ИСТИНА

Mechanisms of formation of Raman spectra of liquid water are not clarified to present day. Model of vibrational processes in water adequately explaining nature of water Raman spectral bands is still not ascertained, there are ambiguity and contradictoriness in conceptions of resonance interactions of vibrations of water molecules. In present work the role of resonances of Fermi and Darling-Dennison in formation of different Raman bands of liquid water is studied experimentally. As a result of conducted researches it was found that Fermi resonance (FR) between symmetric valence vibration and overtone of bending vibration gives substantial contribution in formation of water Raman spectrum. Constant of interaction of FR at room temperature was estimated: WFR=62 cm-1. It was established that W strongly decreases at temperature increase. Explanation of this effect was given from the point of view of strength of hydrogen bonds in water. Constant of interaction of Darling-Dennison resonance between first overtones of symmetric and antisymmetric valence vibrations was estimated. At room temperature WDD=115 cm-1. Obtained value also testifies in favour of important role of Darling-Dennison resonance in formation of band of overtone in water Raman spectrum.