Tuesday, November 6, 2007
19F - 1H HOESY Experiment
Many of you use proton NOESY spectra to establish whether or not two types of protons are close to one another in space. The same type of experiment is also possible between nuclei of different isotopes. This technique is called HOESY (Heteronuclear Overhauser Effect SpectroscopY) and can be used to assess the spatial proximity between 2 heteronuclei. Below is an example of a 19F detected 19F - 1H HOESY spectrum of a sugar. (sample courtesy of Jennifer Chaytor)
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13 comments:
What pulse sequence do you use?
I used a slightly modified version of the one given in the Bruker pulse program library.
Is fhis HOESY experiment published and wher?
What is the modification of the standard HOESY bruker pulse program?
Thank you
bernard.ancian@upmc.fr
Bernard,
These data have not been published. The modification I made to the hoesyfhqfqnrv program was minor. I can't recall at the moment exactly what the modification was except that it was a minor change needed to run a newer pulse program on an older instrument.
Glenn
Is it possible to record 1H-27Al HOESY experiment?
If possible please suggest me HOESY pulse sequence in Bruker spectrometer.
Narendra,
Thank you for your question. In principle a 1H - 27Al HOESY is possible however the T2 of the Al is likely to be too short to permit a hereronuclear NOE measurement. What is the line width of the 27Al resonance?
If the 27Al T2 is sufficiently long, you could try the "hoesyph" pulse program.
Glenn
Thanks for your valuable response.
line width of 27Al resonance is 3389Hz in 500MHz spectrometer.
Narendra,
In the case of a 3.8 kkHz 27Al resonance, I think that a 1H-27Al HOESY measurement is not practical.
Glenn
I need to run 1H{19F} HOESY since the 19F molecule has a very high T1. Do you have the pulse sequence for the inverse HOESY?
Anonymous,
I have tried collecting 1H detected 2D 1H-19F HOESY data however my results were full of artifacts. I really am not sure why this was the case but I think it had something to do with my hardware. I do not have a working pulse sequence for you. I would start by modifying the hoesyfhqfqnrv pulse program in the Bruker library. Good luck.
Glenn
Do you need to degas samples for FH HOESY?
Anonymous,
I did not degas my samples.
Glenn
Hey Glenn
We did this experiment just yesterday using hoesyetgp.2 and it worked a charm (we do have new hardware and software). You need to specify X (for us, 19F, one peak at -165 ppm, run the 1D spectrum first so you know what range to use and where O1P should be) and check the routing diagram :)
With only one peak we ran both the 1D version as well as 2D. Hoping to put the 2D experiment into automation for our users, but then I guess I'll end up building a whole series of 1H-X hoesy experiments. Might not be the worst use of my time.
hope all is well
Hilary
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