Structural determination of a recalcitrant molecule (S2F4)
1983; Elsevier BV; Volume: 100; Linguagem: Inglês
10.1016/0022-2860(83)90090-x
ISSN1872-8014
AutoresMichael Von Carlowitz, Heinz Oberhammer, Helge Willner, James E. Boggs,
Tópico(s)Advanced Chemical Physics Studies
ResumoThe structure determination of S2F4 (or SF3SF), the dimer of SF2, is made difficult by the large variety of possible conformers and the instability of the compound. An electron diffraction and microwave study succeeded only with the help of a molecular model derived from ab initio calculations, after initial experimental attempts had failed. The force field required for a joint electron diffraction and microwave spectroscopy analysis was calculated by ab initio methods and adjusted to the experimental vibrational frequencies. The structure of S2F4 is a trigonal bipyramid with the electron lone pair, the SF group and one fluorine atom in equatorial positions. The SF3 group is strongly distorted with the two axial SF bonds differing by 0.10 Å and bond angles between axial bonds and equatorial plane of about 77° and 92°, respectively. The geometric structure of S2F4 in combination with the ab initio calculations allows one to visualize the dissociation process SF3SF → 2 SF2 more clearly.
Referência(s)