Eshuis, N., et al., Determination of long-range scalar (1)H-(1)H coupling constants responsible for polarization transfer in SABRE. J Magn Reson, 2016. 265: p. 59-66.
SABRE (Signal Amplification By Reversible Exchange) nuclear spin hyperpolarization method can provide strongly enhanced NMR signals as a result of the reversible association of small molecules with para-hydrogen (p-H2) at an iridium metal complex. The conversion of p-H2 singlet order to enhanced substrate proton magnetization within such complex is driven by the scalar coupling interactions between the p-H2 derived hydrides and substrate nuclear spins. In the present study these long-range homonuclear couplings are experimentally determined for several SABRE substrates using an NMR pulse sequence for coherent hyperpolarization transfer at high magnetic field. Pyridine and pyrazine derivatives appear to have a similar approximately 1.2Hz (4)J coupling to p-H2 derived hydrides for their ortho protons, and a much lower (5)J coupling for their meta protons. Interestingly, the (4)J hydride-substrate coupling for five-membered N-heterocyclic substrates is well below 1Hz.
Spin polarization transfer mechanisms of SABRE: A magnetic field dependent study
From The DNP-NMR Blog:
Spin polarization transfer mechanisms of SABRE: A magnetic field dependent study
Pravdivtsev, A.N., et al., Spin polarization transfer mechanisms of SABRE: A magnetic field dependent study. J Magn Reson, 2015. 261: p. 73-82.
http://www.ncbi.nlm.nih.gov/pubmed/26529205
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04-01-2016 09:27 PM
Long-Range Proton-Carbon Coupling Constants: NMR methods and applications
Long-Range Proton-Carbon Coupling Constants: NMR methods and applications
Publication date: Available online 20 July 2013
Source:Progress in Nuclear Magnetic Resonance Spectroscopy</br>
Author(s): Teodor Parella , Juan Félix Espinosa</br>
A general review of novel NMR methods to measure heteronuclear long-range proton-carbon coupling constants ( n J CH ; n>1) in small molecules is made. NMR experiments are classified in terms of NMR pulse scheme and cross-peak nature. A discussion about simplicity, general applicability and accuracy for each...
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07-20-2013 11:27 AM
[NMR paper] Unraveling long range residual dipolar coupling networks in strongly aligned proteins
Unraveling long range residual dipolar coupling networks in strongly aligned proteins
Publication date: Available online 10 July 2013
Source:Journal of Magnetic Resonance</br>
Author(s): Luke Arbogast , Ananya Majumdar , Joel R. Tolman</br>
Long-range residual dipolar couplings (lrRDCs) have the potential to serve as powerful structural restraints in protein NMR spectroscopy as they can provide both distance and orientation information about nuclei separate in sequence but close in space. Current nonselective methods for their measurement are limited to moderate...
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07-11-2013 12:07 PM
[Question from NMRWiki Q&A forum] Long-range 1H-{15N} coupling (HMBC)
Long-range 1H-{15N} coupling (HMBC)
Hello All
I have two examples of what appears to be 6J coupling between 1H and 15N using gradient HMBC experiments with 15N at natural abundance. For such an experiment, 2J and 3J correlations are typical, sometimes 4J (W-type) but I've never seen 6J before.
Has anyone else ever seen correlations over this distance? Any other comments?
Craig.
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10-29-2012 07:03 PM
[U. of Ottawa NMR Facility Blog] Measurement of Long Range C H Coupling Constants
Measurement of Long Range C H Coupling Constants
The stereochemistry of compounds is assigned very often with proton - proton NOE's by applying the 2D NOESY technique or the 1D selective gradient NOESY technique. These methods fail, however when the distance between protons is too large to measure an NOE. When faced with this situation, it may be possible to measure long range proton - carbon coupling constants which are able to provide the necessary information. Three-bond carbon - proton couplings follow a Karplus relationship where the magnitude of the coupling constant is related to...
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08-17-2012 10:44 PM
[NMR paper] De novo determination of protein structure by NMR using orientational and long-range
De novo determination of protein structure by NMR using orientational and long-range order restraints.
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J Mol Biol. 2000 May 19;298(5):927-36
Authors: Hus JC, Marion D, Blackledge M
Orientational and novel long-range order restraints available from paramagnetic systems have been used to determine the backbone solution structure of the cytochrome c' protein to atomic resolution in the complete absence of restraints derived from...
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11-18-2010 09:15 PM
[NMR paper] Defining long range order in NMR structure determination from the dependence of heter
Defining long range order in NMR structure determination from the dependence of heteronuclear relaxation times on rotational diffusion anisotropy.
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Nat Struct Biol. 1997 Jun;4(6):443-9
Authors: Tjandra N, Garrett DS, Gronenborn AM, Bax A, Clore GM
Structure determination by NMR presently relies on short range restraints between atoms in close spatial proximity, principally in the...
Determination of long-range scalar (1)H-(1)H coupling constants responsible for polarization transfer in SABRE #DNPNMR
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