J. Molnar et al., MOLECULAR-STRUCTURE OF SBI3 AND BII3 FROM COMBINED ELECTRON-DIFFRACTION AND VIBRATIONAL SPECTROSCOPIC STUDIES, Inorganic chemistry, 35(26), 1996, pp. 7639-7642
The molecular structure of SbI3 and BiI3 have been studied by gas-phas
e electron diffraction and infrared Spectroscopy, BiI3 has been studie
d by electron diffraction, and SbI3 has been studied by infrared spect
roscopy for the first time. Both molecules are pyramidal (C-3v symmetr
y), and their geometries are characterized by the following bond lengt
hs (r(g)) and bond angles (angle(alpha)): Sb-I 2.721 +/- 0.005 Angstro
m, I-Sb-I 99.0 +/- 0.30, Bi-I 2.807 +/- 0.006 Angstrom, and I-Bi-I 99.
5 +/- 0.3 degrees. Three of the four normal modes of vibration were ob
served for both molecules: SbI3, v(2) = 74.4 cm(-1), v(3) = 193.6 cm(-
1), and v(4) = 54.6 cm(-1); BiI3, v(2) = 59.7 cm(-1), v(3) = 163.5 cm(
-1), and v(4) = 47.0 cm(-1). A joint electron diffraction/vibrational
spectroscopic analysis was also carried out, from which the harmonic e
quilibrium geometries were estimated. Force field parameters from a no
rmal coordinate analysis are reported for both molecules.