Vibrational spectra and assignments of tetrafluorooxirane-16O and -18O
Infrared and Raman spectra are reported for tetrafluorooxirane and its 18O modification. From these spectra and previously reported microwave spectra, a complete assignment of vibrational fundamentals is obtained. For the 16O species the frequencies in cm−1 are (a1) 1610, 1161, 792, 502, 323; (a2) 1242, 515, 234; (b1) 1286, 776, 696, 528; (b2) 1130, 558, 186. For the 18O species they are: (a1) 1611, 1136, 789, 494, 321; (a2) 1242, 515, 234; (b1) 1284, 777, 679, 516; (b2) 1129, 539, 185. Frequency shifts with 18O substitution show that ν2 is symmetric CO stretching, that ν11 and ν12 contain antisymmetric CO stretching, and that ν14 is flapping of the COC part with respect to the F2CCF2 part. Since ν1 is independent of 18O substitution, this mode must be largely CC stretching mixed with symmetric CF2 stretching. This finding corroborates a similar result for trans-2,3-difluorooxirane and negates the previous ascription of “ring breathing” to this mode.
Craig, Norman C. 1989. "Vibrational spectra and assignments of tetrafluorooxirane-16O and -18O." Spectrochimica Acta Part A: Molecular Spectroscopy 45(6): 661-669.
Spectrochimica Acta Part A: Molecular Spectroscopy
Chemistry and Biochemistry