1. Two-Dimensional Chirped-Pulse Fourier Transform Microwave Spectroscopy Amanda Shirar June 22, 2010 65 th OSU International Symposium on Molecular Spectroscopy

2. Introduction: 2D Spectroscopy Barbet-Massin, E. et al. J. Am. Chem. Soc. 2010, 132, 5556-5557. Calhoun, T.; et al. J. Phys. Chem. B 2009, 113, 16291-16295. NMRIRVisibleUVX-ray

3. Initial Limitations Pulse Sequences - Problem: - Problem: - t 1 Resolution - Multiple Microwave Generators Generators - Solution: Arbitrary Waveform - Solution: Arbitrary WaveformGenerator - Pulse Shaping - Sequence Mode 2D CP-FTMW Spectroscopy - Experimental Procedure - Data Processing Vogelsanger, et atl. Chem. Phys. Lett.. 1988, 144, 180-186. 1-Chloro-1-Fluoroethylene

4. CP-FTMW Spectrometer 13 GHz PDRO 12 GHz Oscilloscope (40 Gs/s) 13 GHz Filter 200W Arbitrary Waveform Generator 100 MHz Quartz Oscillator GHz Chirped Pulse 0.1-5 GHz 8-18 GHz Pulsed Nozzle 0.9-10.9 GHz 1) 2) 3) Free Inductive Decay 18.9 GHz PDRO 10 GHz Bandwidth 100 ps t 1 Resolution

5. 2D Autocorrelation Spectrum 0 00 F=1.5 1 11 Energy Level Scheme F=1.5 F=0.5 F=2.5 1-Chloro-1-Fluoroethylene(CFE) Time Domain pump t1t1t1t1 probe (Scan) 1234 t2t2t2t2 ABC t 1 (nsec)

6. 2D Plots of CFE 0 00 F=1.5 1 11 Energy Level Scheme F=1.5 F=0.5 F=2.5 ABC A B C CFE Assignments According To: Leung, H.; et al. J. Mol. Spec. 2009, 253, 116-121.

7. 2D Plots of CFE CFE Assignments According To: Leung, H.; et al. J. Mol. Spec. 2009, 253, 116-121. 0 00 F=1.5 1 11 Energy Level Scheme F=1.5 F=0.5 F=2.5

8. Difficulties of Broadband 2D Problems Acquisition Time: Resolution in t 1 Equipment: Sampling at Nyquist Rate Data Storage: Trillion Data points Solution Set Sampling Rate in t 1 1 ns Step Size: 500 MHz Bandwidth 0.5 ns Step Size: 1 GHz Bandwidth 1D Slices

9. Data Processing Frequency Aliasing 14.120 GHz  120 MHz 14.128 GHz  128 MHz 14.137 GHz  137 MHz ABC AB C A B C

10. Data Processing Predicted Experimental Use the Density Matrix to predict the 1D slices TC09: David Wilcox

11. Further Research Kelly Hotopp TC12: Applications of 2D CP- FTMW Spectroscopy Non-Selective Excitation Coherence Transfer

12. Acknowledgements Kelly HotoppKelly Hotopp David WilcoxDavid Wilcox Brian DianBrian Dian Dr. Henry & Camille Dreyfus Foundation - Young Faculty ScholarDr. Henry & Camille Dreyfus Foundation - Young Faculty Scholar

13. Blank 2-D Time Resolved Techniques - Selective Excitation - Selective Excitation - Pump single conformation - Probe all-conformations - Probe all-conformations - Relatively simple interpretation of time domain spectrum - Non-Selective Excitation - Non-Selective Excitation - Pump all conformers - Probe all conformers

14. Aliasing Ultra-Broadband scan ~ 2 months 500 MHz (2048 steps) ~ 3.5 hours 1 GHz (4096 steps) ~ 7 hours

15. Introduction: 2D NMR  -2- Microglobulin Benn & Günther, Ang. Chem. Int. Ed. Engl. 1983, 22, 5350-380. Toluene Derivatives

16. Introduction: Further 2D Shim & Zanni, Chem. Phys. Phys. Chem. 2009, 11, 748-761. Light Harvesting Complex II Amyloid Fiber Formation

17. 2D Rotational Spectroscopy J=2 J=1 J=3 Frequency Domain MW Pump (Single Trans.) MW Probe (Broadband) Benn & Günther, Ang. Chem. Int. Ed. Engl.. 1983, 22, 5350-380.