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Magnetic chemical shift

NMR Nuclear magnetic resonance [223, 224] Chemical shift of splitting of nuclear spin states in a magnetic field H [225], C [226, 227], N [228], F [229], 2 Xe [230] Other Techniques Chemical state diffusion of adsorbed species... [Pg.318]

Chemical shift anisotropy (CSA) 2 Reorientation of the CSA principal axis Increases with the square of the magnetic field [13]... [Pg.1506]

Figure Bl.14.7. Chemical shift imaging sequence [23], Bothx- andj -dimensions are phase encoded. Since line-broadening due to acquiring the echo in the presence of a magnetic field gradient is avoided, chemical shift infonnation is retained in tire echo. Figure Bl.14.7. Chemical shift imaging sequence [23], Bothx- andj -dimensions are phase encoded. Since line-broadening due to acquiring the echo in the presence of a magnetic field gradient is avoided, chemical shift infonnation is retained in tire echo.
A simple, non-selective pulse starts the experiment. This rotates the equilibrium z magnetization onto the v axis. Note that neither the equilibrium state nor the effect of the pulse depend on the dynamics or the details of the spin Hamiltonian (chemical shifts and coupling constants). The equilibrium density matrix is proportional to F. After the pulse the density matrix is therefore given by and it will evolve as in equation (B2.4.27). If (B2.4.28) is substituted into (B2.4.30), the NMR signal as a fimction of time t, is given by (B2.4.32). In this equation there is a distinction between the sum of the operators weighted by the equilibrium populations, F, from the unweighted sum, 7. The detector sees each spin (but not each coherence ) equally well. [Pg.2100]

Chemical shifts are expressed in S units ppm of applied magnetic field with internal TMS peak as reference. [Pg.67]

Acetylenic hydrogens are unusual in that they are more shielded than we would expect for protons bonded to sp hybridized carbon This is because the rr electrons circulate around the triple bond not along it (Figure 13 9a) Therefore the induced magnetic field is parallel to the long axis of the triple bond and shields the acetylenic proton (Figure 13 9b) Acetylenic protons typically have chemical shifts near 8 2 5... [Pg.529]

The physical basis for peak splitting mil dichloroethane can be explained with the aid of Figure 13 13 which examines how the chemical shift of the methyl protons IS affected by the spin of the methme proton There are two magnetic environments for... [Pg.536]

The section on Spectroscopy has been retained but with some revisions and expansion. The section includes ultraviolet-visible spectroscopy, fluorescence, infrared and Raman spectroscopy, and X-ray spectrometry. Detection limits are listed for the elements when using flame emission, flame atomic absorption, electrothermal atomic absorption, argon induction coupled plasma, and flame atomic fluorescence. Nuclear magnetic resonance embraces tables for the nuclear properties of the elements, proton chemical shifts and coupling constants, and similar material for carbon-13, boron-11, nitrogen-15, fluorine-19, silicon-19, and phosphoms-31. [Pg.1284]

Proton chemical shift data from nuclear magnetic resonance has historically not been very informative because the methylene groups in the hydrocarbon chain are not easily differentiated. However, this can be turned to advantage if a polar group is present on the side chain causing the shift of adjacent hydrogens downfteld. High resolution C-nmr has been able to determine position and stereochemistry of double bonds in the fatty acid chain (62). Broad band nmr has also been shown useful for determination of soHd fat content. [Pg.132]

Nuclear magnetic resonance B spectral studies of BF have given a value of 9.4 1.0 ppm for the chemical shift relative to BF3 0(02113)3 as the... [Pg.159]

Nuclear Magnetic Resonance Spectroscopy. Nmr is a most valuable technique for stmeture determination in thiophene chemistry, especially because spectral interpretation is much easier in the thiophene series compared to benzene derivatives. Chemical shifts in proton nmr are well documented for thiophene (CDCl ), 6 = 7.12, 7.34, 7.34, and 7.12 ppm. Coupling constants occur in well-defined ranges J2-3 = 4.9-5.8 ... [Pg.19]


See other pages where Magnetic chemical shift is mentioned: [Pg.229]    [Pg.136]    [Pg.229]    [Pg.136]    [Pg.90]    [Pg.64]    [Pg.587]    [Pg.588]    [Pg.1437]    [Pg.1445]    [Pg.1446]    [Pg.1450]    [Pg.1472]    [Pg.1519]    [Pg.1526]    [Pg.2096]    [Pg.2098]    [Pg.520]    [Pg.155]    [Pg.67]    [Pg.526]    [Pg.536]    [Pg.484]    [Pg.307]    [Pg.210]    [Pg.204]    [Pg.405]    [Pg.54]    [Pg.56]    [Pg.299]    [Pg.396]    [Pg.214]    [Pg.308]    [Pg.354]    [Pg.257]    [Pg.391]    [Pg.30]    [Pg.195]    [Pg.248]   
See also in sourсe #XX -- [ Pg.406 , Pg.407 , Pg.425 , Pg.426 , Pg.430 ]




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Carbon-13 nuclear magnetic resonance chemical-shifts

Carbon-13 nuclear magnetic resonance spectroscopy chemical shifts

Chemical shift anisotropies magnetic field dependency

Chemical shift local magnetic field

Chemical shift magnetic anisotropy, effect

Chemical shift magnetic contributions

Chemical shift magnetic susceptibility, effect

Chemical shift ranges, nuclear magnetic

Chemical shift ranges, nuclear magnetic resonance

Chemical shift, nuclear magnetic

Chemical shifts carbon-13 nuclear magnetic

Chemical shifts external magnetic field

Chemical shifts proton nuclear magnetic resonance

Magnetic chemical shift imaging

Magnetic field effects proton chemical shifts

Magnetic resonance spectroscopy chemical shifts

Magnetic shift

Molecular Hamiltonians, nuclear magnetic resonance chemical shifts

Nuclear Magnetic Resonance Data H Chemical Shifts and Coupling Constants for Phosphorus

Nuclear Magnetic Resonance chemical shift mapping

Nuclear magnetic resonance Chemical shift values

Nuclear magnetic resonance NMR chemical shift

Nuclear magnetic resonance chemical shift

Nuclear magnetic resonance chemical shift index

Nuclear magnetic resonance chemical shift interaction

Nuclear magnetic resonance chemical shift references

Nuclear magnetic resonance chemical shift-based methods

Nuclear magnetic resonance chemical shifts and

Nuclear magnetic resonance chemical shifts, electron-correlated calculations

Nuclear magnetic resonance signals chemical shift

Nuclear magnetic resonance spectra chemical shift

Nuclear magnetic resonance spectrometry chemical shifts

Nuclear magnetic resonance spectroscop chemical shift

Nuclear magnetic resonance spectroscopy chemical shift anisotropy

Nuclear magnetic resonance spectroscopy chemical shift reagents

Nuclear magnetic resonance spectroscopy chemical shifts

Proton magnetic resonance spectroscopy chemical shift

Solid-state nuclear magnetic chemical shift anisotropy

Solid-state nuclear magnetic resonance chemical shifts

Spin-rotation constants, nuclear magnetic resonance chemical shifts

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