VIBRATIONAL-SPECTRA AND STRUCTURE FROM AB-INITIO CALCULATIONS OF TETRAFLUORODIPHOSPHINE

Authors
Citation
Jr. Durig et Zn. Shen, VIBRATIONAL-SPECTRA AND STRUCTURE FROM AB-INITIO CALCULATIONS OF TETRAFLUORODIPHOSPHINE, Vibrational spectroscopy, 13(2), 1997, pp. 195-203
Citations number
16
Categorie Soggetti
Spectroscopy,"Chemistry Analytical","Chemistry Physical
Journal title
ISSN journal
09242031
Volume
13
Issue
2
Year of publication
1997
Pages
195 - 203
Database
ISI
SICI code
0924-2031(1997)13:2<195:VASFAC>2.0.ZU;2-P
Abstract
Ab initio calculations have been carried out for tetrafluorodiphosphin e, P2F4, up to the MP2/6-311 + G level. The harmonic force constants and vibrational frequencies along with infrared and Raman intensities for the most stable trans conformer have been obtained from these calc ulations which provide a basis for the vibrational assignment. Several reassignments of the fundamentals from those previously given were re quired from these data. The calculations indicate that the gauche conf ormer should be a stable rotamer but more than 800 cm(-1) (2.3 kcal/mo l) higher in energy which helps explain why this conformer has not bee n observed in the vibrational spectrum of the sample at ambient temper ature. The predicted P-F distances from the MP2/6-311 + G calculation s are more than 0.031 Angstrom longer than the experimentally determin ed values. The potential function governing conformer interchange and the change in geometric parameters with internal rotation have been pr edicted from the ab initio calculations. The results are compared to t he corresponding results from similar molecules.