Dynamic Nuclear Polarization (DNP) has become a key element in nuclear magnetic resonance (NMR). Recently, we developed a novel approach to DNP enhanced liquid-state NMR based on rapid melting of a solid hyperpolarized sample followed by ‘in situ’ liquid-state NMR detection. This method allows 1 H detection with fast cycling options for signal averaging. In nonpolar solvents, doped with BDPA radicals, proton enhancement factors were achieved of up to 400. A short recycling delay of about 5 s allows for a fast determination of the hyper-polarization dynamics as function of the microwave frequency and power. Here, we use the rapid melt dnp method to study the mechanisms for DNP in the solid phase in more detail. Solid Effect, Cross Effect, Solid Overhauser and Liquid-state (supercritical) Overhauser DNP enhancement can be observed in the same setup. In this paper, we concentrate on Solid Effect DNP observed with both homogeneous narrow line radicals such as BDPA and with wide line anisotropic nitroxide radicals such as TEMPOL. We find indications that BDPA protons play an important role in Solid Effect DNP with this radical. A simplified spin diffusion model for BDPA can give a semi-quantitative description of the enhancements as function of the microwave power and as function of the proton concentration in the solid solution. For aqueous frozen samples we observe a similar Solid Effect DNP enhancement, which is analyzed within the simplified spin diffusion model.
Rapid-melt Dynamic Nuclear Polarization
From The DNP-NMR Blog:
Rapid-melt Dynamic Nuclear Polarization
Sharma, M., et al., Rapid-melt Dynamic Nuclear Polarization. J Magn Reson, 2015. 258: p. 40-8.
http://www.ncbi.nlm.nih.gov/pubmed/26225439
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12-12-2015 03:39 AM
Spin-Label CW Microwave Power Saturation and Rapid Passage with Triangular Non-Adiabatic Rapid Sweep (NARS) and Adiabatic Rapid Passage (ARP) EPR Spectroscopy
Spin-Label CW Microwave Power Saturation and Rapid Passage with Triangular Non-Adiabatic Rapid Sweep (NARS) and Adiabatic Rapid Passage (ARP) EPR Spectroscopy
Publication date: Available online 11 April 2015
Source:Journal of Magnetic Resonance</br>
Author(s): Aaron W. Kittell , James S. Hyde</br>
Non-adiabatic rapid passage (NARS) electron paramagnetic resonance (EPR) spectroscopy was introduced by Kittell, A.W., Camenisch, T.G., Ratke, J.J. Sidabras, J.W., Hyde, J.S., 2011 as a general purpose technique to collect the pure absorption response. The technique has...
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04-12-2015 02:40 AM
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
Postdoctoral positions "high field ?MAS-DNP- NMR” and “Rapid melt DNP"
From The DNP-NMR Blog:
Postdoctoral positions "high field ?MAS-DNP- NMR” and “Rapid melt DNP"
Two postdoc positions for “DNP-enhanced NMR” both in the solid and liquid state are available immediately at the Solid State NMR group of the Institute of Molecules and Materials at the Radboud University of Nijmegen.
The solid NMR group at the Radboud University specializes in developing innovative technology to perform NMR spectroscopy on very small samples volumes both in the solid and in the liquid state. In the solid phase one can obtain ultrahigh proton decoupling fields (above 1...
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06-21-2013 12:16 AM
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
Solid Effect DNP in a Rapid-melt setup #DNPNMR
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