VIBRATIONAL-SPECTRUM OF 1,1,1-TRIFLUOROETHANE

IR spectra of 1,1,1-trifluoroethane (HFC-143a) have been recorded at m edium and high resolution. Raman spectra in polarization controlled ex periments have also been measured. Comparison between the spectra reco rded with the two techniques has made possible a reassignment of the v ibrational spectrum of CH,CF, in the range 200-3100 cm(-1). Room-tempe rature and low-temperature gas-phase spectra were compared in order to assign a large number of hot bands due to the low lying fundamentals v(6) (A(2) ca. 220 cm(-1)) and v(12) (E, 366 cm(-1)). An unambiguous a ssignment for v(8) has been obtained, together with a reliable frequen cy for v(6), which is forbidden in both the IR and Raman.