Simulating a 1H-coupled 1H-15N HSQC experiment with 2 NH-pairs

Pulse Program: invitpHcpl
The pulse program for this example was obtained by modifying the standard Bruker INVITP pulse sequence. The only modification made here was to comment out the 180-deg refocusing 1H-pulse during 15N evolution (line (p2 ph2)) . The corresponding lines in the pulse sequence look like:

(p1 ph3) (p3 ph6):f2
;(p2 ph2)
(p1 ph4) (p3 ph7):f2

Spin System:

The spin system selected for this example consists of 2 protons and 2 nitrogens, grouped in two N-H pairs. The one-bond coupling between 1H and 15N in each pair was set to J = 94 Hz.
Note that this example does not take into account differences in the transition rates between different spin states of the AX-spin system. For a demonstration of this feature and how to use the Relaxation Calculator see the example of a Fully coupled HSQC experiment with spin-transition-specific linewidths.
Program Parameters:

Set the following values: nd0=4, cnst2=94, d1=1s. After setting cnst2, the value of delay d4 should automatically change to 1/(cnst2*4) which corresponds to 1/(4J).
Experimental Parameters:

td1=128, td2=64, ns=1, SWp1=4 ppm, SWp2=0.5 ppm, Op(1H)=7.1ppm, Op(15N)=115.5ppm.
Set channel 2 to 15N. Associate td1 with 15N by setting BF1 to CH2.
Data Processing:

Select TPPI for proper processing in the f1 dimension.

The resulting HSQC spectrum should look like this one:

Here is a 3D-view of the resulting HSQC spectrum:

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This manual page was designed by David Fushman & Olivier Walker.
(c) Copyright 2003 by David Fushman, University of Maryland.