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

Abstract

The Raman spectra of chlorate Cl${\mathrm{O}}_3$, bromate Br${\mathrm{O}}_3$ and iodate I${\mathrm{O}}_3$ 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 ${\mathrm{cm}}^{-1\mathrm{}}$ of Cl${\mathrm{O}}_3$ and that at 800 ${\mathrm{cm}}^{-1\mathrm{}}$ of I${\mathrm{O}}_3$ 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.