Vibrational spectra and force constants of symmetric tops—XXII. Rotational analysis of ν2 + ν3 and ν1 + ν2 + ν3 of CF379Br and CF381Br☆

Abstract The rovibrational spectra of CF 3 79 Br and CF 3 81 Br in the region of ν 2 +ν 3 near 1120 cm −1 and ν 1 +ν 2 +ν 3 near 2200 cm −1 have been investigated with a resolution of 0.04 and 0.03 cm −1 respectively. The rotational J structures have been resolved and were analyzed by means of polynomial and band contour simulation procedures. Molecular parameters (ν 0 , x ij , α A,B ) have been obtained from the analysis of the cold bands and the hot bands involving ν 6 , 2ν 6 , ν 3 and ν 5 for both isotopomers.