1. The CP-FTMW Spectrum of Verbenone
Frank E. Marshalla, Galen Sedob, Channing Westc, Brooks H. Patec, Stephanie M. Allpressd, Corey J. Evansd, Peter D. Godfreye, Don McNaughtone, G. S. Grubbs IIa
aMissouri University of Science and Technology
bUniversity of Virginia’s College at Wise
cUniversity of Virginia
dUniversity of Leicester
eMonash University

2. Motivation Verbenone is chiral Verbenone is a monoterpene1
Motivation
Verbenone is chiral
Good candidate for determining enantiomeric excess (EE) through chiral tagging (insert chiral tagging talk reference)
Determining EE Requires a very thorough understanding of the molecule
Verbenone is a monoterpene
Recent studies of terpenoids show splittings that arise from various molecular motions
Our goal is to determine if any of these motions are present in this system
1By Edgar181 - Own work, Public Domain,

3. Missouri S&T CP-FTMW 6-18 GHz linear frequency sweep (“chirp”)
Expandable to 2-18 GHz with a specific amplifier
4us, 6GHz chirps
Low noise, High fidelity instrument
Minimal number of parts
AWG and Oscilloscope eliminate multiple circuit components
23GHz, 100GS/s oscilloscope
40W Solid state power amplifier
50GS/s digitization rate, 20GHz bandwidth AWG
Insert ArHCl spectra.

5. Verbenone – Missouri S&T
CP-FTMW
>93% (1S)-(-)-Verbenone purchased from Sigma Aldrich
Liquid sample was placed in a U shaped tube and heated to 80C approximately 1 meter from the nozzle
6-10 psig of Argon gas was bubbled through the sample
Pulsed into the chamber at 1 Hz.
Data collected at 5 FIDs per gas pulse from 6-18 GHz
1 million averages collected

6. Verbenone – University of Virginia
CP-FTMW2
>93% (1S)-(-)-Verbenone purchased from Sigma Aldrich
Liquid sample was heated to 65 C in a heated nozzle
4 nozzles were utilized
10 psig of Neon backing gas was used
Data collected from 2-8 GHz
1 million averages collected
2J. L. Neill, S. T. Shipman, L. Alvarez-Valtierra, A. Lesarri, Z. Kisiel, B. H. Pate, J. Mol. Spectrosc. 269 (2011) 21

7. Verbenone - Monash Free jet Stark-modulated spectrometer3
>93% (1S)-(-)-Verbenone purchased from Sigma Aldrich
Sample heated to 80C
Jet stream of 30 kPa of Argon was used
48-72 GHz frequeny range
3D. McNaughton, P. D. Godfrey, J.-U. Grabow, J. Mol. Spectrosc. 274 (2012) 1

8. Quantum Chemical Calculations
Geometry Optimizations in Gaussian09
B3LYP D3BJ with a def2-TZVP basis set
A more in depth paper is in the works from Pate and
coworkers

12. Analysis b type R branch spectra primarily observed
a, c type R branch transitions were observed with weaker intensity
633 transitions assigned for parent between 2-69 GHz
1250 total transitions across 12 isotopologues
Only parent transitions were observed above 8 GHz
Weaker isotopologues were observed in natural abundance for each heavy atom
No splittings observed

14. Atoms 2,4,6,25 off axis -> more transitions
Atoms 2,4,6,25 off axis -> more transitions. O (25) only has 25, but is 5x less abundant. 5*25 = 125 transitions. Planar atoms have about the same # of transitions.
Parent transitions include stark spectrometer, which has much higher uncertainty. Monash transitions allowed for determination of constants below d2.

15. Discussion
Important to determine complete experimental structure for chiral tagging
Observed structures were in excellent agreement with theoretical structures
Theoretical vs. Experimental errors were -0.41%, -0.32%, and -0.31% for A, B, C respectively
re structure for theory and experiment were determined to be virtually identical
Important to accurately calculate theoretical structures for Chiral Tagging

16. Conclusion CP-FTMW spectrum of (1S)-(-)-Verbenone has been reported
Substitution structure was derived
Theoretical substitution structure was in excellent agreement with experimental structure
No splittings due to internal motion were observed

17. Acknowledgements Dr. Garry Grubbs and Missouri S&T Lab members
Galen Sedo, Brooks Pate, Galen Sedo, Channing West, Brooks H. Pate, Stephanie M. Allpress, Corey J. Evans, Peter D. Godfrey, Don McNaughto
University of Missouri Research Board Grant
Uva-Wise Faculty Development Committee
NSF MRI Award
Pictures of Galen, Brooks, Corey Evans