Coherence selection and excitation sculpting using RF-gradients in selective 1D experiments and nonselective 2D experiments
The B0 gradient pulses can be replaced with long high-power pulses (RF-gradients) in z-rotation composite sandwiches. By doing this, practically all B0 gradient-based pulse sequences can be performed with instruments lacking a field gradient accessory. We have implemented RF-gradients into selective 1D and nonselective 2D TOCSY and NOESY experiments. The spectral quality obtained with the RF-gradient method was comparable to that of the B0 method for small- to medium-sized molecules. There are also some advantages in using RF-gradients instead of B0 gradients. There is practically no shift or coupling evolution during RF-gradient pulses. This may be significant in some experiments. Copyright 1998 Academic Press.
Heikkinen
S
Department of Chemistry, University of Oulu, Oulu, FIN-90570, Finlandand.
Rahkamaa
E
Kilpelainen
I