Knowledge Bank

The Raman (1800 to $10cm-1$) and infrared (2000 to $400cm-1$) spectra of bromodifluoroacetyl chloride, $CBrF2C(O)Cl$, are reported for the gas and polycrystalline solid. Additionally, the Raman spectrum of the liquid together with qualitative depolarization ratios is reported from 1800 to $80cm-1$. Aided by ab initio and scaled computations of the vibrational spectrum at the STO-3G* and, for the trans conformer (bromine atom trans to the chlorine atom) at the 4-31G*/MIDI-4* level of the theory, complete assignments of observed bands to fundamental vibrations of the gauche conformer are made, whereas partial assignment is reported for the trans conformer. Optimized geometries, dipole moments, unscaled and scaled vibrational frequencies and harmonic force fields are reported for both conformers. From a study of the Raman spectrum of the liquid at various temperatures, a value for $\Delta$H was obtained with the gauche conformer as the more stable form. With the STO-3G* basis set the gauche conformer is also calculated to be more stable than the trans conformer.