The 2H lock of an NMR spectrometer continuously monitors the frequency of the 2H resonance of a deuterated solvent used to prepare the NMR sample. If the frequency of the 2H resonance changes due to an environmental instability while the lock is engaged, a feedback mechanism is used to correct the magnetic field via a Bo shim coil, returning the 2H resonance to its original position. It is very effective at reducing (if not eliminating) environmental instability from NMR data collected over periods of time spanning minutes or hours. The effect of the lock is illustrated in the figure below.
Each panel in the figure represents a contour plot of a pseudo 2D 1H NMR data set for the residual protons of D2O on a Bruker Fourier 300 NMR spectrometer. Each panel represents 2048 single-scan 1D 1H NMR spectra collected over 1.5 hours. The data in the left-hand panel were collected during the day without the 2H lock. The data in the center panel were collected in the middle of the night without the 2H lock. The data in the right-hand panel were collected during the day using the 2H lock. The 2H lock clearly compensates for environmental instability. There was no student traffic in the lab during the collection of any of the data. Outside of the lab are two construction sites which are busiest during the day and quieter at night. This is reflected in a comparison between the left-hand and center panels of the figure. The data collected in the middle of the night without the 2H lock show somewhat less instability compared to similar data collected during the day.
Correction: Theory of solid effect and cross effect dynamic nuclear polarization with half-integer high-spin metal polarizing agents in rotating solids #DNPNMR
From The DNP-NMR Blog:
Correction: Theory of solid effect and cross effect dynamic nuclear polarization with half-integer high-spin metal polarizing agents in rotating solids #DNPNMR
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Corzilius, B., Correction: Theory of solid effect and cross effect dynamic nuclear polarization with half-integer high-spin metal polarizing agents in rotating solids. Phys. Chem. Chem. Phys., 2016. 18(42): p. 29643-29643.
http://dx.doi.org/10.1039/C6CP90249A
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12-17-2016 07:18 AM
Theory of solid effect and cross effect dynamic nuclear polarization with half-integer high-spin metal polarizing agents in rotating solids #DNPNMR
From The DNP-NMR Blog:
Theory of solid effect and cross effect dynamic nuclear polarization with half-integer high-spin metal polarizing agents in rotating solids #DNPNMR
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Corzilius, B., Theory of solid effect and cross effect dynamic nuclear polarization with half-integer high-spin metal polarizing agents in rotating solids. Phys. Chem. Chem. Phys., 2016. 18(39): p. 27190-27204.
http://dx.doi.org/10.1039/C6CP04621E
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11-21-2016 11:02 PM
Static (1)H dynamic nuclear polarization with the biradical TOTAPOL: a transition between the solid effect and the cross effect
From The DNP-NMR Blog:
Static (1)H dynamic nuclear polarization with the biradical TOTAPOL: a transition between the solid effect and the cross effect
Shimon, D., et al., Static (1)H dynamic nuclear polarization with the biradical TOTAPOL: a transition between the solid effect and the cross effect. Phys Chem Chem Phys, 2014. 16(14): p. 6687-99.
http://www.ncbi.nlm.nih.gov/pubmed/24585094
The interplay between the solid effect and the cross effect mechanisms in solid state 13C DNP at 95 GHz using trityl radicals
From The DNP-NMR Blog:
The interplay between the solid effect and the cross effect mechanisms in solid state 13C DNP at 95 GHz using trityl radicals
Banerjee, D., et al., The interplay between the solid effect and the cross effect mechanisms in solid state 13C DNP at 95 GHz using trityl radicals. J. Magn. Reson., 2013. 230(0): p. 212-219.
http://dx.doi.org/10.1016/j.jmr.2013.02.010
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05-07-2013 12:31 AM
[Question from NMRWiki Q&A forum] NMR resonance Lock
NMR resonance Lock
I am running a varian gemini 300 on SUN microsystems with UNIX. I am trying to lock on my sample, and my lock is not showing up as a "step" as usual. Instead, it has troughs in it. What are some options in fixing this, or is this acceptable?
-Jon K.
Check if somebody has answered this question on NMRWiki QA forum
The Effect of the 2H Lock on Environmental Instability
Linear Mode
