Edited H2BC for Bruker

Pulse programs

• Multiplicity edited H2BC with third order low-pass J filter (XWinNMR 2.6+):
  h2bc_cteal3
• Multiplicity edited H2BC (TopSpin 1.3):
  h2bc_one

AU-programs for processing

• General split and combination of interleaved 2D-data:
  splitcomb
• General split of interleaved 2D-data:
  splitil

Procedure for pulseprogram h2bc_one

1. Start with a HSQC parameterset rpar HSQCETGP all
2. Change pulse program to h2bc_one pulprog h2bc_one
3. Set up the acquisition parameters ased
4. Set cnst6 to 125 Hz, cnst8 to 165 Hz and cnst15 to 20 ms.
5. • For a standard H2BC-experiment:
     set the ZGOPTNS to -DSUB and L31 to 0 ZGOPTNS -DSUB; l31 0
   • For a up-down H2BC-experiment:
     set the ZGOPTNS to -DSUB and L31 to 1 ZGOPTNS -DSUB; l31 1
   • For an edited H2BC-experiment (i.e.,standard and up-down experiments acquierd in an interleaved mode):
     leave ZGOPTNS empty
6. Adjust sw and/or cnst15 until the calculated parameter TD1MAX is less or equal to the current td1 (= number of increments of t₁ × 4 for the interleaved experiments)
7. Make sure the power for the decoupling schemes is suitable for your system.
8. Set the number of scans to ~ 4× that of a decent HSQC on the same sample. Keep the same receiver gain.
9. Start the experiment and keep an eye on the amplifiers and temperature of the sample.

Processing of interleaved data

1. Split and combine the dataset to two new datasets: splitcomb 2
2. Change to the first of the two datasets: re <expno×100+1>
3. Do two-dimesional Fourier transform XFB
4. Phase the signals to either pure absorption or pure dispersion. Weak signals will benefit from the latter.
5. Process the second dataset (<expno×100+2>) the same way with multixfb.
6. Cross peaks generally correlates protons with carbons two bonds away. The first dataset contains signals from CH and CH₃-groups while the second dataset contains signals from CH₂-groups.