VIBRATIONAL SPECTRA OF GROUP IIB HALIDES .2. HALIDES OF CADMIUM AND MERCURY

The infrared spectra of the vapors of all cadmium and mercury halides were studied at low temperatures by matrix isolation. The spectra are classified into four absorption regions recorded in the 800-35-cm-1 range. The highest and lowest frequencies are assigned to the antisymmetric stretching mode and the doubly degenerate bending modes, respectively, of the MX2 molecules. The nature of the bonding in the molecule is discussed and statistically calculated entropy values are compared with corresponding values obtained from thermochemical measurements.