SELECTIVE PULSES AND THEIR APPLICATIONS TO THE ATTRIBUTION OF RESONANCES AND TO STRUCTURE DETERMINATION IN NMR
Aspects of shaped selective pulses and their applications in assignment and structure determination by NMR are considered. Specifically, strategies for the design of selective pulses for in-phase excitation are covered. In the simplest case, 270-degrees Gaussian pulses are used to excite a multiplet with only a small residual phase dispersion. In more demanding cases, more complex analytical pulse shapes are discussed. The most succesful pulse shapes to date are described by either a sum of Gaussians, or a Fourier series. Both types of pulse can produce excitation over a very well defined region with virtually no phase dispersion. We also consider multi-dimensional techniques which use shaped pulses to assign resonances, and to derive coupling constants. The soft-COSY experiment is considered in some detail, followed by a brief description of experiments which are designed to simplify complex spectra on die basis of the topologies of networks of coupled spins. The methods are illustrated with examples from peptides and DNA fragments.
13th Germ Congress, GIENS, FRANCE, MAR 29-APR 03, 1994
Record created on 2015-01-08, modified on 2016-08-09