Relaxation Time Correlation NMR for Mechanochemical in-situ Reaction Monitoring of Metal-Organic Frameworks

Leger, Madeleine; Guo, Jiangfeng; MacMillan, Bryce; Friščić, Tomislav; Blight, Barry A.; Balcom, Bruce J.

doi:10.26434/chemrxiv-2021-rbj0t

Cited by 7 publications

(11 citation statements)

References 69 publications

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“…Mechanochemical reaction profiles have been followed using various TRIS experimental methods, including manometry, [32–34] thermometry, [35, 36] X‐ray [10, 12, 37] and neutron [38] diffraction, and vibrational, [39–42] nuclear magnetic resonance, [43] and X‐ray absorption [44] spectroscopy. Whereas techniques based on manometric and thermometric measurements provide an indirect measure of reaction progress, the remaining techniques offer direct structural detail regarding mechanochemical transformations.…”

Section: Methods For Tris Monitoring Of Mechanochemistrymentioning

confidence: 99%

“…With this setup, product formation was monitored over time and the influence of the number of milling balls and milling frequency was studied quantitatively. Leger et al [43] . proposed another in situ approach for mechanochemical processes, through the introduction of magnetic resonance relaxation time correlation measurements to access the hydrogen environments of reactants and products.…”

Section: Methods For Tris Monitoring Of Mechanochemistrymentioning

confidence: 99%

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Time‐Resolved In Situ Monitoring of Mechanochemical Reactions

2022

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Mechanochemical transformations offer environmentally benign synthesis routes, whilst enhancing both the speed and selectivity of reactions. In this regard, mechanochemistry promises to transform the way in which chemistry is done in both academia and industry but is greatly hindered by a current lack of mechanistic understanding. The continued development and use of time‐resolved in situ (TRIS) approaches to monitor mechanochemical reactions provides a new dimension to elucidate these fascinating transformations. We here discuss recent trends in method development that have pushed the boundaries of mechanochemical research. New features of mechanochemical reactions obtained by TRIS techniques are subsequently discussed, which sheds light on how different TRIS approaches have been used. Emphasis is placed on the strength of combining complementary techniques. Finally, we outline our views on the potential of TRIS methods in mechanochemical research, towards establishing a new, environmentally benign paradigm in the chemical sciences.

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Section: Methods For Tris Monitoring Of Mechanochemistrymentioning

confidence: 99%

Section: Methods For Tris Monitoring Of Mechanochemistrymentioning

confidence: 99%

Time‐Resolved In Situ Monitoring of Mechanochemical Reactions

2022

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“…For real-time Raman spectroscopy monitoring, the choice of the milling jar material is limited to optically transparent solids, such as different types of plastics or inorganic materials (e.g., quartz, 18 sapphire 19 ). Although recent work has highlighted routes to follow mechanochemical reactions using chemoluminescence 20 and magnetic resonance techniques, 21 the only currently wellestablished techniques are based on Raman spectroscopy and synchrotron PXRD.…”

Section: ■ Methodologymentioning

confidence: 99%

“…Although significant advances have been achieved in methodologies for real-time observation of such reactivity, we believe these have so far only begun to scratch the surface of understanding, predicting, and controlling the course of chemical and materials transformations in a ball mill. Further advances and insights will be enabled through expanding the toolbox on monitoring techniques to approaches different from conventional diffraction and spectroscopy, for example, based on nuclear magnetic resonance 21,86 and magnetic relaxation, as well as by closer integration of advanced theoretical approaches with outcomes of real-time measurements.…”

Section: ■ Outlookmentioning

confidence: 99%

Toward Mechanistic Understanding of Mechanochemical Reactions Using Real-Time In Situ Monitoring

et al. 2022

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Conspectus The past two decades have witnessed a rapid emergence of interest in mechanochemistry–chemical and materials reactivity achieved or sustained by the action of mechanical force–which has led to application of mechanochemistry to almost all areas of modern chemical and materials synthesis: from organic, inorganic, and organometallic chemistry to enzymatic reactions, formation of metal–organic frameworks, hybrid perovskites, and nanoparticle-based materials. The recent success of mechanochemistry by ball milling has also raised questions about the underlying mechanisms and has led to the realization that the rational development and effective harnessing of mechanochemical reactivity for cleaner and more efficient chemical manufacturing will critically depend on establishing a mechanistic understanding of these reactions. Despite their long history, the development of such a knowledge framework for mechanochemical reactions is still incomplete. This is in part due to the, until recently, unsurmountable challenge of directly observing transformations taking place in a rapidly oscillating or rotating milling vessel, with the sample being under the continuous impact of milling media. A transformative change in mechanistic studies of milling reactions was recently introduced through the first two methodologies for real-time in situ monitoring based on synchrotron powder X-ray diffraction and Raman spectroscopy. Introduced in 2013 and 2014, the two new techniques have inspired a period of tremendous method development, resulting also in new techniques for mechanistic mechanochemical studies that are based on temperature and/or pressure monitoring, extended X-ray fine structure (EXAFS), and, latest, nuclear magnetic resonance (NMR) spectroscopy. The new technologies available for real-time monitoring have now inspired the development of experimental strategies and advanced data analysis approaches for the identification and quantification of short-lived reaction intermediates, the development of new mechanistic models, as well as the emergence of more complex monitoring methodologies based on two or three simultaneous monitoring approaches. The use of these new opportunities has, in less than a decade, enabled the first real-time observations of mechanochemical reaction kinetics and the first studies of how the presence of additives, or other means of modifying the mechanochemical reaction, influence reaction rates and pathways. These studies have revealed multistep reaction mechanisms, enabled the identification of autocatalysis, as well as identified molecules and materials that have previously not been known or have even been considered not possible to synthesize through conventional approaches. Mechanistic studies through in situ powder X-ray diffraction (PXRD) and Raman spectroscopy have highlighted the formation of supramolecular complexes (for example, cocrystals) as critical intermediates in organic and metal–organic synthesis and have also been combined with isotope labeling strategies to provide a deep...

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“…An alternative magnetic resonance imaging methodology that could enable the monitoring of mechanochemical processes throughout the entire reaction vessel has been proposed by the Balcom group, based on relaxation time NMR spectroscopy. 160 A route for monitoring of mechanically induced processes using enzymatic luminescence was proposed by Schramm et al, 161 who took advantage of bio-and/or chemiluminescent processes based on luciferase enzyme.…”

Section: Emerging Opportunitiesmentioning

confidence: 99%

Methods for Monitoring Milling Reactions and Mechanistic Studies of Mechanochemistry: A Primer

Julien

Friščić

2022

Crystal Growth & Design

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Mechanochemistry by ball milling is garnering significant attention as an efficient and versatile means of chemical synthesis which minimizes the need for solvents and reduces the amount of energy required to conduct many molecular transformations. Understanding milling reactions often requires monitoring the reaction of solid forms, with little or ideally no disruption of the milling process. Herein, we provide a broad but succinct summary of how different ex situ and the more recently developed in situ techniques have been applied to monitor mechanochemical reactions, revealing reaction pathways and the mechanisms driving different solid-state molecular and materials transformations by milling. The rapidly evolving field of monitoring milling reactions has already revolutionized our understanding of mechanochemical reactions, revealing complex self-assembled phases as intermediates in catalytic and other types of synthesis through ball milling. The multitude of recently reported techniques for investigating ball milling reactions, many of which are touched upon in this summary, promise to dramatically increase the pace of mechanochemical reaction development and the understanding of solid-state chemistry.

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Relaxation Time Correlation NMR for Mechanochemical in-situ Reaction Monitoring of Metal-Organic Frameworks

Cited by 7 publications

References 69 publications

Time‐Resolved In Situ Monitoring of Mechanochemical Reactions

Time‐Resolved In Situ Monitoring of Mechanochemical Reactions

Toward Mechanistic Understanding of Mechanochemical Reactions Using Real-Time In Situ Monitoring

Methods for Monitoring Milling Reactions and Mechanistic Studies of Mechanochemistry: A Primer

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