146 (327) BRUKER BIOSPIN User Manual Version 002
Proton Driven Spin Diffusion (PDSD)
2D Experiment Setup 11.2.1
8. Type iexpno to create a new data file and switch to the 2D mode using the
“123” button. Load the pulse program cpspindiff.
9. Recheck pulse widths and power levels, using ased.
10. Go into eda and set parameters for sampling in the indirect dimension, the
spectral width 1 swh. Note, that in TopSpin 2.1 or later the parameter IN_F1 re
-
places the parameters in0 and nd0. Usually, 1 swh equals swh. Choose a suit-
able spin rate such that no RR condition occurs and sidebands do not overlap
with peaks, if possible set the sweep width in F1 1 swh equal to the spin rate or
such that sidebands folding in along F1 do not interfere.
11. Make sure the correct nucleus is selected in the F1 dimension; make sure to
choose an appropriate quadrature detection mode in FnMode (usually
STATES-TPPI).
12. Choose the appropriate sampling time (td1) so that the required resolution (FI-
DRES) in the indirect dimension is achieved.
13. Set the desired mixing time as d8. The required multiple of spin periods (from
cnst31) is calculated as l1, the real mixing time may deviate by fractions of a
rotor period. The required mixing time may vary widely depending on the sam
-
ple properties, from a few milliseconds to hundreds of milliseconds, if long dis-
tance correlations in a mobile sample need to be observed. Note that longer
mixing times will result in S/N deterioration, as the mixing time approaches the
T
1
of the observed nuclei.
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