¹³C Spectrum with Proton Decoupling
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9 ¹³C Spectrum with Proton
Decoupling
This  chapter  describes  the  acquisition  and  processing  of  a  one-dimensional 
13
C  NMR
spectrum. The standard Bruker parameter set C13CPD includes the pulse sequence zgpg30
shown in the figure below. The 
13
C channel consists of the recycling delay, a RF pulse, and
the acquisition time during which the signal is recorded. The pulse angle is shown to be 30°.
The two parameters, d1 and p1, correspond to the length of the recycle delay, and the length
of the  90°  RF pulse,  respectively. The 
1
H channel  consists  of two  decoupling pulses  which
can be power gated. The first pulse, an NOE build-up pulse during the recycle delay, may be
of  lower  power  than  the  second  pulse  during  the  acquisition  which  is  the  true  decoupling
pulse.  This  can  be  useful  to  avoid  RF  heating  on  salty  samples  or  probes  where  a  higher
decoupling power can be problematic.
The  time  intervals  depicted  in  the  pulse  sequence  diagrams  are  not  drawn  to  scale.  For
example, d1 is typically a few seconds, while p1 is typically a few microseconds in length.
The sample to be used is 30 mg of Menthyl Antranilate in DMSO-d6.