It arises from dipolar coupling between isolated two spin-1/2 nuclei, or from transitions in quadrupolar nuclei such as deuterium. It is the general shape obtained from an orientationally dependent doublet. The "horns" of the Pake doublet correspond to the situation when the principal axis of the coupling interaction (the internuclear vector in the case dipolar coupling and the principal component of the electric field gradient tensor for quadrupolar nuclei) is perpendicular to the magnetic field. This situation is the most probable and the intensity is much higher. The "feet" of the lineshape correspond to the situation when the principal axis of the coupling interaction is parallel to the magnetic field which is much less statistically relevant.
Pake was the first to describe this lineshape and used it to extract the proton-proton distance from his experiments on a single crystal and powdered hydrates of gypsum (CaSO4.2H2O).[1] This made it possible to experimentally determine the internuclear distance between the hydrogen atoms in water.
In solids with vacant positions, dipole coupling is averaged partially due to water diffusion which proceeds according to the symmetry of the solids and the probability distribution of molecules between the vacancies.[2] In the case the averaged lineshape is used to analyze crystal symmetry, phase transitions, and the degree of molecular disorder in crystalline hydrates, zeolites, clays and biological tissues.
Referencesedit
^Nuclear Resonance Absorption in Hydrated Crystals: Fine Structure of the Proton Line,G. E. Pake, J. Chem. Phys. 16, 327 (1948); doi:10.1063/1.1746878; [1]
pake, doublet, pake, doublet, pake, pattern, characteristic, line, shape, seen, solid, state, nuclear, magnetic, resonance, electron, paramagnetic, resonance, spectroscopy, first, described, george, pake, simulated, pake, doublet, arises, from, dipolar, coupli. A Pake Doublet or Pake Pattern is a characteristic line shape seen in solid state nuclear magnetic resonance and electron paramagnetic resonance spectroscopy It was first described by George Pake Simulated pake doublet It arises from dipolar coupling between isolated two spin 1 2 nuclei or from transitions in quadrupolar nuclei such as deuterium It is the general shape obtained from an orientationally dependent doublet The horns of the Pake doublet correspond to the situation when the principal axis of the coupling interaction the internuclear vector in the case dipolar coupling and the principal component of the electric field gradient tensor for quadrupolar nuclei is perpendicular to the magnetic field This situation is the most probable and the intensity is much higher The feet of the lineshape correspond to the situation when the principal axis of the coupling interaction is parallel to the magnetic field which is much less statistically relevant Pake was the first to describe this lineshape and used it to extract the proton proton distance from his experiments on a single crystal and powdered hydrates of gypsum CaSO4 2H2O 1 This made it possible to experimentally determine the internuclear distance between the hydrogen atoms in water In solids with vacant positions dipole coupling is averaged partially due to water diffusion which proceeds according to the symmetry of the solids and the probability distribution of molecules between the vacancies 2 In the case the averaged lineshape is used to analyze crystal symmetry phase transitions and the degree of molecular disorder in crystalline hydrates zeolites clays and biological tissues References edit Nuclear Resonance Absorption in Hydrated Crystals Fine Structure of the Proton Line G E Pake J Chem Phys 16 327 1948 doi 10 1063 1 1746878 1 Diffusion of Water Molecules in Hydrates and NMR Spectra S P Gabuda A G Lundin JETP 28 555 1969 http www jetp ras ru cgi bin dn e 028 03 0555 pdf nbsp This nuclear magnetic resonance related article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Pake doublet amp oldid 1165998559, wikipedia, wiki, book, books, library,
