Ab-initio studies of fluoroxytrifluoromethane geometry and electronic structure

Abstract

Ab-initio molecular orbital calculations using both minimal or STO-3G and extended or 4-31G basis sets have been applied to fluoroxytrifluormethane. Complete geometry optimizations using both basis sets have been applied to this molecule and the calculated structural parameters have been compared to the electron diffraction data. The extended basis set calculations are found to be in much better overall agreement with experiment although the minimal basis set does reproduce the angular parameters well, including the tilt angle. The barrier to the CF 3 torsion has been computed and it compares favorably with the microwave spectral value. The electronic structure of CF 3OF and some related molecules have been examined by partitioning the electrons according to the method of Mulliken. The highest occupied orbital in CF 3OF is found to be largely an O-F π * orbital and the O-F bond is also found to be the least ionic and weakest bond in the molecule. The computed dipole moment of CF 3OF agrees well with the experimental value.