6.6 HETCORCP1—Solid-State HETCOR
01-999162-00 C0402
VNMR 6.1C User Guide: Solid-State NMR
92
6.6 HETCORCP1—Solid-State HETCOR
HETCORCP1 is a
1
H –
13
C heteronuclear chemical shift correlation (HETCOR)
experiment for solid-state materials. Analogous to solution-state HETCOR experiments,
this sequence provides correlation between
1
H and
13
C chemical shifts. The HETCORCP1
experiment differs from the solution-state HETCOR in that correlation depends on dipolar
interactions rather than J coupling.
Applicability
HETCORCP1 is available on
UNITY
INOVA, UNITYplus, and UNITY systems. It is found in
psglib
.
Macro
The macro
hetcorcp1
converts a parameter set, obtained with XPOLAR or XPOLAR1,
for the solids HETCOR experiment HETCORCP1. Power levels and the proton 90
°
pulse
width are retained. Default parameters set up for a phase-sensitive hypercomplex data set
acquisition. The correct
sw1
is calculated and
srate
is set to the preferred value. Set the
actual spin rate equal to
srate
. A single decoupler offset
dof
is used throughout.
Parameters
hetcorcp1
uses the
UNITY
INOVA and UNITYplus parameters
tpwr
,
tpwrm
,
dpwr
,
cppwr
,
dipolr
,
crossp
,
dblvl2
,
pw
, and
cntct
for a description of
these parameters.
setup
is set to
'n'
to obtain a 2D spectrum (normal operation). Set
setup='y'
to
obtain a single t
1
FID,
blew
is the number of BLEW-12 cycles. You may use
setup
set
to
'y'
to obtain a one-dimensional spectrum using a “proton chemical shift selection
pulse” or to observe the pulse sequence with
dps
for
ni
greater than 1.
pw
is both the
1
H 90
°
pulse and the
13
C 90
°
pulse—the pulses must be equal. Adjust
tpwrm
(using
xpwxcal
) to make the pulse lengths equal.
wim
is the number of WIM-24 cycles used for cross-polarization. For best results, set the
length of the WIM-24 cross-polarization to occupy one-half a rotor period, for example,
wim=1
,
pw=4.0
, and
srate=5208
yields 96 microseconds of CP and a rotor cycle of
192 microseconds.
srate
is the actual rotor speed (see
wim
above). It is preferable, but not necessary, to use
rotor speed control.
bmult
is the number of BLEW-12 cycles per f
1
dwell time. Set parameter
sw1
to the value
1.0/(bmult*12*pw*1e-6)
. Default values are
bmult=2
for
phase=1,2
(hypercomplex), alternatively
bmult=1
for
phase=3
(TPPI).
phase=1,2
for the hypercomplex method (use
wft2da
for the 2D FT);
phase=3
for
TPPI (use
wft2d(1,0,0,0)
for the 2D FT).
dipof2
is set to
'y'
to use a second decoupler offset during acquisition.
dof
determines
the f
1
offset, which may be set above or below the
1
H chemical shift region if a pedestal is
present in f
1
. In this case, set
dipoff
for the center of the
1
H shift region for best
decoupling.
dipof2
is set to
'n'
to use
dof
during the evolution period and decoupling.