The hydroxyl frequency in the Raman spectra of acids and acid salts
The Raman spectra of sulphuric, iodic, selenious and telluric acids and sodium dihydrogen phosphate and potassium bisulphate have been obtained under long exposure and using complementary filters. In every case, a band characteristic of the O−H group has been recorded. The band is weak and diffuse and is shifted to a frequency considerably lower than that due to free hydroxyl group. The results are discussed in relation to electrolytic dissociation and molecular structure of these compounds. From the nature of the spectra, the characteristic features of the Raman band due to the so-called hydrogen bond are deduced. Some new Raman frequencies in selenious and telluric acids are indicated in the paper.