Outline

1
Outline

• Introduction (physical background)
• Magic Angle Spinning
• Advanced Pulse Techniques
• Applications
• Instrument Setup
• Measurements

2
Selection of multiquantum coherence
3
Selection of multiquantum coherence
4
Correlation experiment
5
Homonuclear correlation
6
Homonuclear correlation establishing
connectivities
7
Dipolar Coupling
8
Measuring dipolar coupling constants
9
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10
Dipolar recovery at the magic angle (DRAMA)
11
Full DRAMA sequence
12
Zero and double quantum coherence
13
Double quantum filtered experiments
14
The C7 recoupling sequence
15
Rotational resonance experiment
16
Data resulting from rotational resonance
17
Heteronuclear correlation general spin-echo
sequence
18
Spin-echo double resonance experiment (SEDOR)
19
The REDOR experiment
20
Transfer of population in double resonance
(TRAPDOR )
21
Adiabatic zero crossing
22
REAPDOR sequence for measuring dipolar couplings
between I 1 and I 1/2 spins
23
Homonuclear correlation between I 1/2 spins
24
Double/single quantum correlation
25
Homonuclear double/single-quantum correlation
26
Outline

• Introduction (physical background)
• Magic Angle Spinning
• Advanced Pulse Techniques
• Applications
• Instrument Setup
• Measurements

27
Investigating reaction products
28
Chemical shift information
29
Tolane sample 13C spectrum CP-MAS _at_ 12 kHz
30
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31
Selective experiment Quaternary carbon signals
only (NQS)
32
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33
Measuring molecular motion
34
Dipolar interaction and molecular motion
35
Two site jumps
Three site jumps
109.5
120
70.5
36
Two site hopping, 120 reorientation, shielding
tensor 10 kHz
37
Basic 2D exchange experiment
38
2D exchange spectrum
39
3D exchange sequence
40
Outline

• Introduction (physical background)
• Magic Angle Spinning
• Advanced Pulse Techniques
• Applications
• Instrument Setup
• Measurements

41
Temperature ranges
VTN Variable Temperature Normal
(BN-Stator) WVT Wide Variable Temperature
(MgO-Stator) DVT Direct Variable Temperature
(BN-Stator)
150C
300C
-120C
-140C
T
VTN
WVT
DVT
Exception 2,5-mm-probe heads -30C 70C
42
Probehead design
VTN/WVT variable temperature with bearing
DVT separate cooling gas supply
43
Positioning of the thermocouples (DVT)
TC 1 control
PH MAS DVT 600 WB BL4 (H8724)
TC 2 regulation
44
Rotor caps
ZrO2
Macor
BN
Kel-F
Vespel
45
Application range of rotor caps
Kel-F (polymer) room temp. , (shrinks at low
temp., deformation at high temp.), easy
removal BN (ceramics) low and high temp.,
mechanically sensitive, to be glued Macor
(ceramics) low and high temp., mechanically
sensitive, to be glued ZrO2 (ceramics) low
and high temp., mechanically tolerant, easy
removal, expensive ... Vespel (polymer) high
speed and high temperature, easy removal
46
Decoupling sequences TPPM
TPPM Two Pulse Phase Modulation
Pulse length tp ? tp - e e ? 0 0.6 ms,
optimize!
Phaseshift ? ? 15, evt. optimize!
47
TPPM- decoupling, optimize tp
Ca-signal in Glycine-2-13C-15N, nrot 30 kHz, ?
15
ndec 150 kHz
optimum pulse length tp 2.9 ms, (tp 3.2 ms)
48
XiX - decoupling
XiX X Inverse X
Pulse length tp x tR, x ? n, but x ? n, ...
(recoupling at (n/4)tR ) optimize!
49
XiX- decoupling, optimize tp
Ca-signal of glycine-2-13C-15N, nrot 30 kHz,
ndec 150 kHz
50
Comparison of decoupling methods
Ca-signal of glycine-2-13C-15N, ndec 150 kHz
10 kHz
TPPM (15)
CW
XiX
30 kHz
51
Decoupling methods p-pulse decoupling
Rotorsynchronised train of 180-pulses xy-16-phase
cycle for large band width
xy-16-phase cycle 090900090900180270270
180180270270180
52
p-pulse decoupling for 19F
19F Dipol-Dipol-coupling spun out at fast
rotation but large chemical shift
anisotropy ? large band width important
19F-spectrum of teflon at 30 kHz
53
p-pulse-decoupling for 19F
13C19F-CP/MAS-spectrum of Teflon, nrot 30 kHz
CW
TPPM 15
p-pulse
54
Cross polarization
Condition for contact pulsesHartmann-Hahn
matching
55
Efficiency for (1H? X)-CP
Acquisition
X
CP
decoupling
1H
56
Comparison of standard and ramp-CP
Carbonyl-signal of glycine (nat. abundance), nrot
20 kHz, as function of 1H-power
rectangle
ramp
57
unwanted CP during the C7 sequence
avoid CP
58
Double-CP
CP 1
Decoupling
Avoid CP
1H
CP 2
Y
Acquisition
X