Identification of Polyaromatic Spin Systems of Complex Mixtures by TOCSY, Using Specific Time Dependence during Isotropic Mixing

Doan, Bich‐Thuy; Gillet, B.; Blondel, Benoît; Belœil, Jean‐Claude

doi:10.1006/jmra.1995.1132

Cited by 5 publications

(2 citation statements)

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“…It has been reported that the determination of reactivity ratios in the cases where the difference in reactivity is large is difficult due to errors involved in their estimation 13. The contribution of 13 C{ 1 H} NMR and two‐dimensional (2D) NMR spectroscopy to the study of polymer microstructure has been universally recognized 14–23…”

Section: Introductionmentioning

confidence: 99%

Microstructure determination and thermal studies ofn‐acryloylcarbazole/vinyl acetate copolymers

Brar

Singh

2006

J of Applied Polymer Sci

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Copolymers of N-acryloylcarbazole (A) and vinyl acetate (V) were synthesized by bulk polymerization using benzoyl peroxide (BPO) as free-radical initiator at 658C in different in-feed ratios. The composition of the copolymer was determined by H} NMR spectra of the copolymers were done by the help of distortionless enhancement by polarization transfer (DEPT) and two-dimensional NMR techniques such as heteronuclear single quantum coherence (HSQC) and total correlation spectroscopy (TOCSY). The methine and methylene carbon resonances were found to be compositional as well as configurational sensitive. The signals obtained were broad pertaining to the restricted rotation of bulky carbazole group. The thermal stability and glass-transition temperatures (T g ) of the copolymers were found to be dependant on polymer composition and characteristic of rotational rigidity of the polymer chain. Variation in the values of T g with the copolymer composition was found to be in good agreement with theoretical values obtained from Johnston and Barton equations.

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Section: Introductionmentioning

confidence: 99%

Microstructure determination and thermal studies ofn‐acryloylcarbazole/vinyl acetate copolymers

Brar

Singh

2006

J of Applied Polymer Sci

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“…Mixture component resolution by NMR has caught considerable attention for more than 20 years and many approaches have been explored to date, such as liquid chromatography (LC)–NMR hyphenation, diffusion-ordered spectroscopy (DOSY), assisted or not by matrix effect, multiple-quantum NMR spectroscopy, combined or not with broadband homonuclear decoupling and sparse sampling. Original signal processing algorithms have also been proposed to resolve individual components of mixture spectra. − …”

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confidence: 99%

Highly Viscous Binary Solvents: DMSO-d6/Glycerol and DMSO-d6/Glycerol-d8 for Polar and Apolar Mixture Analysis by NMR

Lameiras

2016

Anal. Chem.

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The use of two new highly viscous binary solvents, DMSO-d6/glycerol (GL) and DMSO-d6/glycerol-d8 (GL-d8), is reported for the first time in order to give access to the individual NMR spectra of mixture components. Their high dissolution power offers a wide range of potential applications to mixture analysis, regardless of polarity. Under particular conditions of viscosity, the tumbling rate of small and medium-sized molecules slows down in solution, so that the longitudinal cross-relaxation regime favors the observation of spin diffusion. As a consequence, all the resonances of the (1)H nuclei within the same molecule tend to correlate together in a 2D nuclear Overhauser effect spectroscopy (NOESY) spectrum, thus opening the way to mixture analysis. This work reports the analysis of a polar mixture composed of Leu-Val, Leu-Tyr, Gly-Tyr, and Ala-Tyr dissolved in DMSO-d6/GL (8:2, v/v) and of an apolar mixture made of β-ionone, (±)-citronellal, (+)-limonene, and flavone dissolved in DMSO-d6/GL-d8 (5:5, v/v) by means of spin diffusion in homonuclear selective 1D NOESY, selective 2D NOESY, NOESY-correlation spectroscopy (COSY), NOESY-total correlation spectroscopy (TOCSY) experiments, and 2D heteronuclear single-quantum correlation spectroscopy (HSQC)-NOESY. DMSO-d6/GL must be preferred to DMSO-d6/GL-d8 for the study of biological active compounds in which labile protons must not be exchanged by deuterium nuclei. DMSO-d6/GL-d8 is more appropriate for organic compounds in which labile protons are not essential to the structure elucidation. DMSO-d6/GL and DMSO-d6/GL-d8 binary mixture solvents seem to be so far the most efficient viscous solvents described in the literature for the resolution of both polar and apolar complex mixtures components by NMR spin diffusion.

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Small Molecule Mixture Analysis by Heteronuclear NMR under Spin Diffusion Conditions in Viscous DMSO–Water Solvent

Lameiras

Patis

Jakhlal

et al. 2017

Chemistry A European J

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Spin diffusion in NMR occurs for small- and medium-sized molecules when their tumbling rate reduces in solution so that magnetization exchange by longitudinal cross relaxation becomes highly efficient. Composite DMSO-water viscous solvents were used for the first time to access the individual NMR spectra of a mixture components in spin diffusion conditions. The easy handling and high dissolution power of [D ]DMSO/H O offers a wide range of potential applications for polar and moderately apolar mixture analysis. In addition to 2D H- H NOESY and H- C HSQC-NOESY, H- N HSQC-NOESY, 1D and 2D H- F heteronuclear NOESY (HOESY) experiments were set up to offer new ways to individualize molecules within a mixture. This article reports the analysis of a polar mixture of four dipeptides dissolved in [D ]DMSO/H O (7:3 v/v) and that of a medium-polarity fluorinated dinucleotide dissolved in [D ]DMSO/H O (8:2 v/v) by means of spin diffusion in NOESY, HOESY, and HSQC-NOESY experiments.

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Identification of Polyaromatic Spin Systems of Complex Mixtures by TOCSY, Using Specific Time Dependence during Isotropic Mixing

Cited by 5 publications

References 0 publications

Microstructure determination and thermal studies ofn‐acryloylcarbazole/vinyl acetate copolymers

Microstructure determination and thermal studies ofn‐acryloylcarbazole/vinyl acetate copolymers

Highly Viscous Binary Solvents: DMSO-d6/Glycerol and DMSO-d6/Glycerol-d8 for Polar and Apolar Mixture Analysis by NMR

Small Molecule Mixture Analysis by Heteronuclear NMR under Spin Diffusion Conditions in Viscous DMSO–Water Solvent

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