HETCOR with DUMBO, PMLG or w-PMLG, Using Shapes
User Manual Version 002 BRUKER BIOSPIN 133 (327)
edumbohet 9.2.3
DUMBO decoupling is as efficient as PMLG decoupling. As discussed in chapters
22 and 23, it requires to spin a bit slower (up to 12-13 kHz) and to place the carrier
closer to resonance. Faster spinning is possible with higher power pulses and
shorter pulse widths (24 usec or 16 usec).
The library of AU-programs in TopSpin
includes dumbo, which calculates the desired shapes for windowed and window
-
less DUMBO shapes. If the windowless version is desired, the e-dumbo shape is
preferred. Typing xau dumbo starts a dialog, in which e (for e-dumbo 22), 1 for the
number of cycles, 64 for the number of steps, and 0 for an added angle (this value
would be added to all phases in the shape). The program sets p20 to 32 µsec as
default. This is appropriate for an RF field of 100 kHz. Spnam2 is set to
edumbo22_1+0.
Table 9.4. Acquisition Parameters for e-DUMBO-HETCOR (on tyrosine-HCl)
Parameter Value Comments
pulprog edumbohet windowless dumbo shape.
nuc1 13C
o1p 100 ppm
nuc2 1H
cnst24 1000-3000 Place carrier within proton spectrum for evolution.
pl1 Power level channel 1 for contact pulse.
pl12 Power level channel 2 TPPM/SPINAL decoupling.
pl13 for 100 kHz Power level channel 2 DUMBO decoupling.
sp0 Power level channel 2 for contact pulse.
spnam0 ramp.100 or similar Shape for contact pulse channel f2.
sp2 set to pl13 100 kHz for default duration 32 µs.
spnam2 edumbo22_1+0 Both include one e-DUMBO cycle.
p3 2.5 – 3 µsec 90º pulse channel 2 at pl12.
p15 50 -500μs Contact pulse width.
p20 32 μs 32 µs for 100 kHz field, set by xau dumbo.
pcpd2 ≈ 2*p3 SPINAL64 /TPPM decoupling pulse.
CPDPRG2 SPINAL64/TPPM15 Decoupling sequence.
F1
1
H indirect
l0 0 Start value 0, incremented during expt.
l3 2- 4 Multiples of e-DUMBO period, increment per row.
in_f1 =in0 as calculated Set according to value calculated by ased.
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