Solid-state NMR, high

The general problem of solution homogeneity represents a major area of concern in high-resolution solution NMR studies of complex hydrocarbon mixtures encountered in coal products. Although alternate NMR approaches could be used or developed (e.g., solid-state NMR, high-temperature NMR, ideal NMR solvents, etc.), the quantitative NMR approach used in the present study can distinguish this problem when complementary elemental combustion data is available. 

Once we have recorded a solid-state NMR high-resolution spectra, a... 

See also C NMR, Parameter Survey NMR, Methods High Resolution Solid State NMR, High Resolution Solid State NMR, H, Magnetic Fieid Gradients in High Resoiution NMR NMR Principies NMR Puise Sequences Soiid State NMR, Methods Soiid State NMR, Rotationai Resonance. 

G values for scission and crosslinking were estimated from these peaks and are shown in Table 3. There is good agreement between the G values for scission and crosslinking derived from soluble fractions (D>Dg -> Dg, solution NMR (low doses D<4Dg) and solid-state NMR (high doses D Dg). This agreement is persuasive that the crosslinks and scissions occur spatially at random in these copolymers and that the yields are independent of radiation dose. 

The principal dilTerence from liquid-state NMR is that the interactions which are averaged by molecular motion on the NMR timescale in liquids lead, because of their anisotropic nature, to much wider lines in solids. Extra infonnation is, in principle, available but is often masked by the lower resolution. Thus, many of the teclmiques developed for liquid-state NMR are not currently feasible in the solid state. Furthemiore, the increased linewidth and the methods used to achieve high resolution put more demands on the spectrometer. Nevertheless, the field of solid-state NMR is advancing rapidly, with a steady stream of new experiments forthcoming. 

Engelhardt G and Gunter 1987 High-Resolution Solid-State NMR of Silicates and Zeolites (Chichester Wiley)... 

J. S. Falcone, Jr., andJ. G. Blumberg, in O. Hutzinger, ed.. Handbook of Environmental Chemisty, Vol. 3, Pt. F, Springer-Vedag, Berlin, 1992. G. EngeUiardt and D. Michel, High Resolution Solid State NMR of Silicates and Zeolites, Chichester, John Wiley Sons, Ltd., 1987. 

Solid state NMR is a relatively recent spectroscopic technique that can be used to uniquely identify and quantitate crystalline phases in bulk materials and at surfaces and interfaces. While NMR resembles X-ray diffraction in this capacity, it has the additional advantage of being element-selective and inherently quantitative. Since the signal observed is a direct reflection of the local environment of the element under smdy, NMR can also provide structural insights on a molecularlevel. Thus, information about coordination numbers, local symmetry, and internuclear bond distances is readily available. This feature is particularly usefrd in the structural analysis of highly disordered, amorphous, and compositionally complex systems, where diffraction techniques and other spectroscopies (IR, Raman, EXAFS) often fail. 

High-Resolution Solid-State NMR Study of Reversible 1,5-Proton Shifts in Organic Solids [90MRC(S)29] NMR of Pyrazoles ... 

V. Laperche, J. F. Lambert, R. Prost, R., and J. J. Fripiat, High-resolution solid-state NMR of exchangeable cations in the interlayer surface of a swelling mica %a. 

Potrzebowski MJ, Kazmierski S (2005) High-Resolution Solid-State NMR Studies of Inclusion Complexes. 246 91-140 Poulin P, see Loudet JC (2003) 226 173-196 Raghuraman K, see Katti KV (2003) 229 121-141... 

Vinogradov E, Madhu PK, Vega S (2005) Strategies for High-Resolution Proton Spectroscopy in Solid-State NMR. 246 33-90... 

Many components of food are in the solid state and possess very short T2. The linewidths from solid components are generally too wide to be observed directly by solution state NMR methods. However, these components can be detected by the special techniques of solid state NMR. These techniques involve the use of cross polarization excitation (from 3H to 13C), high power 3H decoupling (to inhibit... 

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