Nuclear magnetic resonance , solids development

Solid state materials have been studied by nuclear magnetic resonance methods over 30 years. In 1953 Wilson and Pake ) carried out a line shape analysis of a partially crystalline polymer. They noted a spectrum consisting of superimposed broad and narrow lines which they ascribed to rigid crystalline and amorphous material respectively. More recently several books and large articles have reviewed the tremendous developments in this field, particularly including those of McBrierty and Douglas 2) and the Faraday Symposium (1978)3) —on which this introduction is largely based. 

Nuclear magnetic resonance (NMR) spectroscopy in pharmaceutical research has been used primarily in a classical, organic chemistry framework. Typical studies have included (1) the structure elucidation of compounds [1,2], (2) investigating chirality of drug substances [3,4], (3) the determination of cellular metabolism [5,6], and (4) protein studies [7-9], to name but a few. From the development perspective, NMR is traditionally used again for structure elucidation, but also for analytical applications [10]. In each case, solution-phase NMR has been utilized. It seems ironic that although —90% of the pharmaceutical products on the market exist in the solid form, solid state NMR is in its infancy as applied to pharmaceutical problem solving and methods development. 

Abstract This chapter describes the experimentai compiement of theoretical models of the microscopic mechanism of ferroelectric transitions. We use the hydrogen-bonded compounds as examples, and attempt to show that the new experimental data obtained via recently developed high resolution nuclear magnetic resonance techniques for solids clearly support the hypothesis that the transition mechanism must involve lattice polarizability (i.e. a displacive component), in addition to the order/disorder behaviour of the lattices. 

Wheat starch lysophospholipid forms tiny liposomes in water that could readily be transported into the interior of a starch granule during its development. Solid-state nuclear magnetic resonance spectroscopy suggests that the phospholipids in wheat starch are predominantly complexed with amylose in an amorphous form in the granules.354-356... 

Forbes J, Bowers J, Shan X, Moran L, Oldfield E, Moscarello MA, Some new developments in solid-state nuclear magnetic resonance spectroscopic studies of lipids and biological membranes, including the effects of cholesterol in model and natural systems, /. Chem. Soc. Faraday Trans., 84 3821-3849, 1988. 

The purpose of this article is to review the progress of solid-state nuclear magnetic resonance over the last 4 years (ca. May 1995-May 1999) and is written as a sequel to our previous review.1 As in that review, the emphasis will be placed on the methodological developments. Nevertheless, the applications of the technical advances, particularly those that are significant to chemistry, biochemistry, biology and materials science, will also be mentioned. 

These advances, mainly in hardware, along with developments of pulse sequences, have tremendous potential in virtually every aspect of solid-state NMR and nuclear magnetic resonance imaging. Each will be covered in the following sections. 

Pulse techniques are fairly well developed for nuclear magnetic resonances, and the experimental requirements are less restrictive for nitrogen quadrupole resonance than for standard proton resonance in solids, so we shall not describe them here. 

Wu, G. (1998) Recent developments in solid-state nuclear magnetic resonance of quadrupolar nuclei and applications to biological systems, Biochemistry and Cell Biology, 76, 429-442. 

Physicists have long been aware of the power and usefulness of high-resolution solid-state NMR. Even prior to the development of cross-polarization, in the early to mid-seventies, it was clear that, by recording the nuclear magnetic resonance spectrum when the sample was spun at the magic angle (5 M1) to the magnetic field, chemical shifts could be readily identified... 

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