Coherence transfer between spy nuclei and nitrogen-14 in solids

Cavadini, Simone; Abraham, Anuji; Bodenhausen, Geoffrey

doi:10.1016/j.jmr.2007.10.008

Cited by 42 publications

(58 citation statements)

References 28 publications

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“…3), and is thus attributed to the protonproton flip-flop terms. This problem could now be partly reduced by using a D-HSQC type of experiment as it was very recently proposed by Antonijevic et al [20] and Cavadini et al [21] The 2D 13 C-14 N-13 C R 3 D-HMQC spectrum (Fig. 3) has been acquired at a slower spinning speed (m R = 12.5 kHz) due to a 'conflict' between the spinning speed, the R 3 irradiation and the proton decoupling rf-field.…”

Section: Resultsmentioning

confidence: 99%

3D 1H–13C–14N correlation solid-state NMR spectrum

Siegel

Trébosc

Amoureux

et al. 2008

Journal of Magnetic Resonance

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Section: Resultsmentioning

confidence: 99%

3D 1H–13C–14N correlation solid-state NMR spectrum

Siegel

Trébosc

Amoureux

et al. 2008

Journal of Magnetic Resonance

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“…An important alternative to the HMQClike experiment described above is the HSQC scheme, [9,33] characterized by two additional π/2 pulses applied to spin S at the beginning and at the end of the evolution period. These pulses convert the coherence T .…”

Section: Methodsmentioning

confidence: 99%

New Tools in Bio-NMR: Indirect Detection of Nitrogen-14 in Solids

Ulzega

2010

Chimia

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Nnuclei.Thetwo-dimensionalcorrelationmethodspresentedherearecloselyrelatedtothewellknownheteronuclearsingle-andmultiple-quantumcorrelation(HSQCandHMQC,respectively)experiments, alreadywidelyusedfortheinvestigationofmoleculesinliquids.Nitrogen-14NMRspectraexhibitpowderpat-ternscharacterizedbysecond-andthird-orderquadrupolarcouplingswhichcanprovideimportantinformation aboutstructureanddynamicsofmoleculesinpowdersamples.

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“…Interestingly, spectral features are more evident in the 14 N lineshapes observed for partially deuterated glycine, NH 3 + CD 2 COO − , in a 14 N-1 H heteronuclear single-quantum correlation (HSQC) spectrum as compared to a HMQC spectrum. 31 This difference is due to the 1 H component of the heteronuclear coherence being along z in the HSQC experiment as compared to x or y in the HMQC experiment. As in the first solid-state NMR 14 N-1 H HMQC experiment, 9 the HSQC pulse sequence employed here 31,32 is based upon free evolution during the τ periods under heteronuclear through-bond 14 N-1 H J-couplings as well as residual second-order quadrupolar-dipolar couplings that are not removed by MAS.…”

Section: Overcoming Proton-proton Dipolar Couplingsmentioning

confidence: 99%

Nitrogen-Proton Correlation Experiments of Organic Solids at Natural Isotopic Abundance

Brown

2014

eMagRes

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Solid-state NMR methods for recording two-dimensional nitrogen-proton correlation spectra at natural isotopic abundance are presented. There are two isotopes of nitrogen: the spin I = 1 14 N (99.6% natural abundance) and the spin I = 1/2 15 N (0.4% natural abundance). The reduced natural abundance and smaller magnetogyric ratio as compared to 13 C explain the comparative scarcity of nitrogen-proton spectra for 15 N in the literature. While this article describes these few examples of 1 H-15 N and 15 N-1 H experiments, including the first applications of DNP to increase sensitivity, the focus is on 14 N-1 H heteronuclear multiple-quantum coherence (HMQC) MAS NMR spectroscopy using inverse (i.e., 1 H) detection. Specifically, HMQC can be created following free evolution under heteronuclear through-bond 14 N-1 H J-couplings as well as residual second-order quadrupolar-dipolar couplings that are not removed by MAS or by recoupling of 14 N-1 H dipolar couplings using n = 2 rotary resonance recoupling (R 3 ) or symmetry-based sequences. The quadrupolar interaction for 14 N causes anisotropic broadening and an isotropic second-order quadrupolar shift and affects the optimization of 14 N RF irradiation, for which high 14 N nutation frequencies are important. Fast MAS improves sensitivity by narrowing 1 H resonances and lengthening 1 H coherence lifetimes. The creation of double-quantum or overtone 14 N coherence has the advantage of insensitivity (compared to 14 N single-quantum coherence) to motion and small deviations away from the perfect setting of the magic angle. Applications to supramolecular chemistry and pharmaceuticals are presented; changing the recoupling duration allows longer range N· · ·H proximities to be identified, thus identifying specific intermolecular hydrogen bonding arrangements.

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Coherence transfer between spy nuclei and nitrogen-14 in solids

Cited by 42 publications

References 28 publications

3D 1H–13C–14N correlation solid-state NMR spectrum

3D 1H–13C–14N correlation solid-state NMR spectrum

New Tools in Bio-NMR: Indirect Detection of Nitrogen-14 in Solids

Nitrogen-Proton Correlation Experiments of Organic Solids at Natural Isotopic Abundance

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