Varian Solid-State NMR - SPINDIFF-Spin Diffusion in Solids; FASTACQ-Multinuclear Fast Acquisition; Figure 58. SPINDIFF Pulse Sequence

6.29 SPINDIFF—Spin Diffusion in Solids
01-999162-00 C0402 VNMR 6.1C User Guide: Solid-State NMR 124
6.29 SPINDIFF—Spin Diffusion in Solids
SPINDIFF is a pulse sequence for 2D exchange spectroscopy in which spin diffusion is
occurring in solid dense homonuclear dipolar coupled spin systems. Figure 58 is a diagram
of the sequence.
Macro
The macro spindiff retrieves a parameter set suitable for the SPINDIFF experiment.
Parameters
The parameters used are analogous to those used in other multiple-pulse experiments:
pw is the 90
° pulse length, in microseconds.
tau is time delay between the pulses, in microseconds.
mix is the mixing time, in microseconds, for spin diffusion.
ni is the number of increments, as defined in standard 2D NMR usage. ni s is typically
set to either 64 or 128.
Reference
Zheng, L.; Fishbein, K. W.; Griffin, R. G.; Herzfeld, J. J. Am. Chem. Soc. 1993, 115,
6254.
6.30 FASTACQ—Multinuclear Fast Acquisition
Fast acquisition of data has interesting applications, particularly in high-temperature, fast
kinetic studies. Of particular interest is the ability to perform fast acquisitions in the
following manner: to do in double resonance (X,Y) the fastest possible acquisition of
sequential spectra of two nuclei—for example, pulse – acquire (27Al) – pulse acquire (2H)
– pulse – acquire (27Al)—storing FIDs in separate buffers.
Figure 58. SPINDIFF Pulse Sequence
Tx
d1
pw
dtau
pw
dtau
pw
tau+dtau
pw
dtau
pw
tau+dtau
pw
dtau
pw
tau+dtau
pw
dtau
pw
tau
pw
dmix
pw
dtau
pw
dtau
pw
tau+dtau
pw
dtau
pw
tau+dtau-2.0e-7
.
pw
dtau
pw
tau+dtau
pw
dtau
pw
tau
A
1.0u
1
.
0
u
1.0u
1
.
0
u
1.0u
1
.
0
u
1.0u
1
.
0
u
1.0u
1
.
0
u
1.0u
1
.
0
u
1.0u
1
.
0
u
1.0u 1.0u
1
.
0
u
1
.
0
u
1
.
0
u
1
.
0
s
0.8u
0.8u 4.3u
0.8u
4.3u
0.8u
4.3u
0.8u
3.5u
20.0u
0.8u
0.8u
4.3u
0.8u
4.1u 0.8u
4.3u
0.8u
3.5u