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Spectral Spin Diffusion Enhancement by Recoupling Quadrupolar Spins under Magic-Angle-Spinning. Shangwu Ding , Shun-liang Tseng, Jian-ming Chen, Hsuan-sheng Huang - PowerPoint PPT Presentation
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Spectral Spin Diffusion Enhancement by Recoupling Quadrupolar Spins under Magi
c-Angle-Spinning
Shangwu Ding , Shun-liang Tseng, Jian-ming Chen, Hsuan-sheng Huang
Department of Chemistry and Center for Nanoscience and Nanotechnology, National Sun Yat-sen University, 70 Lien-Hai Road, Kaohsiung, Taiwan 80424, Republic of
China
What MQMAS Tells And Does Not TellThree Principal Values—Yes! Plus Isotropic Chemical ShiftThree Principal Values—Yes! Plus Isotropic Chemical Shift
VV3333VV2222
VV1111
XX
YY
ZZ
Orientation—No For Powder Samples UsedOrientation—No For Powder Samples Used
The The Relative OrientationRelative Orientation Between Two Between Two Quadrupolar TensorsQuadrupolar Tensors
What MQMAS May Tell
VV33,B33,B
YYBB
VV33,A33,A
VV11,A11,A
XXAA
YYAA
VV11,B11,B
VV22,A22,A
VV22,B22,B
XXB B
ZZAAZZBB
Generic Spin Diffusion/Exchange Pulse Sequence
PP1 1 tt11 P P22 ttmm P P33 tt22
Evolution of Spin A(B)Evolution of Spin A(B) Evolution of Spin Evolution of Spin B(A)B(A)
Two Spin-3/2 MQMAS-Spin Diffusion Spectrum
MQMAS PeaksMQMAS PeaksCross PeaksCross Peaks
(3/2,-3/2)(3/2,-3/2)(1/2,-1/2)(1/2,-1/2)(3/2,-3/2)(3/2,-3/2)(1/2,-1/2)(1/2,-1/2)
)45,0,90(),,(
.1.0,4.1
,5.0,5.2
0
22,
11,
oo
q
q
MHzC
MHzC
)45,0,90(),,(
.1.0,4.1
,5.0,5.2
0
22,
11,
oo
q
q
MHzC
MHzC
A Real Pulse
Finite WidthFinite Width Finite PowerFinite Power Phase/Amplitude Imperfections Phase/Amplitude Imperfections
tt
MAS Suppressed Spin Diffusion
rIID kM /1 rIID kM /1
2,1
2
)(1
)(2 ||22
12
12
m
dmm
mBASD AR
Dr
DrD
2,1
2
)(1
)(2 ||22
12
12
m
dmm
mBASD AR
Dr
DrD
2,1m
timdm
DSS
reAH
2,1m
timdm
DSS
reAH
Recoupling Schemes Rotational Resonance MethodRotational Resonance Method Rotary Resonance MethodRotary Resonance Method Shaped Pulse Method:Shaped Pulse Method:
A. Applied to Quadrupolar ChannelA. Applied to Quadrupolar Channel
B. Applied to Proton ChannelB. Applied to Proton Channel
C. Applied to Both ChannelC. Applied to Both Channel
xSxIm
timdm
DSS StIteAHH r )()( 11
2,11
xSxI
m
timdm
DSS StIteAHH r )()( 11
2,11
To maximize polarization transfer during mixing timeTo maximize polarization transfer during mixing time
by optimizing recoupling pulses.by optimizing recoupling pulses.
Using An Actual Pulse Sequence
FF22
FF11kHz
sPsPsP
MHzC
MHzC
oo
q
q
80
,3,3,9
)20,90,40(),,(
.4.0,2.1
,3.0,5.2
1
111
0
22,
11,
kHz
sPsPsP
MHzC
MHzC
oo
q
q
80
,3,3,9
)20,90,40(),,(
.4.0,2.1
,3.0,5.2
1
111
0
22,
11,
F1F1
IntensityIntensity
F2 F2
Using An Actual Pulse Sequence
FF22
FF11
Using An Actual Pulse Sequence
kHz
sPsPsP
MHzC
MHzC
oo
q
q
80
,3,3,9
)40,30,60(),,(
.6.0,8.2
,3.0,0.4
1
111
0
22,
11,
kHz
sPsPsP
MHzC
MHzC
oo
q
q
80
,3,3,9
)40,30,60(),,(
.6.0,8.2
,3.0,0.4
1
111
0
22,
11,
F1F1
Intensi tyI ntens it y
F2 F2
Using An Actual Pulse Sequence
Experimental
Sodium 3QC-1QC Cross Peak (Na2HPO4, tm=200 ms)
QCC=2.13, 1.37 MHz,
Eta=0.7,0.2 .200,55
4,12,12
)40,30,60(),,(
.2.0,37.1
,7.0,13.2
1
111
0
22,
11,
mstkHz
sPsPsP
MHzC
MHzC
m
oo
q
q
.200,55
4,12,12
)40,30,60(),,(
.2.0,37.1
,7.0,13.2
1
111
0
22,
11,
mstkHz
sPsPsP
MHzC
MHzC
m
oo
q
q
““Normal” SchemeNormal” Scheme
Sodium 3QC-1QC Cross Peak (Na2HPO4, tm=200ms)
QCC=2.13, 1.37 MHz,
Eta=0.7,0.2 .200,55
4,8,8
)40,30,60(),,(
.2.0,37.1
,7.0,13.2
1
111
0
22,
11,
mstkHz
sPsPsP
MHzC
MHzC
m
oo
q
q
.200,55
4,8,8
)40,30,60(),,(
.2.0,37.1
,7.0,13.2
1
111
0
22,
11,
mstkHz
sPsPsP
MHzC
MHzC
m
oo
q
q
Scheme 1Scheme 1
Sodium 3QC-1QC Cross Peak (Na2HPO4, tm=100 ms)
QCC=2.13, 1.37 MHz,
Eta=0.7,0.2
.100,55
4,12,12
)40,30,60(),,(
.2.0,37.1
,7.0,13.2
1
111
0
22,
11,
mstkHz
sPsPsP
MHzC
MHzC
m
oo
q
q
.100,55
4,12,12
)40,30,60(),,(
.2.0,37.1
,7.0,13.2
1
111
0
22,
11,
mstkHz
sPsPsP
MHzC
MHzC
m
oo
q
q
Scheme 2Scheme 2
QCC=2.13, 1.37 MHz,
Eta=0.2,0.1
Sodium 3QC-1QC Cross Peak (Na2HPO4, tm=160 ms)
.160,55
4,12,12
)40,30,60(),,(
.2.0,37.1
,7.0,13.2
1
111
0
22,
11,
mstkHz
sPsPsP
MHzC
MHzC
m
oo
q
q
.160,55
4,12,12
)40,30,60(),,(
.2.0,37.1
,7.0,13.2
1
111
0
22,
11,
mstkHz
sPsPsP
MHzC
MHzC
m
oo
q
q
Scheme 3Scheme 3
Other Work
Pulse Sequence Simplification/OptimizationPulse Sequence Simplification/Optimization 3D Exchange-Correlation3D Exchange-Correlation Spin-5/2, 7/2, 9/2 SystemsSpin-5/2, 7/2, 9/2 Systems More Versatile Applications More Versatile Applications
A Possible Modified Pulse Sequence
tt11 t t22
Soft Pulses For Accelerating Equilibration Soft Pulses For Accelerating Equilibration
3D Pulse Sequence For Spin Diffusion
kk11tt11 k k22tt11 t tmm k k11tt22 k k22tt22 t t33
3D MQMAS Exchange Spectrum
F2F2
F3F3F1F1 F2F2
F2F2
F1F1
F1F1
RemovingRemoving
Diagonal PeaksDiagonal Peaks
FF11-F-F2 2 Proj.Proj.
Applications To Biological Systems
Relative Orientation Between Quadrupolar Relative Orientation Between Quadrupolar Tensors in Disodium ATP Tensors in Disodium ATP
Relative Orientation Between Quadrupolar Relative Orientation Between Quadrupolar Tensors in Zinc Metalloproteins Tensors in Zinc Metalloproteins
Conclusions
Spectral Spin Diffusion Of Half-Integer Spectral Spin Diffusion Of Half-Integer Quadrupolar Spins Can Be Enhanced With Quadrupolar Spins Can Be Enhanced With Recoupling Pulses During Mixing TimeRecoupling Pulses During Mixing Time
The Principal Components Of The EFG Tensors The Principal Components Of The EFG Tensors And The Relative Orientations of EFG Tensors Of And The Relative Orientations of EFG Tensors Of Coupled Spins Can Be DeterminedCoupled Spins Can Be Determined
Many Extensions and Applications Are FeasibleMany Extensions and Applications Are Feasible
Acknowledgment:National Science Council & Ministry of Education, Taiwan, ROC.
References:References: [1] S. Ding, C.A.McDowell, Mol. Phys. 85,283(1995).[1] S. Ding, C.A.McDowell, Mol. Phys. 85,283(1995). [2] L. Frydman, J.S.harwood, J. Am. Chem. Soc. [2] L. Frydman, J.S.harwood, J. Am. Chem. Soc.
117,5367(1995).117,5367(1995). [3] N.G.Dowell, S.E.Askbrook, J. McManus, S. Wimperis, [3] N.G.Dowell, S.E.Askbrook, J. McManus, S. Wimperis,
J. Am. Chem. Soc. 123,8135 (2001).J. Am. Chem. Soc. 123,8135 (2001). [4] M.Baldus, D.Rovnyak, R. G. Griffin, J. Chem. Phys. [4] M.Baldus, D.Rovnyak, R. G. Griffin, J. Chem. Phys.
112,5902 (2000).112,5902 (2000). [5] S. Ding, S.L.Tseng, J.M.Chen, H.S.Huang, submitted.[5] S. Ding, S.L.Tseng, J.M.Chen, H.S.Huang, submitted.