Kemp, T.F., et al., Dynamic Nuclear Polarization enhanced NMR at 187GHz/284MHz using an Extended Interaction Klystron amplifier. J Magn Reson, 2016. 265: p. 77-82.
A Dynamic Nuclear Polarisation (DNP) enhanced solid-state Magic Angle Spinning (MAS) NMR spectrometer which uses a 187GHz (corresponding to (1)H NMR frequency of 284MHz) Extended Interaction Klystron (EIK) amplifier as the microwave source is briefly described. Its performance is demonstrated for a biomolecule (bacteriorhodopsin), a pharmaceutical, and surface functionalised silica. The EIK is very compact and easily incorporated into an existing spectrometer. The bandwidth of the amplifier is sufficient that it obviates the need for a sweepable magnetic field, once set, for all commonly used radicals. The variable power (CW or pulsed) output from the EIK is transmitted to the DNP-NMR probe using a quasi-optic system with a high power isolator and a corrugated waveguide which feeds the microwaves into the DNP-NMR probe. Curved mirrors inside the probe project the microwaves down the axis of the MAS rotor, giving a very efficient system such that maximum DNP enhancement is achieved with less than 3W output from the microwave source. The DNP-NMR probe operates with a sample temperature down to 90K whilst spinning at 8kHz. Significant enhancements, in excess of 100 for bacteriorhodopsin in purple membrane (bR in PM), are shown along with spectra which are enhanced by approximately 25 with respect to room temperature, for both the pharmaceutical furosemide and surface functionalised silica. These enhancements allow hitherto prohibitively time consuming experiments to be undertaken. The power at which the DNP enhancement in bR in PM saturates does not change significantly between 90K and 170K even though the enhancement drops by a factor of approximately 11. As the DNP build up time decreases by a factor 3 over this temperature range, the reduction in T1n is presumably a significant contribution to the drop in enhancement.
Is solid-state NMR enhanced by dynamic nuclear polarization?
From The DNP-NMR Blog:
Is solid-state NMR enhanced by dynamic nuclear polarization?
Lee, D., S. Hediger, and G. De Paepe, Is solid-state NMR enhanced by dynamic nuclear polarization? Solid State Nucl Magn Reson, 2015. 66-67C(0): p. 6-20.
http://www.ncbi.nlm.nih.gov/pubmed/25779337
Dynamic nuclear polarization enhanced NMR spectroscopy for pharmaceutical formulations
From The DNP-NMR Blog:
Dynamic nuclear polarization enhanced NMR spectroscopy for pharmaceutical formulations
Rossini, A.J., et al., Dynamic nuclear polarization enhanced NMR spectroscopy for pharmaceutical formulations. J Am Chem Soc, 2014. 136(6): p. 2324-34.
http://www.ncbi.nlm.nih.gov/pubmed/24410528
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03-07-2014 06:47 PM
Overhauser dynamic nuclear polarization-enhanced NMR relaxometry
From The DNP-NMR Blog:
Overhauser dynamic nuclear polarization-enhanced NMR relaxometry
Franck, J.M., R. Kausik, and S. Han, Overhauser Dynamic Nuclear Polarization-Enhanced NMR Relaxometry. Microporous Mesoporous Mater, 2013. 178(0): p. 113-118.
http://www.ncbi.nlm.nih.gov/pubmed/23837010
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11-21-2013 01:14 AM
Dynamic Nuclear Polarization Enhanced NMR in the Solid-State
From The DNP-NMR Blog:
Dynamic Nuclear Polarization Enhanced NMR in the Solid-State
Akbey, Ü., et al., Dynamic Nuclear Polarization Enhanced NMR in the Solid-State. 2013, Springer Berlin Heidelberg. p. 1-48.
http://dx.doi.org/10.1007/128_2013_436
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08-26-2013 08:46 PM
[NMR paper] Dynamic Nuclear Polarization Enhanced NMR in the Solid-State.
Dynamic Nuclear Polarization Enhanced NMR in the Solid-State.
Dynamic Nuclear Polarization Enhanced NMR in the Solid-State.
Top Curr Chem. 2013 Jul 7;
Authors: Akbey U, Franks WT, Linden A, Rydmark MO, Lange S, Oschkinat H
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is one of the most commonly used spectroscopic techniques to obtain information on the structure and dynamics of biological and chemical materials. A variety of samples can be studied including solutions, crystalline solids, powders and hydrated protein...
Surface Enhanced NMR Spectroscopy by Dynamic Nuclear Polarization
Surface Enhanced NMR Spectroscopy by Dynamic Nuclear Polarization
Anne Lesage, Moreno Lelli, David Gajan, Marc A. Caporini, Veronika Vitzthum, Pascal Mie?ville, Johan Alauzun, Arthur Roussey, Chloe? Thieuleux, Ahmad Medhi, Geoffrey Bodenhausen, Christophe Cope?ret and Lyndon Emsley
http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/0/jacsat.ahead-of-print/ja104771z/aop/images/medium/ja-2010-04771z_0004.gif
Journal of the American Chemical Society
DOI: 10.1021/ja104771z
http://feeds.feedburner.com/~ff/acs/jacsat?d=yIl2AUoC8zA...
Dynamic Nuclear Polarization enhanced NMR at 187GHz/284MHz using an Extended Interaction Klystron amplifier #DNPNMR
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