Depolarization of Raman Lines and Structure of Chlorate, Bromate and Iodate Ions

The Raman spectra of chlorate ClO₃, bromate BrO₃ and iodate IO₃ in solutions are examined under high dispersion and the degrees of depolarization of the Raman lines measured. It is shown that the strong line at 930 cm^-1 of ClO₃ and that at 800 cm^-1 of IO₃ in solutions, which are regarded as single lines in the literature, are each really composed of two lines. The presence of four lines in each ion in the Raman effect, together with the depolarization measurement, and the infrared data, shows that these ions have pyramidal structure. The valence force constants of these ions are calculated from the present data according to the equations of Lechner.