• Title/Summary/Keyword: perfluoroalkanes

Search Result 2, Processing Time 0.023 seconds

Theoretical study on the structures and the electron affinities of cyclic perfluoroalkanes (c-PFA) (Cyclic perfluoroalkanes(c-PFA)의 분자구조 및 분광학적 성질에 관한 이론 연구)

  • Jeong, Sung-Yup;Shin, Chang-Ho;Kim, Seung-Joon
    • Analytical Science and Technology
    • /
    • v.26 no.1
    • /
    • pp.51-60
    • /
    • 2013
  • The geometrical parameters, vibrational frequencies, and adiabatic electron affinities (AEAs) for c-$C_nF_{2n}$ (n=8, 9) and $C_{10}F_{18}$ (perfluorodecalin) have been investigated using various quantum mechanical techniques. The possible structures for the neutrals and anions of c-PFA are fully optimized and electron affinities are predicted using energy difference between the neutral and anion. The harmonic vibrational frequencies are also determined and zero-point vibrational energies (ZPVEs) are considered for the better prediction of the electron affinities. The electron affinities are predicted to be 1.18 eV for c-$C_8F_{16}$ (ortho), 1.37 eV for c-$C_9F_{18}$, and 1.38 eV for $C_{10}F_{18}$ (perfluorodecalin) at the MP2 level of theory after ZPVE correction.

Structure and Dynamics of Perfluoroalkanes and Their ${\beta}$-Cyclodextrin Inclusion Compounds Investigated by Solid-state $^{19}F$ MAS NMR

  • Tatsuno, Hiroto;Ando, Shinji
    • Proceedings of the Polymer Society of Korea Conference
    • /
    • 2006.10a
    • /
    • pp.305-305
    • /
    • 2006
  • The molecular structure and dynamics of inclusion compounds (ICs) consisting of n-perfluoroalkane (PFA) guests and ${\Box}-cyclodextrin$ (${\Box}-CD$) host were investigated using $^{19}F$ magic angle spinning (MAS) and $^{1}H{\to}^{19}F$ cross polarization (CP) / MAS NMR spectroscopy with the aid of thermal analyses, FT-IR spectroscopy, X-ray diffraction, and $^{1}H{\to}^{19}F$ CP/MAS technique revealed that $C_{9}F_{20}$ molecules included in ${\Box}-CD$ undergo vigorous molecular motion and partly come out of the ${\Box}-CD$ channel above $80^{\circ}C$. In case of $C_{20}F_{42}/{\Box}-CD$, an exothermic peak is observed by differential scanning calorimetry (DSC) at ca. $40^{\circ}C$ which suggests that ${\Box}-CD$ molecules become mobile and commence rearrangements that form more ordered structures at higher temperatures.

  • PDF