Preparation and Properties of Trifluorothioacetic Acid-S-(trifluoromethyl)ester, CF3C(O)SCF3

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• 作者：Sonia E. Ulic ; Carlos O. Della Vé ; dova ; Angelika Hermann ; Hans-Georg Mack ; Heinz Oberhammer
• 刊名：Journal of Physical Chemistry A
• 出版年：2008
• 出版时间：July 10, 2008
• 年：2008
• 卷：112
• 期：27
• 页码：6211 - 6216
• 全文大小：121K
• 年卷期：v.112,no.27(July 10, 2008)
• ISSN：1520-5215

文摘

Trifluorothioacetic acid-S-(trifluoromethyl)ester, CF₃C(O)SCF₃, was prepared by reacting CF₃C(O)Cl and AgSCF₃ at 50 °C. The compound was characterized by ¹³C-, ¹⁹F-NMR, UV, and vibrational spectroscopy as well as by gas electron diffraction (GED) and quantum chemical calculations (HF, MP2, and B3LYP methods 6−31G(d) and 6−311+G(2df) basis sets). GED and vibrational spectroscopy result in the presence of a single conformer with C₁ symmetry and synperiplanar orientation of the S−CF₃ bond relative to the CO bond. This result is in agreement with quantum chemical calculations which predict the anti conformer to be higher in energy by about 4 kcal/mol. An assignment of the IR (gas) and Raman (liquid) spectra is proposed, and the GED analysis results in the following skeletal geometric parameters (r_a and ∠_a values with 3σ uncertainties; these parameters are thermal averages and are not inconsistent with calculated equilibrium values): CO = 1.202(6) Å, C−C = 1.525(10) Å, S−C(sp²) = 1.774(3) Å, S−C(sp³) = 1.824 (3) Å. O=C−C = 118.7(21)°, O=C−S = 127.1(15)°, C−S−C = 99.8 (13)°.