EXPERIMENTS ON SELECTIVE EXCITATION OF MULTIPLE-QUANTUM TRANSITIONS IN NMR SPECTROSCOPY [electronic resource].

Published:: Berkeley, Calif. : Lawrence Berkeley National Laboratory, 1980.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
Physical Description:: 30 pages : digital, PDF file
Additional Creators:: Lawrence Berkeley National Laboratory and United States. Department of Energy. Office of Scientific and Technical Information

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Summary:

By irradiating a spin system with an appropriate sequence of phase shifted pulses only certain orders of multiple-quantum transitions can be excited. Using such sequences in preparation and detection produces a large signal/noise enhancement for the high multiple-quantum spectra over nonselective excitation, as predicted from theory. In a previous paper the theory was presented in detail. In this paper some aspects of the theory are first outlined briefly. Experimental results are then presented demonstrating 4-quantum, 6-quantum and A-symmetry selection in oriented benzene and 8-quantum selection in oriented 1-bromobutane. A 6-quantum selective sequence applied to benzene with non-equilibrium initial reduced density matrix proportional to Iₓ produces 1- and 5-quantum spectra. The n-quantum signal/noise enhancements are obtained and the selectivity is measured as a function of pulse sequence parameters. The behavior is that expected if one assumes that the limit to selectivity is determined by leading nonselective terms in an average Hamiltonian expansion.

Report Numbers:

E 1.99:lbl-11916
lbl-11916

Subject(s):

Note:

Published through SciTech Connect.
10/01/1980.
"lbl-11916"
Journal of Chemical Physics 73 5 ISSN 0021-9606 FT
Pines, A.; Warren, W. S.
Materials Sciences Division

Funding Information:

DE-AC02-05CH11231

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