If you have gradients you'll be well aware how much of an improvement
they make to the standard 2D experiments, COSY, HMQC, HMBC, and NOESY.
There is a reduction in the number of scans per increment and a reduction
in the level of stripes and other rubbish in the spectra. Everything's
far quicker and your customers go away with clean shiny spectra and happy
smiling faces.
Unless, that is, you need to do a ROESY spectrum.
Most of our molecules are in the 300-1200 MW range, so we don't have to
do ROESYs that often to avoid the zero NOE crossing-point problem.
However, the method has a couple of other advantages that would make it
more popular _if_ I could get hold of a ROESY pulse sequence that used
Z-gradients for coherence selection. Without gradients the experiment
times are rather long and there are always a selection of odd peaks and
other junk in the spectra that ought not be there. This distresses the
customers.
Has anyone got a 2D ROESY sequence that uses gradients? (Preferably also
incorporating A.J.Shaka's excellent modification for eliminating TOCSY
peaks)
Alan
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Dr A.S.F.Boyd Chemistry Department
NMR Spectroscopist Heriot-Watt University
phone: +44-131-451 3214 Riccarton
fax: +44-131-451 3180 Edinburgh
email: a.s.f.boyd@hw.ac.uk EH14 4AS
http://dava.che.hw.ac.uk/ Scotland
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