Ian Whitcombe
Subj: 1D Gradient Enhanced NOEs (GOESY)
1D GRADIENT ENHANCED NOEs (GOESY)
Following on from his publication of the GOESY technique [1],
James Keeler has made available pulse sequences for an improved version
of the experiment.
The new sequences use a double pulsed field-gradient echo for selective
excitation of the chosen resonance (see Hwang and Shaka [2]) and are written
for a Bruker DMX/DRX spectrometer. They can be obtained by anonymous ftp from:
felafel.ch.cam.ac.uk (131.111.112.9)
followed by cd to pub/noe.
cd pub/noe
ls -l
total 5
-rw-r--r-- 1 root 307 May 16 17:12 README
-rw-r--r-- 1 root 606 May 16 17:10 g2se
-rw-r--r-- 1 root 145 May 16 16:59 selcal
-rw-r--r-- 1 root 612 May 16 17:06 upup
-rw-r--r-- 1 root 768 May 16 17:08 upup180
The sequences selcal and g2se are used to calibrate the selective 180 degree
pulse and the gradients which are used to defocus the non-selected
magnetisation.
We find that gaussian pulses work well and that sinusoidal gradients (1ms
duration, 17 G/cm and 11 G/cm for the two gradient pairs with 40 G/cm for
the purging gradient) give good sensitivity and selectivity.
James Keeler can be contacted at:
Department of Chemistry
Lensfield Road
Cambridge CB2 1EW
UK
Telephone (01223) 336428 (Secretary 336369, FAX 336913)
EMAIL : jhk10@nmrtd.ch.cam.ac.uk
[1] Stonehouse, Adell, Keeler and Shaka, J. Am. Chem. Soc. 116, 6037-6038
(1994)
[2] Hwang and Shaka, J. Mag. Res. Ser. A, 112, 275-279 (1995)
****************************************************************
* Dr Glyn Williams Tel:(0)1707-366548 *
* Physical Methods Fax:(0)1707-373504 *
* Roche Products Ltd email:glyn.williams@roche.com *
* PO Box 8 *
* Welwyn Garden City *
* Herts AL7 3AY, UK *
****************************************************************