1. Javix Thomas, Wenyuan Huang, Xunchen Liu, a Wolfgang Jäger, and Yunjie Xu Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada a School of Mechanical Engineering, Shanghai Jiao Tong University, China. ISMS, Noyes Laboratory 274, WJ02, 1:47 pm, Wednesday, June 24, 2015 Rotational spectroscopy of monofluoroethanol aggregates with itself and with water J. Thomas 2014 X. Liu W. Huang

2. Motivation Fluoroalcohols http://www.chem.ualberta.ca/~xu/ 2 Fluoroethanols as co- solvents for structural study. Fluoroethanols as solvent for enantioselective reactions and separation. Science, 2007, 317, 1881. Permanent chirality (reactants/catalysts)  new chirality in activated complexes formed with transiently chiral solvents  one or more new permanent stereogenic centers or helicity of the product. Fluoroalcohol clusters have been identified as an important factor in protein folding events. D. Roccatano, G. Colombo, M. Fioroni, A. E. Mark, Proc. Natl. Acad. Sci. 2002, 99, 12179. R. M. Culik, R. M. Abaskharon, I. M. Pazos, F. Gai, J. Phys. Chem. B 2014, 118, 11455. Debates on H-bond interactions involving organofluorines. Chem. Eur. J. 1997, 3, 89. Chem. Sci. 2012, 3, 1381.

3. FE http://www.chem.ualberta.ca/~xu/ 3 τ (FCCO) Τ(CCOH) T t G+ g+ G- g- Nine possible FE conformations

4. FE http://www.chem.ualberta.ca/~xu/ 4 Five groups of the FE conformers K. S. Buckton, R. G. Azrak, J. Chem. Phys. 1970, 52, 5652; Pate, et. al. J. Chem. Phys. 1999, 110, 1979; 1990, 110, 2000. Cal. Rel. energy (kJ/mol) MP2/6-311++G** level 10.1 9.9 7.6 7.2 0.0

5. Brown, Dian, Douglass, Geyer, Shipman, Pate, Rev. Sci. Inst. 2008, 79, 053103; Dempster, Sukhorukov, Lei, Jäger, J. Chem. Phys. 2012, 137, 174303. Thomas, Yiu, Rebling, Jäger, Xu, J. Phys. Chem. A. 2013, 117, 13249. Rotational spectroscopy with a cavity-based and a chirped pulse FTMW spectrometer microwave cavity nozzle Balle, Flygare, Rev. Sci. Instrum. 1981, 52, 33; Xu, Jäger, J. Chem. Phys. 1997, 106, 7968. 5 Instruments http://www.chem.ualberta.ca/~xu/

6. Some previous studies of alcohol-water complexes The alcohol-water complex http://www.chem.ualberta.ca/~xu/ 6 Trans is ~ 39.5 cm -1 more stable than g+/- Ethanol FE G+g-/G-g+ TFE gauche conf. M. Nedić, T. N. Wassermann, Z. Xue, P. Zielke, M. A. Suhm, Phys. Chem. Chem. Phys. 2008, 10, 5953; M. Nedić, T. N. Wassermann, R. W. Larsen, M. A. Suhm, Phys. Chem. Chem. Phys. 2011, 13, 14050. add H 2 O Water acts as a donor and ethanol switches from its preferred trans structure to a gauche conformation. The energy penalty for the inverted complex with water as an acceptor is ~ 3-4 kJ/mol. M. Heger, T. Scharge, M. A. Suhm, Phys. Chem. Chem. Phys. 2013, 15, 16065; J. Thomas, Y. Xu, J. Chem. Phys. 2014, 140, 234307/1-5. Water is inserted into the existing CF∙∙∙HO bond. Fluorination may turn this trend around.

7. 7 Spectroscopic constants of the FE∙∙∙H 2 O conformers The FE-water complex http://www.chem.ualberta.ca/~xu/ MP2/6-311++G(2d,p) Para.IIIIIIIVV ∆D e (kJ/mol)01.324.1914.248.49 ∆D 0 (kJ/mol)00.803.7411.5328.55 A (MHz)494549446300655913566 B (MHz)34473407239523181590 C (MHz)22162180209120421513 |μ a | (Debye)0.370.780.201.690.79 |μ b | (Debye)1.611.580.870.730.24 |μ c | (Debye)0.122.320.600.211.15

8. 8 Preliminary experimental results for FE∙∙∙H 2 O The FE-water complex http://www.chem.ualberta.ca/~xu/ Constants Ortho Para A (MHz) 4953.6159(18)4953.659(12) B (MHz) 3365.6300(13)3365.6494(74) C (MHz) 2171.8136(11)2171.7885(88) D J (kHz) 10.56(31)4.1(18) D JK (kHz) -12.88(38)0.8(33) D K (kHz) 7.553(61)4.65(34) d 1 (kHz) -0.821(31)-0.74(57) d 2 (kHz) -0.951(33)-1.97(35) N 2215 σ (kHz) 5.024 The optimized MW pulse widths for the a-, b- and c- type transitions suggest that μ a << μ b ~ μ c. III |μ a | (Debye)0.370.78 |μ b | (Debye)1.611.58 |μ c | (Debye)0.122.32 Some transitions show obvious splitting, possibly due to the tunneling of the water subunit. Preliminary fits

9. Previous spectroscopic studies of the alcohol dimers Alcohol adimers http://www.chem.ualberta.ca/~xu/ 9 Ethanol FE G-g+ or G+g- TFE J. P. Hearn, R, V, Cobley, B. J. Howard, J. Chem. Phys. 2005, 123, 134324. Dimers Slight heterochiral preference T. Scharge, C. Emmeluth, T. Hber, M. A. Suhm, J. Mol. Struct. 2006, 786, 86. X. Liu, N. Borho, Y. Xu, Eur. J. Chem. 2009, 15, 270. Strong homochiral preference C. Emmeluth, V. Dyczmons, T. Kinzel, P. Botschwina, M. A. Suhm, M. Yanez, Phys. Chem. Chem. Phys. 2005, 7, 991. J. Thomas, Y. Xu, J. Chem. Phys. Lett. 2014, 5, 1850. t is ~ 39.5 cm -1 more stable than g+/- g-/g- I, g-t II, g-t III G-g+ or G+g- G-g+/G+g- I, G-g+/G-g+ II, G-g+/G+g- III, G-g+/G-g+ IV G-g+/G-g+ I, G-g+/G+g- II

10. Previous studies of the trimers of water and alcohols Water and alcohol trimers http://www.chem.ualberta.ca/~xu/ 10 1. Water trimer 2. Methanol and ethanol trimers 3. Phenol trimer 1.F. N. Keutsch, J. D. Cruzan, R. J. Saykally, Chem. Rev. 2003, 103, 2533. 2. R. A. Provencal, et al. J. Chem. Phys. 1999, 110, 4258-4267; G. S. Tschumper, J. M. Gonzales, H. F. Schaefer III, J. Chem. Phys. 1999, 111, 3027.. 3. T. Ebata, T. Watanabe, N. Mikami, J. Phys. Chem. 1995, 99, 5761; M. Schmitt,et al. ChemPhysChem 2006, 7, 1241; N. A. Seifert, et al. Phys. Chem. Chem. Phys. 2013, 15, 11468. 4. Borho, M. A. Suhm, Org. Biomol. Chem. 2003, 1, 4351; T. B. Adler, et al. Angew. Chem. Int. Ed. 2006, 45, 3440. 5. T. Scharge, et al. Phys. Chem. Chem. Phys. 2007, 9, 4472. 4. Methyl lactate trimer 5. TFE trimer (tentative assignment)

11. Previous Attempts 11 Unique H-bond Topology of (FE) 3 http://www.chem.ualberta.ca/~xu/ Columbus 2008, RH02 15min 1:42 CHIRAL SELF-RECOGNITION: DIRECT ROTATIONAL SPECTROSCOPIC DETECTION OF 2- FLUOROETHANOL DIMERS AND TRIMERS IN THE GAS PHASE. XUNCHEN LIU, NICOLE BORHO, YUNJIE XU, Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada, T6G 2G2.

12. 12 Start from the beginning again FE clusters http://www.chem.ualberta.ca/~xu/ * 125 starting geometries by using subunits from all five groups. * Special attention to chirality of the subunits. * About 30 low energy conformers optimized at the MP2/6-311++G(2d,p) level.

13. 13 Four most stable conformers FE clusters http://www.chem.ualberta.ca/~xu/

14. Spectroscopic constants of the FE trimers FE clusters http://www.chem.ualberta.ca/~xu/ 14 Para a IIIIIIIV ∆D e 04.155.235.63 ∆D 0 03.324.554.74 ∆D 0 BSSE 00.932.112.32 A 844677798895 B 610677582481 C 455465438388 |μa||μa| 1.330.000.031.84 |μb||μb| 0.740.00 1.50 |μc||μc|1.122.072.210.41 MP2/6-311++G(2d,p) a) Energy in kJ/mol, rotational constants in MHz, and dipole moments in Debye. PaPa I A828.79997(18) B596.39423(11) C441.971596(94) DJDJ 0.12440(65) DJKDJK -0.0674(51) DKDK 0.4588(54) dJdJ -0.03558(37) d2d2 -0.00501(26) N60 σ1.7 Experimental results 60 transitions including all a-, b- and c-type observed.

15. Why conformer I is more stable than II? FE clusters http://www.chem.ualberta.ca/~xu/ 15 R. F. W. Bader, Atoms in Molecules: A Quantum Theory (Oxford University Press, New York, 1990; R. F. W. Bader, Chem. Rev. 1991, 91, 893-928; P Popelier, Atoms in Molecules: An Introduction, Prentice Hall, Harlow, 2000. 3 OH∙∙∙OH H-bonds 3 CH∙∙∙FCH H-bonds 2 OH∙∙∙OH H-bonds 1 OH∙∙∙FC H-bond 2 different types of bifurcated H-bonds

16. 1 2 3 4 5 6 II 1 3 4 5 7 6 2 Comparison of H-bond energies in I &II FE clusters http://www.chem.ualberta.ca/~xu/ 16 R. F. W. Bader, Atoms in Molecules: A Quantum Theory (Oxford University Press, New York, 1990; R. F. W. Bader, Chem. Rev. 1991, 91, 893-928; P Popelier, Atoms in Molecules: An Introduction, Prentice Hall, Harlow, 2000. 17.96 CH∙∙∙FC 227.82 OH∙∙∙OH 329.59 OH∙∙∙OH 428.44 OH∙∙∙OH 58.57CH∙∙∙FC 68.48CF∙∙∙HC Sum=110.85 kJ/mol 143.34 OH∙∙∙OH 251.77 OH∙∙∙OH 319.98OH∙∙∙FC 44.90CH∙∙∙OH 56.48CH∙∙∙FC 68.18CH∙∙∙FC 78.95CH∙∙∙FC Sum=143.63 kJ/mol E HB =0.5*a 0 3 *V(r), I II 171° and 164° 146°

17. Conclusion and future work 17 1. An unusual H-bond topology is revealed for the 2-fluoroethanol trimer. 2. Bifurcated H-bonds may play an important role even in a small alcohol cluster. 3. We are working on rotational spectroscopic studies of 2-fluoroethanol- water clusters and larger 2-fluoroethanol clusters and their mixed clusters. Fluoroalcohol and fluoroalcohol/water clusters http://www.chem.ualberta.ca/~xu/

18. 18Acknowledgements Funding $$$: Dr. Barbara Mez-Starck Foundation. Thank you for your attention! We thank Elijagh G. Schnitzler for discussions about AIM analyses.