Intermolecular Coupling of Water Molecules in Copper Chloride Dihydrate

Abstract

Polarized and unpolarized infrared spectra have been obtained for copper chloride dihydrate samples, containing low mole ratios of H₂O and D₂O. The positions of the absorption bands of these samples are shown to differ from those of samples, containing high percentages of these same molecules. The spectral differences noted are shown to be related to the interactions between water molecules in the solid. Furthermore, a criterion is provided for sensing a variation of hydrogen bond strength with deuteration, and the origin of bands in the ${\nu }_2$ overtone regions of H₂O, D₂O, and HOD is also considered.