Knowledge Bank

The gas phase infrared absorption spectram of difluorodichloro- methane has been recorded under medium resolution in the range $3000-300cm-1$ , A vibrational analysis has been carried out, with the aid of the expected band contours of the three different isotopic species present in the sample in natural abundance $(CF2\mathrm{<mrow\; data-mjx-texclass="ORD">35</mrow>}C12,CF2\mathrm{<mrow\; data-mjx-texclass="ORD">35</mrow>}C1\mathrm{<mrow\; data-mjx-texclass="ORD">37</mrow>}C1,CF2\mathrm{<mrow\; data-mjx-texclass="ORD">37</mrow>}C12)$. An assignment of the fundamentals, as well as of several overtone, combination and difference bands, some of which contributed to clarify the vibrational assignment in the low infrared region, will be presented. Emphasis on the spectroscopic features at $925-880cm-1$ and at $1245-1200cm-1$, where Fermi resonances occur, will be given. A general harmonic force field and a potential energy distribution calculation will be reported. In addition, some spectroscopic features of trifluorochloromethane will be briefly presented.