INSIBIO   05451
INSTITUTO SUPERIOR DE INVESTIGACIONES BIOLOGICAS
Unidad Ejecutora - UE
artículos
Título:
Structure and conformations of N-(chloroformyl) iminosulfur dichloride, ClC(O)N=SCl2
Autor/es:
ROBLES, N.L.; CUTIN, E.; ROSA MARIA SUSANA ALVAREZ; OBERHAMMER, H.
Revista:
JOURNAL OF MOLECULAR STRUCTURE
Editorial:
Elsevier
Referencias:
Año: 2008 vol. 891 p. 40 - 44
ISSN:
0022-2860
Resumen:
Vibrational spectra [FT IR (gas and liquid); FT Raman (liquid)] and quantum chemical calculations at different
levels of theory (HF, B3LYP and MP2 using 6-31G(d), 6-311 + G(2df) and cc-pVTZ base sets) demonstrate
that N-(chloroformyl) iminosulfur dichloride (ClC(O)N=SCl2) is present in the fluid phases as a
mixture of synsyn and synanti forms (syn orientation of the C-N bond with respect to the Cl-S-Cl
bisector; syn or anti orientation of the carbonyl group with respect to the N=S bond). From the relative
IR intensities of the C=O stretching bands the contribution of the syn-anti form is calculated to be 6(2)% in
the gas, corresponding to a Gibbs free energy difference DG = Gsynanti Gsynsyn = 1.6(3) kcal/mol. This
value is reproduced very well by quantum chemical calculations which include electron correlation
effects (DG = 1.591.91 kcal/mol). The HF approximation overestimates this energy difference
(DG = 4.45 kcal/mol). On the basis of theoretical calculations and reported data for other iminosulfur
dichlorides, a complete assignment of the fundamental modes for ClC(O)N@SCl2 is proposed.