CEQUINOR   05415
CENTRO DE QUIMICA INORGANICA "DR. PEDRO J. AYMONINO"
Unidad Ejecutora - UE
artículos
Título:
Investigation of the gas-phase structure and rotational barrier of trimethylsilyl trifluoromethanesulfonate and comparison with covalent sulfonates
Autor/es:
M. E. DEFONSI LESTARD; M. E.TUTTOLOMONDO; E. L. VARETTI; D. A. WANN; H. E. ROBERTSON; D. W. H. RANKING; A. BEN ALTABEF
Revista:
JOURNAL OF MOLECULAR STRUCTURE
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Año: 2010 vol. 984 p. 376 - 382
ISSN:
0022-2860
Resumen:
The molecular structure of trimethylsilyl
tri.uoromethanesulfonate, CF3SO2OSi(CH3)3, has been determined
in the gas phase from electron-diffraction data
supplemented by ab initio (MP2) and DFT calculations
using 6-31G(d), 6-311++G(d,p) and
6-311G++(3df,3pd) basis sets. Both experimental and
theoretical data indicate that only one gauche
conformer is possible by rotating about the OS bond.
The anomeric effect is a fundamental
stereoelectronic interaction and presents a profound influence on
the electronic geometry. We have investigated
the origin of the anomeric effect by means of NBO and
AIM analysis. A natural bond orbital analysis
showed that the lpp [O bonded to Si)] > s*
[CS] hyperconjugative interaction favors the gauche conformation. In addition,
comparison of the structural and stereoelectronic properties of the title
molecule with those of silyl trifluoromethanesulfonate and methyl trifluoromethanesulfonate
has been carried out.