Shielding, long-range

The NMR spectra of the various deuterated tetramethyltin compounds demonstrated that the long-range isotope effects on the chemical shift are additive and operate in the direction of increased shielding. However, there is no significant isotope effect on the H—Sn coupling constant. 

This shows that the second and further solvation shells still have a non-negligible effect on NMR chemical shielding constants through the long-range electrical field they create. The approximation of an isolated molecular cluster in vacuo is valid for large clusters only this eventually makes determination of the shieldings of all protons computationally much more expensive than the fully periodic ab initio calculation. 

Based upon the foregoing experiences, some researchers observed that the same reluctance to interact with matter is responsible for the neutrino s long range and ability to resist detection. Tlios, it was reasoned that an apparatus for detecting neutrinos should be massive and shielded from the interference of other particles and radiation. As a solution to these problems, some researchers proposed a deep underwater muon and neutrino detector (acronym DUMAND). 

The intermolecular shielding surface and the effects of electric fields on shielding (shielding polarizabilities and hyperpolarizabilities) are useful in the interpretation of long-range intramolecular effects and in intermolecular effects on shielding. 

Local and Long-Range Effects on NMR Shieldings in Main-Group Metal Oxides and Nitrides... 

O and N shieldings more difficult to interpret and to model, but it also suggests that the shieldings of these elements can potentially give valuable information on the long-range structure of amorphous solids. 

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