An MP2/6-31G*//MP2/6-31G* vibrational analysis of s-trans- and s-cis-acryloyl fluoride, CH2=CH-CF=O

The MP2/6-31G * //MP2/6-31G * harmonic force fields are calculated for s-trans- and s-cis-acryloyl fluoride. The scale factors for the quantum mechanical force field of s-trans-acryloyl fluoride are optimized using the experimental vibrational frequencies. The set of scale factors obtained is then transferred to the computed MP2/6-31G * //MP2/6-31G * force field of the s-cis rotational isomer. The vibrational frequencies are computed using the corresponding scaled quantum mechanical force fields and compared with experiment. In general, recent reassignments of the vibrational spectra of the acryloyl fluoride rotamers, based on the RHF/6-31G/ /RHF/6-31G level calculations, are confirmed (the exceptions being υ 7 for the s-trans and υ 7 and υ 9 for the s-cis conformers)