title: A Direct Link from the Gas to the Condensed Phase: A Rotational Spectroscopic Study of 2,2,2-Trifluoroethanol Trimers.
abstract: Rotational spectra of the three most stable conformers (I, II, III) of the ternary 2,2,2-trifluoroethanol (TFE) cluster were measured using Fourier transform microwave spectrometers, and unambiguously assigned with the aid of ab initio calculations. The most stable conformer, I, contains one trans-TFE subunit which is unstable in its isolated gas phase form. The study offers new insights into how the trans conformation is stabilized in TFE clusters of increasing size, and eventually becomes a dominant conformation in the liquid phase. A detailed analysis shows that while O-H⋅⋅⋅O-H and O-H⋅⋅⋅F-C hydrogen bonds are the most significant attractive interactions which stabilize all three conformers, the main driving force for the stability of I over III, which has all gauche-TFE subunits, is the attractive interaction of C-F⋅⋅⋅F-C contact pairs. A new type of three-point F⋅⋅⋅F⋅⋅⋅F attractive contact interaction is also identified.
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada.
authors.forename: Javix
authors.identifier: 0000-0002-0210-7982
authors.initials: J
authors.lastname: Thomas
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada.
authors.forename: Nathan A
authors.initials: NA
authors.lastname: Seifert
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada.
authors.forename: Wolfgang
authors.identifier: 0000-0002-2841-2125
authors.initials: W
authors.lastname: Jäger
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada.
authors.forename: Yunjie
authors.identifier: 0000-0003-3736-3190
authors.initials: Y
authors.lastname: Xu
keywords: F⋅⋅⋅F contacts; halogen-halogen bonds; hydrogen bonds; rotational spectroscopy; trans-trifluoroethanol