Accession Number : AD0786735

Title :   Time Dependent Magnetic Perturbations.

Descriptive Note : Technical rept.,


Personal Author(s) : Gutowsky,H. S.

Report Date : JUN 1974

Pagination or Media Count : 47

Abstract : An introductory review is given of time dependent magnetic perturbations, with emphasis upon their utility in nuclear magnetic resonance experiments designed to determine the nature and rate of dynamic processes in solids and fluids. The types of magnetic perturbations considered include dipole-dipole interactions, chemical shifts, the scalar coupling of nuclei and magnetic field inhomogeneities. These perturbations can be made time dependent in a random manner by molecular reorientations and diffusion, conformational changes, and exchange of nuclei among different chemical species. Also, coherent time dependence can be generated by the application of rf magnetic fields at or near the Larmor frequency, by sample rotation in an inhomogeneous field, and by modulation of the main magnetic field. The phenomenological aspects of these cases are considered and the development of particular methods for studying chemical exchange is reviewed. The prospects for future research and applications in the field are assessed. (Author)

Descriptors :   *Magnetic disturbances, *Nuclear magnetic resonance, *Time dependence, Stereochemistry, Magnetic dipoles, Magnetic fields, Exchange reactions, Molecular spectroscopy, Diffusion, Molecular structure

Subject Categories : Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE