RE: AMMRL: Summary of X-decoupled H1-spectrum on Avance III HD

From: Hsin Wang <hwang1_at_ccny.cuny.edu>
Date: Wed, 26 Apr 2017 21:35:02 +0000

Dear AMMRLs,

I would like to make a summary to my post "H2-decoupled H1-spectrum on Avance III HD". I have changed the subject title to "X-decoupled" to reflect that this is really a question about X-decoupling, including the special cases of H2-decoupling and also F19-decoupling which is possible with BBFO probe.

I would like to thank Yizhou Liu, Sebastien Kemper, Clemens Anklin, Paul Cope, Bob Berno, and Wei Wycoff for their helpful advice.

One condition that is perhaps most important with X-decoupling is that it uses more power. Clemens advises to set the acquisition time (AQ) between 0.25 and 0.5 seconds. A few others have pointed out that D1 should be relatively long (low duty cycle) to allow adequate heat dissipation.

--
X-decoupling set up, excluding H2 and F19
Two ways were described to me.  The way I like better  is to rpar either "PROP31DEC" or "PROB11DEC".   Then in edasp edit NUC2 to nucleus of interest.  Make sure the pulse program is zgig.  (This is also described in TopSpin Help Mannuals > "Pulse Program Catalogue, 1D/2D" > "Basic 1D pulse sequences, page 67").
Another way is rpar the H1-decoupled X-nucleus experiments, such as C13IG, N15IG, Si29IG or Sn199IG.  The in edasp use the switch f1/f2 button and change f2 to the nucleus of interest.
It is possible the prosol table may not have that nucleus set up properly.  One should enter the correct P90 for X observe and decouple, go to "square pulses" to enter desired PCPD.  The 'edprosol' should calculate the power level properly.
I had asked specifically about B11-CPD in a glass tube and was told that it is not a problem.
--
H2-decoupling of H1 spectrum
I will just quote Clemens here:
for the deuterium decoupling experiment (use "zgig2h" as the pulse sequence)  you just select 2H as nucleus in F2 and click on default. This should correctly route the signal. You do not have to worry about the lock. This experiment will lock during the relaxation delay and decouple during acquisition all the switching is taken care of by the pulse program.
--
F19-decoupling H1 spectrum
I have heretofore not discussed this with anyone.  But I noticed there is an rpar "PROF19DEC", which loads the pulse program "zghfigqn".  The program indicates QNP-operation (F19 - via X-QNP output of switchbox).  I should probably verify that this is standard with BBFO and Avance III HD.  If it is, then it seems straightforward.  Except that one should probably be very careful of the CPD pulses because of the wide dispersion of F19 signal and avoid probe heating.  Probably experts should be consulted anyway.
Hsin
--
Hsin Wang, Ph.D.
Center for Discovery and Innovation, Room 01304
The City College of New York
85 St. Nicholas Terrace
New York, NY 10031
Phone: 212-650-5831
Email: hwang1_at_ccny.cuny.edu
From: Hsin Wang
Sent: Monday, April 24, 2017 4:45 PM
To: 'ammrl_at_ammrl.org' <ammrl_at_ammrl.org>
Subject: H2-decoupled H1-spectrum on Avance III HD
I would like to know how to set up H2-decoupled H1 experiment on a 2-channel Avance III HD spectrometer with a BBFO probe.
I would also like to do X-decoupled H1-experiments on the same spectrometer.
Perhaps these are fairly simple experiments.  But I am not familiar.  Any pointer (rpar, etc) would be greatly appreciated.
Hsin
--
Hsin Wang, Ph.D.
Center for Discovery and Innovation, Room 01304
The City College of New York
85 St. Nicholas Terrace
New York, NY 10031
Phone: 212-650-5831
Email: hwang1_at_ccny.cuny.edu<mailto:hwang1_at_ccny.cuny.edu>

Received on Wed Apr 26 2017 - 11:40:14 MST