A Novel Multiple-Quantum Correlation NMR Scheme to Separate Components of a Mixture According to Their Diffusion Coefficients

Shukla, Matsyendranath; Dorai, Kavita

doi:10.1007/s00723-012-0316-y

Cited by 5 publications

(8 citation statements)

References 37 publications

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“…All chemical shifts are given relative to the residual solvent signal (CHCl 3 : δ =7.26 ppm). Standard DOSY spectra were recorded by a conventional pulse sequence, based on the stimulated echo and incorporated bipolar gradient pulses and an eddy‐current delay (BPP‐LED); the diffusion delay (Δ) was set at 25 ms, the gradient strength ( g ) was linearly incremented in 32 steps from 2 to 9 % of its maximum value, and 8 scans were recorded for each experiment.…”

Section: Methodsmentioning

confidence: 99%

Characterization of a Dinuclear Copper(II) Complex and Its Fleeting Mixed‐Valent Copper(II)/Copper(III) Counterpart

et al. 2017

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International audienceThe synthesis of a dinuclear copper(II) complex, supported by a 1,3-diamino-2-propanol-based tetraamide ligand, is reported. Structural properties in the solid state and in solution, by means of XRD analysis and NMR spectroscopy, respectively, provide evidence of a highly flexible complex that can display several conformations, leading to the image of the wings of a butterfly. The complex was fully characterized and the redox properties were investigated. Room-temperature spectro-electrochemistry was used to monitor the formation of a metastable mono-oxidized product that displayed an absorption band centered at λ=463 nm. EPR investigation of the low-temperature, chemically generated, mono-oxidized product reveals the presence of an intermediate described as a mixed-valent CuIICuIII species, which is a model of the possible highly oxidizing intermediate in particulate methane monooxygenase

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Section: Methodsmentioning

confidence: 99%

Characterization of a Dinuclear Copper(II) Complex and Its Fleeting Mixed‐Valent Copper(II)/Copper(III) Counterpart

et al. 2017

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“…However, the hydrodynamic radius shows an insignificant variation in the LiClO 4 /D 2 O/CD 3 CN mixture, possibly due to the high diffusional dynamics of PEG in CD 3 CN as compared with other mixtures. A detailed diffusional and hydrodynamic study of these PEG/lithium salt mixtures is underway using a newly developed 3D diffusion pulse sequence and will be communicated shortly …”

Section: Resultsmentioning

confidence: 99%

“…A detailed diffusional and hydrodynamic study of these PEG/lithium salt mixtures is underway using a newly developed 3D diffusion pulse sequence and will be communicated shortly. [45][46][47]…”

Section: Nmr Diffusion and Hydrodynamic Structurementioning

confidence: 99%

Structural and dynamical aspects of PEG/LiClO₄ in solvent mixtures via NMR spectroscopy

Singh

Nanda

Dorai

2019

Magnetic Reson in Chemistry

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Motivated by the potential usefulness of polyethylene glycol (PEG)/Li+ salt mixtures in several industrial applications, we investigated the structure and dynamics of PEG/LiClO4 mixtures in D2O and its mixtures with CD3CN and DMSO‐d6, in a series of PEG‐based polymers with a wide variation in their molecular weights. 1H NMR chemical shifts, T1/T2 relaxation rates, pulsed‐field gradient NMR diffusion experiments, and 2D HOESY NMR studies have been performed to understand the structural and dynamical aspects of these mixtures. Increasing the temperature of the medium results in a significant perturbation in the H‐bonded structure of PEG in its PEG/LiClO4/D2O mixtures as observed from the increase in chemical shifts. On the other hand, the addition of molecular cosolvents has a negligible effect. The hydrodynamic structure of PEG shows a pronounced variation at low temperature with increasing molecular weight, which, however, disappears at higher temperatures. Increasing the temperature leads to a decrease in the hydrodynamic structure of PEG, which can be explained on the basis of solvation–desolvation phenomena. The 2D HOESY NMR spectra reveal a new finding of Li+‐water binding in the PEG/LiClO4/D2O mixtures with the addition of molecular solvents, suggesting that the Li+ cation diffuses freely in the D2O mixtures of polymers as compared with the polymer mixtures with DMSO or CD3CN.

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“…All NMR datasets were processed in TOPSPIN 3.2 version (Bruker BioSpin, Germany). To obtain reference values of diffusion coefficients, standard DOSY spectra were recorded by a conventional pulse sequence, based on the stimulated echo and incorporated bipolar gradient pulses and an eddy‐current delay (BPP‐LED) . The shape of all gradient pulses was Smoothed Square and the LED delay was of 5 ms. For all experiments, the diffusion delay Δ was set at 100 ms, the gradient strength, g , was linearly incremented in 32 steps from 2% to 95% of its maximum value, and four scans were recorded for each experiment.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…In this experiment, the diffusion effects were encoded with p = 1 . Recently, a similar application using a 3D version was proposed by sequentially concatenating a DWDQ and DOSY …”

Section: Introductionmentioning

confidence: 99%

Combined maximum‐quantum and DOSY 3D experiments provide enhanced resolution for small molecules in mixtures

Reddy

Yemloul

Caldarelli

2016

Magnetic Reson in Chemistry

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We illustrate here as the combination of high-order maximum-quantum (MaxQ) and Diffusion-Ordered SpectroscopY (DOSY) NMR experiments in a 3D layout allows superior resolution for crowded NMR spectra. Non-uniform sampling (NUS) allows compressing the experimental time effectively to reasonable durations. Because diffusion effects were encoded within multiple-quantum coherences, increased sensitivity to magnetic field gradients is observed, requiring compensation for convection effects. The experiment was demonstrated on the spectra of a mix of small polyaromatic molecules. Specifically, in the case analyzed, the experiment provided an extreme simplification through the MaxQDOSY-MaxQ projection plane that presents one peak per molecule. Copyright © 2016 John Wiley & Sons, Ltd.

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A Novel Multiple-Quantum Correlation NMR Scheme to Separate Components of a Mixture According to Their Diffusion Coefficients

Cited by 5 publications

References 37 publications

Characterization of a Dinuclear Copper(II) Complex and Its Fleeting Mixed‐Valent Copper(II)/Copper(III) Counterpart

Characterization of a Dinuclear Copper(II) Complex and Its Fleeting Mixed‐Valent Copper(II)/Copper(III) Counterpart

Structural and dynamical aspects of PEG/LiClO₄ in solvent mixtures via NMR spectroscopy

Combined maximum‐quantum and DOSY 3D experiments provide enhanced resolution for small molecules in mixtures

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A Novel Multiple-Quantum Correlation NMR Scheme to Separate Components of a Mixture According to Their Diffusion Coefficients

Cited by 5 publications

References 37 publications

Characterization of a Dinuclear Copper(II) Complex and Its Fleeting Mixed‐Valent Copper(II)/Copper(III) Counterpart

Characterization of a Dinuclear Copper(II) Complex and Its Fleeting Mixed‐Valent Copper(II)/Copper(III) Counterpart

Structural and dynamical aspects of PEG/LiClO4 in solvent mixtures via NMR spectroscopy

Combined maximum‐quantum and DOSY 3D experiments provide enhanced resolution for small molecules in mixtures

Contact Info

Product

Resources

About

Structural and dynamical aspects of PEG/LiClO₄ in solvent mixtures via NMR spectroscopy