Chapter 6. Solid-State NMR Experiments
105
VNMR 6.1C User Guide: Solid-State NMR
01-999162-00 C0402
For CPNOESY, cross peaks occur between resonances that share mutual through-space
dipolar coupling or interact through weak spin diffusion. Coupling can be enhanced with
the insertion of rotor synchronized
π
pulses during the mixing period. Cross peaks are also
observed between resonances with chemical exchange and CPNOESYPS can be used to
observe exchange between static powder spectra. Use XNOESYSYNC to characterize
molecular motion in the presence of MAS.
Applicability
CPNOESYPS, found in
userlib
, is available only on
UNITY
INOVA and UNITYplu
Macro
The macro
cpnoesyps
converts a parameter set, obtained with XPOLAR or XPOLAR1,
for the solids 2D exchange correlation experiment CPNOESYPS. Power levels and the
proton 90
°
pulse width are retained. Default parameters set up for a phase-sensitive
hypercomplex acquisition with
rfdr
set to
'y'
. Also,
sw1
is set equal to
sw
and
xpol='y'
.
Figure 45. CPNOESYPS Pulse Sequence
pw
cntct
cntct
(tpwrm)
(crossp)
(dipolr)
Tx
Dec
at
d1
A
C
pwx
d2
pwx
mix
X
Y
Y
X
X
Y
Y
X
(2*pwx)
<if rfdr='y'>
n*(1/srate)