1
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Kaup R, Velders AH. Controlling Trapping, Release, and Exchange Dynamics of Micellar Core Components. ACS NANO 2022; 16:14611-14621. [PMID: 36107137 PMCID: PMC9527800 DOI: 10.1021/acsnano.2c05144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 09/13/2022] [Indexed: 06/15/2023]
Abstract
Whereas the formation and overall stability of hierarchically organized self-assembled supramolecular structures have been extensively investigated, the mechanistic aspects of subcomponent dynamics are often poorly understood or controlled. Here we show that the dynamics of polyamidoamine (PAMAM) dendrimer based micelles can be manipulated by changes in dendrimer generation, pH, and stoichiometry, as proven by NMR and FRET. For this, dendrimers were functionalized with either fluorescein (donor) or rhodamine (acceptor) and encapsulated into separate micelles. Upon mixing, exchange of dendrimers is revealed by an increase in FRET. While dendrimicelles based on dendrimer generations 4 and 5 show a clear increase in FRET in time, revealing the dynamic exchange of dendrimers between micellar cores, generation 6 based micelles appear to be kinetically trapped systems. Interestingly, generation 6 based dendrimicelles prepared at a pH of 7.8 rather than 7.0 do show exchange dynamics, which can be attributed to about 25% less charge of the dendrimer, corresponding to the charge of a virtual generation 5.5 dendrimer at neutral pH. Changing the pH of dendrimicelle solutions prepared at a pH of 7.8 to 7.0 shows the activated release of dendrimers. High-resolution NMR spectra of the micellar core are obtained from a 1.2 GHz spectrometer with sub-micromolar sensitivity, with DOSY discriminating released dendrimers from dendrimers still present in the micellar core. This study shows that dendrimer generation, charge density, and stoichiometry are important mechanistic factors for controlling the dynamics of complex coacervate core micelles. This knowledge can be used to tune micelles between kinetically trapped and dynamic systems, with tuning of exchange and/or release speeds, to be tailored for applications in, e.g., material science, sensors, or drug delivery.
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Affiliation(s)
- Rebecca Kaup
- Laboratory
of BioNanoTechnology, Wageningen University. Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands
| | - Aldrik H. Velders
- Laboratory
of BioNanoTechnology, Wageningen University. Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands
- Interventional
Molecular Imaging Laboratory, Department of Radiology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands
- Instituto
Regional de Investigacion Cientifica Aplicada (IRICA), Universidad de Castilla-La Mancha, Ciudad Real, 13071, Spain
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2
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Marchand A, Mishra R, Bernard A, Dumez J. Online Reaction Monitoring with Fast and Flow‐Compatible Diffusion NMR Spectroscopy. Chemistry 2022; 28:e202201175. [DOI: 10.1002/chem.202201175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Indexed: 11/08/2022]
Affiliation(s)
| | - Rituraj Mishra
- Nantes Université CNRS CEISAM UMR 6230 44000 Nantes France
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3
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Emsley L. Editorial Summary of the Comment and Responses on "Following Molecular Mobility during Chemical Reactions: No Evidence for Active Propulsion" and "Molecular Diffusivity of Click Reaction Components: The Diffusion Enhancement Question". J Am Chem Soc 2022; 144:13429-13430. [PMID: 35919984 DOI: 10.1021/jacs.2c05873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Lyndon Emsley
- École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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4
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Fillbrook LL, Günther JP, Majer G, O'Leary DJ, Price WS, Van Ryswyk H, Fischer P, Beves JE. Response to Comment on "Following Molecular Mobility during Chemical Reactions: No Evidence for Active Propulsion" and "Molecular Diffusivity of Click Reaction Components: The Diffusion Enhancement Question". J Am Chem Soc 2022; 144:13436-13440. [PMID: 35919987 DOI: 10.1021/jacs.2c02830] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In their Comment (DOI: 10.1021/jacs.2c02965) on two related publications by our groups (J. Am. Chem. Soc. 2021, 143, 20884-20890; DOI: 10.1021/jacs.1c09455) and another (J. Am. Chem. Soc. 2022, 144, 1380-1388; DOI: 10.1021/jacs.1c11754), Huang and Granick discuss the diffusion NMR measurements of molecules during a copper-catalyzed azide-alkyne cycloaddition (CuAAC) "click" reaction. Here we respond to these comments and maintain that no diffusion enhancement was observed for any species during the reaction. We show that the relaxation agent does not interfere with the CuAAC reaction kinetics nor the diffusion of the molecules involved. Similarly, the gradient pulse length and diffusion time do not affect the diffusion coefficients. Peak overlap was completely removed in our study with the use of hydrazine as the reducing agent. The steady-state assumption does not hold for these diffusion measurements that take several minutes, which is the reason monotonic gradient orders are not suitable. Finally, we discuss the other reactions where similar changes in diffusion have been claimed. Our conclusions are fully supported by the results represented in our original JACS Article and the corresponding Supporting Information.
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Affiliation(s)
| | - Jan-Philipp Günther
- Max Planck Institute for Intelligent Systems, Heisenbergstraße 3, 70569 Stuttgart, Germany
| | - Günter Majer
- Max Planck Institute for Intelligent Systems, Heisenbergstraße 3, 70569 Stuttgart, Germany
| | - Daniel J O'Leary
- Department of Chemistry, Pomona College, 645 North College Avenue, Claremont, California 91711, United States
| | - William S Price
- Nanoscale Group, School of Science, Western Sydney University, Penrith, NSW 2751, Australia
| | - Hal Van Ryswyk
- Department of Chemistry, Harvey Mudd College, 301 Platt Boulevard, Claremont, California 91711, United States
| | - Peer Fischer
- Max Planck Institute for Intelligent Systems, Heisenbergstraße 3, 70569 Stuttgart, Germany.,Institute of Physical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
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5
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Kristinaityte K, Mames A, Pietrzak M, Westermair FF, Silva W, Gschwind RM, Ratajczyk T, Urbańczyk M. Deeper Insight into Photopolymerization: The Synergy of Time-Resolved Nonuniform Sampling and Diffusion NMR. J Am Chem Soc 2022; 144:13938-13945. [PMID: 35852987 PMCID: PMC9354252 DOI: 10.1021/jacs.2c05944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
The comprehensive real-time in situ monitoring of chemical
processes
is a crucial requirement for the in-depth understanding of these processes.
This monitoring facilitates an efficient design of chemicals and materials
with the precise properties that are desired. This work presents the
simultaneous utilization and synergy of two novel time-resolved NMR
methods, i.e., time-resolved diffusion NMR and time-resolved nonuniform
sampling. The first method allows the average diffusion coefficient
of the products to be followed, while the second method enables the
particular products to be monitored. Additionally, the average mass
of the system is calculated with excellent resolution using both techniques.
Employing both methods at the same time and comparing their results
leads to the unequivocal validation of the assignment in the second
method. Importantly, such validation is possible only via the simultaneous
combination of both approaches. While the presented methodology was
utilized for photopolymerization, it can also be employed for any
other polymerization process, complexation, or, in general, chemical
reactions in which the evolution of mass in time is of importance.
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Affiliation(s)
- Kristina Kristinaityte
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Adam Mames
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Mariusz Pietrzak
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Franz F. Westermair
- Faculty of Chemistry and Pharmacy, Univeristy of Regensburg, Universitätsstraßze 31, 93053 Regensburg, Germany
| | - Wagner Silva
- Faculty of Chemistry and Pharmacy, Univeristy of Regensburg, Universitätsstraßze 31, 93053 Regensburg, Germany
| | - Ruth M. Gschwind
- Faculty of Chemistry and Pharmacy, Univeristy of Regensburg, Universitätsstraßze 31, 93053 Regensburg, Germany
| | - Tomasz Ratajczyk
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Mateusz Urbańczyk
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
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6
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Fillbrook LL, Nothling MD, Stenzel MH, Price WS, Beves JE. Rapid Online Analysis of Photopolymerization Kinetics and Molecular Weight Using Diffusion NMR. ACS Macro Lett 2022; 11:166-172. [PMID: 35574764 DOI: 10.1021/acsmacrolett.1c00719] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Online, high-throughput molecular weight analysis of polymerizations is rare, with most studies relying on tedious sampling techniques and batchwise postanalysis. The ability to track both monomer conversion and molecular weight evolution in real time could underpin precision polymer development and facilitate study of rapid polymerization reactions. Here, we use a single time-resolved diffusion nuclear magnetic resonance (NMR) experiment to simultaneously study the kinetics and molecular weight evolution during a photopolymerization, with in situ irradiation inside the NMR instrument. As a model system, we used a photoinduced electron transfer reversible addition-fragmentation chain transfer (PET-RAFT) polymerization. The data allow diffusion coefficients and intensities to be calculated every 14 s from which the polymer size and monomer conversion can be extracted. Key to this approach is (1) the use of shuffled gradient amplitudes in the diffusion NMR experiment to access reactions of any rate, (2) the addition of a relaxation agent to increase achievable time resolution and, (3) a sliding correction that accounts for viscosity changes during polymerization. Diffusion NMR offers a uniquely simple, translatable handle for online monitoring of polymerization reactions.
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Affiliation(s)
| | | | | | - William S. Price
- Nanoscale Group, School of Science, Western Sydney University, Penrith, NSW 2751, Australia
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7
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Fillbrook LL, Günther JP, Majer G, O'Leary DJ, Price WS, Van Ryswyk H, Fischer P, Beves JE. Following Molecular Mobility during Chemical Reactions: No Evidence for Active Propulsion. J Am Chem Soc 2021; 143:20884-20890. [PMID: 34856103 DOI: 10.1021/jacs.1c09455] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The reported changes in self-diffusion of small molecules during reactions have been attributed to "boosted mobility". We demonstrate the critical role of changing concentrations of paramagnetic ions on nuclear magnetic resonance (NMR) signal intensities, which led to erroneous measurements of diffusion coefficients. We present simple methods to overcome this problem. The use of shuffled gradient amplitudes allows accurate diffusion NMR measurements, even with time-dependent relaxation rates caused by changing concentrations of paramagnetic ions. The addition of a paramagnetic relaxation agent allows accurate determination of both diffusion coefficients and reaction kinetics during a single experiment. We analyze a copper-catalyzed azide-alkyne cycloaddition "click" reaction, for which boosted mobility has been claimed. With our methods, we accurately measure the diffusive behavior of the solvent, starting materials, and product and find no global increase in diffusion coefficients during the reaction. We overcome NMR signal overlap using an alternative reducing agent to improve the accuracy of the diffusion measurements. The alkyne reactant diffuses slower as the reaction proceeds due to binding to the copper catalyst during the catalytic cycle. The formation of this intermediate was confirmed by complementary NMR techniques and density functional theory calculations. Our work calls into question recent claims that molecules actively propel or swim during reactions and establishes that time-resolved diffusion NMR measurements can provide valuable insight into reaction mechanisms.
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Affiliation(s)
| | - Jan-Philipp Günther
- Max Planck Institute for Intelligent Systems, Heisenbergstr. 3, 70569 Stuttgart, Germany.,Institute of Physical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Günter Majer
- Max Planck Institute for Intelligent Systems, Heisenbergstr. 3, 70569 Stuttgart, Germany
| | - Daniel J O'Leary
- Department of Chemistry, Pomona College, 645 North College Ave., Claremont, California 91711, United States
| | - William S Price
- Nanoscale Group, School of Science, Western Sydney University, Penrith, NSW 2751, Australia
| | - Hal Van Ryswyk
- Department of Chemistry, Harvey Mudd College, 301 Platt Blvd., Claremont, California 91711, United States
| | - Peer Fischer
- Max Planck Institute for Intelligent Systems, Heisenbergstr. 3, 70569 Stuttgart, Germany.,Institute of Physical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
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8
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Telkki VV, Urbańczyk M, Zhivonitko V. Ultrafast methods for relaxation and diffusion. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2021; 126-127:101-120. [PMID: 34852922 DOI: 10.1016/j.pnmrs.2021.07.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 07/07/2021] [Accepted: 07/08/2021] [Indexed: 06/13/2023]
Abstract
Relaxation and diffusion NMR measurements offer an approach to studying rotational and translational motion of molecules non-invasively, and they also provide chemical resolution complementary to NMR spectra. Multidimensional experiments enable the correlation of relaxation and diffusion parameters as well as the observation of molecular exchange phenomena through relaxation or diffusion contrast. This review describes how to accelerate multidimensional relaxation and diffusion measurements significantly through spatial encoding. This so-called ultrafast Laplace NMR approach shortens the experiment time to a fraction and makes even single-scan experiments possible. Single-scan experiments, in turn, significantly facilitate the use of nuclear spin hyperpolarization methods to boost sensitivity. The ultrafast Laplace NMR method is also applicable with low-field, mobile NMR instruments, and it can be exploited in many disciplines. For example, it has been used in studies of the dynamics of fluids in porous materials, identification of intra- and extracellular metabolites in cancer cells, and elucidation of aggregation phenomena in atmospheric surfactant solutions.
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Affiliation(s)
| | - Mateusz Urbańczyk
- NMR Research Unit, University of Oulu, P.O. Box 3000, FIN-90014, Finland; Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097 Warsaw, Poland
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9
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Wang H, Huang T, Granick S. Using NMR to Test Molecular Mobility during a Chemical Reaction. J Phys Chem Lett 2021; 12:2370-2375. [PMID: 33656893 DOI: 10.1021/acs.jpclett.1c00066] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We evaluate critically the use of pulsed gradient spin-echo nuclear magnetic resonance to measure molecular mobility during chemical reactions. With raw NMR spectra available in a public depository, we confirm the boosted mobility during the click chemical reaction (Wang et al. Science 2020 369, 537-541) regardless of the order of magnetic field gradient (linearly increasing, linearly decreasing, random sequence). We also confirm boosted mobility for the Diels-Alder chemical reaction. The conceptual advantage of the former chemical system is that a constant reaction rate implies a constant catalyst concentration, whereas that of the latter is the absence of a paramagnetic catalyst, precluding paramagnetism as an objection to the measurements. The data and discussion in this paper show the reliability of experiments when one avoids convection, allows decay of nuclear spin magnetization between successive pulses and recovery of its intensity between gradients, and satisfies quasi-steady state during the time window to acquire each datum. Especially important is to make comparisons on the time scale of the actual chemical reaction kinetics. We discuss possible sources of mistaken conclusions that are desirable to avoid.
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Affiliation(s)
- Huan Wang
- Center for Soft and Living Matter, Institute for Basic Science, Ulsan 44919, South Korea
- College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Tian Huang
- Center for Soft and Living Matter, Institute for Basic Science, Ulsan 44919, South Korea
| | - Steve Granick
- Center for Soft and Living Matter, Institute for Basic Science, Ulsan 44919, South Korea
- Departments of Chemistry and Physics, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea
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10
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Günther JP, Fillbrook LL, MacDonald TSC, Majer G, Price WS, Fischer P, Beves JE. Comment on “Boosted molecular mobility during common chemical reactions”. Science 2021; 371:371/6526/eabe8322. [DOI: 10.1126/science.abe8322] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 12/07/2020] [Indexed: 12/21/2022]
Abstract
The apparent “boosted mobility” observed by Wang et al. (Reports, 31 July 2020, p. 537) is the result of a known artifact. When signal intensities are changing during a nuclear magnetic resonance (NMR) diffusion measurement for reasons other than diffusion, the use of monotonically increasing gradient amplitudes produces erroneous diffusion coefficients. We show that no boosted molecular mobility is observed when shuffled gradient amplitudes are applied.
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Affiliation(s)
- Jan-Philipp Günther
- Max Planck Institute for Intelligent Systems, 70569 Stuttgart, Germany
- Institute of Physical Chemistry, University of Stuttgart, 70569 Stuttgart, Germany
| | | | | | - Günter Majer
- Max Planck Institute for Intelligent Systems, 70569 Stuttgart, Germany
| | - William S. Price
- Nanoscale Group, School of Science, Western Sydney University, Penrith, NSW 2751, Australia
| | - Peer Fischer
- Max Planck Institute for Intelligent Systems, 70569 Stuttgart, Germany
- Institute of Physical Chemistry, University of Stuttgart, 70569 Stuttgart, Germany
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11
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Urbańczyk M, Kharbanda Y, Mankinen O, Telkki VV. Accelerating Restricted Diffusion NMR Studies with Time-Resolved and Ultrafast Methods. Anal Chem 2020; 92:9948-9955. [PMID: 32551510 PMCID: PMC7439255 DOI: 10.1021/acs.analchem.0c01523] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Restricted
diffusion of fluids in porous materials can be studied
by pulsed field gradient nuclear magnetic resonance (NMR) non-invasively
and without tracers. If the experiment is repeated many times with
varying diffusion delays, detailed information about pore sizes and
tortuosity can be recorded. However, the measurements are very time-consuming
because numerous repetitions are needed for gradient ramping and varying
diffusion delays. In this paper, we demonstrate two different strategies
for acceleration of the restricted diffusion NMR measurements: time-resolved
diffusion NMR and ultrafast Laplace NMR. The former is based on time-resolved
non-uniform sampling, while the latter relies on spatial encoding
of two-dimensional data. Both techniques allow similar 1–2
order of magnitude acceleration of acquisition, but they have different
strengths and weaknesses, which we discuss in detail. The feasibility
of the methods was proven by investigating restricted diffusion of
water inside tracheid cells of thermally modified pine wood.
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Affiliation(s)
| | | | - Otto Mankinen
- NMR Research Unit, University of Oulu, 90014 Oulu, Finland.,Oulu Functional NeuroImaging Group, Research Unit of Medical Imaging, Physics and Technology, Medical Research Center Oulu, University of Oulu and Oulu University Hospital, 90029 Oulu, Finland
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12
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Abstract
The exchange of molecules between different physical or chemical environments due to diffusion or chemical transformations has a crucial role in a plethora of fundamental processes such as breathing, protein folding, chemical reactions and catalysis. Here, we introduce a method for a single-scan, ultrafast NMR analysis of molecular exchange based on the diffusion coefficient contrast. The method shortens the experiment time by one to four orders of magnitude. Consequently, it opens the way for high sensitivity quantification of important transient physical and chemical exchange processes such as in cellular metabolism. As a proof of principle, we demonstrate that the method reveals the structure of aggregates formed by surfactants relevant to aerosol research. Analysis of exchange processes is time consuming by two-dimensional exchange NMR spectroscopy. Here the authors demonstrate a single-scan ultrafast Laplace NMR approach based on spatial encoding to measure molecular diffusion, with an increase by a factor six in the sensitivity per unit time.
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13
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Vaneeckhaute E, De Man WL, Duerinckx K, Delcour JA, Martens JA, Taulelle F, Breynaert E. 13C-DOSY-TOSY NMR Correlation for In Situ Analysis of Structure, Size Distribution, and Dynamics of Prebiotic Oligosaccharides. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:3250-3259. [PMID: 32045528 DOI: 10.1021/acs.jafc.9b06442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Arabinoxylan oligosaccharides (AXOS) are a complex mixture of cereal derived, water-soluble prebiotics, obtained by enzymatic hydrolysis of arabinoxylan, a group of dietary fibers exerting numerous nutritional and health-beneficial effects. Such complex biomolecular mixtures are notoriously difficult to characterize without initial physical fractionation. Here we present the in situ analysis of AXOS using a variety of state-of-the-art sensitivity-enhanced 13C-DOSY methods, enabling virtual separation and identification of the components. Three dimensional correlation plots displaying 13C diffusivity (DOSY: Diffusion Ordered SpectroscopY), relaxation parameters (TOSY: raTe of relaxation Ordered SpectrscopY), and chemical shift offer a unique way to elucidate the composition of mixtures. We have demonstrated this multifaceted 13C probed correlation strategy in standard mixtures of aliphatic and aromatic compounds, before implementing it on AXOS. These 3D-DOSY-TOSY plots in combination with 2D-NMR correlation experiments offer unprecedented clarity for assigning chemical functions, molecular size distribution, and dynamics of oligosaccharide mixtures.
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Affiliation(s)
- Ewoud Vaneeckhaute
- COK-KAT, KU Leuven, Celestijnenlaan 200F - box 2461, B-3001 Heverlee, Belgium
| | - Wannes L De Man
- Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium
| | - Karel Duerinckx
- COK-KAT, KU Leuven, Celestijnenlaan 200F - box 2461, B-3001 Heverlee, Belgium
| | - Jan A Delcour
- Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium
| | - Johan A Martens
- COK-KAT, KU Leuven, Celestijnenlaan 200F - box 2461, B-3001 Heverlee, Belgium
| | - Francis Taulelle
- COK-KAT, KU Leuven, Celestijnenlaan 200F - box 2461, B-3001 Heverlee, Belgium
| | - Eric Breynaert
- COK-KAT, KU Leuven, Celestijnenlaan 200F - box 2461, B-3001 Heverlee, Belgium
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14
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MacDonald TSC, Price WS, Beves JE. Time‐Resolved Diffusion NMR Measurements for Transient Processes. Chemphyschem 2019; 20:926-930. [DOI: 10.1002/cphc.201900150] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Indexed: 11/06/2022]
Affiliation(s)
| | - William S. Price
- Nanoscale Organisation and Dynamics Group School of Science and Health Western Sydney University Penrith NSW 2751 Australia
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15
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Guduff L, Berthault P, van Heijenoort C, Dumez J, Huber G. Single‐Scan Diffusion‐Ordered NMR Spectroscopy of SABRE‐Hyperpolarized Mixtures. Chemphyschem 2019; 20:392-398. [DOI: 10.1002/cphc.201800983] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 11/30/2018] [Indexed: 12/11/2022]
Affiliation(s)
- Ludmilla Guduff
- Institut de Chimie des Substances Naturelles, CNRS UPR2301 Univ. Paris SudUniversité Paris-Saclay 91190 Gif-sur-Yvette France
| | - Patrick Berthault
- NIMBE, CEA, CNRSUniversité Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette France
| | - Carine van Heijenoort
- Institut de Chimie des Substances Naturelles, CNRS UPR2301 Univ. Paris SudUniversité Paris-Saclay 91190 Gif-sur-Yvette France
| | - Jean‐Nicolas Dumez
- Institut de Chimie des Substances Naturelles, CNRS UPR2301 Univ. Paris SudUniversité Paris-Saclay 91190 Gif-sur-Yvette France
| | - Gaspard Huber
- NIMBE, CEA, CNRSUniversité Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette France
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16
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Mannu A, Ferro M, Möller S, Heller D. Monomerisation of [Rh2(1,3-Bis-(Diphenylphosphino)-Propane)2(μ2-Cl)2] Detected by Pulsed Gradient Spin Echo Spectroscopy and 31P Nmr Monitoring of Metathesis Experiments. JOURNAL OF CHEMICAL RESEARCH 2018. [DOI: 10.3184/174751918x15333065984578] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A pulsed gradient spin echo experiment on [Rh2(1,3-bis-(diphenylphosphino)-propane)2(μ2-Cl)2] complex has been conducted in order to shed light on the supposed monomerisation process of [Rh2(diphosphine)2(μ2-Cl)2] complexes in solution. Such a process should generate a 14-electron [Rh(diphosphine)Cl] complex, which has only been postulated to date. Metathesis experiments on [Rh2(1,3-bis-(diphenylphosphino)-propane)2(μ2-Cl)2] and [Rh2(bis[2-(diphenylphosphino)phenyl]ether)2(μ2-Cl)2] complexes, analysed by 31P NMR, reveal that monomerisation of [Rh2(diphosphine)2(μ2-Cl)2] complexes is not restricted to the case of 1,3-bis-(diphenylphosphino)propane.
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Affiliation(s)
- Alberto Mannu
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock (LIKAT Rostock), Albert-Einstein-Straße 29a, 18059 Rostock, Germany
| | - Monica Ferro
- Department of Chemistry, Materials and Chemical Engineering ‘G. Natta’, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milan, Italy
| | - Saskia Möller
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock (LIKAT Rostock), Albert-Einstein-Straße 29a, 18059 Rostock, Germany
| | - Detlef Heller
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock (LIKAT Rostock), Albert-Einstein-Straße 29a, 18059 Rostock, Germany
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17
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Thevenon A, Cyriac A, Myers D, White AJP, Durr CB, Williams CK. Indium Catalysts for Low-Pressure CO 2/Epoxide Ring-Opening Copolymerization: Evidence for a Mononuclear Mechanism? J Am Chem Soc 2018; 140:6893-6903. [PMID: 29782169 DOI: 10.1021/jacs.8b01920] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The alternating copolymerization of CO2/epoxides is a useful means to incorporate high levels of carbon dioxide into polymers. The reaction is generally proposed to occur by bimetallic or bicomponent pathways. Here, the first indium catalysts are presented, which are proposed to operate by a distinct mononuclear pathway. The most active and selective catalysts are phosphasalen complexes, which feature ligands comprising two iminophosphoranes linked to sterically hindered ortho-phenolates. The catalysts are active at 1 bar pressure of carbon dioxide and are most effective without any cocatalyst. They show low-pressure activity (1 bar pressure) and yield polymer with high carbonate linkage selectivity (>99%) and isoselectivity ( Pm > 70%). Using these complexes, it is also possible to isolate and characterize key catalytic intermediates, including the propagating indium alkoxide and carbonate complexes that are rarely studied. The catalysts are mononuclear under polymerization conditions, and the key intermediates show different coordination geometries: the alkoxide complex is pentacoordinate, while the carbonate is hexacoordinate. Kinetic analyses reveal a first-order dependence on catalyst concentration and are zero-order in carbon dioxide pressure; these findings together with in situ spectroscopic studies underpin the mononuclear pathway. More generally, this research highlights the future opportunity for other homogeneous catalysts, featuring larger ionic radius metals and new ligands, to operate by mononuclear mechanisms.
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Affiliation(s)
- Arnaud Thevenon
- Department of Chemistry , University of Oxford , 13 Mansfield Road , Oxford OX1 3TA , United Kingdom
| | - Anish Cyriac
- Department of Chemistry , Imperial College London , London SW7 2AZ , United Kingdom
| | - Dominic Myers
- Department of Chemistry , Imperial College London , London SW7 2AZ , United Kingdom
| | - Andrew J P White
- Department of Chemistry , Imperial College London , London SW7 2AZ , United Kingdom
| | - Christopher B Durr
- Department of Chemistry , University of Oxford , 13 Mansfield Road , Oxford OX1 3TA , United Kingdom
| | - Charlotte K Williams
- Department of Chemistry , University of Oxford , 13 Mansfield Road , Oxford OX1 3TA , United Kingdom
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18
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Ning C, Ge W, Lyu Z, Luo D, Shi K, Pedersen CM, Nielsen MM, Qiao Y, Wang Y. Ca2+
-Assisted DOSY NMR: An Unexpected Tool for Anomeric Identification for d
-Glucopyranose. ChemistrySelect 2018. [DOI: 10.1002/slct.201800316] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Caifang Ning
- Institute of Coal Chemistry; Chinese Academy of Sciences; 27 South Taoyuan Road Taiyuan 030001, People's Republic of China
- Graduate University of Chinese Academy of Sciences; Beijing, People's Republic of China
| | - Wenzhi Ge
- Institute of Coal Chemistry; Chinese Academy of Sciences; 27 South Taoyuan Road Taiyuan 030001, People's Republic of China
- Bruker (Beijing) Scientific Technology Co. Ltd. 8F, Tower C, Building B-6; No 66 Xi Xiao Kou Road, Haidian District Beijing China 100192
| | - Zexiang Lyu
- Institute of Coal Chemistry; Chinese Academy of Sciences; 27 South Taoyuan Road Taiyuan 030001, People's Republic of China
| | - Dan Luo
- Institute of Coal Chemistry; Chinese Academy of Sciences; 27 South Taoyuan Road Taiyuan 030001, People's Republic of China
- Graduate University of Chinese Academy of Sciences; Beijing, People's Republic of China
| | - Kemeng Shi
- Institute of Coal Chemistry; Chinese Academy of Sciences; 27 South Taoyuan Road Taiyuan 030001, People's Republic of China
- Graduate University of Chinese Academy of Sciences; Beijing, People's Republic of China
| | | | - Michael Martin Nielsen
- Department of Chemistry; University of Copenhagen; Universitetsparken 5 DK-2100 Copenhagen Denmark
| | - Yan Qiao
- Institute of Coal Chemistry; Chinese Academy of Sciences; 27 South Taoyuan Road Taiyuan 030001, People's Republic of China
| | - Yingxiong Wang
- Institute of Coal Chemistry; Chinese Academy of Sciences; 27 South Taoyuan Road Taiyuan 030001, People's Republic of China
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19
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Hamdoun G, Guduff L, van Heijenoort C, Bour C, Gandon V, Dumez JN. Spatially encoded diffusion-ordered NMR spectroscopy of reaction mixtures in organic solvents. Analyst 2018; 143:3458-3464. [DOI: 10.1039/c8an00434j] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Using a spatial encoding of the diffusion dimension, DOSY NMR data are acquired in less than one second for reaction mixtures in organic solvents.
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Affiliation(s)
- Ghanem Hamdoun
- Institut de Chimie des Substances Naturelles
- CNRS UPR2301
- Univ. Paris Sud
- Université Paris-Saclay
- 91190 Gif-Sur-Yvette
| | - Ludmilla Guduff
- Institut de Chimie des Substances Naturelles
- CNRS UPR2301
- Univ. Paris Sud
- Université Paris-Saclay
- 91190 Gif-Sur-Yvette
| | - Carine van Heijenoort
- Institut de Chimie des Substances Naturelles
- CNRS UPR2301
- Univ. Paris Sud
- Université Paris-Saclay
- 91190 Gif-Sur-Yvette
| | - Christophe Bour
- Institut de Chimie Moléculaire et des Matériaux d'Orsay
- CNRS UMR 8182
- Univ. Paris Sud
- Université Paris-Saclay
- 91405 Orsay
| | - Vincent Gandon
- Institut de Chimie Moléculaire et des Matériaux d'Orsay
- CNRS UMR 8182
- Univ. Paris Sud
- Université Paris-Saclay
- 91405 Orsay
| | - Jean-Nicolas Dumez
- Institut de Chimie des Substances Naturelles
- CNRS UPR2301
- Univ. Paris Sud
- Université Paris-Saclay
- 91190 Gif-Sur-Yvette
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20
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Mamedov I, Abbasoglu R, Bayramov M, Maharramov A. Synthesis of a new 1,2,3,4,5-pentasubstituted cyclohexanol and determining its stereochemistry by NMR spectroscopy and quantum-chemical calculations. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2016; 54:315-319. [PMID: 26939987 DOI: 10.1002/mrc.4377] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 09/20/2015] [Accepted: 10/02/2015] [Indexed: 06/05/2023]
Abstract
The presence of substituents in cyclohexane can influence to the ratio of conformers; for some cases, the boat form is preferable. The new six-membered cyclohexanol derivative 2 has been obtained by the synthesis of (E)-1-(bromophenyl)-3-phenylpropen-2-one (1). The NMR and quantum-chemical conformational analysis for the 2 have carried out, and its possible mechanism of formation was given. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Ibrahim Mamedov
- Chemical Faculty, NMR Laboratory, Baku State University, Z. Khalilov 23, Baku, Azerbaijan
| | - Rza Abbasoglu
- Department of Chemistry, Karadeniz Technical University, 61080, Trabzon, Turkey
| | - Musa Bayramov
- Chemical Faculty, NMR Laboratory, Baku State University, Z. Khalilov 23, Baku, Azerbaijan
| | - Abel Maharramov
- Chemical Faculty, NMR Laboratory, Baku State University, Z. Khalilov 23, Baku, Azerbaijan
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21
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Urbańczyk M, Bernin D, Czuroń A, Kazimierczuk K. Monitoring polydispersity by NMR diffusometry with tailored norm regularisation and moving-frame processing. Analyst 2016; 141:1745-52. [DOI: 10.1039/c5an02304a] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new way of processing diffusion NMR data is proposed that exploits p-norm regularization of the inverse Laplace transform tailored to polydisperse macromolecular samples.
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Affiliation(s)
- Mateusz Urbańczyk
- Faculty of Chemistry
- Biological and Chemical Research Centre
- University of Warsaw
- 02-089 Warszawa
- Poland
| | - Diana Bernin
- Swedish NMR Centre
- University of Gothenburg
- 40530 Göteborg
- Sweden
| | - Alan Czuroń
- Institute of Mathematics
- Polish Academy of Sciences
- 00-656 Warszawa
- Poland
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