Vibrational spectra and gas phase structure of N-trifluoroacetylimidosulfurous difluoride, CF3C(O)NSF2

Structures and Conformations of ((Trifluoroacetyl)imido)(trifluoromethyl)sulfur Fluoride, CF3C(O)NS(F)CF3

“…In the prevailing anti-syn form the S-C bond is orientated antiperiplanar and the S-F bond nearly perpendicular with respect to the N-C bond (φ(CsNdSsC) ) -164(5)°and φ(CsNd SsF) ) 98(4)°). The NdS bond in 1 and 2 (1.549(5) and 1.554(8) Å, respectively) is much longer than that in imidosulfurous difluorides (1.48 ( 0.01 Å) [1][2][3][4][5][6][7] and in dichlorides (1.515 ( 0.005 Å). 8,9 The lengthening of this bond can be attributed partially to the lower electronegativity of the substituents and partially to the absence of anomeric interactions in the anti-syn conformer.…”

“…The feature observed at 847 cm -1 in IR spectra and 849 cm -1 in Raman spectra was assigned to the C-N stretching fundamental mode, a position that can be compared with the same mode in FC(O)NdS(F)CF 3 13 (854 cm -1 ), CF 3 C(O)NdSF 2 6 (855 cm -1 ), and FC(O)NdSF 2 15 (859 cm -1 ). The NdS stretching mode can be assigned to the band centered at 988 cm -1 in the Raman spectrum.…”

“…The band appearing at 1347 cm -1 in the IR spectra and at 1353 cm -1 in the Raman spectra can be assigned to the C-C stretching fundamental mode by comparison with the value found in CF 3 C(O)NdSF 2 . 6 Four deformations are expected for the CCO group: the rocking mode can be observed in the Raman spectrum at 202 cm -1 , while the other symmetric deformation was assigned to the band appearing in the Raman spectrum at 416 cm -1 . The feature corresponding to the outof-plane deformation band was observed at 787 cm -1 in the Raman spectrum.…”

“…The two torsion fundamental modes could not be observed in the spectra, but they are expected to appear below 40 cm -1 . This assignment was made by comparison with the reported values for FC(O)NdSFCF 3 , 13 CF 3 C(O)NdSF 2 , 6 and CF 3 C(O)NCO. 14 A signal appearing at 82 cm -1 in the Raman spectrum was assigned to the SdN skeletal torsion.…”

Anomeric Interactions in Pentafluoroethylimidosulfurous Dichloride, CF3CF2N=SCl2: Structural, Conformational and Configurational Properties in the Gaseous and Condensed Phases

“…Vibrational spectroscopy, gas electron diffraction, X‐ray crystallography, quantum chemical calculations, and other techniques have proved to be powerful tools to understand the structural properties of sulfur imide molecules containing fluorine atoms or fluorinated substituents groups. Thus, the structure and conformational and configurational properties of molecules of the type R F N=SF 2 [R F = CF 3 ,13–16 FC(O),17,18 NC,19 CF 3 C(O),20 and FSO 2 21,22] and R F N=SCl 2 [R F = CF 3 23,24 and FC(O)25] have been studied, all of which show only a ( Z ) configuration around the putative N=S double bond. It is interesting to note that compounds with different substituents attached at the sulfur atom of the N=S group favor the ( E ) form.…”