The Experts below are selected from a list of 2601 Experts worldwide ranked by ideXlab platform
Tomislav Friscic - One of the best experts on this subject based on the ideXlab platform.
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real time in situ monitoring of particle and structure evolution in the mechanochemical synthesis of uio 66 metal organic frameworks
Crystal Growth & Design, 2020Co-Authors: Luzia S Germann, Tomislav Friscic, Krunoslav Užarevic, Athanassios D Katsenis, Igor Huskic, Patrick A Julien, Martin Etter, Omar K Farha, Robert E DinnebierAbstract:While in situ synchrotron X-ray powder diffraction has revolutionized mechanistic studies of Mechanochemistry and inspired the development of other real-time monitoring approaches, the full potenti...
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Mechanochemistry vs solution growth striking differences in bench stability of a cimetidine salt based on a synthetic method
CrystEngComm, 2018Co-Authors: Ghada Ayoub, Vjekoslav Štrukil, Audrey Moores, Cristina Mottillo, Laszlo Fabian, Huizhi Bao, Yasujiro Murata, Davor Margetic, Mirjana Eckertmaksic, Tomislav FriscicAbstract:A mechanochemically prepared solvated salt of the archetypal blockbuster drug cimetidine exhibits significantly different bench stability to an analogous material made in solution. Samples obtained from solution are stable for weeks at room temperature and 45 °C, but mechanochemically made ones readily desolvate and convert to a new polymorph of non-solvated salt. While Mechanochemistry becomes increasingly popular in synthesising drug solid forms, this work illustrates that it can have a profound effect on material stability.
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Mechanochemistry for organic chemists an update
European Journal of Organic Chemistry, 2018Co-Authors: Davin Tan, Tomislav FriscicAbstract:We provide a brief overview of recent advances in the use of mechanochemical techniques for the synthesis of organic molecules and materials, highlighting selected examples of mechanochemical organic transformations and mechanistic studies, and especially those that illustrate chemical reactions or syntheses of molecular targets that have remained elusive to conventional solution techniques.
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one step solvent free mechanosynthesis of silver nanoparticle infused lignin composites for use as highly active multidrug resistant antibacterial filters
RSC Advances, 2016Co-Authors: Monika J Rak, Tomislav Friscic, Audrey MooresAbstract:Silver nanoparticles were synthesized in a solvent-free fashion from a simple silver salt by ball milling Mechanochemistry, using lignin as a biodegradable reducer and polyacrylamide polymer as a support. The resulting material proved very efficient as an antimicrobial filter for complete killing of both Gram positive and Gram negative bacteria, including multi-drug resistant strains.
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towards medicinal Mechanochemistry evolution of milling from pharmaceutical solid form screening to the synthesis of active pharmaceutical ingredients apis
Chemical Communications, 2016Co-Authors: Davin Tan, Leigh Loots, Tomislav FriscicAbstract:This overview highlights the emergent area of mechanochemical reactions for making active pharmaceutical ingredients (APIs), and covers the latest advances in the recently established area of mechanochemical screening and synthesis of pharmaceutical solid forms, specifically polymorphs, cocrystals, salts and salt cocrystals. We also provide an overview of the most recent developments in pharmaceutical uses of Mechanochemistry, including real-time reaction monitoring, techniques for polymorph control and approaches for continuous manufacture using twin screw extrusion, and more. Most importantly, we show how the overlap of previously unrelated areas of mechanochemical screening for API solid forms, organic synthesis by milling, and mechanochemical screening for molecular recognition, enables the emergence of a new research discipline in which different aspects of pharmaceutical and medicinal chemistry are addressed through Mechanochemistry rather than through conventional solution-based routes. The emergence of such medicinal Mechanochemistry is likely to have a strong impact on future pharmaceutical and medicinal chemistry, as it offers not only access to materials and reactivity that are sometimes difficult or even impossible to access from solution, but can also provide a general answer to the demands of the pharmaceutical industry for cleaner, safer and efficient synthetic solutions.
Stephen L. Craig - One of the best experts on this subject based on the ideXlab platform.
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the role of polymer Mechanochemistry in responsive materials and additive manufacturing
Nature Reviews Materials, 2021Co-Authors: Maroun Abi Ghanem, Stephen L. Craig, Amrita Basu, Reza Behrou, Nicholas Boechler, Andrew J Boydston, Yangju Lin, Brock E Lynde, Alshakim Nelson, Hang ShenAbstract:The use of mechanical forces to chemically transform polymers dates back decades. In recent years, the use of Mechanochemistry to direct constructive transformations in polymers has resulted in a range of engineered molecular responses that span optical, mechanical, electronic and thermal properties. The chemistry that has been developed is now well positioned for use in materials science, polymer physics, mechanics and additive manufacturing. Here, we review the historical backdrop of polymer Mechanochemistry, give an overview of the existing toolbox of mechanophores and associated theoretical methods, and speculate as to emerging opportunities in materials science for which current capabilities are seemingly well suited. Non-linear mechanical responses and internal, amplifying stimulus–response feedback loops, including those enabled by, or coupled to, microstructured metamaterial architectures, are seen as particularly promising. Polymer Mechanochemistry converts mechanical forces in materials to chemical reactions through the response of functional groups known as mechanophores. This Review discusses the colorimetric, mechanical, chemical and electronic responses of mechanophores that may be useful in materials for strain sensing and strengthening, soft devices and additive manufacturing.
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generalizing metallocene Mechanochemistry to ruthenocene mechanophores
Chemical Science, 2019Co-Authors: Yudi Zhang, Enhua Xu, Wayne C Mcalister, Stephen L. Craig, Chuanbing TangAbstract:Recent reports have shown that ferrocene displays an unexpected combination of force-free stability and mechanochemical activity, as it acts as the preferred site of chain scission along the backbone of highly extended polymer chains. This observation raises the tantalizing question as to whether similar mechanochemical activity might be present in other metallocenes, and, if so, what features of metallocenes dictate their relative ability to act as mechanophores. In this work, we elucidate polymerization methodologies towards main-chain ruthenocene-based polymers and explore the Mechanochemistry of ruthenocene. We find that ruthenocene, in analogy to ferrocene, acts as a highly selective site of main chain scission despite the fact that it is even more inert. A comparison of ruthenocene and ferrocene reactivity provides insights as to the possible origins of metallocene Mechanochemistry, including the relative importance of structural and thermodynamic parameters such as bond length and bond dissociation energy. These results suggest that metallocenes might be privileged mechanophores through which highly inert coordination complexes can be made dynamic in a stimuli-responsive fashion, offering potential opportunities in dynamic metallo-supramolecular materials and in mechanochemical routes to reactive intermediates that are otherwise difficult to obtain.
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reactivity and mechanism of a mechanically activated anti woodward hoffmann depuy reaction
Journal of the American Chemical Society, 2015Co-Authors: Junpeng Wang, Tatiana B. Kouznetsova, Stephen L. CraigAbstract:Mechanical forces, applied via covalent polymer Mechanochemistry, have been used to bias reaction pathways and activate otherwise inaccessible reactions. Here, single-molecule polymer Mechanochemistry is used to induce the disrotatory outward ring opening of a cis-dialkyl substituted syn-chloro-gem-chlorofluorocyclopropane, in violation of the Woodward–Hoffmann–DePuy (WHD) rule. The forces required to trigger the anti-WHD pathway on the ∼100 ms time scale of the experiment are about 200 pN greater than those involved in the WHD favored process (1290 vs 1500 pN). The kinetics are complemented by tension trapping experiments that suggest that the reaction proceeds along a reaction pathway that generates substantial diradicaloid character.
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Reactivity and Mechanism of a Mechanically Activated anti-Woodward–Hoffmann–DePuy Reaction
2015Co-Authors: Junpeng Wang, Tatiana B. Kouznetsova, Stephen L. CraigAbstract:Mechanical forces, applied via covalent polymer Mechanochemistry, have been used to bias reaction pathways and activate otherwise inaccessible reactions. Here, single-molecule polymer Mechanochemistry is used to induce the disrotatory outward ring opening of a cis-dialkyl substituted syn-chloro-gem-chlorofluorocyclopropane, in violation of the Woodward–Hoffmann–DePuy (WHD) rule. The forces required to trigger the anti-WHD pathway on the ∼100 ms time scale of the experiment are about 200 pN greater than those involved in the WHD favored process (1290 vs 1500 pN). The kinetics are complemented by tension trapping experiments that suggest that the reaction proceeds along a reaction pathway that generates substantial diradicaloid character
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a backbone lever arm effect enhances polymer Mechanochemistry
Nature Chemistry, 2013Co-Authors: Hope M Klukovich, Tatiana B. Kouznetsova, Zachary S Kean, Jeremy M Lenhardt, Stephen L. CraigAbstract:Polymer Mechanochemistry can trigger a wide range of often unanticipated reactivity, but the focus of these systems typically falls on the structure of the mechanophore rather than the intervening polymer backbone. Now, it has been shown that a poly(norbornene) backbone has a substantial impact on a mechanochemical ring-opening reaction, despite having only a minor effect on the force-free reaction.
Davin Tan - One of the best experts on this subject based on the ideXlab platform.
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completely solvent free protocols to access phase pure metastable metal halide perovskites and functional photodetectors from the precursor salts
iScience, 2019Co-Authors: Zonghan Hong, Davin Tan, Rohit Abraham John, Yong Kang Eugene Tay, Xin Zhao, Tze Chien Sum, Nripan Mathews, Felipe Garcia, Han Sen SooAbstract:Summary Mechanochemistry is a green, solid-state, re-emerging synthetic technique that can rapidly form complex molecules and materials without exogenous heat or solvent(s). Herein, we report the application of solvent-free mechanochemical ball milling for the synthesis of metal halide perovskites, to overcome problems with solution-based syntheses. We prepared phase-pure, air-sensitive CsSnX3 (X = I, Br, Cl) and its mixed halide perovskites by Mechanochemistry for the first time by reactions between cesium and tin(II) halides. Notably, we report the sole examples where metastable, high-temperature phases like cubic CsSnCl3, cubic CsPbI3, and trigonal FAPbI3 were accessible at ambient temperatures and pressures without post-synthetic processing. The perovskites can be prepared up to “kilogram scales.” Lead-free, all-inorganic photodetector devices were fabricated using the mechanosynthesized CsSnBr1.5Cl1.5 under solvent-free conditions and showed 10-fold differences between on-off currents. We highlight an essentially solvent-free, general approach to synthesize metastable compounds and fabricate photodetectors from commercially available precursors.
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Mechanochemistry for organic chemists an update
European Journal of Organic Chemistry, 2018Co-Authors: Davin Tan, Tomislav FriscicAbstract:We provide a brief overview of recent advances in the use of mechanochemical techniques for the synthesis of organic molecules and materials, highlighting selected examples of mechanochemical organic transformations and mechanistic studies, and especially those that illustrate chemical reactions or syntheses of molecular targets that have remained elusive to conventional solution techniques.
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towards medicinal Mechanochemistry evolution of milling from pharmaceutical solid form screening to the synthesis of active pharmaceutical ingredients apis
Chemical Communications, 2016Co-Authors: Davin Tan, Leigh Loots, Tomislav FriscicAbstract:This overview highlights the emergent area of mechanochemical reactions for making active pharmaceutical ingredients (APIs), and covers the latest advances in the recently established area of mechanochemical screening and synthesis of pharmaceutical solid forms, specifically polymorphs, cocrystals, salts and salt cocrystals. We also provide an overview of the most recent developments in pharmaceutical uses of Mechanochemistry, including real-time reaction monitoring, techniques for polymorph control and approaches for continuous manufacture using twin screw extrusion, and more. Most importantly, we show how the overlap of previously unrelated areas of mechanochemical screening for API solid forms, organic synthesis by milling, and mechanochemical screening for molecular recognition, enables the emergence of a new research discipline in which different aspects of pharmaceutical and medicinal chemistry are addressed through Mechanochemistry rather than through conventional solution-based routes. The emergence of such medicinal Mechanochemistry is likely to have a strong impact on future pharmaceutical and medicinal chemistry, as it offers not only access to materials and reactivity that are sometimes difficult or even impossible to access from solution, but can also provide a general answer to the demands of the pharmaceutical industry for cleaner, safer and efficient synthetic solutions.
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mechanosynthesis of pharmaceutically relevant sulfonyl thio ureas
ChemInform, 2014Co-Authors: Davin Tan, Vjekoslav Štrukil, Cristina Mottillo, Tomislav FriscicAbstract:The first application of Mechanochemistry to conduct the synthesis of sulfonyl-(thio)ureas (III), (VI), and (X), including antidiabetic drugs tolbutamide, chlorpropamide (VIa) and glibenclamide (X) by either stoichiometric base-assisted or Cu-catalyzed coupling of sulfonamides and iso(thio)cyanates, is reported.
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mechanosynthesis of pharmaceutically relevant sulfonyl thio ureas
Chemical Communications, 2014Co-Authors: Davin Tan, Vjekoslav Štrukil, Cristina Mottillo, Tomislav FriscicAbstract:We demonstrate the first application of Mechanochemistry to conduct the synthesis of sulfonyl-(thio)ureas, including known anti-diabetic drugs tolbutamide, chlorpropamide and glibenclamide, in good to excellent isolated yields by either stoichiometric base-assisted or copper-catalysed coupling of sulfonamides and iso(thio)cyanates.
Tatiana B. Kouznetsova - One of the best experts on this subject based on the ideXlab platform.
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reactivity and mechanism of a mechanically activated anti woodward hoffmann depuy reaction
Journal of the American Chemical Society, 2015Co-Authors: Junpeng Wang, Tatiana B. Kouznetsova, Stephen L. CraigAbstract:Mechanical forces, applied via covalent polymer Mechanochemistry, have been used to bias reaction pathways and activate otherwise inaccessible reactions. Here, single-molecule polymer Mechanochemistry is used to induce the disrotatory outward ring opening of a cis-dialkyl substituted syn-chloro-gem-chlorofluorocyclopropane, in violation of the Woodward–Hoffmann–DePuy (WHD) rule. The forces required to trigger the anti-WHD pathway on the ∼100 ms time scale of the experiment are about 200 pN greater than those involved in the WHD favored process (1290 vs 1500 pN). The kinetics are complemented by tension trapping experiments that suggest that the reaction proceeds along a reaction pathway that generates substantial diradicaloid character.
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Reactivity and Mechanism of a Mechanically Activated anti-Woodward–Hoffmann–DePuy Reaction
2015Co-Authors: Junpeng Wang, Tatiana B. Kouznetsova, Stephen L. CraigAbstract:Mechanical forces, applied via covalent polymer Mechanochemistry, have been used to bias reaction pathways and activate otherwise inaccessible reactions. Here, single-molecule polymer Mechanochemistry is used to induce the disrotatory outward ring opening of a cis-dialkyl substituted syn-chloro-gem-chlorofluorocyclopropane, in violation of the Woodward–Hoffmann–DePuy (WHD) rule. The forces required to trigger the anti-WHD pathway on the ∼100 ms time scale of the experiment are about 200 pN greater than those involved in the WHD favored process (1290 vs 1500 pN). The kinetics are complemented by tension trapping experiments that suggest that the reaction proceeds along a reaction pathway that generates substantial diradicaloid character
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a backbone lever arm effect enhances polymer Mechanochemistry
Nature Chemistry, 2013Co-Authors: Hope M Klukovich, Tatiana B. Kouznetsova, Zachary S Kean, Jeremy M Lenhardt, Stephen L. CraigAbstract:Polymer Mechanochemistry can trigger a wide range of often unanticipated reactivity, but the focus of these systems typically falls on the structure of the mechanophore rather than the intervening polymer backbone. Now, it has been shown that a poly(norbornene) backbone has a substantial impact on a mechanochemical ring-opening reaction, despite having only a minor effect on the force-free reaction.
Junpeng Wang - One of the best experts on this subject based on the ideXlab platform.
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reactivity and mechanism of a mechanically activated anti woodward hoffmann depuy reaction
Journal of the American Chemical Society, 2015Co-Authors: Junpeng Wang, Tatiana B. Kouznetsova, Stephen L. CraigAbstract:Mechanical forces, applied via covalent polymer Mechanochemistry, have been used to bias reaction pathways and activate otherwise inaccessible reactions. Here, single-molecule polymer Mechanochemistry is used to induce the disrotatory outward ring opening of a cis-dialkyl substituted syn-chloro-gem-chlorofluorocyclopropane, in violation of the Woodward–Hoffmann–DePuy (WHD) rule. The forces required to trigger the anti-WHD pathway on the ∼100 ms time scale of the experiment are about 200 pN greater than those involved in the WHD favored process (1290 vs 1500 pN). The kinetics are complemented by tension trapping experiments that suggest that the reaction proceeds along a reaction pathway that generates substantial diradicaloid character.
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Reactivity and Mechanism of a Mechanically Activated anti-Woodward–Hoffmann–DePuy Reaction
2015Co-Authors: Junpeng Wang, Tatiana B. Kouznetsova, Stephen L. CraigAbstract:Mechanical forces, applied via covalent polymer Mechanochemistry, have been used to bias reaction pathways and activate otherwise inaccessible reactions. Here, single-molecule polymer Mechanochemistry is used to induce the disrotatory outward ring opening of a cis-dialkyl substituted syn-chloro-gem-chlorofluorocyclopropane, in violation of the Woodward–Hoffmann–DePuy (WHD) rule. The forces required to trigger the anti-WHD pathway on the ∼100 ms time scale of the experiment are about 200 pN greater than those involved in the WHD favored process (1290 vs 1500 pN). The kinetics are complemented by tension trapping experiments that suggest that the reaction proceeds along a reaction pathway that generates substantial diradicaloid character