Chapter 6. Solid-State NMR Experiments
115
VNMR 6.1C User Guide: Solid-State NMR 01-999162-00 C0402
Array the value of crossp2. The Hartmann-Hahn match corresponds to the minimum
signal intensity.
cntct2 is the contact time for the dilute-spin cross polarization, in microseconds.
References
Schaefer, J.; Stejskal, E. O.; Garbow, J. R.; McKay, R. A. J. Magn. Reson. 1984, 59,
150.
Stejskal, E. O.; Schaefer, J.; McKay, R. A. J. Magn. Reson. 1984, 57, 471.
6.22 T1CP1—
T
1
Measurement with Cross-Polarization
The pulse sequence T1CP1 is used to measure the T
1
of X-nuclei (e.g.,
13
C) by cross-
polarization (CP), as published by Torchia. Figure 51 is a diagram of the sequence.
Macro
The macro t1cp converts a parameter set obtained by XPOLAR or XPOLAR1, for the
measurement of T
1
. Observe and decoupler power levels and the 90° pulse width are
retained. By default pwx=pw. Fine calibration of pwx is recommended.
Parameters
T1CP1 uses the
UNITY
INOVA and UNITYplus parameters tpwr, tpwrm, dpwr, cppwr,
dipolr, crossp, dplvl2, pw, and cntct. See page 85 for a description of these
parameters.
pwx is the observe 90
° pulse, in microseconds.
d2 is the delay of the T
1
inversion recovery, in seconds.
Figure 51. T1CP1 Pulse Sequence
pw
cntct
cntct
(tpwrm)
(crossp)
(dipolr)
Tx
Dec
at
d1
AC
pwx
d2
pwx
AC
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