Vibrational Spectra of the Ices. Raman Spectra of Ice VI and Ice VII

The Raman spectra at 77°K and atmospheric pressure of Ices VI and VII made from both H2O and D2O have been obtained in the O–H and O—D stretching regions using Hg 4047‐A and Hg 4358‐A radiation. Ice VI has only one band, and this band is slightly higher in frequency than the corresponding band of Ices II, III, and V. It seems likely from this that Ice VI is still fully hydrogen bonded and essentially four coordinated. Ice VII has three bands, and all are shifted considerably from the bands of Ices I, II, III, V, and VI towards the vapor frequencies. It seems likely that the hydrogen bonding has been altered from that of Ice I more profoundly in Ice VII than in Ices II, III, V, and VI, but that strong hydrogen bonds are still present.