Perras, F.A., et al., Optimal sample formulations for DNP SENS: The importance of radical-surface interactions. Current Opinion in Colloid & Interface Science, 2018. 33: p. 9-18.
The efficacy of dynamic nuclear polarization (DNP) surface-enhanced NMR spectroscopy (SENS) is reviewed for alumina, silica, and ordered mesoporous carbon (OMC) materials, with vastly different surface areas, as a function of the biradical concentration. Importantly, our studies show that the use of a “one-size-fits-all” biradical concentration should be avoided when performing DNP SENS experiments and instead an optimal concentration should be selected as appropriate for the type of material studied as well as its surface area. In general, materials with greater surface areas require higher radical concentrations for best possible DNP performance. This result is explained with the use of a thermodynamic model wherein radical-surface interactions are expected to lead to an increase in the local concentration of the polarizing agent at the surface. We also show, using plane-wave density functional theory calculations, that weak radical-surface interactions are the cause of the poor performance of DNP SENS for carbonaceous materials.
In Situ Characterization of Pharmaceutical Formulations by Dynamic Nuclear Polarization Enhanced MAS NMR #DNPNMR
From The DNP-NMR Blog:
In Situ Characterization of Pharmaceutical Formulations by Dynamic Nuclear Polarization Enhanced MAS NMR #DNPNMR
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Ni, Q.Z., et al., In Situ Characterization of Pharmaceutical Formulations by Dynamic Nuclear Polarization Enhanced MAS NMR. The Journal of Physical Chemistry B, 2017. 121(34): p. 8132-8141.
http://dx.doi.org/10.1021/acs.jpcb.7b07213
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12-09-2017 07:49 AM
Characterizing Substrate-Surface Interactions on Alumina-Supported Metal Catalysts by Dynamic Nuclear Polarization-Enhanced Double-Resonance NMR Spectroscopy #DNPNMR
From The DNP-NMR Blog:
Characterizing Substrate-Surface Interactions on Alumina-Supported Metal Catalysts by Dynamic Nuclear Polarization-Enhanced Double-Resonance NMR Spectroscopy #DNPNMR
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Perras, F.A., et al., Characterizing Substrate-Surface Interactions on Alumina-Supported Metal Catalysts by Dynamic Nuclear Polarization-Enhanced Double-Resonance NMR Spectroscopy. J Am Chem Soc, 2017. 139(7): p. 2702-2709.
https://www.ncbi.nlm.nih.gov/pubmed/28112506
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06-13-2017 06:55 AM
Atomistic Description of Reaction Intermediates for Supported Metathesis Catalysts Enabled by DNP SENS #DNPNMR
From The DNP-NMR Blog:
Atomistic Description of Reaction Intermediates for Supported Metathesis Catalysts Enabled by DNP SENS #DNPNMR
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Ong, T.C., et al., Atomistic Description of Reaction Intermediates for Supported Metathesis Catalysts Enabled by DNP SENS. Angew Chem Int Ed Engl, 2016. 55(15): p. 4743-7.
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12-23-2016 03:30 PM
Efficient DNP NMR of membrane proteins: sample preparation protocols, sensitivity, and radical location
From The DNP-NMR Blog:
Efficient DNP NMR of membrane proteins: sample preparation protocols, sensitivity, and radical location
Liao, S.Y., et al., Efficient DNP NMR of membrane proteins: sample preparation protocols, sensitivity, and radical location. J Biomol NMR, 2016: p. 1-15.
http://www.ncbi.nlm.nih.gov/pubmed/26873390
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02-25-2016 05:21 AM
[NMR paper] Efficient DNP NMR of membrane proteins: sample preparation protocols, sensitivity, and radical location.
Efficient DNP NMR of membrane proteins: sample preparation protocols, sensitivity, and radical location.
Related Articles Efficient DNP NMR of membrane proteins: sample preparation protocols, sensitivity, and radical location.
J Biomol NMR. 2016 Feb 12;
Authors: Liao SY, Lee M, Wang T, Sergeyev IV, Hong M
Abstract
Although dynamic nuclear polarization (DNP) has dramatically enhanced solid-state NMR spectral sensitivities of many synthetic materials and some biological macromolecules, recent studies of membrane-protein DNP using...
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02-14-2016 08:25 PM
Efficient DNP NMR of membrane proteins: sample preparation protocols, sensitivity, and radical location
Efficient DNP NMR of membrane proteins: sample preparation protocols, sensitivity, and radical location
Abstract
Although dynamic nuclear polarization (DNP) has dramatically enhanced solid-state NMR spectral sensitivities of many synthetic materials and some biological macromolecules, recent studies of membrane-protein DNP using exogenously doped paramagnetic radicals as polarizing agents have reported varied and sometimes surprisingly limited enhancement factors. This motivated us to carry out a systematic evaluation of sample preparation protocols...
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02-12-2016 11:26 PM
Silica-surface reorganization during organotin grafting evidenced by 119Sn DNP SENS: a tandem reaction of gem-silanols and strained siloxane bridges
From The DNP-NMR Blog:
Silica-surface reorganization during organotin grafting evidenced by 119Sn DNP SENS: a tandem reaction of gem-silanols and strained siloxane bridges
Conley, M.P., et al., Silica-surface reorganization during organotin grafting evidenced by 119Sn DNP SENS: a tandem reaction of gem-silanols and strained siloxane bridges. Phys. Chem. Chem. Phys., 2014. 16(33): p. 17822-17827.
http://dx.doi.org/10.1039/C4CP01973C
Grafting reactive molecular complexes on dehydroxylated amorphous silica is a strategy to develop "single-site" heterogeneous catalysts. In...
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08-06-2014 08:39 PM
[Question from NMRWiki Q&A forum] What is the optimal sample length with Shigemi tubes?
What is the optimal sample length with Shigemi tubes?
Our coil area length is 16 mm. Should we be making samples exactly 16 mm long in the Shigemi tubes for the best sensitivity (assuming that we are limited on amount of material)?
For example, we use D2O matched shigemi tubes for samples in 90/10 H2O/D2O. Is susceptibility matching affected by switch from D2O to H2O?
Thanks!