Low Temperature IR Study of Shape Transition in Carbon-, Silicon-and Germanium Tetrachlorides

The IR data in 20-296 K temperatures interval for carbon-, silicon- and germanium tetrachlorides are given. It is shown that the spectral picture of bands, appearing in higher frequencies region relatively to element-chlorine stretching, considerably changes at the temperature variation and therefore can be assigned to the vibrations of different molecular shapes. The interpretation of the obtained results based on the suggested model of transformation in the structure of tetrachlorides. This transformation leads to the arising of an active chlorine atom in molecules of element-tetrachlorides.