title: S-(fluoroformyl)O-(trifluoroacetyl) thioperoxide, FC(O)S-OC(O)CF3: gas-phase structure and conformational properties.
abstract: The geometric structure and conformational properties of S-(fluoroformyl)O-(trifluoroacetyl) thioperoxide, FC(O)S-OC(O)CF3, were investigated by gas electron diffraction, matrix isolation infrared spectroscopy, and quantum chemical calculations (B3LYP with the 6-31G and aug-cc-pVTZ basis sets and MP2 with the 6-31G basis set). The experimental methods result in a mixture of two conformers with gauche conformation around the S-O bond. In the main conformer (82(7)% according to GED at 298 K), the C=O bond of the FC(O) group is oriented syn with respect to the S-O bond and phi(C-S-O-C) = 75(3) degrees . In the minor conformer (18(7)%), this C=O is oriented anti. Both conformers possess syn orientation of the C=O bond of the CF3C(O) group. The conformational properties and geometric parameters are reproduced reasonably well by the quantum chemical calculations, except for the S-O bond length, which is predicted too long by 0.04 A (B3LYP/aug-cc-pVTZ).
authors.affiliation: CEQUINOR Facultad de Ciencias Exactas, Universidad Nacional de La Plata, 47 esq. 115, 1900 La Plata, Argentina.
authors.forename: Sonia E
authors.initials: SE
authors.lastname: Ulic
authors.forename: Areti
authors.initials: A
authors.lastname: Kosma
authors.forename: Carlos O
authors.initials: CO
authors.lastname: Della Vedova
authors.forename: Helge
authors.initials: H
authors.lastname: Willner
authors.forename: Heinz
authors.initials: H
authors.lastname: Oberhammer
mesh_terms: D004583:Electrons; D005463:Fluoroacetates; D005740:Gases / Q000737:chemistry; D006845:Hydrocarbons, Fluorinated / Q000138:chemical synthesis / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D010545:Peroxides / Q000138:chemical synthesis / Q000737:chemistry*; D011789:Quantum Theory; D012680:Sensitivity and Specificity; D013055:Spectrophotometry, Infrared / Q000379:methods; D014269:Trifluoroacetic Acid / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D005463:Fluoroacetates; D005740:Gases; D006845:Hydrocarbons, Fluorinated; D010545:Peroxides; C522347:S-(fluoroformyl)O-(trifluoroacetyl) thioperoxide; D014269:Trifluoroacetic Acid