Solid-state nuclear magnetic resonance analysis

DD Beusen, LM McDowell, U Slomczynska, J Schaefer. Solid-state nuclear magnetic resonance analysis of the conformation of an inhibitor bound to thermolysin. J Med Chem 38 2742-2747, 1995. 

Crosslinked polymer networks formed from multifunctional acrylates are completely insoluble. Consequently, solid-state nuclear magnetic resonance (NMR) spectroscopy becomes an attractive method to determine the degree of crosslinking of such polymers (1-4). Solid-state NMR spectroscopy has been used to study the homopolymerization kinetics of various diacrylates and to distinguish between constrained and unconstrained, or unreacted double bonds in polymers (5,6). Solid-state NMR techniques can also be used to determine the domain sizes of different polymer phases and to determine the presence of microgels within a poly multiacrylate sample (7). The results of solid-state NMR experiments have also been correlated to dynamic mechanical analysis measurements of the glass transition (1,8,9) of various polydiacrylates. 

Direct analysis 7.1 XRD, XRF, infrared spectroscopy (NIR and MIR), solid-state nuclear magnetic resonance (NMR), advanced spectroscopy using synchrotron radiation, neutron activation, fluorescence, and visible and electron microscopy... 

These semisynthetic proteins have served as useful tools to investigate and study the role of Ras proteins in the cell, for instance, new insights in the so-called Ras acylation cycle could be obtained as well as solid-state nuclear magnetic resonance (NMR) spectroscopic analysis of the lipidated membrane anchor and proteins became possible. ... 

Kinetic gelation models [178] have been used to determine, within experimental error, the fraction of constrained and unconstrained double bonds over a wide range of conversions in the polymerization of ethylene glycol dimethacrylate. The amount of unconstrained and constrained functional groups was determined experimentally by solid state nuclear magnetic resonance spectroscopy. The rules for determining constraint in the model were that all pendant double bonds and all monomers in pools of six or less are constrained. Monomers in pools of seven or more are assumed to be unconstrained. Whether a site is constrained or not does not affect the reactivity only the analysis of the model is affected by the rules defining constraint. 

Solid-state nuclear magnetic resonance (SSNMR) spectroscopy is a powerful technique used in the analysis of solids, and is currently finding more and more applications, particularly in the analysis of pharmaceutical formulations. It is a non-destructive, non-invasive technique that can be employed to simultaneously examine the physical and chemical states of both the active pharmaceutical ingredient (API) and the excipients present as they exist within the formulation. It is also highly selective, as nuclei of the API often have different chemical shifts than do common excipients. 

Bugay, D.E. Solid-state nuclear magnetic resonance spectroscopy. Drugs Pharm. Sci. 2002,117,467-499. Handbook of Pharmaceutical Analysis. 

Abstract Modern solid state nuclear magnetic resonance presents new powerful opportunities for the elucidation of medium range order in glasses in the sub-nanometer region. In contrast to standard chemical shift spectroscopy, the strategy presented here is based on the precise measurement and quantitative analysis of internuclear magnetic dipole-dipole interactions, which can be related to distance information in a straightforward manner. The... 

There are many other characterization methods (e.g., small-angle X-ray scattering, solid-state nuclear magnetic resonance, and Fourier-transformed infrared analysis) for investigating nanocomposite structure. These techniques are extensively reviewed in Ray and Okamoto. ... 

Detection and characterization of polymorphs and/or solvates rely on various experimental techniques. X-ray powder diffraction (XRPD), solid state nuclear magnetic resonance (NMR), solid state infrared (IR) and solid state Raman are useful in demonstrating differences in the solid state. Thermal analytical techniques, including differential thermal analysis (DTA), differential scanning calorimetry (DSC), and thermogravimetry (TG), are also... 

The characterization of the physical properties of pharmaceutical compounds under development is often conducted using a variety of techniques including DSC, TGA, XRD, HSM, solid-state nuclear magnetic resonance (NMR), infrared (IR) and Raman spectroscopy, moisture uptake, particle size analysis, scanning electron microscopy (SEM), and micromeritic assays. A typical initial analysis of a pharmaceutical compound under development in a materials characterization group would include DSC, TGA, HSM, and XRD analyses. These four techniques are chosen because the data generated from them, when viewed collectively, comprise a relatively complete initial analysis of the physical properties of the compound. The DSC, TGA, and HSM assays... 

Measuring the acidity of the Bronsted and Lewis acid sites is problematic. The adsorption and desorption of various amines has been used, but there is some disagreement about what it means.160 Some workers prefer to use isopropylamine, which desorbs only from Bronsted sites. Solid-state nuclear magnetic resonance (NMR) has also been used in the study of reactions on zeolites.161 Many zeolites crystallize into crystals that are too fine for conventional X-ray analysis. A new method that uses synchrotron X rays on microcrystalline powders promises to make it much easier to determine the structures of zeolites and related materials.162... 

McDowell, R.W., Condron, L.M., Mahieu, N., Brookes, P.C., Poulton, P.R. and Sharpley, A.N. (2002b) Analysis of potentially mobile phosphorus in arable soils using solid-state nuclear magnetic resonance. Journal of Environmental Quality 31,450 56. 

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