Related ArticlesRefocused continuous-wave decoupling: a new approach to heteronuclear dipolar decoupling in solid-state NMR spectroscopy.
J Chem Phys. 2012 Dec 7;137(21):214202
Authors: Vinther JM, Nielsen AB, Bjerring M, van Eck ER, Kentgens AP, Khaneja N, Nielsen NC
Abstract
A novel strategy for heteronuclear dipolar decoupling in magic-angle spinning solid-state nuclear magnetic resonance (NMR) spectroscopy is presented, which eliminates residual static high-order terms in the effective Hamiltonian originating from interactions between oscillating dipolar and anisotropic shielding tensors. The method, called refocused continuous-wave (rCW) decoupling, is systematically established by interleaving continuous wave decoupling with appropriately inserted rotor-synchronized high-power ? refocusing pulses of alternating phases. The effect of the refocusing pulses in eliminating residual effects from dipolar coupling in heteronuclear spin systems is rationalized by effective Hamiltonian calculations to third order. In some variants the ? pulse refocusing is supplemented by insertion of rotor-synchronized ?/2 purging pulses to further reduce the residual dipolar coupling effects. Five different rCW decoupling sequences are presented and their performance is compared to state-of-the-art decoupling methods. The rCW decoupling sequences benefit from extreme broadbandedness, tolerance towards rf inhomogeneity, and improved potential for decoupling at relatively low average rf field strengths. In numerical simulations, the rCW schemes clearly reveal superior characteristics relative to the best decoupling schemes presented so far, which we to some extent also are capable of demonstrating experimentally. A major advantage of the rCW decoupling methods is that they are easy to set up and optimize experimentally.
[NMR paper] Designing Dipolar Recoupling and Decoupling Experiments for Biological Solid-State NMR Using Interleaved Continuous Wave and rf Pulse Irradiation.
Designing Dipolar Recoupling and Decoupling Experiments for Biological Solid-State NMR Using Interleaved Continuous Wave and rf Pulse Irradiation.
Designing Dipolar Recoupling and Decoupling Experiments for Biological Solid-State NMR Using Interleaved Continuous Wave and rf Pulse Irradiation.
Acc Chem Res. 2013 Apr 4;
Authors: Bjerring M, Jain S, Paaske B, Vinther JM, Nielsen NC
Abstract
Rapid developments in solid-state NMR methodologyhave boosted this technique into a highly versatile tool for structural biology. The invention of...
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04-06-2013 11:18 AM
[Question from NMRWiki Q&A forum] adiabatic decoupling
adiabatic decoupling
Hi NMRwikiers, for measuring scalar couplings we use some HSQC pulse sequences modified for obtaining the coupling in F1-dimension as a splitting of doublets for CH2 groups. As high resolution is needed we use high folding in the acqusition, but as a result we obtain a lot of coupling artifacts in phenyl signals. We think that the use of adiabatic decoupling schemes should give a reasonably good spectrum of phenyls but I have no experience in adiabatic decoupling. Anyone can give me a hand for Bruker spectrometers?
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05-24-2011 10:02 PM
Accurate measurement of one-bond H-X heteronuclear dipolar couplings in MAS solid-state NMR.
Accurate measurement of one-bond H-X heteronuclear dipolar couplings in MAS solid-state NMR.
Accurate measurement of one-bond H-X heteronuclear dipolar couplings in MAS solid-state NMR.
J Magn Reson. 2011 Mar 21;
Authors: Schanda P, Meier BH, Ernst M
The accurate experimental determination of dipolar-coupling constants for one-bond heteronuclear dipolar couplings in solids is a key for the quantification of the amplitudes of motional processes. Averaging of the dipolar coupling reports on motions on time scales up to the inverse of the coupling...
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04-13-2011 11:57 PM
Accurate Measurement of One-Bond H-X Heteronuclear Dipolar Couplings in MAS Solid-State NMR
Accurate Measurement of One-Bond H-X Heteronuclear Dipolar Couplings in MAS Solid-State NMR
Publication year: 2011
Source: Journal of Magnetic Resonance, In Press, Accepted Manuscript, Available online 21 March 2011</br>
Paul, Schanda , Beat H., Meier , Matthias, Ernst</br>
The accurate experimental determination of dipolar-coupling constants for one-bond heteronuclear dipolar couplings in solids is a key for the quantification of the amplitudes of motional processes. Averaging of the dipolar coupling reports on motions on time scales up to the inverse of the coupling constant, in...
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03-22-2011 07:30 AM
Continuous-wave EPR at 275 GHz: Application to high-spin Fe3+ systems
Continuous-wave EPR at 275 GHz: Application to high-spin Fe3+ systems
Publication year: 2011
Source: Journal of Magnetic Resonance, In Press, Accepted Manuscript, Available online 11 March 2011</br>
G., Mathies , H., Blok , J.A.J.M., Disselhorst , P., Gast , H., van der Meer , ...</br>
The 275 GHz electron-paramagnetic-resonance spectrometer we reported on in 2004 has been equipped with a new probe head, which contains a cavity especially designed for operation in continuous-wave mode. The sensitivity and signal stability that is achieved with this new probe head is illustrated...
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03-12-2011 05:21 PM
Straightforward, effective calibration of SPINAL-64 decoupling results in the enhancement of sensitivity and resolution of biomolecular solid-state NMR.
Straightforward, effective calibration of SPINAL-64 decoupling results in the enhancement of sensitivity and resolution of biomolecular solid-state NMR.
Straightforward, effective calibration of SPINAL-64 decoupling results in the enhancement of sensitivity and resolution of biomolecular solid-state NMR.
J Magn Reson. 2010 Dec 31;
Authors: Comellas G, Lopez JJ, Nieuwkoop AJ, Lemkau LR, Rienstra CM
We describe a simple yet highly effective optimization strategy for SPINAL-64 (1)H decoupling conditions for magic-angle spinning solid-state NMR. With...
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02-08-2011 06:28 PM
Straightforward, effective calibration of SPINAL-64 decoupling results in the enhancement of sensitivity and resolution of biomolecular solid-state NMR
Straightforward, effective calibration of SPINAL-64 decoupling results in the enhancement of sensitivity and resolution of biomolecular solid-state NMR
Publication year: 2010
Source: Journal of Magnetic Resonance, In Press, Accepted Manuscript, Available online 31 December 2010</br>
Gemma, Comellas , Jakob J., Lopez , Andrew J., Nieuwkoop , Luisel R., Lemkau , Chad M., Rienstra</br>
We describe a simple yet highly effective optimization strategy for SPINAL-64 1H decoupling conditions for magic-angle spinning solid-state NMR. With adjustment of the phase angles in a coupled manner,...
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01-01-2011 08:57 AM
2H decoupling in gNhsqc
hi, I had an insteresting problem with 2H decoupling on the Varian 600 machine for the gNhsqc experiment. I am doing locking and shimming without 2H decoupling. once you set dn3='H2' and submit the experiment, the lock level with drop to around half. and for the similar ghnca_P expriment, there is no such problem. the lock always stays the same level no matter decoupling on or off. Could anyone give me some suggestion? thanks.