Varian Solid-State NMR - Figure 13. Protonated Carbon Suppression of Alanine (Spectrum and Sequence); Figure 14. Rotating-Frame Spin-Lattice Relaxation Measurements Sequence

Chapter 2. CP/MAS Solids Operation
43 VNMR 6.1C User Guide: Solid-State NMR 01-999162-00 C0402
13
C T
1ρ
Experiments
Measurements of the spin-lattice relaxation time in the rotating frame (T
lρ
) are possible
using the standard XPOLAR1 pulse sequence. Anytime that pcrho is set to a non-zero
value, a T
lρ
decay is introduced; thus, by setting pcrho to an array, T
lρ
is measured.
Typical values for pcrho would range from 50 to 5000
µs.
To analyze a T
lρ
experiment for the decay time constant, enter
analyze('expfit','pcrho','t2','list')
In experiments other than T
lρ
experiments, pcrho should be set to 0. Figure 14 shows the
spin-lattice relaxation measurement pulse sequence.
pdp='n'
pdp='y'
Figure 13. Protonated Carbon Suppression of Alanine (Spectrum and Sequence)
13
C
1
H
(dipolr)
xpol='y' pdp='y'
d1
pw
(crossp)
cntct
pdpd2
1/srate
2*pw
1/srate
tpwrm
Figure 14. Rotating-Frame Spin-Lattice Relaxation Measurements Sequence
13
C
1
H
d1
pw
(crossp)
cntct
(dipolr)
xpol='y'
pcrho
cntct
(tpwrm)
(tpwrm)