1. 1 Ab initio and Infrared Studies of Carbon Dioxide Containing Complex Zheng Su and Yunjie Xu Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada June, 2005

2. 2 Introduction Chirality and chiral interaction Our approaches  Ab initio theoretical investigations  High resolution molecular spectroscopy enantiomers

3. 3 Molecules under Investigation Cyclopropane(C 3 H 6 )CO 2 CO 2 monomer : asym = 2349 cm -1 Accessible region of our laser: 2336 – 2434 cm -1 Propylene Oxide(PO)CO 2

4. 4 Ab initio Calculations for POCO 2 ‡ ∆  = -2.8 cm -1 ∆ E = -18.91 kJ/mol A = 3.987 GHz B = 1.635 GHz C = 1.482 GHz ∆  = -3.3 cm -1 ∆ E = -18.21 kJ/mol A = 5.363 GHz B = 1.261 GHz C = 1.206 GHz ‡ Gaussian 03, MP2/cc-pVDZ for harmonic frequency calculations; MP2/aug-cc-pVDZ for geometry optimizations. Å Å

5. 5 Simulated Spectrum of POCO 2 T=2K Q-branch Kisiel, Z., Białkowska-Jaworska, E. and Pszczółkowski, L., J. Chem. Phys. 109(23), 10263, 1998. Frequency /cm -1

6. 6 Rapid Scan Mid-IR Diode Laser Spectrometer L5830 TDL control L5740 TDL Dewar Off-axis parabolic mirror Beam splitter iris Ref. cell or étalon L3L3 D2D2 Amplifier 2 Nozzle driver nozzle To pump L1L1 L2L2 D1D1 Amplifier 1 Vacuum chamber cell Computer Function generator

7. 7 Experimental Setup Laser source dewar Collimation assembly Reference detection Signal detection of the molecular complex Vacuum chamber

8. 8 Astigmatic Multi-path Cell Assembly backfront spot pattern of 182-pass configuration → 37m absorption length Mirror mount McManus, J.B., Kebabian, P.L. and Zahniser, M.S., Appl. Opt. 34(18), 3336, 1995.

9. 9 Rapid Scan Technique trigger for nozzle driver current ramp for laser controller trigger for data acquisition Piante, A.D., et al., Rev. Sci. Instrum. 60(5), 858, 1989. Time /ms background pulse signal 01 2345

10. 10 Example Spectrum of ArCO 2 R(0) R 08 Q0Q0 Randall, R.W., et al., Faraday Discuss. Chem. Soc., 85, 13, 1988. R(17) R(37) R(25) 2349.06 2349.42 2349.78 Frequency /cm -1

11. 11 Search for POCO 2 Complex Carrier gas: Ar, Ne, He Nozzle: 0.8mm pinhole, 60  m slit PO/CO 2 ratio: 1/3, 1/1, 2/1, 5/1,10/1 — 0.5% CO 2 in 1.5 bar Ar — 0.5% CO 2 5% PO in 1.5 bar Ar 2349.24 2349.78 Frequency /cm -1

12. 12 ∆ E = -28.57 kJ/mol Vs. ∆ E = -18.91 kJ/mol Vs. ∆ E = - 7.24 kJ/mol Competing Formation of Dimers POPOCO 2 CO 2 C3H6C3H6

13. 13 Rovibrational Spectra of C 3 H 6 CO 2 2348.82 2349.06 2349.30 Frequency /cm -1 R(16) R(37) R(25)R(32)

14. 14 Comparison of Nozzles C 3 H 6 :CO 2 = 3:1 100 averaging cycles 2347.20 2347.30 2349.40 2349.50 Frequency /cm -1 R(9) R(22) R(28)

15. 15 Simulated Spectra of C 3 H 6 CO 2 ∆ E = -8.756 kJ/mol ∆  = -2.18 cm -1 Frequency /cm -1 ∆ E = -9.329 kJ/mol ∆  = -5.08 cm -1

16. 16 Comparison between Experimental and Simulated Spectra 2344.2 2345.0 2347.84 2348.08 2348.48 2348.22 Cal. Exp. Frequency /cm -1

17. 17 Summary and Future Work Construction of a rapid scan mid-IR diode laser spectrometer Measurements of C 3 H 6 CO 2 complex Structural analysis of C 3 H 6 CO 2 complex Investigation of POCO 2 complex Study of chiral interactions

18. 18 Acknowledgement Dr. Waishun Tam and Dr. Nicole Borho Dr. Wolfgang Jäger and his group Dr. Igor Leonov for programming Roman Lipiecki for the mechanical parts Alberta Ingenuity Fund for a Studentship NSERC Thank you for the attention !!!