Investigations of the structure of water using mid-IR fiberoptic evanescent wave spectroscopy.

Liquid water is one of the most studied but still one of the least understood substances. The absorption spectra of water in the mid-IR were measured from -10 and up to 90 degrees C using fiberoptic evanescent wave spectroscopy. The changes in the spectrum and the existence of an isosbestic point during the ice-liquid phase transition were studied. Based on the spectroscopic data we propose a multispecies model for the structure of liquid water. The new model provides an explanation for the results of the measurements reported in this work. It also provides an explanation for some of the unique thermodynamic and kinetic properties of liquid water and for many of the anomalies of water.