Infrared and Raman spectra and crystal structure of solid bromotrifluoromethane

Infrared and Raman spectra of polycrystalline films of CF 3 Br have been recorded at 77 K. All six fundamentals of the molecule have been observed in both spectra. Observed splittings of fundamentals have been attributed to Fermi resonance (ν 1 ), bramine isotope splitting (ν 3 ) and crystal splitting (ν 4 , ν 5 and ν 6 ). Some bands due to 13 CF 3 Br have also been identified. The crystal splittings can be explained if it is assumed that the structure is monuclinic with factor group C 2 h and two molecules per unit cell on sites of C s symmetry.