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Skala ME, Zeitler SM, Golder MR. Liquid-assisted grinding enables a direct mechanochemical functionalization of polystyrene waste. Chem Sci 2024; 15:10900-10907. [PMID: 39027266 PMCID: PMC11253180 DOI: 10.1039/d4sc03362k] [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: 05/22/2024] [Accepted: 06/07/2024] [Indexed: 07/20/2024] Open
Abstract
The plastic waste crisis has grave consequences for our environment, as most single-use commodity polymers remain in landfills and oceans long after their commercial lifetimes. Utilizing modern synthetic techniques to chemically modify the structure of these post-consumer plastics (e.g., upcycling) can impart new properties and added value for commercial applications. To expand beyond the abilities of current solution-state chemical processes, we demonstrate post-polymerization modification of polystyrene via solid-state mechanochemistry enabled by liquid-assisted grinding (LAG). Importantly, this emblematic trifluoromethylation study modifies discarded plastic, including dyed materials, using minimal exogenous solvent and plasticizers for improved sustainability. Ultimately, this work serves as a proof-of-concept for the direct mechanochemical post-polymerization modification of commodity polymers, and we expect future remediation of plastic waste via similar mechanochemical reactions.
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Affiliation(s)
- Morgan E Skala
- Department of Chemistry, Molecular Engineering & Science Institute, University of Washington 36 Bagley Hall Seattle WA 98195 USA
| | - Sarah M Zeitler
- Department of Chemistry, Molecular Engineering & Science Institute, University of Washington 36 Bagley Hall Seattle WA 98195 USA
| | - Matthew R Golder
- Department of Chemistry, Molecular Engineering & Science Institute, University of Washington 36 Bagley Hall Seattle WA 98195 USA
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2
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Zhao H, Liu Y, Li G, Lei D, Du Y, Li Y, Tang H, Dou X. Electrophilicity Modulation for Sub-ppm Visualization and Discrimination of EDA. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2400361. [PMID: 38447144 PMCID: PMC11095169 DOI: 10.1002/advs.202400361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 02/07/2024] [Indexed: 03/08/2024]
Abstract
Precise and timely recognition of hazardous chemical substances is of great significance for safeguarding human health, ecological environment, public security, etc., especially crucial for adopting appropriate disposition measures. Up to now, there remains a practical challenge to sensitively detect and differentiate organic amines with similar chemical structures with intuitive analysis outcomes. Here, a unique optical probe with two electrophilic recognition sites for rapid and ultra-sensitive ratiometric fluorescence detection of ethylenediamine (EDA) is presented, while producing distinct fluorescence signals to its structural analog. The probe exhibits ppb/nmol level sensitivity to liquidous and gaseous EDA, specific recognition toward EDA without disturbance to up to 28 potential interferents, as well as rapid fluorescence response within 0.2 s. By further combining the portable sensing chip with the convolutional algorithm endowed with image processing, this work cracked the problem of precisely discriminating the target and non-targets at extremely low concentrations.
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Affiliation(s)
- Hao Zhao
- Key Laboratory of Xinjiang Phytomedicine Resource and UtilizationMinistry of EducationSchool of PharmacyShihezi UniversityShihezi832000China
- Xinjiang Key Laboratory of Trace Chemical Substances SensingXinjiang Technical Institute of Physics and ChemistryChinese Academy of SciencesUrumqi830011China
| | - Yuan Liu
- Xinjiang Key Laboratory of Trace Chemical Substances SensingXinjiang Technical Institute of Physics and ChemistryChinese Academy of SciencesUrumqi830011China
| | - Gaosheng Li
- Xinjiang Key Laboratory of Trace Chemical Substances SensingXinjiang Technical Institute of Physics and ChemistryChinese Academy of SciencesUrumqi830011China
| | - Da Lei
- Xinjiang Key Laboratory of Trace Chemical Substances SensingXinjiang Technical Institute of Physics and ChemistryChinese Academy of SciencesUrumqi830011China
| | - Yuwan Du
- Xinjiang Key Laboratory of Trace Chemical Substances SensingXinjiang Technical Institute of Physics and ChemistryChinese Academy of SciencesUrumqi830011China
| | - Yudong Li
- Xinjiang Key Laboratory of Trace Chemical Substances SensingXinjiang Technical Institute of Physics and ChemistryChinese Academy of SciencesUrumqi830011China
| | - Hui Tang
- Key Laboratory of Xinjiang Phytomedicine Resource and UtilizationMinistry of EducationSchool of PharmacyShihezi UniversityShihezi832000China
| | - Xincun Dou
- Xinjiang Key Laboratory of Trace Chemical Substances SensingXinjiang Technical Institute of Physics and ChemistryChinese Academy of SciencesUrumqi830011China
- Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of SciencesBeijing100049China
- Key Laboratory of Improvised Explosive Chemicals for State Market RegulationUrumqi830011China
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Sterling AJ, Ciccia NR, Guo Y, Hartwig JF, Head-Gordon M. Mechanistic Insights into the Origins of Selectivity in a Cu-Catalyzed C-H Amidation Reaction. J Am Chem Soc 2024; 146:6168-6177. [PMID: 38381006 DOI: 10.1021/jacs.3c13822] [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
The catalytic transformation of C-H to C-N bonds offers rapid access to fine chemicals and high-performance materials, but achieving high selectivity from undirected aminations of unactivated C(sp3)-H bonds remains an outstanding challenge. We report the origins of the reactivity and selectivity of a Cu-catalyzed C-H amidation of simple alkanes. Using a combination of experimental and computational mechanistic studies and energy decomposition techniques, we uncover a switch in mechanism from inner-sphere to outer-sphere coupling between alkyl radicals and the active Cu(II) catalyst with increasing substitution of the alkyl radical. The combination of computational predictions and detailed experimental validation shows that simultaneous minimization of both Cu-C covalency and alkyl radical size increases the rate of reductive elimination and that both strongly electron-donating and electron-withdrawing substituents on the catalyst accelerate the selectivity-determining C-N bond formation process as a result of a change in mechanism. These findings offer design principles for the development of improved catalyst scaffolds for radical C-H functionalization reactions.
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Affiliation(s)
- Alistair J Sterling
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Nicodemo R Ciccia
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Yifan Guo
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - John F Hartwig
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Martin Head-Gordon
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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Neidhart EK, Hua M, Peng Z, Kearney LT, Bhat V, Vashahi F, Alexanian EJ, Sheiko SS, Wang C, Helms BA, Leibfarth FA. C-H Functionalization of Polyolefins to Access Reprocessable Polyolefin Thermosets. J Am Chem Soc 2023; 145:27450-27458. [PMID: 38079611 DOI: 10.1021/jacs.3c08682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Upcycling plastic waste into reprocessable materials with performance-advantaged properties would contribute to the development of a circular plastics economy. Here, we modify branched polyolefins and postconsumer polyethylene through a versatile C-H functionalization approach using thiosulfonates as a privileged radical group transfer functionality. Cross-linking the functionalized polyolefins with polytopic amines provided dynamically cross-linked polyolefin networks enabled by associative bond exchange of diketoenamine functionality. A combination of resonant soft X-ray scattering and grazing incidence X-ray scattering revealed hierarchical phase morphology in which diketoenamine-rich microdomains phase-separate within amorphous regions between polyolefin crystallites. The combination of dynamic covalent cross-links and microphase separation results in useful and improved mechanical properties, including a ∼4.5-fold increase in toughness, a reduction in creep deformation at temperatures relevant to use, and high-temperature structural stability compared to the parent polyolefin. The dynamic nature of diketoenamine cross-links provides stress relaxation at elevated temperatures, which enabled iterative reprocessing of the dynamic covalent polymer network with little cycle-to-cycle property fade. The ability to convert polyolefin waste into a reprocessable thermoformable material with attractive thermomechanical properties provides additional optionality for upcycling to enable future circularity.
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Affiliation(s)
- Eliza K Neidhart
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, United States
| | - Mutian Hua
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Zhengxing Peng
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Logan T Kearney
- Chemical Science Division, Oak Ridge National Lab, Oak Ridge, Tennessee 37830, United States
| | - Vittal Bhat
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, United States
| | - Foad Vashahi
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, United States
| | - Erik J Alexanian
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, United States
| | - Sergei S Sheiko
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, United States
| | - Cheng Wang
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Brett A Helms
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Frank A Leibfarth
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, United States
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Scott SS, Kaur B, Zheng CHM, Brant P, Gilmour DJ, Schafer LL. Amine-Functionalized Polybutadiene Synthesis by Tunable Postpolymerization Hydroaminoalkylation. J Am Chem Soc 2023; 145:22871-22877. [PMID: 37819801 DOI: 10.1021/jacs.3c07564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
Early transition metal-catalyzed hydroaminoalkylation is a powerful single-step method to selectively add amines to polybutadienes, offering an efficient strategy to access amine-functionalized polyolefins. Aryl and alkyl secondary amines were used with a tantalum catalyst to functionalize both 28 wt% (PBD13) and 70 wt% (PBD50) 1,2-polybutadiene polymers. The degree of amination was controlled by modifying amine and catalyst loading in both small- and multigram-scale reactions. The vinyl groups of 1,2-polybutadiene were aminated with ease, and unexpectedly the hydroaminoalkylation of challenging internal alkenes of the 1,4-polybutadiene unit was observed. This unanticipated reactivity was proposed to be due to a directing group effect. This hypothesis was supported with small-molecule model substrates, which also showed directed internal alkene amination. Increasing degrees of amination resulted in materials with dramatically higher and tunable glass transition temperature (Tg) values, due to the dynamic cross-linking accessible to hydrogen-bonding, amine-containing materials. Primary amine-functionalized polybutadiene was also prepared, demonstrating that a broad new class of amine-containing polyolefins can be accessed by postpolymerization hydroaminoalkylation.
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Affiliation(s)
- Sabrina S Scott
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - Brahmjot Kaur
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
- A2O Advanced Materials Inc., University P.O. Box 78552, 5754 University Blvd, Vancouver, BC V6T 1K0, Canada
| | - Cameron H M Zheng
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - Patrick Brant
- A2O Advanced Materials Inc., University P.O. Box 78552, 5754 University Blvd, Vancouver, BC V6T 1K0, Canada
| | - Damon J Gilmour
- A2O Advanced Materials Inc., University P.O. Box 78552, 5754 University Blvd, Vancouver, BC V6T 1K0, Canada
| | - Laurel L Schafer
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
- A2O Advanced Materials Inc., University P.O. Box 78552, 5754 University Blvd, Vancouver, BC V6T 1K0, Canada
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