1. Conformational Analysis of R-(+)-3-Methylcyclopentanone by IR Spectroscopy in Para-Hydrogen Crystal Watheq Al-Basheer 1,2, Shin Y. Toh 2, Jun Miyazaki 2,3 and Takamasa Momose 2 1 Dep. of Physics, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia 2 Dep. of Chemistry, University of British Columbia, Vancouver, BC, Canada 3 Dep. of Liberal Arts and Basic Sciences, College of Industrial Technology, niho, japan 69 th International Symposium on Molecular Spectroscopy University of Illinois at Urbana-Champaign, Jun. 19 th 2014

2. Isolation Matrix Infrared Spectroscopy In 1954, George C. Pimentel (Berkeley) proposed using inert elements as isolation matrices due to: 1- Unreactive with entrapped molecule due to completely filled outermost shell 2- Weak forces between atoms (induced p-p) (Van der Waals forces). 3- Electron distribution in crystals close to free atoms (crystals are transparent insulators) 4- Atoms pack as close as possible (fcc structure)

3. Hydrogen Molecule (H 2 ) para-hydrogenortho-hydrogen I = 0I = 1 Pure para-Hydrogen (pH 2 ) Matrix will work as a good isolation Matrix

4. Macroscopic View of pH 2 as an Isolation Matrix Hydrogen crystal structure is hexagonal close packed (hcp) which is an ideal isolation matrix due to: 1- Large lattice constant (~ 3.78 ᴼA). 2- Because pH 2 is light, it has large zero-point vibration (Amplitude of vibration ~ 20% of the lattice constant). 3- Capability to repair itself of crystal defects. 4- Solvent cage effects are minimal Para-hydrogen crystal is a soft quantum crystal Momose et al, J. Chem. Phys. 107 (19), (1997).

5. Making & Doping para-hydrogen (pH 2 ) crystal

6. Candidate dopant molecule (chiral R-(+)-3-Methylcyclopentanone) R-(+)-3-Methylcyclopentanone (R3MCP) is a chiral ketone. Exists in all living cells (drug industry applications). Has high optical activity. Has enough vapor pressure at room temp. Has two different conformers (Equatorial, Axial). Has 45 vibrational degrees of freedom (possible IR modes [70-3000 cm -1 ] ) W. Al-Basheer, J. Sol. Chem. 41, 1495-1506 (2012) W. Al-Basheer et al, J. Phys. Chem. A. 111(12),(2007)

7. Para-hydrogen crystal(pH 2 ) Matrix Vs Argon and pure sample Exp. In pH2 (cm -1 ) DFT Equatorial (cm -1 ) DFT Axial (cm -1 ) 664.78 -662.47 721.13 -723.11 790.91788.94 - 807.55826.71 - 877.09875.82 - 925.42922.05 - 935.67936.44 - 987.38988.54 -

8. Para-hydrogen crystal(pH 2 ) Matrix Vs Argon and pure sample Exp. In pH2 (cm -1 ) DFT Equatorial (cm -1 ) DFT Axial (cm -1 ) 1024.90 -1021.97 1133.201125.91 - 1147.10 - 1148.01 1198.90 - 1198.62 1238.52 - 1236.17 1266.711267.52 - 1286.951287.97 - 1316.82 -1316.10 1354.901345.95 - 1383.361381.70 - 1407.201407.62 - 1411.01411.17 - 1462.38 -1464.91 1482.921484.49 -

9. Para-hydrogen crystal(pH 2 ) Matrix Vs Argon and pure sample

11. R3MCP concentration in pH 2 crystal

14. Summary & Conclusions pH 2 crystal is an ideal isolation matrix that can yield high resolution IR spectra of molecules due to its intrinsic nature as a cold and soft quantum crystal. Isolation Matrix IR spectroscopy in pH 2 is an efficient tool to study molecular structure of polyatomic chiral molecules. 50 ppm chiral R3MCP molecule concentration in para-hydrogen crystal has yielded the highest resolved IR spectrum. It is possible that pH 2 dimers are more likely to form at higher concentrations.

15. Acknowledgements KFUPM’s International Summer Scholarly Program (ISSP) for Generous financial support Prof. Takamasa Momose, University of British Columbia for hosting.