1. Jason J. Pajski, Matt Logan, Brian C. Dian 1, Gordon G. Brown, Kevin O. Douglass, Richard D. Suenram and Brooks H. Pate Department of Chemistry, University of Virginia, McCormick Rd., P.O. Box 400319, Charlottesville, VA 22904 1.) Department of Chemistry, Purdue University, 560 Oval Dr., West Lafayette, IN 47907 David F. Plusquellic Optical Technology Division, National Institute of Standards and Technology, Gaithersburg, MD 20899 BROADBAND ROTATIONAL SPECTRA OF THE SOMAN-RELATED COMPOUNDS: PINACOLYL ALCOHOL AND PINACOLONE

2. 11 GHz CP-FTMW Spectrometer Pulse Monitor 12 GHz Oscilloscope (40 Gs/s) Free Induction Decay 0.5– 11.5 GHz Arbitrary Waveform Generator Chirped Pulse Frequency Sweep 4 GS/s x8 7.5-18.5 GHz TWT Amplifier FID acquisition and Fourier transform 9.9 GHz PDRO 2 GHz Bandwidth Nozzle Sample Feed 18.99 GHz PDRO

3. Chemical Warfare Agent Simulants Pinacolone Pinacolyl Alcohol Soman (GD) – nerve agent (cholinesterase inhibitor)

4. Pinacolyl Alcohol

5. Pinacolyl Alcohol Constants 1 Calculated with MP2/6-311++G(d,p) ExperimentalCalculated 1 Δ (obs-calc) A (MHz)3085.10613095-9.894 B (MHz)2226.00682251-24.99 C (MHz)1858.61231874-15.39 Δ J (kHz)1.01×10 -3 Δ JK (kHz)1.21×10 -4 Δ K (kHz)-5.64×10 -4 δ J (kHz)2.93×10 -4 δ K (kHz)-4.09×10 -3

6. Pinacolone A-E splitting

7. Pinacolone - MP2/cc-pVTZ Rotational constants (MHz): A=3211 B=2334 C=1936 Dipole moment (Debye): μ a = -1.1 μ b = 2.3 μ c = 0.0 Tot= 2.6 Rotational constants (MHz): A = 3218 B = 2322 C = 1935 Top-of-barrier - Planar – E Rel = 151.55 cm -1 Equilibrium - Non-Planar – E Rel = 0.0 cm -1 Dipole moment (Debye): μ a = -1.1 μ b = 2.4 μ c = 0.0 Tot= 2.6 Rotational constants (MHz): A = 3213 B = 2326 C = 1932 Equilibrium - Planar – E Rel = 149.68 cm -1 Dipole moment (Debye): μ a = -1.1 μ b = 2.4 μ c = 0.0 Tot= 2.6

8. 13 C Isotopomers Relative Intensity 1- 13 C1.16 % 3- 13 C1.22 % 4- 13 C1.14 % 8- 13 C1.01 % 12- 13 C + 16- 13 C2.84 %

9. Unassigned Line

10. Qualitative Quantum Mechanical Argument

11. Pinacolone Constants

12. Experimental vs. Calculated Parameters for Pinacolone Experimental 1 Calculated 2 Δ (obs-calc) A (MHz)3192.091(2)3211-18.909 B (MHz)2292.898(2)2334-41.102 C (MHz)1928.181(2)1936-7.819 Barrier to rotation (cm -1 ) 122.3(5)109.3912.91 1 Values are for the A-state. 2 Calculated at MP2/cc-pVTZ level.

13. Conclusions for Pinacolone A-E splittings from methyl rotor Experimental barrier determined to be 122.3(5) cm -1 Pinacolone is dynamically planar Some molecules cool only to next-lowest energy state in a double well with a probability density centered off the c-axis giving rise to extra lines in the spectrum

14. Acknowledgements Pate Lab Group Members Rick Suenram and David Plusquellic at NIST Funding: NSF Chemistry SELIM Program NSF MRI Program (with Tom Gallagher, UVa Physics) University of Virginia John D. and Catherine T. Macarthur Foundation The Jeffress Trust

15. Approximate Energy Gap for c-Type Transitions with the Double Well Assumption ΔE ~ 2-4 cm -1 ~ 60-120 GHz

16. Pinacolone - MP2/6-311++G(d,p) Rotational constants (MHz): 13 C Isotopomers C1 3187 2306 1917 C3 3188 2310 1919 C4 3167 2281 1891 C8 3155 2294 1898 C12 3145 2283 1913 C16 3143 2294 1905

17. Chirped Pulse Generation: x8 Scheme x4 x2 7.5 – 18.5 GHz To Experiment Chirped Pulse Frequency Sweep 162.5 – 1537.5 MHz Phase locked oscillator 9.9 GHz 10 MHz Rb Oscillator 4 GHz Arb. Waveform Generator Dual Channel Independent Trigger Laser/TWT Trigger Scope Trigger 0-80 dB Programmable Atten. Single Sideband Filter Sweep 9.7375 – 8.3625 GHz Sweep 19.15 – 13.65 GHz 19.8 GHz High Power TWT Amplifier x2 Low Power Loop

18. 2 nd Generation Chirped Pulse Design 7.5 – 18.5 GHz To Experiment Chirped Pulse Frequency Phase locked oscillator 13.0 GHz 10 MHz Rb Oscillator Arbitrary Waveform Generator Dual Channel Independent Trigger Laser/TWT Trigger Scope Trigger High Power TWT Amplifier

19. Chirped Pulse (Linear Frequency Sweep) Excitation Chirped Pulse Instantaneous Frequency:  = sweep rate Need: 11,000 GHz/1  s Synthesizer: 300MHz/1ms Use arbitrary waveform generator as the frequency source Need sweep rates that are 10 5 times faster than standard synthesizers

20. 11 GHz Chirped Pulse Frequency Sweep in TimeFrequency Sweep in Frequency Signal recorded at -60 dB from 1kW TWT

21. Pinacolyl Alcohol - MP2/6-311++G(d,p) Principal axis orientation: --------------------------------------------------------------------- Center Atomic Coordinates (Angstroms) Number Number X Y Z --------------------------------------------------------------------- 1 6 -0.650404 0.032244 0.004389 2 6 -1.350092 -1.214783 -0.552939 3 1 -2.412953 -1.199323 -0.286090 4 1 -1.274510 -1.243391 -1.646845 5 1 -0.901567 -2.127883 -0.154701 6 6 -0.753548 0.029199 1.533699 7 1 -0.350085 0.949614 1.968617 8 1 -1.805919 -0.042861 1.831211 9 1 -0.214816 -0.822931 1.957450 10 6 -1.344202 1.278396 -0.558481 11 1 -1.222157 1.341073 -1.646826 12 1 -2.417517 1.232254 -0.343728 13 1 -0.956358 2.199782 -0.112868 14 6 0.817475 0.008628 -0.459379 15 1 0.802567 -0.009424 -1.561871 16 6 1.663694 1.191937 -0.001797 17 1 1.719657 1.228696 1.089120 18 1 2.684030 1.088694 -0.389624 19 1 1.267264 2.139412 -0.375790 20 8 1.387245 -1.216911 0.018817 21 1 2.320061 -1.204391 -0.215811 --------------------------------------------------------------------- Rotational constants (MHZ): 3095.1951021 2250.9551932 1873.5365802

22. Pinacolone - MP2/6-311++G(d,p) Principal axis orientation: --------------------------------------------------------------------- Center Atomic Coordinates (Angstroms) Number Number X Y Z --------------------------------------------------------------------- 1 6 0.884204 -0.173084 -0.015204 2 8 1.365019 -1.296014 -0.022361 3 6 -0.632438 0.046343 -0.006184 4 6 1.782644 1.051913 -0.006567 5 1 1.407179 1.834645 0.657137 6 1 2.787990 0.753317 0.293749 7 1 1.824740 1.468676 -1.018755 8 6 -1.342606 -1.254925 -0.381769 9 1 -2.426918 -1.100734 -0.361246 10 1 -1.055174 -1.580544 -1.386322 11 1 -1.086291 -2.057253 0.314085 12 6 -1.036003 0.455622 1.422104 13 1 -0.568880 1.398108 1.725585 14 1 -2.122703 0.588764 1.468339 15 1 -0.755514 -0.320547 2.142141 16 6 -1.022012 1.157367 -0.991699 17 1 -0.702012 0.911595 -2.010664 18 1 -2.111652 1.270494 -0.999520 19 1 -0.587370 2.122896 -0.715873 --------------------------------------------------------------------- Rotational constants (MHZ): 3187.9664865 2314.6458259 1922.0286113