-PMA was subjected to ultrasonication, and size exclusion chromatography (SEC) and fluorescence spectroscopy were employed to monitor the changes in molecular weight and fluorescence emission. The results showed that the molecular weight of ATM-PMA decreased upon ultrasonication, accompanied by a shift of fluorescence emission from bright yellow to light blue. This mechanophore of a simple functional group of ATM has great potential to be used in mechanochromic polymer materials.
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Affiliation(s)
- Min Tan
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Sun Yat-Sen University, Guangzhou 510006, China
| | - Zhitao Hu
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Sun Yat-Sen University, Guangzhou 510006, China
| | - Yunkai Dai
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Sun Yat-Sen University, Guangzhou 510006, China
| | - Yanling Peng
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Sun Yat-Sen University, Guangzhou 510006, China
| | - Yecheng Zhou
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Sun Yat-Sen University, Guangzhou 510006, China
| | - Yi Shi
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Sun Yat-Sen University, Guangzhou 510006, China
| | - Yuanchao Li
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Sun Yat-Sen University, Guangzhou 510006, China
| | - Yongming Chen
- School of Materials Science and Engineering, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Research Center for Functional Biomaterials Engineering and Technology Guangdong, Sun Yat-Sen University, Guangzhou 510006, China
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28
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Qi Q, Sekhon G, Chandradat R, Ofodum NM, Shen T, Scrimgeour J, Joy M, Wriedt M, Jayathirtha M, Darie CC, Shipp DA, Liu X, Lu X. Force-Induced Near-Infrared Chromism of Mechanophore-Linked Polymers. J Am Chem Soc 2021; 143:17337-17343. [PMID: 34586805 DOI: 10.1021/jacs.1c05923] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A near-infrared (NIR) mechanophore was developed and incorporated into a poly(methyl acrylate) chain to showcase the first force-induced NIR chromism in polymeric materials. This mechanophore, based on benzo[1,3]oxazine (OX) fused with a heptamethine cyanine moiety, exhibited NIR mechanochromism in solution, thin-film, and bulk states. The mechanochemical activity was validated using UV-vis-NIR absorption/fluorescence spectroscopies, gel permeation chromatography (GPC), NMR, and DFT simulations. Our work demonstrates that NIR mechanochromic polymers have considerable potential in mechanical force sensing, damage detection, bioimaging, and biomechanics.
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Affiliation(s)
| | | | | | | | - Tianruo Shen
- Fluorescence Research Group, Singapore University of Technology and Design, 8 Somapah Road, 487372 Singapore
| | | | | | | | | | | | | | - Xiaogang Liu
- Fluorescence Research Group, Singapore University of Technology and Design, 8 Somapah Road, 487372 Singapore
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29
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Jung S, Yoon HJ. Mechanical Force for the Transformation of Aziridine into Imine. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202109358] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Sangmin Jung
- Department of Chemistry Korea University Seoul 02841 South Korea
| | - Hyo Jae Yoon
- Department of Chemistry Korea University Seoul 02841 South Korea
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30
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Jung S, Yoon HJ. Mechanical Force for the Transformation of Aziridine into Imine. Angew Chem Int Ed Engl 2021; 60:23564-23568. [PMID: 34499388 DOI: 10.1002/anie.202109358] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/12/2021] [Indexed: 11/07/2022]
Abstract
Force-selective mechanochemical reactions may be important for applications in polymer mechanochemistry, yet it is difficult to achieve such reactions. This paper reports that cis-N-phthalimidoaziridine incorporated into a macromolecular backbone undergoes migration of N-phthalimido group to afford imine under mechanochemical condition and not thermal one. The imine is further hydrolyzed by water bifurcating into amine and aldehyde. These structural transformations are confirmed by 1 H NMR and FT-IR spectroscopic analyses. Computational simulations are conducted for the aziridine mechanophore to propose the mechanism of reaction and define the substrate scope of reaction.
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Affiliation(s)
- Sangmin Jung
- Department of Chemistry, Korea University, Seoul, 02841, South Korea
| | - Hyo Jae Yoon
- Department of Chemistry, Korea University, Seoul, 02841, South Korea
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31
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Ikenaga A, Akiyama Y, Ishiyama T, Gon M, Tanaka K, Chujo Y, Isoda K. Stimuli-Responsive Self-Assembly of π-Conjugated Liquids Triggers Circularly Polarized Luminescence. ACS APPLIED MATERIALS & INTERFACES 2021; 13:47127-47133. [PMID: 34581177 DOI: 10.1021/acsami.1c13119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We developed novel room-temperature stimuli-responsive N-heteroacene-based liquid materials bearing a chiral alkyl chain. When these liquid materials were exposed to HCl vapor as an external stimulus, a disordered-ordered state change occurred immediately to yield self-assembled solid states from fluidic liquids. The self-assembly mechanism during this state change was evaluated by experimental in situ observations and molecular dynamics simulations over various spatiotemporal scales. These self-assembled structures led to supramolecular chirality through the influence of the chiral alkyl chain. As a result, circularly polarized luminescence (CPL) was triggered in the solid state, which was absent in the precursor liquid, thereby rendering this the first report on a stimuli-responsive CPL on/off liquid material. In addition, the initial state was recovered by exposure to air or upon heating. Moreover, the synergy between the experimental and the theoretical studies opens a new avenue to develop a novel class of stimuli-responsive materials and to discover novel phenomena in such materials.
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Affiliation(s)
- Ayumi Ikenaga
- Division of Advanced Materials Science, Graduate School of Engineering, Kagawa University, 2217-20 Hayashi-cho, Takamatsu, Kagawa 761-0396, Japan
| | - Yuichi Akiyama
- Division of Advanced Materials Science, Graduate School of Engineering, Kagawa University, 2217-20 Hayashi-cho, Takamatsu, Kagawa 761-0396, Japan
| | - Tatsuya Ishiyama
- Department of Applied Chemistry, Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555, Japan
| | - Masayuki Gon
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Kazuo Tanaka
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Yoshiki Chujo
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Kyosuke Isoda
- Program in Advanced Materials Science, Faculty of Engineering and Design, Kagawa University, 2217-20 Hayashi-cho, Takamatsu, Kagawa 761-0396, Japan
- Health and Medical Research Institute, National Institute of Advanced Industrial Science and Technology, 2217-14 Hayashi-cho, Takamatsu, Kagawa 761-0395, Japan
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Nowicki K, Pacholak P, Luliński S. Heteroelement Analogues of Benzoxaborole and Related Ring Expanded Systems. Molecules 2021; 26:5464. [PMID: 34576937 PMCID: PMC8468133 DOI: 10.3390/molecules26185464] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 09/03/2021] [Accepted: 09/06/2021] [Indexed: 11/16/2022] Open
Abstract
The review covers the chemistry of organoboron heterocycles structurally related to benzoxaboroles where one of the carbon atoms in a boracycle or a fused benzene ring is replaced by a heteroelement such as boron, silicon, tin, nitrogen, phosphorus, or iodine. Related ring expanded systems including those based on naphthalene and biphenyl cores are also described. The information on synthetic methodology as well as the basic structural and physicochemical characteristics of these emerging heterocycles is complemented by a presentation of their potential applications in organic synthesis and medicinal chemistry, the latter aspect being mostly focused on the promising antimicrobial activity of selected compounds.
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Affiliation(s)
- Krzysztof Nowicki
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, PL-00-664 Warsaw, Poland; (K.N.); (P.P.)
| | - Piotr Pacholak
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, PL-00-664 Warsaw, Poland; (K.N.); (P.P.)
- Faculty of Chemistry, University of Warsaw, Pasteura 1, PL-02-093 Warsaw, Poland
| | - Sergiusz Luliński
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, PL-00-664 Warsaw, Poland; (K.N.); (P.P.)
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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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Kida J, Aoki D, Otsuka H. Self-Strengthening of Cross-Linked Elastomers via the Use of Dynamic Covalent Macrocyclic Mechanophores. ACS Macro Lett 2021; 10:558-563. [PMID: 35570767 DOI: 10.1021/acsmacrolett.1c00124] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The creation of polymeric materials that self-strengthen in response to a mechanical force is an important objective in the field of polymer chemistry. Here, the mechanochemical strengthening of cross-linked elastomers using macrocyclic mechanophores that contain a dynamic covalent disulfide bond is reported. Cross-linked poly(hexyl methacrylate) (CPHMA) polymers with macrocyclic mechanophores inserted at the cross-linking points were synthesized via free radical polymerization. Tensile and swelling tests showed that the addition of the macrocyclic mechanophores to the CPHMA polymers successfully impart them with self-strengthening functionality following compression, without the need for any additives such as monomers and modifiers, or any other stimuli.
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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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Qian H, Purwanto NS, Ivanoff DG, Halmes AJ, Sottos NR, Moore JS. Fast, reversible mechanochromism of regioisomeric oxazine mechanophores: Developing in situ responsive force probes for polymeric materials. Chem 2021. [DOI: 10.1016/j.chempr.2021.02.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Abstract
In an effort to develop polymers that can undergo extensive backbone degradation in response to mechanical stress, we report a polymer system that is hydrolytically stable but unmasks easily hydrolysable enol ether backbone linkages when force is applied. These polymers were synthesized by ring-opening metathesis polymerization (ROMP) of a novel mechanophore monomer consisting of cyclic ether fused bicyclohexene. Hydrogenation of the resulting polymers led to significantly enhanced thermal stability (Td > 400 °C) and excellent resistance toward acidic or basic conditions. Solution ultrasonication of the polymers resulted in up to 65% activation of the mechanophore units and conversion to backbone enol ether linkages, which then allowed facile degradation of the polymers to generate small molecule or oligomeric species under mildly acidic conditions. We also achieved solid-state mechano-activation and polymer degradation via grinding the solid polymer. Force-induced hydrolytic polymer degradability can enable materials that are stable under force-free conditions but readily degrade under stress. Facile degradation of mechanically activated polymechanophores also facilitates the analysis of mechanochemical products. A mechanically responsive polymer system that is hydrolytically stable without stress, but unmasks enol ether backbone linkages under force to allow facile hydrolytic degradation.![]()
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Affiliation(s)
- Jinghui Yang
- Department of Chemistry, Stanford University Stanford California 94305 USA
| | - Yan Xia
- Department of Chemistry, Stanford University Stanford California 94305 USA
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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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Klein IM, Husic CC, Kovács DP, Choquette NJ, Robb MJ. Validation of the CoGEF Method as a Predictive Tool for Polymer Mechanochemistry. J Am Chem Soc 2020; 142:16364-16381. [DOI: 10.1021/jacs.0c06868] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Isabel M. Klein
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Corey C. Husic
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Dávid P. Kovács
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Nicolas J. Choquette
- 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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