Structure and Conformations of N-(Fluoroformyl)imidosulfurous Dichloride, FC(O)NSCl₂

Abstract

The IR (gas) and Raman (liquid) spectra of FC(O)NSCl(2) demonstrate the presence of a conformational mixture in both phases. According to a gas electron diffraction study, the main conformer (94(8)%) possesses a syn-syn structure (C(O)F group synperiplanar with respect to the SCl(2) bisector and the C=O bond synperiplanar to the N=S bond). Quantum chemical calculations (HF, B3LYP and MP2 with 6-31G basis set, and MP2/6-311(2df)) predict a syn-anti structure for the second conformer. Analysis of the IR (gas) spectrum results in a contribution of 5(1)% of the minor form, corresponding to a Gibbs free energy difference DeltaG degrees = G degrees (syn-anti) - G degrees (syn-syn) = 1.75(15) kcal/mol. This value is reproduced very well by quantum chemical calculations, which include electron correlation effects (DeltaG degrees = 1.28-1.56 kcal/mol). The HF approximation overestimates this energy difference (DeltaG degrees = 3.24 kcal/mol).

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

“…The vibrational spectra can be interpreted satisfactorily on the basis of the presence of only one form. Assignment of the bands related to the N=SCl 2 moiety was performed on the basis of the corresponding features for similar S , S ‐dichlorosulfur imide derivatives such as CF 3 N=SCl 2 ,23 FC(O)N=SCl 2 ,25 and ClSO 2 N=SCl 2 31. The corresponding S , S ‐difluoro derivatives CF 3 N=SF 2 ,32 FC(O)N=SF 2 ,23 and ClSO 2 N=SF 2 22 were also taken into account to establish a correlation between the different modes.…”

“…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.…”

((Fluoroformyl)imido)sulfuryl Difluoride, FC(O)NS(O)F2: Structural, Conformational, and Configurational Properties in the Gaseous and Condensed Phases

“…The results will be compared with related species (OSF 2 , O 2 SF 2 , HNS(O)F 2 , ClNS VI (O)F 2 , NCNS(O)F 2 , FC(O)NSF 2 , and FC(O)NS(F)CF 3 6 ) sequenced by using the Lewis formalism. This comparison also includes related previously reported compounds CF 3 C(O)NS(F)CF 3 and FC(O)NSCl 2 …”

Morpholine sulfur trifluoride: Vibrational spectra, conformational properties and crystal structure

“…In fact, so far the only reported compound with a single N-S bond and S(+2) is CF 3 -S-NF 2 [1], whereas several S(+6)-compounds such NBBSF 2 -N5 5SF 2 and NBBSF 2 -N5 5S(O)F 2 , possessing not only a single, but also a triple sulfur-nitrogen bond, have recently been prepared and characterized [2]. In contrast, plenty stable S(+4) compounds with N5 5S double bond have been studied so far, for example molecules of the type R-N5 5SX 2 (CF 3 N5 5SF 2 [3], CF 3 N5 5SCl 2 [4], FC(O)N5 5SF 2 [5], FC(O)N5 5SCl 2 [6], C 2 F 5 N5 5SF 2 [7], C 2 F 5 N5 5SCl 2 [8] and CH 3 N5 5S(CF 3 ) 2 [9]) and RN5 5S5 5O (CF 3 -N5 5S5 5O and SF 5 N5 5S5 5O [10]). However, those which have attracted our present interest are the S(+4)-compounds with single N-S bonds, particularly a substance containing the entity N-SF 3 , in account of its influence on the reactivity and the conformational properties.…”