High-resolution infrared study of FCl18O3 : rovibrational analysis of the ν1 and ν2 bands and ground state constants

Abstract The infrared spectrum of FCl 18 O 3 has been recorded in the 610-1170 cm −1 range, using a Fourier transform spectrometer with a resolution of 0.0024 cm −1 . The ν 1 and ν 2 parallel bands (with bandcenters at 1011.107 and 708.235 cm −1 for the (F 35 Cl 18 O 3 isotopomer and 1007.483 and 699.330 cm −1 for the (F 37 Cl 18 O 3 ) isotopomer) have been studied and their resolved J and K structures have been analyzed. A set of accurate molecular constants has been determined for the ground and v 1 = 1 and v 2 = 1 excited states of both isotopic species which reproduce ca. 9700 observed lines with a standard deviation of ≈ 1 × 10 −4 cm −1 . No perturbation was found at the present level of accuracy. A r 0 structure of FClO 3 has been deduced.