title: Chirality induction and amplification in the 2,2,2-trifluoroethanol⋅⋅⋅propylene oxide adduct.
abstract: Chirality induction and amplification in a model system, that is, the 2,2,2-trifluoroethanol (TFE)⋅⋅⋅propylene oxide (PO) adduct, were investigated using free-space and cavity-based Fourier transform microwave spectroscopy, complemented with high level ab initio calculations. Rotational spectra of four out of eight predicted TFE⋅⋅PO adducts were assigned, and the remaining four were shown to relax to the geometries of the four observed in a jet expansion. The g+ TFE⋅⋅⋅S-PO adduct was found to be favored over that of g- TFE⋅⋅⋅S-PO by a factor of 2.8 at 60 K. This difference contrasts the TFE dimer for which an extreme case of chirality synchronization was previously reported. All TFE⋅⋅⋅PO conformers observed take on the open arrangement, in contrast to 2-fluoroethanol⋅⋅⋅PO, which prefers the closed arrangement. Furthermore, perfluorination at CH3 increases the hydrogen-bonding energy by about 70 % over its ethanol counterpart.
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, AB, T6G 2G2 (Canada).
authors.forename: Javix
authors.initials: J
authors.lastname: Thomas
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Jäger
authors.forename: Yunjie
authors.initials: Y
authors.lastname: Xu
mesh_terms: D004852:Epoxy Compounds / Q000737:chemistry*; D006860:Hydrogen Bonding; D008968:Molecular Conformation; D011789:Quantum Theory; D013237:Stereoisomerism; D014270:Trifluoroethanol / Q000737:chemistry*
chemical_list: D004852:Epoxy Compounds; D014270:Trifluoroethanol; C009068:propylene oxide
keywords: chirality; computational chemistry; conformation analysis; perfluorinated solvents; rotational spectroscopy