Intermolecular coupling in liquid water

Changes in the Raman spectra of H2O from addition of OD oscillators indicate that there is significant intermolecular coupling of OH stretching vibrations in H2O at temperatures from −10 to 70°C. Measurements on solutions of KI in H2O indicate that the primary effect of salt addition on the spectrum of H2O is to diminish intermolecular coupling of OH oscillators. The disruption of intermolecular coupling by addition of a K+ and I− ion is about nine times more effective than addition of a single OD oscillator.