NOE Enhancement in Continuous-Flow13C and15N FT NMR Using Upstream1H Preirradiation

Günther, Ulrich L.; Sudmeier, James L.; Albert, Klaus; Bachovchin, William W.

doi:10.1006/jmra.1995.9970

Cited by 3 publications

(3 citation statements)

References 6 publications

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“…However, to achieve the Boltzmann distribution it is necessary that the nuclei remain for a time 3−5 times larger than T 1 in the magnetic field. This requirement leads to very large premagnetization volumes for higher flow rates. ,, …”

Section: Theorymentioning

confidence: 99%

“…This requirement leads to very large premagnetization volumes for higher flow rates. 16,17,33 It is possible to reduce the premagnetization volume by manipulating the spin-lattice relaxation times of sample nuclei. This is accomplished by adding stable free radicals or other paramagnetic relaxation agents, such as Gd(III) complexes, to the solution.…”

Section: Theorymentioning

confidence: 99%

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Quantification Studies in Continuous-Flow ¹³C Nuclear Magnetic Resonance Spectroscopy by Use of Immobilized Paramagnetic Relaxation Agents

Fischer¹,

Seiler²,

Ertl³

et al. 2003

J. Phys. Chem. B

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Different types of immobilized free radicals as well as immobilized paramagnetic gadolinium(III) complexes were synthesized and used as relaxation agents to shorten the spin-lattice relaxation times T 1 of analytes in quantitative continuous-flow 13 C nuclear magnetic resonance spectroscopy (NMR). The immobilized paramagnetic relaxation agents were characterized with electron paramagnetic resonance spectroscopy (EPR) and extended X-ray absorption fine structure spectroscopy (EXAFS). With these types of paramagnetic relaxation agents, it was possible to obtain a 4-fold increase in signal-to-noise ratio per unit time, and an almost quantitative NMR spectra in continuous-flow 13 C NMR spectroscopy could be acquired with this method.

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Section: Theorymentioning

confidence: 99%

Section: Theorymentioning

confidence: 99%

Quantification Studies in Continuous-Flow ¹³C Nuclear Magnetic Resonance Spectroscopy by Use of Immobilized Paramagnetic Relaxation Agents

Fischer¹,

Seiler²,

Ertl³

et al. 2003

J. Phys. Chem. B

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“…With flow-through NMR, − it is possible to investigate chemical reactions provided the equilibrium Boltzmann distribution of nuclei spin states is not violated by rapid flow rates. Applications and technical concerns using flow NMR have been previously discussed. − …”

Section: Introductionmentioning

confidence: 99%

Kinetics of Deuterium Exchange on Resorcinol in D₂O at High Pressure and High Temperature

1999

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The kinetics of deuteration of resorcinol in pure D2O were studied for the first time using a flow-through capillary tubular reactor with on-line, proton, and deuterium NMR detection at high temperatures and high pressure. The global rate constants for hydrogen/deuterium (H/D) exchange were determined from temperatures of 200−450 °C (723 K) at a pressure of ∼400 bar (the critical temperature and pressure of water are 374.2 °C and 218.3 bar, respectively). The H/D exchange rate in resorcinol (1,3-dihydroxybenzene) under these extreme conditions was determined using proton NMR as a function of the resorcinol residence time in a capillary tubular reactor, which also served as a high-pressure NMR cell. The 1H and 2H NMR results indicate that H/D exchange in resorcinol for the ring protons was observed at temperatures as low as 200 °C. The kinetics of H/D exchange in resorcinol and the activation energy was extracted from the experimental 1H NMR data.

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Application of immobilized free radicals in supercritical fluid chromatography hyphenated with proton nuclear magnetic resonance spectroscopy

et al. 2000

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NOE Enhancement in Continuous-Flow13C and15N FT NMR Using Upstream1H Preirradiation

Cited by 3 publications

References 6 publications

Quantification Studies in Continuous-Flow ¹³C Nuclear Magnetic Resonance Spectroscopy by Use of Immobilized Paramagnetic Relaxation Agents

Quantification Studies in Continuous-Flow ¹³C Nuclear Magnetic Resonance Spectroscopy by Use of Immobilized Paramagnetic Relaxation Agents

Kinetics of Deuterium Exchange on Resorcinol in D₂O at High Pressure and High Temperature

Application of immobilized free radicals in supercritical fluid chromatography hyphenated with proton nuclear magnetic resonance spectroscopy

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NOE Enhancement in Continuous-Flow13C and15N FT NMR Using Upstream1H Preirradiation

Cited by 3 publications

References 6 publications

Quantification Studies in Continuous-Flow 13C Nuclear Magnetic Resonance Spectroscopy by Use of Immobilized Paramagnetic Relaxation Agents

Quantification Studies in Continuous-Flow 13C Nuclear Magnetic Resonance Spectroscopy by Use of Immobilized Paramagnetic Relaxation Agents

Kinetics of Deuterium Exchange on Resorcinol in D2O at High Pressure and High Temperature

Application of immobilized free radicals in supercritical fluid chromatography hyphenated with proton nuclear magnetic resonance spectroscopy

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Product

Resources

About

Quantification Studies in Continuous-Flow ¹³C Nuclear Magnetic Resonance Spectroscopy by Use of Immobilized Paramagnetic Relaxation Agents

Quantification Studies in Continuous-Flow ¹³C Nuclear Magnetic Resonance Spectroscopy by Use of Immobilized Paramagnetic Relaxation Agents

Kinetics of Deuterium Exchange on Resorcinol in D₂O at High Pressure and High Temperature