ELASTIC BEHAVIOR OF THE CARBON TETRABROMIDE CLATHRATE OF HEXAKIS(PHENYLTHIO)BENZENE AS DETERMINED BY BRILLOUIN SPECTROSCOPY

Brillouin scattering measurements have been carried out at room temper ature on the CBr4 clathrate of hexakis(phenylthio)benzene. This materi al crystallizes in the R-3BAR space group (trigonal system), with a ho st:guest mole ratio of 1:2. The values of all seven adiabatic elastic constants were determined. The material is elastically more anisotropi c than the previously investigated ethanol-Dianin's compound clathrate which has the same space group, yet the bulk modulus and the linear c ompressibilities of these materials are similar. These investigations reveal that noncentral forces act in the CBr4-HPTB crystal; these elas tic properties may significantly affect other properties such as therm al conductivity.