Pulse sequences and AU programs for broadband proton-decoupled proton spectra
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Contents

	1. Notes
	2. List of Files
	3. Experimental Setup
	4. Data Processing

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1. Notes

a) Please feel free to use and modify the pulse sequences and and AU programs.
However, we take no responsibility for any damage caused.
Please check all the power levels and gradient strengths before running the experiment.

b) The pulse sequences and AU programs have been tested on a couple of spectrometers running XWIN-NMR 3.5 and TOPSPIN 1.3, so you may get machine-dependent errors.

c) Refer to the following paper for further details:

   Magn. Reson. Chem., 45, 296-316 (2007).

If you have any queries, send an email to AJP or JHK.

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2. List of Files

Pulse sequences:-

	ajp_antizcosy : the basic anti z-COSY pulse sequence that has been modified to include the single-scan zero-quantum suppression scheme.

	ajp_antizcosy_vd : N- and P-type pulse sequences used to record an anti z-COSY spectrum with multiple-scan suppression of the cross peaks.

	ajp_dosy : sequence used to record a diffusion-weighted anti z-COSY spectrum.

	ajp_t1 : sequence used to record a T1 relaxation-weighted anti z-COSY spectrum.

AU programs:-

	ajp_shear : performs the two shear operations.  Includes linear interpolation.

	ajp_sym : symmetrizes the spectrum after shearing.

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3. Experimental Setup

Calibration of the swept pulse and gradient for zero-quantum suppression:-

This must be done before running any of the above experiments.
For details on how to do this, refer to the following paper and the supporting information that comes with it:

Angew. Chem., Int. Ed. Engl., 42, 3938-3941 (2003).

The calibration pulse sequence (mjt_2pul_aqg) is available on the "Downloads" page under "z-Filter".
Please read the readme.txt file that accompanies it!



The z-filter:-

All the pulse sequences have been written for a mixing pulse with a flip angle of 10 degrees, which gives excellent suppression of the unwanted components of the diagonal-peak multiplets.
However, if sensitivity is low, the flip angle can be increased up to 20 degrees.  However, note that doing so will increase the intensity of the unwanted peaks.
The delays d2 and d3 must be kept as short as possible to minimize the effects of longitudinal relaxation during the z-filter (no more than 2 msec each).



Direct suppression of the cross peaks:-

The delays for the cross-peak suppression sequence (ajp_antizcosy_vd) are specified in the list "vdlist".
The values of the delay are chosen in the same way as for the old multiple-scan suppression of zero-quantum.
Remember that increasing the value of the maxmium delay will increase the amount of J-modulation during the N-type experiment!



Diffusion and relaxation measurements:-

Each pulse sequence (ajp_dosy and ajp_t1) are set up to record a single diffusion/relaxation-weighted experiment, which is repeated several times for a range of values of the gradient/delay.

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4. Data processing

The data processing is done as follows:

a) Fourier transform the data in the usual way, making sure that the peaks are all phased to double absorption.

b) Shear the spectrum by running the AU program "ajp_shear".

c) If necessary, symmetrize the spectrum by running "ajp_sym".

d) Select the region of the spectrum that you wish to project.

e) Project this region onto the F2 axis in the usual way.  The standard Bruker command "f2sum", or clicking on "utilities" then "f2scalc" will do this.