1. Spectral Spin Diffusion Enhancement by Recoupling Quadrupolar Spins under Magic-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

2. What MQMAS Tells And Does Not Tell Three Principal Values—Yes! Plus Isotropic Chemical Shift V 33 V 22 V 11 X Y Z Orientation—No For Powder Samples Used

3. The Relative Orientation Between Two Quadrupolar Tensors The Relative Orientation Between Two Quadrupolar Tensors What MQMAS May Tell V 33,B YBYBYBYB V 33,A V 11,A XAXAXAXA YAYAYAYA V 11,B V 22,A V 22,B XBXBXBXB ZAZAZAZA ZBZBZBZB

4. Generic Spin Diffusion/Exchange Pulse Sequence P 1 t 1 P 2 t m P 3 t 2 P 1 t 1 P 2 t m P 3 t 2 Evolution of Spin A(B) Evolution of Spin B(A)

5. Two Spin-3/2 MQMAS-Spin Diffusion Spectrum MQMAS Peaks Cross Peaks (3/2,-3/2)  (1/2,-1/2)

6. A Real Pulse Finite Width Finite Width Finite Power Finite Power Phase/Amplitude Imperfections Phase/Amplitude Imperfections t

7. MAS Suppressed Spin Diffusion

8. Recoupling Schemes Rotational Resonance Method Rotational Resonance Method Rotary Resonance Method Rotary Resonance Method Shaped Pulse Method: Shaped Pulse Method: A. Applied to Quadrupolar Channel A. Applied to Quadrupolar Channel B. Applied to Proton Channel B. Applied to Proton Channel C. Applied to Both Channel C. Applied to Both Channel To maximize polarization transfer during mixing time by optimizing recoupling pulses.

9. Using An Actual Pulse Sequence F 2 F 2 F 1 F 1

10. Intensity F2 Using An Actual Pulse Sequence

11. F 2 F 2 F 1 F 1 Using An Actual Pulse Sequence

12. F1 F1 Intensity Intensity F2 Using An Actual Pulse Sequence

13. Experimental Sodium 3QC-1QC Cross Peak (Na 2 HPO 4, t m =200 ms) QCC=2.13, 1.37 MHz, Eta=0.7,0.2 “ Normal ” Scheme

14. Sodium 3QC-1QC Cross Peak (Na 2 HPO 4, t m =200ms) QCC=2.13, 1.37 MHz, Eta=0.7,0.2 Scheme 1 Scheme 1

15. Sodium 3QC-1QC Cross Peak (Na 2 HPO 4, t m =100 ms) QCC=2.13, 1.37 MHz, Eta=0.7,0.2 Scheme 2 Scheme 2

16. QCC=2.13, 1.37 MHz, Eta=0.2,0.1 Sodium 3QC-1QC Cross Peak (Na 2 HPO4, t m =160 ms) Scheme 3 Scheme 3

17. Other Work Pulse Sequence Simplification/Optimization Pulse Sequence Simplification/Optimization 3D Exchange-Correlation 3D Exchange-Correlation Spin-5/2, 7/2, 9/2 Systems Spin-5/2, 7/2, 9/2 Systems More Versatile Applications More Versatile Applications

18. A Possible Modified Pulse Sequence t 1 t 2 t 1 t 2 Soft Pulses For Accelerating Equilibration

19. 3D Pulse Sequence For Spin Diffusion k 1 t 1 k 2 t 1 t m k 1 t 2 k 2 t 2 t 3 k 1 t 1 k 2 t 1 t m k 1 t 2 k 2 t 2 t 3

20. 3D MQMAS Exchange SpectrumF2 F3 F1 F2 F2 F1 F1 Removing Diagonal Peaks F 1 -F 2 Proj.

21. Applications To Biological Systems Relative Orientation Between Quadrupolar Tensors in Disodium ATP Relative Orientation Between Quadrupolar Tensors in Disodium ATP Relative Orientation Between Quadrupolar Tensors in Zinc Metalloproteins Relative Orientation Between Quadrupolar Tensors in Zinc Metalloproteins

22. Conclusions Spectral Spin Diffusion Of Half-Integer Quadrupolar Spins Can Be Enhanced With Recoupling Pulses During Mixing Time Spectral Spin Diffusion Of Half-Integer Quadrupolar Spins Can Be Enhanced With Recoupling Pulses During Mixing Time The Principal Components Of The EFG Tensors And The Relative Orientations of EFG Tensors Of Coupled Spins Can Be Determined The Principal Components Of The EFG Tensors And The Relative Orientations of EFG Tensors Of Coupled Spins Can Be Determined Many Extensions and Applications Are Feasible Many Extensions and Applications Are Feasible

23. Acknowledgment: National Science Council & Ministry of Education, Taiwan, ROC. 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. 117,5367(1995). [2] L. Frydman, J.S.harwood, J. Am. Chem. Soc. 117,5367(1995). [3] N.G.Dowell, S.E.Askbrook, J. McManus, S. Wimperis, J. Am. Chem. Soc. 123,8135 (2001). [3] N.G.Dowell, S.E.Askbrook, J. McManus, S. Wimperis, J. Am. Chem. Soc. 123,8135 (2001). [4] M.Baldus, D.Rovnyak, R. G. Griffin, J. Chem. Phys. 112,5902 (2000). [4] M.Baldus, D.Rovnyak, R. G. Griffin, J. Chem. Phys. 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.