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Phuong J, Mross S, Bellaire D, Hasse H, Münnemann K. Determination of self-diffusion coefficients in mixtures with benchtop 13C NMR spectroscopy via polarization transfer. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2024; 62:386-397. [PMID: 38014888 DOI: 10.1002/mrc.5412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 10/18/2023] [Accepted: 10/25/2023] [Indexed: 11/29/2023]
Abstract
Nuclear magnetic resonance (NMR) is an established method to determine self-diffusion coefficients in liquids with high precision. The development of benchtop NMR spectrometers makes the method accessible to a wider community. In most cases, 1H NMR spectroscopy is used to determine self-diffusion coefficients due to its high sensitivity. However, especially when using benchtop NMR spectrometers for the investigation of complex mixtures, the signals in 1H NMR spectra can overlap, hindering the precise determination of self-diffusion coefficients. In 13C NMR spectroscopy, the signals of different compounds are generally well resolved. However, the sensitivity of 13C NMR is significantly lower than that of 1H NMR spectroscopy leading to very long measurement times, which makes diffusion coefficient measurements based on 13C NMR practically infeasible with benchtop NMR spectrometers. To circumvent this problem, we have combined two known pulse sequences, one for polarization transfer from 1H to the 13C nuclei (PENDANT) and one for the measurement of diffusion coefficients (PFG). The new method (PENPFG) was used to measure the self-diffusion coefficients of three pure solvents (acetonitrile, ethanol and 1-propanol) as well as in all their binary mixtures and the ternary mixture at various compositions. For comparison, also measurements of the same systems were carried out with a standard PFG-NMR routine on a high-field NMR instrument. The results are in good agreement and show that PENPFG is a useful tool for the measurement of the absolute value of the self-diffusion coefficients in complex liquid mixtures with benchtop NMR spectrometers.
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Affiliation(s)
- Johnnie Phuong
- Laboratory of Engineering Thermodynamics (LTD), RPTU Kaiserslautern, Kaiserslautern, Germany
| | - Sarah Mross
- Laboratory of Engineering Thermodynamics (LTD), RPTU Kaiserslautern, Kaiserslautern, Germany
| | - Daniel Bellaire
- Laboratory of Engineering Thermodynamics (LTD), RPTU Kaiserslautern, Kaiserslautern, Germany
| | - Hans Hasse
- Laboratory of Engineering Thermodynamics (LTD), RPTU Kaiserslautern, Kaiserslautern, Germany
| | - Kerstin Münnemann
- Laboratory of Engineering Thermodynamics (LTD), RPTU Kaiserslautern, Kaiserslautern, Germany
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2
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Matrix-Assisted 1H DOSY Applied to Flavonoid Analysis in Scutellaria baicalensis. SEPARATIONS 2022. [DOI: 10.3390/separations9120388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Matrix-assisted diffusion-ordered spectroscopy (MA DOSY) technology enables efficient the virtual separation of components in a mixture according to their coefficients (D). In the current research, MA DOSY technology was applied for the analysis of a flavonoid mixture. To establish the method, five representative active flavonoid ingredients, including baicalein, baicalin, quercetin, puerarin and rutinum, were selected for the mixture model. The effects of the type and concentration of the matrix, solvent polarity, and nuclear magnetic resonance (NMR) experimental conditions on the resolution of the DOSY spectrum were investigated. It turned out that sodium dodecyl sulfate (SDS) showed the best performance in increasing the resolution of different analytes, which initially increased to the peak below the added amount of 9 mg, and decreased upon the addition of more SDS. In addition, the five flavonoids showed higher resolution in DMSO–d6 than in MeOD. Experimental parameters of DOSY, including the number of scans (NS), dummy scans (DS), and value of the FID data points (TD), were also optimized. Finally, the above optimized method was used for the qualitative analysis of the total flavonoid mixture extracted from Scutellaria baicalensis Georgi. A total of nine compounds were identified and confirmed by comparing them with mass spectrometry data, which further verifies the practical value of this method upon analyzing flavonoid mixtures and provides some reference significance for the follow-up research.
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3
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Ben-Tal Y, Boaler PJ, Dale HJA, Dooley RE, Fohn NA, Gao Y, García-Domínguez A, Grant KM, Hall AMR, Hayes HLD, Kucharski MM, Wei R, Lloyd-Jones GC. Mechanistic analysis by NMR spectroscopy: A users guide. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2022; 129:28-106. [PMID: 35292133 DOI: 10.1016/j.pnmrs.2022.01.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/05/2022] [Accepted: 01/06/2022] [Indexed: 06/14/2023]
Abstract
A 'principles and practice' tutorial-style review of the application of solution-phase NMR in the analysis of the mechanisms of homogeneous organic and organometallic reactions and processes. This review of 345 references summarises why solution-phase NMR spectroscopy is uniquely effective in such studies, allowing non-destructive, quantitative analysis of a wide range of nuclei common to organic and organometallic reactions, providing exquisite structural detail, and using instrumentation that is routinely available in most chemistry research facilities. The review is in two parts. The first comprises an introduction to general techniques and equipment, and guidelines for their selection and application. Topics include practical aspects of the reaction itself, reaction monitoring techniques, NMR data acquisition and processing, analysis of temporal concentration data, NMR titrations, DOSY, and the use of isotopes. The second part comprises a series of 15 Case Studies, each selected to illustrate specific techniques and approaches discussed in the first part, including in situ NMR (1/2H, 10/11B, 13C, 15N, 19F, 29Si, 31P), kinetic and equilibrium isotope effects, isotope entrainment, isotope shifts, isotopes at natural abundance, scalar coupling, kinetic analysis (VTNA, RPKA, simulation, steady-state), stopped-flow NMR, flow NMR, rapid injection NMR, pure shift NMR, dynamic nuclear polarisation, 1H/19F DOSY NMR, and in situ illumination NMR.
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Affiliation(s)
- Yael Ben-Tal
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Patrick J Boaler
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Harvey J A Dale
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Ruth E Dooley
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom; Evotec (UK) Ltd, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, United Kingdom
| | - Nicole A Fohn
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Yuan Gao
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Andrés García-Domínguez
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Katie M Grant
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Andrew M R Hall
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Hannah L D Hayes
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Maciej M Kucharski
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Ran Wei
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom
| | - Guy C Lloyd-Jones
- School of Chemistry, Joseph Black Building, David Brewster Road, Edinburgh, EH9 3FJ, United Kingdom.
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4
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Lüert D, Kreyenschmidt AK, Legendre CM, Herbst-Irmer R, Stalke D. A Sodium Sodate as Precursor for Lanthanide Bis(4- R-benzoxazol-2-yl)methanide Single-Molecule Magnets. Inorg Chem 2022; 61:5234-5244. [PMID: 35316598 DOI: 10.1021/acs.inorgchem.1c03714] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
From the sodium sodate precursor [(Na(thf)6][Na{(4-Me-NCOC6H3)2CH}2] (1) three isostructural dinuclear lanthanide complexes [(μ-Cl)LnIII{(4-MeNCOC6H3)2CH}2]2 with Ln = Gd (2), Dy (3), and Er (4) based on the N,N'-chelating monoanionic bis(4-methylbenzoxazol-2-yl)methanide ligand (titled "Mebox") were synthesized and characterized by X-ray diffraction and magnetic measurements. The sodium precursor 1 was analyzed via X-ray diffraction and diffusion-ordered NMR spectroscopy experiments (DOSY-NMR) in order to investigate its aggregation in solution and the solid state. The sodium analog [(thf)3Na(NCOC6H4)2CH] (1') based on the bis(benzoxazol-2-yl)-methanide ligand (titled "box") was prepared and analyzed for comparison reasons. From the lanthanide derivatives 2-4, the DyIII complex 3 displays slow relaxation of magnetization at zero field, with a relaxation barrier of U = 315.7 cm-1. The coupling strength between the two lanthanide centers was estimated with the GdIII equivalent 2, giving a weak antiferromagnetic coupling of J = -0.035 cm-1.
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Affiliation(s)
- Daniel Lüert
- Department of Inorganic Chemistry, University of Goettingen, Tammannstrasse 4, 37077 Goettingen, Germany
| | - Anne-Kathrin Kreyenschmidt
- Department of Inorganic Chemistry, University of Goettingen, Tammannstrasse 4, 37077 Goettingen, Germany
| | - Christina M Legendre
- Department of Inorganic Chemistry, University of Goettingen, Tammannstrasse 4, 37077 Goettingen, Germany
| | - Regine Herbst-Irmer
- Department of Inorganic Chemistry, University of Goettingen, Tammannstrasse 4, 37077 Goettingen, Germany
| | - Dietmar Stalke
- Department of Inorganic Chemistry, University of Goettingen, Tammannstrasse 4, 37077 Goettingen, Germany
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5
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Thomlinson IA, Davidson M, Lyall C, Lowe JP, Hintermair U. Fast and Accurate Diffusion NMR Acquisition in Continuous Flow. Chem Commun (Camb) 2022; 58:8242-8245. [DOI: 10.1039/d2cc03054c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
FlowNMR spectroscopy has become a popular and powerful technique for online reaction monitoring. DOSY NMR is an established technique for obtaining information about diffusion rates and molecular size on static...
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6
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Evans R. The interpretation of small molecule diffusion coefficients: Quantitative use of diffusion-ordered NMR spectroscopy. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2020; 117:33-69. [PMID: 32471534 DOI: 10.1016/j.pnmrs.2019.11.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 11/20/2019] [Accepted: 11/20/2019] [Indexed: 06/11/2023]
Abstract
Measuring accurate molecular self-diffusion coefficients, D, by nuclear magnetic resonance (NMR) techniques has become routine as hardware, software and experimental methodologies have all improved. However, the quantitative interpretation of such data remains difficult, particularly for small molecules. This review article first provides a description of, and explanation for, the failure of the Stokes-Einstein equation to accurately predict small molecule diffusion coefficients, before moving on to three broadly complementary methods for their quantitative interpretation. Two are based on power laws, but differ in the nature of the reference molecules used. The third addresses the uncertainties in the Stokes-Einstein equation directly. For all three methods, a wide range of examples are used to show the range of chemistry to which diffusion NMR can be applied, and how best to implement the different methods to obtain quantitative information from the chemical systems studied.
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Affiliation(s)
- Robert Evans
- Aston Institute of Materials Research, School of Engineering and Applied Science, Aston University, Birmingham B4 7ET, United Kingdom.
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7
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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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8
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Day IJ. Matrix-assisted DOSY. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2020; 116:1-18. [PMID: 32130955 DOI: 10.1016/j.pnmrs.2019.09.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/30/2019] [Accepted: 09/01/2019] [Indexed: 06/10/2023]
Abstract
The analysis of mixtures by NMR spectroscopy is challenging. Diffusion-ordered NMR spectroscopy enables a pseudo-separation of species based on differences in their translational diffusion coefficients. Under the right circumstances, this is a powerful technique; however, when molecules diffuse at similar rates separation in the diffusion dimension can be poor. In addition, spectral overlap also limits resolution and can make interpretation challenging. Matrix-assisted diffusion NMR seeks to improve resolution in the diffusion dimension by utilising the differential interaction of components in the mixture with an additive to the solvent. Tuning these matrix-analyte interactions allows the diffusion resolution to be optimised. This review presents the background to matrix-assisted diffusion experiments, surveys the wide range of matrices employed, including chromatographic stationary phases, surfactants and polymers, and demonstrates the current state of the art.
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Affiliation(s)
- Iain J Day
- School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QJ, UK.
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9
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Howe PWA. Selective diffusion spectroscopy using excitation sculpting. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2017; 55:433-437. [PMID: 26711326 DOI: 10.1002/mrc.4402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 11/19/2015] [Accepted: 11/30/2015] [Indexed: 06/05/2023]
Abstract
Diffusion spectroscopy NMR provides a sensitive and fast way of determining diffusion coefficient. The coefficient is measured by fitting attenuation of resonance intensities to the Stejskal-Tanner equation, but, because it is an exponential equation, this fitting is quite sensitive to experimental artefacts. Intense resonances in NMR spectra, such as solvent signals, are a particular problem because small fractions of intensity of the intense resonances can significantly change the intensities of minor resonances and distort their calculated diffusion coefficients. This problem can be overcome by selective excitation of only the minor resonances, and the method of choice for this is excitation sculpting. This paper shows that the conventional excitation sculpting pulse sequence can be used directly for DOSY spectroscopy with minimal modification. The sequence suppresses intense resonances very effectively, allowing the reproducible measurement of diffusion coefficients of minor solutes in a solvent containing five separate resonances. It is sensitive and robust to convection. Excitation sculpting will allow the application of diffusion spectroscopy to samples which include multiple intense resonances, such as polymeric solvents. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Peter W A Howe
- Product Safety, Syngenta Ltd, Jealott's Hill Research Centre, Bracknell, RG42 6EY, UK
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10
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Hou J, He Y, Sabatino P, Yuan L, Redwine D. Generic applications of (13) C-detected NMR diffusion to formulated systems with suppression of thermal convection induced by proton decoupling. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2016; 54:584-591. [PMID: 26845387 DOI: 10.1002/mrc.4404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 12/02/2015] [Accepted: 12/04/2015] [Indexed: 06/05/2023]
Abstract
Fast and effective structural/compositional analysis on formulated systems represents one of the major challenges encountered in analytical science. (13) C-detected diffusion represents a promising tool to tackle the aforementioned challenges, particularly in industry. Toward exploring the generic applications of (13) C-detected diffusion, thermal convection induced by (1) H decoupling has been identified as a key factor that resulted in significantly reduced resolution in the diffusion dimension. Optimization of experimental parameters and utilization of double-stimulated echo-based pulse sequence both can effectively suppress the thermal convection caused by the (1) H decoupling, the success of which allows robust and generic applications of (13) C-detected diffusion to systems from mixtures of small molecules, polymer blends, and copolymers to actual complex formulated systems. The method is particularly powerful in differentiating small molecules from polymers, polymer blends from copolymers, and end-group analysis. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Jianbo Hou
- Corporate R&D, The Dow Chemical Company, 1897 Building, Midland, MI, 48667, USA
| | - Yiyong He
- Corporate R&D, The Dow Chemical Company, 1897 Building, Midland, MI, 48667, USA
| | - Paolo Sabatino
- Analytical Technology Center, Dow Benelux B.V., 446 Building, 4530 AA, Terneuzen, the Netherlands
| | - Ling Yuan
- Corporate R&D, The Dow Chemical Company, 936 Zhangheng Rd, Shanghai, 201203, China
| | - David Redwine
- Corporate R&D, The Dow Chemical Company, 1897 Building, Midland, MI, 48667, USA
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11
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Power JE, Foroozandeh M, Moutzouri P, Adams RW, Nilsson M, Coombes SR, Phillips AR, Morris GA. Very broadband diffusion-ordered NMR spectroscopy: (19)F DOSY. Chem Commun (Camb) 2016; 52:6892-4. [PMID: 27138866 DOI: 10.1039/c6cc02917e] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
A new pulse sequence, CHORUS Oneshot, allows measurements of diffusion-ordered spectroscopy (DOSY) spectra over the full chemical shift range of (19)F for the first time. Swept-frequency pulses are used to give very broadband excitation; the sequence is a prototype for a large family of very broadband liquid state NMR methods.
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Affiliation(s)
- Jane E Power
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
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12
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Bénéteau R, Boussonnière A, Rouaud JC, Lebreton J, Graton J, Jacquemin D, Sebban M, Oulyadi H, Hamdoun G, Hancock AN, Schiesser CH, Dénès F. Radical Cyclisation of α-Halo Aluminium Acetals: A Mechanistic Study. Chemistry 2016; 22:4809-24. [PMID: 26890896 DOI: 10.1002/chem.201504780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Indexed: 11/06/2022]
Abstract
α-Bromo aluminium acetals are suitable substrates for Ueno-Stork-like radical cyclisations affording γ-lactols and acid-sensitive methylene-γ-lactols in high yields. The mechanistic study herein sets the scope and limitation of this reaction. The influence of the halide (or chalcogenide) atom X (X=Cl, Br, I, SPh, SePh) in the precursors α-haloesters, as well as influence of the solvent and temperature was studied. The structure of the aluminium acetal intermediates resulting from the reduction of the corresponding α-haloesters has been investigated by low-temperature (13) C-INEPT diffusion-ordered NMR spectroscopy (DOSY) experiments and quantum calculations, providing new insights into the structures of these thermally labile intermediates. Oxygen-bridged dimeric structures with a planar Al2 O2 ring are proposed for the least hindered aluminium acetals, while monomeric structures seem to prevail for the most hindered species. A comparison against the radical cyclisation of aluminium acetals derived from allyl and propargyl alcohols with the parent Ueno-Stork has been made at the BHandHLYP/6-311++G(d,p) level of theory, highlighting mechanistic similarities and differences.
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Affiliation(s)
- Romain Bénéteau
- CEISAM UMR 6230 - UFR des Sciences et des Techniques, Université de Nantes, 2 rue de la Houssinière BP, 92208-44322, Nantes Cedex 3, France
| | - Anne Boussonnière
- CEISAM UMR 6230 - UFR des Sciences et des Techniques, Université de Nantes, 2 rue de la Houssinière BP, 92208-44322, Nantes Cedex 3, France
| | - Jean-Christophe Rouaud
- CEISAM UMR 6230 - UFR des Sciences et des Techniques, Université de Nantes, 2 rue de la Houssinière BP, 92208-44322, Nantes Cedex 3, France
| | - Jacques Lebreton
- CEISAM UMR 6230 - UFR des Sciences et des Techniques, Université de Nantes, 2 rue de la Houssinière BP, 92208-44322, Nantes Cedex 3, France
| | - Jérôme Graton
- CEISAM UMR 6230 - UFR des Sciences et des Techniques, Université de Nantes, 2 rue de la Houssinière BP, 92208-44322, Nantes Cedex 3, France
| | - Denis Jacquemin
- CEISAM UMR 6230 - UFR des Sciences et des Techniques, Université de Nantes, 2 rue de la Houssinière BP, 92208-44322, Nantes Cedex 3, France.,Institut Universitaire de France, 1, rue Descartes, 75231, Paris Cedex 05, France
| | - Muriel Sebban
- Normandie Université, COBRA UMR6014, FR3038, Université de Rouen; INSA de Rouen; CNRS, 76821, Mont-Saint-Aignan Cedex, France
| | - Hassan Oulyadi
- Normandie Université, COBRA UMR6014, FR3038, Université de Rouen; INSA de Rouen; CNRS, 76821, Mont-Saint-Aignan Cedex, France
| | - Ghanem Hamdoun
- Normandie Université, COBRA UMR6014, FR3038, Université de Rouen; INSA de Rouen; CNRS, 76821, Mont-Saint-Aignan Cedex, France
| | - Amber N Hancock
- School of Chemistry and, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia
| | - Carl H Schiesser
- School of Chemistry and, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia
| | - Fabrice Dénès
- CEISAM UMR 6230 - UFR des Sciences et des Techniques, Université de Nantes, 2 rue de la Houssinière BP, 92208-44322, Nantes Cedex 3, France.
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13
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Hunter SC, Chen SJ, Steren CA, Richmond MG, Xue ZL. Syntheses and Characterization of Tantalum Alkyl Imides and Amide Imides. DFT Studies of Unusual α-SiMe3 Abstraction by an Amide Ligand. Organometallics 2015. [DOI: 10.1021/acs.organomet.5b00558] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Seth C. Hunter
- Department of Chemistry, The University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Shu-Jian Chen
- Department of Chemistry, The University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Carlos A. Steren
- Department of Chemistry, The University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Michael G. Richmond
- Department of Chemistry, The University of North Texas, Denton, Texas 76203, United States
| | - Zi-Ling Xue
- Department of Chemistry, The University of Tennessee, Knoxville, Tennessee 37996, United States
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14
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Guang J, Hopson R, Williard PG. Diffusion Coefficient-Formula Weight (D-FW) Analysis of 2H Diffusion-Ordered NMR Spectroscopy (DOSY). J Org Chem 2015; 80:9102-7. [DOI: 10.1021/acs.joc.5b01457] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jie Guang
- Department
of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Russell Hopson
- Department
of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Paul G. Williard
- Department
of Chemistry, Brown University, Providence, Rhode Island 02912, United States
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15
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Neufeld R, Stalke D. Accurate molecular weight determination of small molecules via DOSY-NMR by using external calibration curves with normalized diffusion coefficients. Chem Sci 2015; 6:3354-3364. [PMID: 29142693 PMCID: PMC5656982 DOI: 10.1039/c5sc00670h] [Citation(s) in RCA: 154] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 03/18/2015] [Indexed: 01/12/2023] Open
Abstract
Determination of the aggregation and solvation numbers of organometallic complexes in solution is an important task to increase insight in reaction mechanisms. Thus knowing which aggregates are formed during a reaction is of high interest to develop better selectivity and higher yields. Diffusion-ordered spectroscopy (DOSY), which separates NMR signals according to the diffusion coefficient, finds increasing use to identify species in solution. However, there still is no simple relationship between diffusion coefficient and molecular weight (MW). Some methods have been developed to estimate the MW but still with a significant error of ±30%. Here we describe a novel development of MW-determination by using an external calibration curve (ECC) approach with normalized diffusion coefficients. Taking the shape of the molecules into account enables accurate MW-predictions with a maximum error of smaller than ±9%. Moreover we show that the addition of multiple internal references is dispensable. One internal reference (that also can be the solvent) is sufficient. If the solvent signal is not accessible, 16 other internal standards (aliphatics and aromatics) are available to avoid signal overlapping problems and provide flexible choice of analytes. This method is independent of NMR-device properties and diversities in temperature or viscosity and offers an easy and robust method to determine accurate MWs in solution.
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Affiliation(s)
- Roman Neufeld
- Institut für Anorganische Chemie , Georg-August-Universität , Tammannstrasse 4 , Göttingen , Germany .
| | - Dietmar Stalke
- Institut für Anorganische Chemie , Georg-August-Universität , Tammannstrasse 4 , Göttingen , Germany .
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16
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Subramanian H, Jasperse CP, Sibi MP. Characterization of Brønsted Acid–Base Complexes by 19F DOSY. Org Lett 2015; 17:1429-32. [PMID: 25730425 DOI: 10.1021/acs.orglett.5b00297] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hariharaputhiran Subramanian
- Department
of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108, United States
| | - Craig P. Jasperse
- Department
of Chemistry, Minnesota State University, Moorhead, Minnesota 56563, United States
| | - Mukund P. Sibi
- Department
of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108, United States
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17
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Wang Z, Zheng L, Li C, Zhang D, Xiao Y, Guan G, Zhu W. Modification of chitosan with monomethyl fumaric acid in an ionic liquid solution. Carbohydr Polym 2015; 117:973-979. [DOI: 10.1016/j.carbpol.2014.10.021] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 10/05/2014] [Accepted: 10/06/2014] [Indexed: 11/30/2022]
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18
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Su C, Hopson R, Williard PG. Influence of Steric Factors on Chiral Lithium Amide Aggregates. J Am Chem Soc 2014; 136:3246-55. [DOI: 10.1021/ja4123957] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Chicheung Su
- Department of Chemistry, Brown University, 324 Brook Street, Providence, Rhode Island 02912 United States
| | - Russell Hopson
- Department of Chemistry, Brown University, 324 Brook Street, Providence, Rhode Island 02912 United States
| | - Paul G. Williard
- Department of Chemistry, Brown University, 324 Brook Street, Providence, Rhode Island 02912 United States
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19
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Hernán-Gómez A, Herd E, Hevia E, Kennedy AR, Knochel P, Koszinowski K, Manolikakes SM, Mulvey RE, Schnegelsberg C. Organozinc Pivalate Reagents: Segregation, Solubility, Stabilization, and Structural Insights. Angew Chem Int Ed Engl 2014; 53:2706-10. [DOI: 10.1002/anie.201309841] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Indexed: 11/09/2022]
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20
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Hernán-Gómez A, Herd E, Hevia E, Kennedy AR, Knochel P, Koszinowski K, Manolikakes SM, Mulvey RE, Schnegelsberg C. Organozinc Pivalate Reagents: Segregation, Solubility, Stabilization, and Structural Insights. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201309841] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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21
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22
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Hamdoun G, Sebban M, Cossoul E, Harrison-Marchand A, Maddaluno J, Oulyadi H. 1H Pure Shift DOSY: a handy tool to evaluate the aggregation and solvation of organolithium derivatives. Chem Commun (Camb) 2014; 50:4073-5. [DOI: 10.1039/c4cc00111g] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The first successful application of 1H PS-DOSY for a quantitative estimation of the degree of solvation and aggregation state of organolithium derivatives.
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Affiliation(s)
- G. Hamdoun
- Normandie Université
- COBRA, UMR6014 and FR3038 CNRS
- Université de Rouen
- INSA de Rouen
- 76821 Mont-Saint-Aignan Cedex, France
| | - M. Sebban
- Normandie Université
- COBRA, UMR6014 and FR3038 CNRS
- Université de Rouen
- INSA de Rouen
- 76821 Mont-Saint-Aignan Cedex, France
| | - E. Cossoul
- Normandie Université
- COBRA, UMR6014 and FR3038 CNRS
- Université de Rouen
- INSA de Rouen
- 76821 Mont-Saint-Aignan Cedex, France
| | - A. Harrison-Marchand
- Normandie Université
- COBRA, UMR6014 and FR3038 CNRS
- Université de Rouen
- INSA de Rouen
- 76821 Mont-Saint-Aignan Cedex, France
| | - J. Maddaluno
- Normandie Université
- COBRA, UMR6014 and FR3038 CNRS
- Université de Rouen
- INSA de Rouen
- 76821 Mont-Saint-Aignan Cedex, France
| | - H. Oulyadi
- Normandie Université
- COBRA, UMR6014 and FR3038 CNRS
- Université de Rouen
- INSA de Rouen
- 76821 Mont-Saint-Aignan Cedex, France
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23
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Su C, Hopson R, Williard PG. Isotopically Enriched 13C Diffusion-Ordered NMR Spectroscopy: Analysis of Methyllithium. J Org Chem 2013; 78:11733-46. [DOI: 10.1021/jo401740g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Chicheung Su
- Department
of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Russell Hopson
- Department
of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Paul G. Williard
- Department
of Chemistry, Brown University, Providence, Rhode Island 02912, United States
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24
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Toumi I, Torrésani B, Caldarelli S. Effective Processing of Pulse Field Gradient NMR of Mixtures by Blind Source Separation. Anal Chem 2013; 85:11344-51. [DOI: 10.1021/ac402085x] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Ichrak Toumi
- Aix Marseille Université, CNRS, Centrale
Marseille, iSm2 UMR 7313, 13397, Marseille, France
| | - Bruno Torrésani
- Aix Marseille Université, CNRS, Centrale Marseille, LATP
UMR 7353, 13453, Marseille, France
| | - Stefano Caldarelli
- Aix Marseille Université, CNRS, Centrale
Marseille, iSm2 UMR 7313, 13397, Marseille, France
- CNRS UPR 2301 ICSN 91190, Gif-sur-Yvette, France
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25
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Mulvey RE, Robertson SD. Synthetically important alkali-metal utility amides: lithium, sodium, and potassium hexamethyldisilazides, diisopropylamides, and tetramethylpiperidides. Angew Chem Int Ed Engl 2013; 52:11470-87. [PMID: 24133015 DOI: 10.1002/anie.201301837] [Citation(s) in RCA: 151] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Indexed: 11/08/2022]
Abstract
Most synthetic chemists will have at some point utilized a sterically demanding secondary amide (R2 N(-) ). The three most important examples, lithium 1,1,1,3,3,3-hexamethyldisilazide (LiHMDS), lithium diisopropylamide (LiDA), and lithium 2,2,6,6-tetramethylpiperidide (LiTMP)-the "utility amides"-have long been indispensible particularly for lithiation (Li-H exchange) reactions. Like organolithium compounds, they exhibit aggregation phenomena and strong Lewis acidity, and thus appear in distinct forms depending on the solvents employed. The structural chemistry of these compounds as well as their sodium and potassium congeners are described in the absence or in the presence of the most synthetically significant donor solvents tetrahydrofuran (THF) and N,N,N',N'-tetramethylethylenediamine (TMEDA) or closely related solvents. Examples of hetero-alkali-metal amides, an increasingly important composition because of the recent escalation of interest in mixed-metal synergic effects, are also included.
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Affiliation(s)
- Robert E Mulvey
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL (UK).
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26
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Mulvey RE, Robertson SD. Nützliche Alkalimetallamide für die Synthese: Lithium-, Natrium- und Kaliumhexamethyldisilazide, -diisopropylamide und -tetramethylpiperidide. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201301837] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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27
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Su C, Hopson R, Williard PG. Mixed aggregates of an alkyl lithium reagent and a chiral lithium amide derived from N-ethyl-O-triisopropylsilyl valinol. J Am Chem Soc 2013; 135:14367-79. [PMID: 23980610 DOI: 10.1021/ja406912h] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The crystal structure of a mixed aggregate containing lithiated (S)-N-ethyl-3-methyl-1-(triisopropylsilyloxy)butan-2-amine derived from (S)-valinol and cyclopentyllithium is determined by X-ray diffraction. The mixed aggregate adopts a ladder structure in the solid state. The ladder-type mixed aggregate is also the major species in a toluene-d8 solution containing an approximately 1:1 molar ratio of the lithiated chiral amide to cyclopentyllithium. A variety of NMR experiments including diffusion-ordered NMR spectroscopy (DOSY) with diffusion coefficient-formula (D-FW) weight correlation analyses and other one- and two-dimensional NMR techniques allowed us to characterize the complex in solution. Solution state structures of the mixed aggregates of n-butyl, sec-butyllithium, isopropyllithium with lithiated (S)-N-ethyl-3-methyl-1-(triisopropylsilyloxy)butan-2-amine are also reported. Identical dimeric, ladder-type, mixed aggregates are the major species at a stoichiometric ratio of 1:1 lithium chiral amide to alkyllithium in toluene-d8 solution for all of the different alkyllithium reagents.
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Affiliation(s)
- Chicheung Su
- Department of Chemistry, Brown University , 324 Brook Street,Providence, Rhode Island 02912, United States
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28
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Harrison-Marchand A, Mongin F. Mixed AggregAte (MAA): A Single Concept for All Dipolar Organometallic Aggregates. 1. Structural Data. Chem Rev 2013; 113:7470-562. [DOI: 10.1021/cr300295w] [Citation(s) in RCA: 145] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Anne Harrison-Marchand
- Laboratoire COBRA de l′Université de Rouen, INSA de Rouen, CNRS, UMR 6014 & FR 3038, IRCOF, Rue Tesnière, 76821 Mont St Aignan Cédex, France
| | - Florence Mongin
- Équipe Chimie et Photonique Moléculaires, Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, Bâtiment 10A, case 1003, Avenue du Général Leclerc, 35042 Rennes Cédex, France
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29
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Su C, Hopson R, Williard PG. Characterization of cyclopentyllithium and cyclopentyllithium tetrahydrofuran complex. J Am Chem Soc 2013; 135:12400-6. [PMID: 23875807 DOI: 10.1021/ja4059102] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The solid-state structures of unsolvated, hexameric cyclopentyllithium and tetrameric cyclopentyllithium tetrahydrofuran solvate were determined by single-crystal X-ray diffraction. Cyclopentyllithium easily crystallized in hydrocarbon solvents. Solution-state structural analyses of cyclopentyllithium and cyclopentyllithium-tetrahydrofuran complexes in toluene-d8 were also carried out by diffusion-ordered NMR spectroscopy with diffusion coefficient-formula weight correlation analyses and other one- and two-dimensional NMR techniques. The solution-state studies suggest that unsolvated cyclopentyllithium exists as hexamer and tetramer equilibrating with each other. Upon solvation with tetrahydrofuran, cyclopentyllithium exists mostly as a tetrahydrofuran tetrasolvated tetramer.
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Affiliation(s)
- Chicheung Su
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
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30
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Su C, Hopson R, Williard PG. Characterization of Hexameric and Octameric
sec
‐Butyllithium/
sec
‐Butoxide Mixed Aggregates. Eur J Inorg Chem 2013. [DOI: 10.1002/ejic.201300749] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Chicheung Su
- Department of Chemistry, Brown University, 324 Brook Street, Providence, RI 02912, USA
| | - Russell Hopson
- Department of Chemistry, Brown University, 324 Brook Street, Providence, RI 02912, USA
| | - Paul G. Williard
- Department of Chemistry, Brown University, 324 Brook Street, Providence, RI 02912, USA
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31
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Su C, Hopson R, Williard PG. Crystal structure and solution state characterization of lithium (S)-(1-(bis(2-methoxyethyl)amino)-3-methylbutan-2-yl)(methyl)amide. J Org Chem 2013; 78:7288-92. [PMID: 23767993 DOI: 10.1021/jo400839q] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The solid state structure of lithiated (S)-N(1),N(1)-bis(2-methoxyethyl)-N(2),3-dimethylbutane-1,2-diamine, which is a chiral amide base synthesized from (S)-valine was determined by single-crystal X-ray diffraction. The complex in solution state is also characterized by a variety of NMR experiments including diffusion-ordered NMR spectroscopy (DOSY) with diffusion coefficient-formula weight correlation analyses and other one- and two-dimensional NMR techniques by dissolving the crystal in toluene-d8. The crystallography and NMR results suggest that the chiral amide is dimeric in both solid and solution states.
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Affiliation(s)
- Chicheung Su
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
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32
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Armstrong DR, Kennedy AR, Mulvey RE, Robertson SD. A hetero-alkali-metal version of the utility amide LDA: lithium-potassium diisopropylamide. Dalton Trans 2013; 42:3704-11. [PMID: 23299468 DOI: 10.1039/c2dt32204h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Designed to extend the synthetically important alkali-metal diisopropylamide [N(i)Pr(2); DA] class of compounds, the first example of a hetero-alkali-metallic complex of DA has been prepared as a partial TMEDA solvate. Revealed by an X-ray crystallographic study, its structure exists as a discrete lithium-rich trinuclear Li(2)KN(3) heterocycle, with TMEDA only solvating the largest of the alkali-metals, with the two-coordinate lithium atoms being close to linearity [161.9(2)°]. A variety of NMR spectroscopic studies, including variable temperature and DOSY NMR experiments, suggests that this new form of LDA maintains its integrity in non-polar hydrocarbon solution. This complex thus represents a rare example of a KDA molecule which is soluble in non-polar medium without the need for excessive amounts of solubilizing Lewis donor being added.
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Affiliation(s)
- David R Armstrong
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL, UK
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33
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Li W, Chung H, Daeffler C, Johnson JA, Grubbs RH. Application of (1)H DOSY for Facile Measurement of Polymer Molecular Weights. Macromolecules 2012; 45:9595-9603. [PMID: 23335819 DOI: 10.1021/ma301666x] [Citation(s) in RCA: 141] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
To address the practical issues of polymer molecular weight determination, the first accurate polymer weight-average molecular weight determination method in diverse living/controlled polymerization via DOSY (diffusion-ordered NMR spectroscopy) is reported. Based on the linear correlation between the logarithm of diffusion coefficient (log D) and the molecular weights (log Mw), external calibration curves were created to give predictions of molecular weights of narrowly-dispersed polymers. This method was successfully applied to atom transfer radical polymerization (ATRP), reversible addition-fragmentation chain transfer (RAFT), and ring-opening metathesis polymerization (ROMP), with weight-average molecular weights given by this method closely correlated to those obtained from GPC measurement.
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Affiliation(s)
- Weibin Li
- The Arnold and Mabel Beckman Laboratories of Chemical Synthesis, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
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34
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Shukla M, Dorai K. Disentangling diffusion information of individual components in a mixture with a 3D COMPACT-IDOSY NMR experiment. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2012; 50:341-346. [PMID: 22467600 DOI: 10.1002/mrc.2877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2011] [Revised: 12/02/2011] [Accepted: 12/05/2011] [Indexed: 05/31/2023]
Abstract
A new 3D diffusion-ordered heteronuclear NMR experiment COMPACT-IDOSY (cross-polarization optimized multisite polarized accelerated time internally encoded diffusion ordered spectroscopy) has been designed and experimentally implemented on a mixture of flavonoids rutin and quercetin. The pulse sequence uses a cross-polarization mixing period and diffusion encoding gradients internally incorporated into the coherence transfer interval of a long-range heteronuclear correlation experiment. Substantial reduction in experimental time, good sensitivity and excellent resolution of signal overlap lead to the accurate determination of translational diffusion coefficients of individual components in the mixture.
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Affiliation(s)
- Matsyendranath Shukla
- Department of Physics, Indian Institute of Science Education & Research (IISER) Mohali, Sector 81 Manauli PO, SAS Nagar, 140306, Punjab, India
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35
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García-Álvarez P, Mulvey RE, Parkinson JA. “LiZn(TMP)3”, a Zincate or a Turbo-Lithium Amide Reagent? DOSY NMR Spectroscopic Evidence. Angew Chem Int Ed Engl 2011; 50:9668-71. [DOI: 10.1002/anie.201104297] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Indexed: 11/06/2022]
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36
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García-Álvarez P, Mulvey RE, Parkinson JA. “LiZn(TMP)3”, a Zincate or a Turbo-Lithium Amide Reagent? DOSY NMR Spectroscopic Evidence. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201104297] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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37
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Botana A, Howe PWA, Caër V, Morris GA, Nilsson M. High resolution 13C DOSY: the DEPTSE experiment. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2011; 211:25-29. [PMID: 21507692 DOI: 10.1016/j.jmr.2011.03.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Revised: 03/11/2011] [Accepted: 03/18/2011] [Indexed: 05/30/2023]
Abstract
High Resolution Diffusion-ordered Spectroscopy (HR-DOSY) is a valuable tool for mixture analysis by NMR. It separates the signals from different components according to their diffusion behavior, and can provide exquisite diffusion resolution when there is no signal overlap. In HR-DOSY experiments on (1)H (by far the most common nucleus used for DOSY) there is frequent signal overlap that confuses interpretation. In contrast, a (13)C spectrum usually has little overlap, and is in this respect a much better option for a DOSY experiment. The low signal-to-noise ratio is a critical limiting factor, but with recent technical advances such as cryogenic probes this problem is now less acute. The most widely-used pulse sequences for (13)C DOSY perform diffusion encoding with (1)H, using a stimulated echo in which half of the signal is lost. This signal loss can be avoided by encoding diffusion with (13)C in a spin echo experiment such as the DEPTSE pulse sequence described here.
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Affiliation(s)
- Adolfo Botana
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK
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38
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Kagan G, Li W, Li D, Hopson R, Williard PG. Characterization of dimeric chiral lithium amide structures derived from N-isopropyl-O- triisopropylsilyl valinol. J Am Chem Soc 2011; 133:6596-602. [PMID: 21486016 DOI: 10.1021/ja109041z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The dimeric structure is characterized for a chiral amide base complex consisting of an (S)-N-isopropyl-O-triisopropylsilyl valinol ligand and lithium. The complex is characterized by a variety of NMR techniques, including multinuclear one- and two-dimensional NMR experiments and diffusion-ordered NMR spectroscopy (DOSY) as well as diffusion coefficient-formula weight (D-fw) correlation analyses. Spartan calculations are presented which support the structural assignment. This structural characterization leads to an explanation of the behavior and the reactivity of these complexes in solution.
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Affiliation(s)
- Gerald Kagan
- Department of Chemistry, Brown University, 324 Brook Street, Providence, Rhode Island 02912, USA
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39
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Armstrong DR, García-Álvarez P, Kennedy AR, Mulvey RE, Robertson SD. Molecular Structures of THF-Solvated Alkali-Metal 2,2,6,6-Tetramethylpiperidides Finally Revealed: X-ray Crystallographic, DFT, and NMR (including DOSY) Spectroscopic Studies. Chemistry 2011; 17:6725-30. [DOI: 10.1002/chem.201100523] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Indexed: 11/09/2022]
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40
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Armstrong DR, Clegg W, García-Alvarez P, McCall MD, Nuttall L, Kennedy AR, Russo L, Hevia E. Shedding new light on ZnCl2-mediated addition reactions of Grignard reagents to ketones: structural authentication of key intermediates and diffusion-ordered NMR studies. Chemistry 2011; 17:4470-9. [PMID: 21365695 DOI: 10.1002/chem.201002544] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Indexed: 11/08/2022]
Abstract
Building on recent advances in synthesis showing that the addition of inorganic salts to Grignard reagents can greatly enhance their performance in alkylation reactions to ketones, this study explores the reactions of EtMgCl with benzophenone in the presence of stoichiometric or catalytic amounts of ZnCl(2) with the aim of furthering the understanding of the role and constitution of the organometallic species involved in these transformations. Investigations into the metathesis reactions of three molar equivalents of EtMgCl with ZnCl(2) led to the isolation and characterisation (X-ray crystallography and (1)H and (13)C NMR spectroscopy) of novel magnesium "zinc-rich" zincate [{(THF)(6)Mg(2)Cl(3)}(+){Zn(2)Et(5)}(-)] (1), whose complicated constitution in THF solutions was assessed by variable-temperature (1)H DOSY NMR studies. Compound 1 reacted with one equivalent of benzophenone to yield magnesium magnesiate [{(THF)(6)Mg(2)Cl(3)}(+){Mg(2)(OC(Et)Ph(2))(2)Cl(3)(THF)}(-)] (3), whose structure was determined by X-ray crystallography. (1)H NMR monitoring of this reaction showed two equivalents of ZnEt(2) formed as a co-product, which together with the "magnesium only constitution" of 3 provides experimental insights into how zinc can be efficiently recycled in these reactions, and therefore used catalytically. The chemoselectivity of this reaction can be rationalised in terms of the synergic effect of magnesium and zinc and contrasts with the results obtained when benzophenone was allowed to react with EtMgCl in the absence of ZnCl(2), where the reduction of the ketone takes place preferentially. The reduction product [{(THF)(5)Mg(3)Cl(4){OC(H)Ph(CF(3))}(2)] (4) obtained from the reaction of EtMgCl with 2,2,2-trifluoroacetophenone was established by X-ray crystallography and multinuclear ((1)H, (13)C and (19)F) NMR spectroscopy. Compounds 3 and 4 exhibit new structural motifs in magnesium chemistry having MgCl(2) integrated within their constitution, which highlights the new role of this inorganic salt in providing structural support for the newly generated alkoxide ligand.
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Affiliation(s)
- David R Armstrong
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL UK
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41
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Kagan G, Li W, Sun C, Hopson R, Williard PG. Synthesis, characterization, and reaction of a ketone-derived 1,4-dienolate compound. J Org Chem 2011; 76:65-70. [PMID: 21141914 DOI: 10.1021/jo1015163] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The tetrahydrofuran tetrasolvated dimeric lithium dienolate derived from 2,2,7,7-tetramethyloctan-3,6-dione is characterized in the solid state by X-ray diffraction analysis and in solution by diffusion NMR. This dienolate was reacted with tropanone to yield two new products that are also described.
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Affiliation(s)
- Gerald Kagan
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
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42
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Li D, Kagan G, Hopson R, Williard PG. Formula weight prediction by internal reference diffusion-ordered NMR spectroscopy (DOSY). J Am Chem Soc 2010; 131:5627-34. [PMID: 19323518 DOI: 10.1021/ja810154u] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Formula weight (FW) information is important to characterize the composition, aggregation number, and solvation state of reactive intermediates and organometallic complexes. We describe an internal reference correlated DOSY method for calculating the FW of unknown species in different solvents with different concentrations. Examples for both the small molecule (DIPA) and the organometallic complex (aggregate 1) yield excellent correlations. We also found the relative diffusion rate is inversely proportional to the viscosity change of the solution, which is consistent with the theoretical Stokes-Einstein equation. The accuracy of the least-squares linear prediction r(2) and the percentage difference of FW prediction are directly related to the density change; greater accuracy was observed with decreasing density. We also discuss the guidelines and other factors for successful application of this internal reference correlated DOSY method. This practical method can be conveniently modified and applied to the characterization of other unknown molecules or complexes.
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Affiliation(s)
- Deyu Li
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
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43
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Li W, Kagan G, Yang H, Cai C, Hopson R, Sweigart DA, Williard PG. Physically Separated References for Diffusion Coefficient-Formula Weight (D-FW) Analysis of Diffusion-Ordered NMR Spectroscopy (DOSY) in Water. Org Lett 2010; 12:2698-701. [DOI: 10.1021/ol100686e] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Weibin Li
- Department of Chemistry, Brown University Providence, Rhode Island 02912
| | - Gerald Kagan
- Department of Chemistry, Brown University Providence, Rhode Island 02912
| | - Huan Yang
- Department of Chemistry, Brown University Providence, Rhode Island 02912
| | - Chen Cai
- Department of Chemistry, Brown University Providence, Rhode Island 02912
| | - Russell Hopson
- Department of Chemistry, Brown University Providence, Rhode Island 02912
| | - Dwight A. Sweigart
- Department of Chemistry, Brown University Providence, Rhode Island 02912
| | - Paul G. Williard
- Department of Chemistry, Brown University Providence, Rhode Island 02912
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44
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Kagan G, Li W, Hopson R, Williard PG. 6Li diffusion-ordered NMR spectroscopy (DOSY) and applications to organometallic complexes. Org Lett 2010; 12:520-3. [PMID: 20041695 DOI: 10.1021/ol902713h] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The development of (6)Li diffusion-ordered NMR spectroscopy (DOSY) is reported. This technique is applied to (6)Li organometallic complexes. (6)Li DOSY provides a facile means of identification of peaks in the (6)Li spectrum, as well as evidence of mixed aggregates based on relative diffusion coefficients. (6)Li data is correlated to (1)H diffusion experiments through (6)Li{(1)H} HOESY and/or (1)H{(6)Li} HMBC experiments to obtain formula weight information of Li aggregates.
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Affiliation(s)
- Gerald Kagan
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
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45
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Li W, Kagan G, Yang H, Cai C, Hopson R, Dai W, Sweigart DA, Williard PG. Accurate Formula Weight Determination in Physically Separated Systems by Diffusion Coefficient−Formula Weight Correlation. Organometallics 2010. [DOI: 10.1021/om901102b] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Weibin Li
- Department of Chemistry, Brown University, 324 Brook Street, Providence, Rhode Island 02912
| | - Gerald Kagan
- Department of Chemistry, Brown University, 324 Brook Street, Providence, Rhode Island 02912
| | - Huan Yang
- Department of Chemistry, Brown University, 324 Brook Street, Providence, Rhode Island 02912
| | - Chen Cai
- Department of Chemistry, Brown University, 324 Brook Street, Providence, Rhode Island 02912
| | - Russell Hopson
- Department of Chemistry, Brown University, 324 Brook Street, Providence, Rhode Island 02912
| | - Wei Dai
- Department of Chemistry, Brown University, 324 Brook Street, Providence, Rhode Island 02912
| | - Dwight A. Sweigart
- Department of Chemistry, Brown University, 324 Brook Street, Providence, Rhode Island 02912
| | - Paul G. Williard
- Department of Chemistry, Brown University, 324 Brook Street, Providence, Rhode Island 02912
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46
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Nilsson M. The DOSY Toolbox: a new tool for processing PFG NMR diffusion data. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2009; 200:296-302. [PMID: 19666235 DOI: 10.1016/j.jmr.2009.07.022] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2009] [Revised: 07/03/2009] [Accepted: 07/11/2009] [Indexed: 05/28/2023]
Abstract
The DOSY Toolbox is a free programme for processing PFG NMR diffusion data (sometimes loosely referred to as DOSY data), distributed under the GNU General Public License. NMR data from three major manufacturers can be imported and all processing is done in a user-friendly graphical user interface. The Toolbox is completely free-standing in the sense that all necessary basic processing of NMR data (e.g., Fourier transformation and phasing) is catered for within the programme, as well as a number of methods specific to DOSY data (e.g., DOSY and SCORE). The programme is written in MATLAB and as such can be run on any platform, but can also run independent of MATLAB in a free-standing compiled version for Windows, Mac, and Linux.
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Affiliation(s)
- Mathias Nilsson
- School of Chemistry, University of Manchester, Manchester, UK.
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47
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Kagan G, Li W, Hopson R, Williard PG. Internally Referenced Diffusion Coefficient−Formula Weight (D-FW) Analysis of 31P Diffusion-Ordered NMR Spectroscopy (DOSY). Org Lett 2009; 11:4818-21. [DOI: 10.1021/ol9019106] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Gerald Kagan
- Department of Chemistry, Brown University, Providence, Rhode Island 02912
| | - Weibin Li
- Department of Chemistry, Brown University, Providence, Rhode Island 02912
| | - Russell Hopson
- Department of Chemistry, Brown University, Providence, Rhode Island 02912
| | - Paul G. Williard
- Department of Chemistry, Brown University, Providence, Rhode Island 02912
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48
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Nilsson M, Botana A, Morris GA. T1-Diffusion-Ordered Spectroscopy: Nuclear Magnetic Resonance Mixture Analysis Using Parallel Factor Analysis. Anal Chem 2009; 81:8119-25. [DOI: 10.1021/ac901321w] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mathias Nilsson
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Adolfo Botana
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Gareth A. Morris
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K
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49
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Yemloul M, Castola V, Leclerc S, Canet D. Self-diffusion coefficients obtained from proton-decoupled carbon-13 spectra for analyzing a mixture of terpenes. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2009; 47:635-640. [PMID: 19431152 DOI: 10.1002/mrc.2442] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In the limit of sufficient sensitivity, natural abundance 13C offers a much better spectral resolution than proton NMR. This is due to an important chemical shift range and to proton-decoupling conditions that yield one peak per carbon with practically no overlap. However, pulsed gradient spin echo experiments, which lead to the diffusion coefficient associated with each peak, have scarcely been employed. In this article, we present and compare different ways to access this quantity and we have effectively verified that, without any precaution, diffusion coefficients cannot be properly determined from standard procedures. The cause of such a failure is decoupling during the gradient pulses. We have used a very simple remedy that proved to be very successful on a model mixture of three monoterpenes and that appears as being of general applicability.
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Affiliation(s)
- Mehdi Yemloul
- Méthodologie RMN, CRM UMR, Nancy-Université-CNRS, Vandoeuvre-lès-Nancy, France
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50
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Vermillion K, Price NPJ. Stable isotope-enhanced two- and three-dimensional diffusion ordered 13C NMR spectroscopy (SIE-DOSY 13C NMR). JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2009; 198:209-214. [PMID: 19303336 DOI: 10.1016/j.jmr.2009.02.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 02/20/2009] [Accepted: 02/20/2009] [Indexed: 05/27/2023]
Abstract
The feasibility of obtaining high quality homonuclear or heteronuclear diffusion-ordered (13)C NMR data is shown to be greatly improved by using (13)C isotopically-enriched samples. Stable isotope-enhanced diffusion ordered (SIE-DOSY) (13)C NMR has been applied to (13)C-enriched carbohydrates, and has been used to determine diffusion coefficients for pentose and hexose monosaccharides, and a disaccharide and trisaccharide. These 2D spectra were obtained with as little as 8 min of acquisition time. Fully resolved 3D DOSY-HMQC NMR spectra of [U-(13)C]xylose, [U-(13)C]glucose, and [1-(13)C(gal)]lactose were obtained in 5h. Sample derivatization with [carbonyl-(13)C]acetate (peracetylation) extends the usefulness of the technique to included non-labeled sugars; the (13)C-carbonyl - carbohydrate ring proton (1)H-(13)C correlations also provide additional structural information, as shown for the 3-D DOSY-HMQC analysis of a mixture of maltotriose and lactose per-[carbonyl-(13)C]acetates.
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Affiliation(s)
- Karl Vermillion
- New Crops and Processing Technology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, United States Department of Agriculture, Peoria, IL 61604, USA.
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