ELECTRON-VIBRATIONAL INTERACTION IN CONDUCTING SALTS OF BIS(ETHYLENEDITHIO)TETRATHIAFULVALENE STUDIED BY INFRARED REFLECTION SPECTROSCOPY

In the spectra of the new family of ET salts with mercury-halide anions, the electron-vibrational bands about 1100-1300 cm-1 (usual for other ET salts) are absent. This may be accounted for by a new type of electron-vibrational interaction including non-totally symmetric modes instead of ''usual'' interaction with totally symmetric ones. The latter fact may be connected with peculiarities of crystal structure due to which the electron transfer between ET molecules takes place through side sulphur atoms, which, in turn, lends to violation of molecular symmetry during the transfer.