Nuclear magnetic resonance spectroscopy line-broadening

CsHsljTi from -27 to + 62 C. The separate resonances observed at low temperature for the two types of Cp rings gradually broaden and collapse, giving a single line at 62 °C. [From Colton, F. A. In Dynamic Nuclear Magnetic Resonance Spectroscopy Jackman, L. M., Cotton,... 

It is useful to emphasise from the outset that alternative techniques for investigating solid samples, other than NMR spectroscopy of the quadrupolar halogen nuclei, tend to be considered first this is likely due to the (perceived) difficulty of the technique and may be related to the issues of sensitivity and line broadening mentioned above. However, the information gained is often complementary, and hence solid state nuclear magnetic resonance (SS NMR) spectroscopy is primarily used when it can provide unique insight unavailable with other techniques. 

Reversible reactions involving second-order steps in both directions. The following examples are taken from the many studies based on line-broadening analyses from nuclear magnetic resonance (NMR) and electron spin resonance (ESR) spectroscopy, respectively. 

The use of NMR spectroscopy to characterize diamagnetic transition metal and posttransition metal complexes has increased tremendously in the past decade (111, 129). Mercury has two NMR-active isotopes, Hg (natural abundance = 13.22%) and (natural abundance = 16.84%). The former is quadrupolar (nuclear spin, / = ), and consequently, much more difficult to observe, due to line broadening. The latter, on the other hand, is one of approximately 20 nuclides in the periodic table with the preferred spin I = i. Its receptivity, a measure of relative signal strength, is five times that of C for comparison, " Cd, the most widely studied of the posttransition nuclei, has a receptivity of only 8 relative to C. Magnetic resonance frequencies are intimately connected with the quantity and dis-... 

Nuclear resonance spectroscopy is based on the nuclear resonance effect, which can occur only in nuclei containing odd numbers of protons and/or neutrons in so far as such nuclei have intrinsic magnetic moments. In other words, NMR is theoretically applicable for nuclei with the nuclear spin number I larger than 0 however, practically only nuclei with 1 = 1/2 are those most used for NMR study since those with I > 1/2 possess electric quadrupole moments which broaden the line width and reduce the resolution of the spectra. 

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