REORIENTATIONAL MOTIONS IN CRYSTALLINE [CH3)3NHCL, STUDIED BY RAMAN-SPECTROSCOPY

The IR and Raman vibrational spectra of crystalline (CH//3)//3NH** plus X** minus (X equals Cl, Br, I) are recorded. A complete assignment of the measured frequencies to the internal vibrational modes of the (CH//3)//3NH** plus cation in the three compounds is obtained. Above the phase transition of (CH//3)//3NH** plus Cl** minus (at 308 K) a reorientational motion of the cation around its threefold axis is deduced from the Raman spectrum.