Issue |
J. Chim. Phys.
Volume 91, 1994
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Page(s) | 607 - 624 | |
DOI | https://doi.org/10.1051/jcp/1994910607 | |
Published online | 29 May 2017 |
Impulsions sélectives et leurs applications à l’attribution des résonances et à la détermination structurale en RMN
Materials Sciences Division, Lawrence Berkeley Laboratory, and Department of Chemistry, University of California, Berkeley, California 94720, États-.
Cette article traite des impulsions sélectives et de leurs applications à l’attribution des résonances et à la détermination structurale par RMN. En premier lieu, nous considérons des approches pour élaborer des impulsions d’excitation en phase. Ensuite, nous discuterons des techniques bi-dimensionelles utilisant des impulsions sélectives pour l’attribution des résonances et pour la détermination précise des constantes de couplage. Les méthodes sont illustrées avec des exemples qui proviennent d’expériences réalisées sur des peptides est des oligonucleotides.
Abstract
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° 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 successful 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 the basis of the topologies of networks of coupled spins. The methods are illustrated with examples from peptides and DNA fragments.
© Elsevier, Paris, 1994