Pub Date : 2024-05-20DOI: 10.1021/acsmacrolett.4c00217
Aristotelis Zografos, Erin M. Maines, Joseph F. Hassler, Frank S. Bates* and Marc A. Hillmyer*,
An H-polymer has an architecture that consists of four branches symmetrically attached to the ends of a polymer backbone, similar in shape to the letter “H”. Here, a renewable H-polymer efficiently synthesized using only ring-opening transesterification is demonstrated. The strategy relies on a tetrafunctional poly(±-lactide) macroinitiator, from which four poly(±-lactide) branches are grown simultaneously. 1H NMR spectroscopy, size exclusion chromatography (SEC), and matrix-assisted laser desorption/ionization (MALDI) spectrometry were used to verify the macroinitiator purity. Branch growth was probed using 1H NMR spectroscopy and SEC to reveal unique transesterification phenomena that can be controlled to yield architecturally pure or more complex materials. H-shaped PLA was prepared at the multigram scale with a weight-average molar mass Mw > 100 kg/mol and low dispersity Đ < 1.15. Purification involved routine precipitations steps, which yielded products that were architecturally relatively pure (∼93%). Small-amplitude oscillatory shear and extensional rheology measurements demonstrate the unique viscoelastic behavior associated with the H-shaped architecture.
{"title":"Preparation and Characterization of H-Shaped Polylactide","authors":"Aristotelis Zografos, Erin M. Maines, Joseph F. Hassler, Frank S. Bates* and Marc A. Hillmyer*, ","doi":"10.1021/acsmacrolett.4c00217","DOIUrl":"10.1021/acsmacrolett.4c00217","url":null,"abstract":"<p >An H-polymer has an architecture that consists of four branches symmetrically attached to the ends of a polymer backbone, similar in shape to the letter “H”. Here, a renewable H-polymer efficiently synthesized using only ring-opening transesterification is demonstrated. The strategy relies on a tetrafunctional poly(±-lactide) macroinitiator, from which four poly(±-lactide) branches are grown simultaneously. <sup>1</sup>H NMR spectroscopy, size exclusion chromatography (SEC), and matrix-assisted laser desorption/ionization (MALDI) spectrometry were used to verify the macroinitiator purity. Branch growth was probed using <sup>1</sup>H NMR spectroscopy and SEC to reveal unique transesterification phenomena that can be controlled to yield architecturally pure or more complex materials. H-shaped PLA was prepared at the multigram scale with a weight-average molar mass <i>M</i><sub>w</sub> > 100 kg/mol and low dispersity <i>Đ</i> < 1.15. Purification involved routine precipitations steps, which yielded products that were architecturally relatively pure (∼93%). Small-amplitude oscillatory shear and extensional rheology measurements demonstrate the unique viscoelastic behavior associated with the H-shaped architecture.</p>","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":null,"pages":null},"PeriodicalIF":5.8,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141064315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-20DOI: 10.1021/acsmacrolett.4c00214
Yuting Wan, Mingwei Wang*, Peng Ding, Yuening Qiu, Xuhong Guo, Martien Cohen Stuart and Junyou Wang*,
Polymer vesicles are of profound interest for designing delivery vehicles and nanoreactors toward a variety of biomedical and catalytic applications, yet robust synthesis of stable and permeable vesicles remains challenging. Here, we propose an electrostatic-templated polymerization that enables fabrication of polyelectrolyte vesicles with simultaneously regulated stability and permeability. In our design, cationic monomers were copolymerized with cross-linkers in the presence of a polyanionic-neutral diblock copolymer as a template. By properly choosing the block length ratio of the template, we fabricated a type of polyion complex vesicle consisting of a cross-linked cationic membrane, electrostatically assembled with the template copolymer which can be removed by sequential dissociation and separation under concentrated salt. We finally obtained stable polyelectrolyte vesicles of regulated size, membrane permeability, and response properties by tuning the synthesis factors including ionic strength, cross-linker type, and fraction as well as different monomers and concentrations. As a proof-of-concept, lipase was loaded in the designed cationic vesicles, which exhibited enhanced enzyme stability and activity. Our study has developed a novel and robust strategy for controllable synthesis of a new class of stable and permeable polymer (polyelectrolyte) vesicles that feature great potential applications as functional delivery carriers and nanoreactors.
{"title":"Robust Electrostatic-Templated Polymerization for Controllable Synthesis of Stable and Permeable Polyelectrolyte Vesicles","authors":"Yuting Wan, Mingwei Wang*, Peng Ding, Yuening Qiu, Xuhong Guo, Martien Cohen Stuart and Junyou Wang*, ","doi":"10.1021/acsmacrolett.4c00214","DOIUrl":"10.1021/acsmacrolett.4c00214","url":null,"abstract":"<p >Polymer vesicles are of profound interest for designing delivery vehicles and nanoreactors toward a variety of biomedical and catalytic applications, yet robust synthesis of stable and permeable vesicles remains challenging. Here, we propose an electrostatic-templated polymerization that enables fabrication of polyelectrolyte vesicles with simultaneously regulated stability and permeability. In our design, cationic monomers were copolymerized with cross-linkers in the presence of a polyanionic-neutral diblock copolymer as a template. By properly choosing the block length ratio of the template, we fabricated a type of polyion complex vesicle consisting of a cross-linked cationic membrane, electrostatically assembled with the template copolymer which can be removed by sequential dissociation and separation under concentrated salt. We finally obtained stable polyelectrolyte vesicles of regulated size, membrane permeability, and response properties by tuning the synthesis factors including ionic strength, cross-linker type, and fraction as well as different monomers and concentrations. As a proof-of-concept, lipase was loaded in the designed cationic vesicles, which exhibited enhanced enzyme stability and activity. Our study has developed a novel and robust strategy for controllable synthesis of a new class of stable and permeable polymer (polyelectrolyte) vesicles that feature great potential applications as functional delivery carriers and nanoreactors.</p>","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":null,"pages":null},"PeriodicalIF":5.8,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141064318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-16DOI: 10.1021/acsmacrolett.4c00085
Yujie Ji, Kai Yang, Biao Zhao*, Kai Pan and Jianping Deng*,
Chiroptical nanomaterials with circularly polarized luminescence (CPL) performance have aroused increasing attention. Herein, multicolor CPL-active Janus nanofibers are prepared through a simple parallel electrospinning method using chiral helical polyacetylenes as the chiral source and achiral fluorophores as the fluorescent source. Interestingly, despite a direct spatial isolation between the chiral component and the fluorescent component, blue and green CPL emissions can still be obtained due to the fluorescence-selective absorption behavior of chiral helical polyacetylenes, with a satisfactory dissymmetric factor (glum) of 2 × 10–2 and 2.5 × 10–3, respectively. Moreover, by taking advantage of the circular polarization fluorescence energy transfer process, red CPL emission is further achieved using the obtained blue and green CPL as energy donors and the achiral red fluorophore as an energy acceptor. The present work offers a facile approach to prepare multilevel-structured chiroptical materials with promising application potentials in a flexible photoelectric device.
{"title":"Fluorescence-Selective Absorption and Circularly Polarized Fluorescence Energy Transfer Assist the Generation of Multicolor Circularly Polarized Luminescence in Chiral Helical Polyacetylene-Based Janus Nanofibers","authors":"Yujie Ji, Kai Yang, Biao Zhao*, Kai Pan and Jianping Deng*, ","doi":"10.1021/acsmacrolett.4c00085","DOIUrl":"10.1021/acsmacrolett.4c00085","url":null,"abstract":"<p >Chiroptical nanomaterials with circularly polarized luminescence (CPL) performance have aroused increasing attention. Herein, multicolor CPL-active Janus nanofibers are prepared through a simple parallel electrospinning method using chiral helical polyacetylenes as the chiral source and achiral fluorophores as the fluorescent source. Interestingly, despite a direct spatial isolation between the chiral component and the fluorescent component, blue and green CPL emissions can still be obtained due to the fluorescence-selective absorption behavior of chiral helical polyacetylenes, with a satisfactory dissymmetric factor (<i>g</i><sub>lum</sub>) of 2 × 10<sup>–2</sup> and 2.5 × 10<sup>–3</sup>, respectively. Moreover, by taking advantage of the circular polarization fluorescence energy transfer process, red CPL emission is further achieved using the obtained blue and green CPL as energy donors and the achiral red fluorophore as an energy acceptor. The present work offers a facile approach to prepare multilevel-structured chiroptical materials with promising application potentials in a flexible photoelectric device.</p>","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":null,"pages":null},"PeriodicalIF":5.8,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140954548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-16DOI: 10.1021/acsmacrolett.4c00216
Linh Duy Thai, Jochen A. Kammerer, Patrick Théato, Hatice Mutlu* and Christopher Barner-Kowollik*,
Main-chain stimuli-responsive polymers synthesized via polymerization techniques that do not rely on metal-based catalysis are highly desirable for economic reasons and to avoid metal–polymer interactions. Herein, we introduce a metal-free head-to-tail organobase-catalyzed hydroxyl-yne click polymerization of an AB-type monomer to realize photoswitchable polymers featuring α-bismines as main-chain repeating units. The prepared main-chain α-bisimine-based polymers show excellent photoswitching in solution. We further post-functionalize the obtained polymers with various thiol compounds via thiol-Michael reactions to significantly lower the glass transition temperature (Tg), likely to be beneficial for the photoswitching process in the solid state. Thus, the herein introduced polymerization technique not only provides metal-free access to main-chain stimuli-responsive polymers, but also allows for the flexible post-modification of the obtained polymers to generate advanced macromolecular architectures with tunable properties.
出于经济原因和避免金属-聚合物相互作用的考虑,通过不依赖金属催化的聚合技术合成的主链刺激响应型聚合物非常受欢迎。在本文中,我们介绍了一种无金属头尾有机碱催化的羟基-炔单键聚合 AB 型单体的方法,从而实现了以α-双胺为主链重复单元的光开关聚合物。所制备的主α-双胺基聚合物在溶液中表现出优异的光开关性能。我们进一步通过硫醇-迈克尔反应,用各种硫醇化合物对获得的聚合物进行后官能化,从而显著降低了玻璃化转变温度(Tg),这可能有利于固态光开关过程。因此,本文介绍的聚合技术不仅提供了获得主链刺激响应型聚合物的无金属途径,还允许对获得的聚合物进行灵活的后修饰,以生成具有可调特性的高级大分子结构。
{"title":"Access to Main-Chain Photoswitching Polymers via Hydroxyl-yne Click Polymerization","authors":"Linh Duy Thai, Jochen A. Kammerer, Patrick Théato, Hatice Mutlu* and Christopher Barner-Kowollik*, ","doi":"10.1021/acsmacrolett.4c00216","DOIUrl":"10.1021/acsmacrolett.4c00216","url":null,"abstract":"<p >Main-chain stimuli-responsive polymers synthesized via polymerization techniques that do not rely on metal-based catalysis are highly desirable for economic reasons and to avoid metal–polymer interactions. Herein, we introduce a metal-free head-to-tail organobase-catalyzed hydroxyl-yne click polymerization of an AB-type monomer to realize photoswitchable polymers featuring α-bismines as main-chain repeating units. The prepared main-chain α-bisimine-based polymers show excellent photoswitching in solution. We further post-functionalize the obtained polymers with various thiol compounds via thiol-Michael reactions to significantly lower the glass transition temperature (<i>T</i><sub>g</sub>), likely to be beneficial for the photoswitching process in the solid state. Thus, the herein introduced polymerization technique not only provides metal-free access to main-chain stimuli-responsive polymers, but also allows for the flexible post-modification of the obtained polymers to generate advanced macromolecular architectures with tunable properties.</p>","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":null,"pages":null},"PeriodicalIF":5.8,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140954509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-16DOI: 10.1021/acsmacrolett.4c00233
Qian Wang, Zhenhao Zhu, Jupen Liu, Zhe Lu, Yanxia Zhao and You Yu*,
Dynamic covalent hydrogels are gaining attention for their potential in smart materials, soft devices, electronics, and more thanks to their impressive mechanical properties, biomimetic structures, and dynamic behavior. However, a significant challenge lies in designing precise and efficient dynamic photochemistry for their preparation, allowing for complex structures and control over the dynamic process. Herein, we propose a general and straightforward orthogonal dynamic covalent photochemistry strategy for preparing high-performance printable dynamic covalent hydrogels, thereby broadening their advanced applications. This photochemical strategy uses a bifunctional photocatalyst to initiate radical polymerization and release ligands through a rapid light-mediated dissociation mechanism. This process leads to a controlled increase in system pH from mildly acidic to alkaline conditions within one hundred seconds, which in turn triggers the pH-sensitive model reactions of boronic acid/diol complexation and Knoevenagel condensation. The orthogonal photochemistry enables the formation of interpenetrated and conjoined networks, significantly enhancing the mechanical properties of the hydrogels. The reversible bonds formed during the process, i.e., boronic ester and unsaturated ketone bonds, confer excellent self-healing, reprocessable, and recyclable properties on the hydrogels through photochemical pH variations. Furthermore, this rapid, controlled fabrication process and dynamic behavior are highly compatible with printing techniques, enabling the design of adaptive and recyclable sensors with different structures. These advancements are promising for various material science, medicine, and engineering applications.
{"title":"Ligand Dissociation of Metal-Complex Photocatalysts toward pH-Photomanipulation in Dynamic Covalent Hydrogels for Printing Reprocessable and Recyclable Devices","authors":"Qian Wang, Zhenhao Zhu, Jupen Liu, Zhe Lu, Yanxia Zhao and You Yu*, ","doi":"10.1021/acsmacrolett.4c00233","DOIUrl":"10.1021/acsmacrolett.4c00233","url":null,"abstract":"<p >Dynamic covalent hydrogels are gaining attention for their potential in smart materials, soft devices, electronics, and more thanks to their impressive mechanical properties, biomimetic structures, and dynamic behavior. However, a significant challenge lies in designing precise and efficient dynamic photochemistry for their preparation, allowing for complex structures and control over the dynamic process. Herein, we propose a general and straightforward orthogonal dynamic covalent photochemistry strategy for preparing high-performance printable dynamic covalent hydrogels, thereby broadening their advanced applications. This photochemical strategy uses a bifunctional photocatalyst to initiate radical polymerization and release ligands through a rapid light-mediated dissociation mechanism. This process leads to a controlled increase in system pH from mildly acidic to alkaline conditions within one hundred seconds, which in turn triggers the pH-sensitive model reactions of boronic acid/diol complexation and Knoevenagel condensation. The orthogonal photochemistry enables the formation of interpenetrated and conjoined networks, significantly enhancing the mechanical properties of the hydrogels. The reversible bonds formed during the process, i.e., boronic ester and unsaturated ketone bonds, confer excellent self-healing, reprocessable, and recyclable properties on the hydrogels through photochemical pH variations. Furthermore, this rapid, controlled fabrication process and dynamic behavior are highly compatible with printing techniques, enabling the design of adaptive and recyclable sensors with different structures. These advancements are promising for various material science, medicine, and engineering applications.</p>","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":null,"pages":null},"PeriodicalIF":5.8,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140954370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-15DOI: 10.1021/acsmacrolett.4c00164
Brennan J. Crawford, Calum Bochenek, Luis D. Garcia Espinosa, Addie R. Keating, Kayla Williams-Pavlantos, Chrys Wesdemiotis and James M. Eagan*,
Nucleophilic and non-nucleophilic bases have been employed in anionic oligomerization of unsaturated δ-valerolactone (3-ethylidene-6-vinyltetrahydro-2H-pyran-2-one) (1). Compared to the seminal findings with 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), the unsaturated lactone reacts with guanidines, disilazanes, and phosphazenes both in bulk and in solution with higher productivities and activities, reaching full conversion with turnover frequencies up to 382 h–1. Additionally, reactions using phosphazenes and NaHMDS were active at 1 mol % catalyst loadings both in solvent and in bulk monomer at room temperature. Characterization of the reaction products by 1H, 13C, FTIR, MALDI-MS, tandem mass spectrometry (MS/MS), and ion mobility mass spectrometry (IM-MS) revealed microstructural differences dependent on the nucleophilicity of the organocatalytic base and reaction conditions. The products from phosphazene-catalyzed reactions are consistent with selective vinylogous 1,4-conjugate addition, whereas both conjugate addition and ring-opening mechanisms are observed in TBD. DSC reveals that these microstructures can be tuned to have a Tg range between −18 and 80 °C, while SEC and MALDI-MS reveal that only low molar mass oligomers are formed (748–5949 g/mol). From these results, an approach for selectively favoring the vinylogous 1,4-conjugate addition pathway is obtained over ring-opening reactivity.
{"title":"Anionic Conjugate Addition Oligomerization of Carbon Dioxide/Butadiene Derived Lactones","authors":"Brennan J. Crawford, Calum Bochenek, Luis D. Garcia Espinosa, Addie R. Keating, Kayla Williams-Pavlantos, Chrys Wesdemiotis and James M. Eagan*, ","doi":"10.1021/acsmacrolett.4c00164","DOIUrl":"10.1021/acsmacrolett.4c00164","url":null,"abstract":"<p >Nucleophilic and non-nucleophilic bases have been employed in anionic oligomerization of unsaturated δ-valerolactone (3-ethylidene-6-vinyltetrahydro-2<i>H</i>-pyran-2-one) (<b>1</b>). Compared to the seminal findings with 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), the unsaturated lactone reacts with guanidines, disilazanes, and phosphazenes both in bulk and in solution with higher productivities and activities, reaching full conversion with turnover frequencies up to 382 h<sup>–1</sup>. Additionally, reactions using phosphazenes and NaHMDS were active at 1 mol % catalyst loadings both in solvent and in bulk monomer at room temperature. Characterization of the reaction products by <sup>1</sup>H, <sup>13</sup>C, FTIR, MALDI-MS, tandem mass spectrometry (MS/MS), and ion mobility mass spectrometry (IM-MS) revealed microstructural differences dependent on the nucleophilicity of the organocatalytic base and reaction conditions. The products from phosphazene-catalyzed reactions are consistent with selective vinylogous 1,4-conjugate addition, whereas both conjugate addition and ring-opening mechanisms are observed in TBD. DSC reveals that these microstructures can be tuned to have a <i>T</i><sub>g</sub> range between −18 and 80 °C, while SEC and MALDI-MS reveal that only low molar mass oligomers are formed (748–5949 g/mol). From these results, an approach for selectively favoring the vinylogous 1,4-conjugate addition pathway is obtained over ring-opening reactivity.</p>","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":null,"pages":null},"PeriodicalIF":5.8,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140920365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-09DOI: 10.1021/acsmacrolett.4c00185
Tamanna Mallick, Debgopal Jana, Alakesh Bisai* and Priyadarsi De*,
To explore the role of proline amide moieties in polymer-supported organocatalysts, side-chain l-proline–l-alanine (Pro-Ala) dipeptide-containing block copolymers were synthesized, and their catalytic potential for the aldol reaction was explored. The dipeptide monomer (Boc-Pro-Ala-HEMA) was polymerized to prepare block copolymers in the presence of hydrophilic poly(poly(ethylene glycol) methyl ether methacrylate) (PPEGMA) and hydrophobic poly(methyl methacrylate) (PMMA) macro-chain transfer agents. Boc group expulsion from the block copolymers produced double hydrophilic PPEGMA-b-P(Pro-Ala-HEMA) (1b) and amphiphilic PMMA-b-P(Pro-Ala-HEMA) (1c) polymers. The solution behaviors of the polymers were studied by various physical techniques, which showed the formation of self-assembled aggregates of 1c in water and N,N-dimethylformamide (DMF)/water solvent mixtures. These polymers are used as organocatalysts during the aldol reaction of cyclohexanone and 4-nitrobenzaldehyde in different solvent polarities, catalyst loadings, temperatures, and reaction times. This work emphasizes superior catalytic activity of 1c at lower catalyst loadings (5%) while maintaining high conversion (95%) and enantioselectivity (94%) across multiple recycling cycles in DMF/water at a 3:1 ratio (v/v).
{"title":"Asymmetric Aldol Reactions Catalyzed by Polymeric Self-Assembly with Side-Chain Dipeptide Pendants","authors":"Tamanna Mallick, Debgopal Jana, Alakesh Bisai* and Priyadarsi De*, ","doi":"10.1021/acsmacrolett.4c00185","DOIUrl":"10.1021/acsmacrolett.4c00185","url":null,"abstract":"<p >To explore the role of proline amide moieties in polymer-supported organocatalysts, side-chain <span>l</span>-proline–<span>l</span>-alanine (Pro-Ala) dipeptide-containing block copolymers were synthesized, and their catalytic potential for the aldol reaction was explored. The dipeptide monomer (Boc-Pro-Ala-HEMA) was polymerized to prepare block copolymers in the presence of hydrophilic poly(poly(ethylene glycol) methyl ether methacrylate) (<b>PPEGMA</b>) and hydrophobic poly(methyl methacrylate) (<b>PMMA</b>) macro-chain transfer agents. Boc group expulsion from the block copolymers produced double hydrophilic <b>PPEGMA-<i>b</i>-P(Pro-Ala-HEMA)</b> (<b>1b</b>) and amphiphilic <b>PMMA-<i>b</i>-P(Pro-Ala-HEMA)</b> (<b>1c</b>) polymers. The solution behaviors of the polymers were studied by various physical techniques, which showed the formation of self-assembled aggregates of <b>1c</b> in water and <i>N</i>,<i>N</i>-dimethylformamide (DMF)/water solvent mixtures. These polymers are used as organocatalysts during the aldol reaction of cyclohexanone and 4-nitrobenzaldehyde in different solvent polarities, catalyst loadings, temperatures, and reaction times. This work emphasizes superior catalytic activity of <b>1c</b> at lower catalyst loadings (5%) while maintaining high conversion (95%) and enantioselectivity (94%) across multiple recycling cycles in DMF/water at a 3:1 ratio (v/v).</p>","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":null,"pages":null},"PeriodicalIF":5.8,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140896510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-08DOI: 10.1021/acsmacrolett.4c00203
Fabiana Siragusa, Lionel Crane, Pierre Stiernet, Thomas Habets, Bruno Grignard, Jean-Christophe M. Monbaliu* and Christophe Detrembleur*,
Flow chemistry presents many advantages over batch processes for the fast and continuous production of polymers under more robust, safer, and easily scalable conditions. Although largely exploited for chain-growth polymerizations, it has rarely been applied to step-growth polymerizations (SGP) due to their inherent limitations. Here, we report the facile and fast preparation of an emerging class of nonisocyanate polyurethanes, i.e., CO2-based poly(oxazolidone)s, by SGP in continuous flow reactors. Importantly, we also demonstrate that functional poly(oxazolidone)s are easily prepared by telescoping a flow module where SGP occurs with reagents able to simultaneously promote two polymer derivatizations in a second module, i.e., dehydration followed by cationic thiol–ene to yield poly(N,S-acetal oxazolidone)s. The functional polymer is produced at a high rate and functionalization degree, without requiring the isolation of any intermediates. This work demonstrates the enormous potential of flow technology for the facile and fast continuous production of functional polymers by SGP.
与间歇式工艺相比,流动化学工艺具有许多优势,可以在更稳健、更安全、更易于扩展的条件下快速连续地生产聚合物。尽管流化学在链增长聚合中得到了广泛应用,但由于其固有的局限性,很少被应用于阶跃增长聚合(SGP)。在此,我们报告了在连续流反应器中通过 SGP 简单快速地制备一类新兴的非异氰酸酯聚氨酯,即基于 CO2 的聚(恶唑烷酮)。重要的是,我们还证明了功能性聚(恶唑烷酮)可通过伸缩流动模块轻松制备,在该模块中,SGP 与试剂可在第二个模块中同时促进两种聚合物衍生,即先脱水再用阳离子巯基烯生成聚(N,S-缩醛恶唑烷酮)。这种功能聚合物的生产率和功能化程度都很高,而且不需要分离任何中间体。这项工作证明了流动技术在利用 SGP 方便、快速地连续生产功能聚合物方面的巨大潜力。
{"title":"Continuous Flow Synthesis of Functional Isocyanate-Free Poly(oxazolidone)s by Step-Growth Polymerization","authors":"Fabiana Siragusa, Lionel Crane, Pierre Stiernet, Thomas Habets, Bruno Grignard, Jean-Christophe M. Monbaliu* and Christophe Detrembleur*, ","doi":"10.1021/acsmacrolett.4c00203","DOIUrl":"10.1021/acsmacrolett.4c00203","url":null,"abstract":"<p >Flow chemistry presents many advantages over batch processes for the fast and continuous production of polymers under more robust, safer, and easily scalable conditions. Although largely exploited for chain-growth polymerizations, it has rarely been applied to step-growth polymerizations (SGP) due to their inherent limitations. Here, we report the facile and fast preparation of an emerging class of nonisocyanate polyurethanes, i.e., CO<sub>2</sub>-based poly(oxazolidone)s, by SGP in continuous flow reactors. Importantly, we also demonstrate that functional poly(oxazolidone)s are easily prepared by telescoping a flow module where SGP occurs with reagents able to simultaneously promote two polymer derivatizations in a second module, i.e., dehydration followed by cationic thiol–ene to yield poly(<i>N</i>,<i>S</i>-acetal oxazolidone)s. The functional polymer is produced at a high rate and functionalization degree, without requiring the isolation of any intermediates. This work demonstrates the enormous potential of flow technology for the facile and fast continuous production of functional polymers by SGP.</p>","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":null,"pages":null},"PeriodicalIF":5.8,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140875203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-06DOI: 10.1021/acsmacrolett.4c00218
Jieyao Wang, Yujie Lei, Shijun Li, Xingyu Ma, Lei Li
Sulfur is a massive byproduct of the petrochemicals industry and hardly employed as a building block for porous organic polymers (POPs). Here, a new family of sulfur-bridged POPs has been prepared via a C–H insertion reaction between sulfur and polycyclic aromatic hydrocarbons. Sulfur works as a solvent, external cross-linker, and porogen simultaneously during the polymerization process. The products demonstrate high porosity and maximum surface area of 1050 m2 g–1 with abundant accessible active sites, contributing to the nanometerization of sulfur and significantly enhancing the inherent affinity between heteroatoms toward soft metal ions. Therefore, they exhibit a high absorption capacity for Au(III) of 3287 mg g–1 and excellent absorption selectivity and removal efficiency via a performance evaluation even in real electronic wastewater. This synthetic strategy to prepare high added-value functional POPs with sulfur not only sheds light on designing high-performance gold adsorption materials and emerging POPs, but also promotes a sustainable development protocol.
{"title":"Three Birds with One Sulfur: Construction of Sulfur-Bridged Porous Organic Polymers for Efficient Gold Adsorption","authors":"Jieyao Wang, Yujie Lei, Shijun Li, Xingyu Ma, Lei Li","doi":"10.1021/acsmacrolett.4c00218","DOIUrl":"https://doi.org/10.1021/acsmacrolett.4c00218","url":null,"abstract":"Sulfur is a massive byproduct of the petrochemicals industry and hardly employed as a building block for porous organic polymers (POPs). Here, a new family of sulfur-bridged POPs has been prepared via a C–H insertion reaction between sulfur and polycyclic aromatic hydrocarbons. Sulfur works as a solvent, external cross-linker, and porogen simultaneously during the polymerization process. The products demonstrate high porosity and maximum surface area of 1050 m<sup>2</sup> g<sup>–1</sup> with abundant accessible active sites, contributing to the nanometerization of sulfur and significantly enhancing the inherent affinity between heteroatoms toward soft metal ions. Therefore, they exhibit a high absorption capacity for Au(III) of 3287 mg g<sup>–1</sup> and excellent absorption selectivity and removal efficiency via a performance evaluation even in real electronic wastewater. This synthetic strategy to prepare high added-value functional POPs with sulfur not only sheds light on designing high-performance gold adsorption materials and emerging POPs, but also promotes a sustainable development protocol.","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":null,"pages":null},"PeriodicalIF":5.8,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140845992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-06DOI: 10.1021/acsmacrolett.4c00218
Jieyao Wang, Yujie Lei, Shijun Li, Xingyu Ma and Lei Li*,
Sulfur is a massive byproduct of the petrochemicals industry and hardly employed as a building block for porous organic polymers (POPs). Here, a new family of sulfur-bridged POPs has been prepared via a C–H insertion reaction between sulfur and polycyclic aromatic hydrocarbons. Sulfur works as a solvent, external cross-linker, and porogen simultaneously during the polymerization process. The products demonstrate high porosity and maximum surface area of 1050 m2 g–1 with abundant accessible active sites, contributing to the nanometerization of sulfur and significantly enhancing the inherent affinity between heteroatoms toward soft metal ions. Therefore, they exhibit a high absorption capacity for Au(III) of 3287 mg g–1 and excellent absorption selectivity and removal efficiency via a performance evaluation even in real electronic wastewater. This synthetic strategy to prepare high added-value functional POPs with sulfur not only sheds light on designing high-performance gold adsorption materials and emerging POPs, but also promotes a sustainable development protocol.
{"title":"Three Birds with One Sulfur: Construction of Sulfur-Bridged Porous Organic Polymers for Efficient Gold Adsorption","authors":"Jieyao Wang, Yujie Lei, Shijun Li, Xingyu Ma and Lei Li*, ","doi":"10.1021/acsmacrolett.4c00218","DOIUrl":"10.1021/acsmacrolett.4c00218","url":null,"abstract":"<p >Sulfur is a massive byproduct of the petrochemicals industry and hardly employed as a building block for porous organic polymers (POPs). Here, a new family of sulfur-bridged POPs has been prepared via a C–H insertion reaction between sulfur and polycyclic aromatic hydrocarbons. Sulfur works as a solvent, external cross-linker, and porogen simultaneously during the polymerization process. The products demonstrate high porosity and maximum surface area of 1050 m<sup>2</sup> g<sup>–1</sup> with abundant accessible active sites, contributing to the nanometerization of sulfur and significantly enhancing the inherent affinity between heteroatoms toward soft metal ions. Therefore, they exhibit a high absorption capacity for Au(III) of 3287 mg g<sup>–1</sup> and excellent absorption selectivity and removal efficiency via a performance evaluation even in real electronic wastewater. This synthetic strategy to prepare high added-value functional POPs with sulfur not only sheds light on designing high-performance gold adsorption materials and emerging POPs, but also promotes a sustainable development protocol.</p>","PeriodicalId":18,"journal":{"name":"ACS Macro Letters","volume":null,"pages":null},"PeriodicalIF":5.8,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140846336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}