L. Emsley, SELECTIVE PULSES AND THEIR APPLICATIONS T O THE ATTRIBUTION OF RESONANCES AND TO STRUCTURE DETERMINATION IN NMR, Journal de chimie physique et de physico-chimie biologique, 91(6), 1994, pp. 607-624
Aspects of shaped selective pulses and their applications in assignmen
t and structure determination by NMR are considered. Specifically, str
ategies for the design of selective pulses for in-phase excitation are
covered. In the simplest case, 270-degrees Gaussian pulses are used t
o excite a multiplet with only a small residual phase dispersion. In m
ore demanding cases, more complex analytical pulse shapes are discusse
d. The most succesful pulse shapes to date are described by either a s
um of Gaussians, or a Fourier series. Both types of pulse can produce
excitation over a very well defined region with virtually no phase dis
persion. We also consider multi-dimensional techniques which use shape
d pulses to assign resonances, and to derive coupling constants. The s
oft-COSY experiment is considered in some detail, followed by a brief
description of experiments which are designed to simplify complex spec
tra on die basis of the topologies of networks of coupled spins. The m
ethods are illustrated with examples from peptides and DNA fragments.