Hydrogen bonded structure of water and aqueous solutions of sodium halides: a Raman spectroscopic study

The OH stretching (2500–4000 cmK1) Raman spectra from pure water and sodium halides solutions are obtained. The Raman contours are deconvoluted with five Gaussian components that their center frequencies are 3051, 3233, 3393, 3511 and 3628 cmK1, respectively. From the Raman spectra and their deconvolutions similarities and differences of the effects of temperature and sodium halides on hydrogen bond structure of water are shown clearly. Like temperature, all of sodium halides break tetrahedral structure of water, and the Gaussian component of 3233 cmK1 decreases and the components of 3393 and 3511 cmK1 increase basically. The differences lie in their effects on the component 3051 and 3628 cmK1. All of halogenic ions break tetrahedral structure of water and their breaking actions are in the order of FK1!ClK1!BrK1!IK1. The reason is relative to the strength of halogenic ion–water and water–water hydrogen bonds. q 2004 Elsevier B.V. All rights reserved