-----Original Message-----
From: BoB LeSuer <rlesuer@zoo.uvm.edu>
To: Bruker Userlist <bruker-users-mail@bloch.cchem.berkeley.edu>
Date: Friday, June 09, 2000 12:56 PM
Subject: NOEDiff experiment
Bob,
> One of the research groups here would like to perform an NOEdiff
>experiment. (The one in 100 and more NMR experiments, #4.8 If I recall
>correctly.) Could someone please tell me what pulse program is
>necessary for this experiment as well as any tips from your
>experiences? Thanks.
AM series: MOEMULT.AU
AMX series: noemul pulse sequence with noemult AU program to drive it.
(I think those are the names)
Avance series: Probably the same as the AMX, but have never done it.
Now that I have gradients and can do GOESY, I wouldn't think of doing
an NOE difference expt. :-)
Stability is the most important thing. Don't spin, and use clean degassed
sample, etc. For processing, use more than the normal amount of LB and
zero filling. You will want to cycle through the frequency list a number of
times.
Power levels are also important with more power typically required for
multiplets
than for methyl singlets. Sometimes it is necessary to run the experiment
twice:
once for any methyls, and again at a higher power level for the multiplets.
Beware that
uneven saturation of a multiplet will result in an "INEPT like" polarization
transfer
to any coupled protons.
With care, on our AMX500, I can see NOE differences less than 1%.
GOESY is typically an order of magnitude better, in a fraction of the
time on either the AMX500 or Avance300.
Hope this helps.
-Kirk
Kirk Marat, Ph.D., NMR Facility Manager
Dept. of Chemistry and Prairie Regional NMR Centre
University of Manitoba
Winnipeg, Manitoba, R3T 2N2, CANADA
kirk_marat@umanitoba.ca
ph. (204) 474-6259, FAX (204) 474-7608
This archive was generated by hypermail 2b29 : Sun Dec 31 2000 - 01:15:02 PST