Earth-field NMR

Earth field NMR with conventional size coils... 

Owing to the sizable Zr Ql, the bulk of Zr zero-field NMR and early field-swept NMR studies focused on Zr-containing metals as well as Laves- and pseudo-Laves-phase compounds, which typically feature Zr centers in environments of exceptionally high spherical symmetry (i.e., cubic) and are associated with near-zero Zr QIs. Laves-phase compounds are intermetaUic materials composed of rare earth metals and 3d transition metals which have peculiar properties, such as stoichiometric and/or... 

Callaghan PT, Coy A, Dykstra R, Eccles CD, Halse ME, Hunter MW, Mercier OR, Robinson IN (2007) New Zealand developments in Earth s field NMR. Appl Magn Reson 32 63—74... 

Halse ME, Callaghan PT (2008) A dynamic nuclear polarization strategy for multi-dimensional Earth s field NMR. J Magn Reson 195 162—168... 

When magnetie fields are present, the intrinsie spin angular momenta of the eleetrons S (j) and of the nuelei I(k) are affeeted by the field in a manner that produees additional energy eontributions to the total Hamiltonian H. The Zeeman interaetion of an external magnetie field (e.g., the earth s magnetie field of 4. Gauss or that of a NMR... 

Figure 12.29 illustrates the 13C-PHIP spectrum obtained when hydrogenating 4-fluoro-l-ethynylbenzene under ALTADENA conditions in the Earth s magnetic field. The reaction proceeds according to Scheme 12.5 and the catalyst used is outlined there. This system and the other isomers thereof, namely the hydrogenation of 2-, 3-, and 4-fluoro-l-ethynylbenzene, have also been studied using XH- and 19F-PHIP-NMR, and the results of the latter will be outlined in the following section (Fig. 12.30). 

Nuclear Magnetic Resonance (NMR) spectroscopic technique utilises photons to interact with the nuclei that display weak magnetic properties. In order to observe this effect, the sample is immersed in a strong magnetic field, 1000 times the earth magnetic field or even stronger. Under these circumstances certain nuclei, such like H, N, and... 

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