Nuclear Overhauser effect


Nuclear Overhauser effect

The Nuclear Overhauser Effect (NOE) is the transfer of nuclear spin polarization from one nuclear spin population to another via cross-relaxation. It is a common phenomenon observed by nuclear magnetic resonance (NMR) spectroscopy. The theoretical basis for the NOE was described and experimentally verified by Anderson and Freeman in 1962.[1] The NOE is an extension of the seminal work of American physicist Albert Overhauser who in 1953 proposed that nuclear spin polarization could be enhanced by the microwave irradiation of the conduction electrons in certain metals.[2] The general Overhauser effect was first demonstrated experimentally by T. R. Carver and C. P. Slichter, also in 1953.[3] Another early explication and experimental observation of the NOE was by Kaiser in 1963 [4] in an NMR experiment where the spin polarization was transferred from one population of nuclear spins to another, rather than from electrons spins to nuclear spins. However, the theoretical basis and the applicable Solomon equations[5] had already been published by Ionel Solomon in 1955[6].

Subsequent to its discovery, the NOE was shown to be highly useful in NMR spectroscopy for characterizing and refining organic chemical structures.[7] In this application, the NOE differs from the application of spin-spin coupling in that the NOE occurs through space, not through chemical bonds. Thus, atoms that are in close proximity to each other can give a NOE, whereas spin coupling is observed only when the atoms are connected by 2-3 chemical bonds. The inter-atomic distances derived from the observed NOE can often help to confirm a precise molecular conformation, i.e. the three-dimensional structure of a molecule. In 2002, Kurt Wüthrich was awarded the Nobel Prize in Chemistry for demonstrating that the NOE could be exploited using two-dimensional NMR spectroscopy to determine the three-dimensional structures of biological macromolecules in solution (see: "The Nobel Prize in Chemistry 2002". http://nobelprize.org/nobel_prizes/chemistry/laureates/2002/. Retrieved 201103324.  ).

Some examples of two-dimensional NMR experimental techniques exploiting the NOE include:

  • NOESY, 'Nuclear Overhauser Effect Spectroscopy
  • HOESY, Heteronuclear Overhauser Effect Spectroscopy
  • ROESY, Rotational Frame Nuclear Overhauser Effect Spectroscopy
  • TRNOE, Transferred Nuclear Overhauser Effect
  • DPFGSE-NOE, Double Pulsed Field Gradient Spin Echo NOE experiment

References

  1. ^ Anderson, W. A.; Freeman, R. (1962). "Influence of a Second Radiofrequency Field on High-Resolution Nuclear Magnetic Resonance Spectra". The Journal of Chemical Physics 37 (1): 411–5. Bibcode 1962JChPh..37...85A. doi:10.1063/1.1732980. http://link.aip.org/link/?JCPSA6/37/85/1. 
  2. ^ Overhauser, Albert W. (1953). "Polarization of Nuclei in Metals". Physical Review 92 (2): 411–5. Bibcode 1953PhRv...92..411O. doi:10.1103/PhysRev.92.411. http://link.aps.org/doi/10.1103/PhysRev.92.411. Retrieved 2009-01-20. 
  3. ^ Carver, T. R.; Slichter, C. P. (1953). "Polarization of Nuclear Spins in Metals". Physical Review 92 (1): 212–213. Bibcode 1953PhRv...92..212C. doi:10.1103/PhysRev.92.212.2. http://link.aps.org/doi/10.1103/PhysRev.92.212.2. 
  4. ^ Kaiser, R. (1962). "Use of the Nuclear Overhauser Effect in the Analysis of High‐Resolution Nuclear Magnetic Resonance Spectra". The Journal of Chemical Physics 39 (1): 2435. Bibcode 1962JChPh..37...85A. doi:10.1063/1.1734045. http://link.aip.org/link/?JCPSA6/37/85/1. 
  5. ^ http://chem.iitm.ac.in/professordetails/chandrakumar/msc_lectures/MSc_Lecture_Notes/The_Solomon_equations.pdf The Solomon Equations and NOE
  6. ^ I. Solomon. Relaxation Processes in a System of Two Spins. Phys. Rev. 99, 559 (1955)
  7. ^ Anet, F. A. L.; Bourn, A. J. R (1965). "Nuclear Magnetic Resonance Spectral Assignments from Nuclear Overhauser Effects". Journal of the American Chemical Society 87 (22): 5250–5251. doi:10.1021/ja00950a048. http://pubs.acs.org/doi/abs/10.1021/ja00950a048. 



Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Nuclear overhauser effect — a) Der Gleichgewichtszustand, b) Die Energieniveaus des ersten Kerns werden durch die Sättigung gleichbesetzt, die dipolare Kopplung mit Umgebungskernen ermöglicht die Übergänge W0 und W2, c) Änderung der Intensität des zweiten Kerns Der Kern… …   Deutsch Wikipedia

  • Nuclear magnetic resonance spectroscopy of proteins — (usually abbreviated protein NMR) is a field of structural biology in which NMR spectroscopy is used to obtain information about the structure and dynamics of proteins. The field was pioneered by Richard R. Ernst and Kurt Wüthrich[1], among… …   Wikipedia

  • Nuclear magnetic resonance spectroscopy of nucleic acids — Nuclear magnetic resonance spectroscopy of nucleic acids, often referred to as nucleic acid NMR, is the use of nuclear magnetic resonance spectroscopy to obtain information about the structure and dynamics of nucleic acid molecules, such as DNA… …   Wikipedia

  • Nuclear magnetic resonance — This article is about the physical phenomenon. For its use as a method in spectroscopy, see Nuclear magnetic resonance spectroscopy. NMR redirects here. For other uses, see NMR (disambiguation). First 1 GHz NMR Spectrometer (1000 MHz,… …   Wikipedia

  • Nuclear magnetic resonance spectroscopy — A 900MHz NMR instrument with a 21.2 T magnet at HWB NMR, Birmingham, UK Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy, is a research technique that exploits the magnetic properties of certain atomic nuclei… …   Wikipedia

  • effect — The result or consequence of an action. [L. efficio, pp. effectus, to accomplish, fr. facio, to do] abscopal e. a reaction produced following irradiation but occurring outside the zone of actual radiation absorption. additive e. an e. wherein two …   Medical dictionary

  • Two-dimensional nuclear magnetic resonance spectroscopy — (2D NMR) is a set of nuclear magnetic resonance spectroscopy (NMR) methods which give data plotted in a space defined by two frequency axes rather than one. Types of 2D NMR include correlation spectroscopy (COSY), J spectroscopy, exchange… …   Wikipedia

  • Espectroscopia de resonancia magnética nuclear — Saltar a navegación, búsqueda La espectroscopia de resonancia magnética nuclear (RMN) es una técnica empleada principalmente en la elucidación de estructuras moleculares, aunque también se puede emplear con fines cuantitativos. Algunos núcleos… …   Wikipedia Español

  • Protein nuclear magnetic resonance spectroscopy — (usually abbreviated protein NMR) is a field of structural biology in which NMR spectroscopy is used to obtain information about the structure and dynamics of proteins. The field was pioneered by, among others, Kurt Wüthrich, who shared the Nobel …   Wikipedia

  • Kern-Overhauser-Effekt — a) Der Gleichgewichtszustand, b) Die Energieniveaus des ersten Kerns werden durch die Sättigung gleichbesetzt, die dipolare Kopplung mit Umgebungskernen ermöglicht die Übergänge W0 und W2, c) Änderung der Intensität des zweiten Kerns Der Kern… …   Deutsch Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.