Abstract
Normal vibration calculations were made, by means of the Ab Initio molecular orbital calculation method, for the water molecules interacting with various low molecular weight compounds. The relation between the calculated νs (OH) and νa (OH) stretching frequencies of water molecules gave two master lines for (a) hydrophobic compounds and (b) hydrophilic compounds, corresponding to the two master lines based on the relation between the observed νs (OH) and νa (OH) stretching frequencies of water molecules sorbed into two kinds of polymers. Moreover, it was found that the origin of these two master lines may be attributed to the anti-symmetrical change in two OH bond distances of water molecule interacting with the compounds.
