The Raman spectra of sulphuric acid solutions of tetra(hydrogensulphato)boric acid and its sodium and hydronium salts have been examined. Frequencies are assigned to some of the vibrations of the sulphuric acidium ion, H3SO4+, and are compared with the frequencies of the analogous vibrations of H2SO4 and HSO4−. Evidence is presented that elimination of disulphuric acid occurs between molecules of HB(HSO4)4 to give polymers containing B—O—B linkages.
