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RESEARCH PRODUCT

Rotation of Molecules and Nuclear Spin Relaxation

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description

Nuclear spin relaxation has been developed as a standard method for studying molecular motions in liquids, solids, polymers, and—to a lesser extent—gases, staring with the pioneering work of Bloembergen, Purcell, and Pound [1]. Of the great variety of molecular motions possible (e.g., translations, rotations, vibrations) rotations are particularly important for nuclear spin relaxation. Conversely, nuclear spin relaxation can be especially successful if information about rotational motions is desired. In this case nuclear spin relaxation can yield quantitative information over an extraordinary wide range of characteristic frequencies, from about 1 Hz to 1014Hz. It shoud be noted that, typically, the nuclear spin relaxation times actually observed are much longer than the characteristic times of rotation of molecules. Therefore, a theory is needed which links the time constants of nuclear spin relaxation to the correlation functions describing the rotational motion, and so a considerable part of this volume is devoted to this goal. For rapid motions in liquids of low viscosity nuclear spin relaxation thus in principle, is inferior to scattering experiments (e.g., light and neutron scattering) which allow the determination of correlation functions.