THE DISORDER-LONGITUDINAL ACOUSTIC MODE OF OLIGO(ETHYLENE GLYCOL)-LITHIUM TRIFLUOROMETHANE SULFONATE SOLUTIONS AS STUDIED BY FT RAMAN-SPECTROSCOPY

This work presents the results of Fourier transform Raman spectroscopy investigations of the disorder-longitudinal acoustic mode (D-LAM) of oligo(ethylene glycol) dimethyl ether-lithium trifluoromethane sulfona te solutions in dependence on oligomer chain length, temperature and s alt concentration. The peak position and the bandwidth of this mode de pend on the long-range conformational disorder of oligo(ethylene glyco l) chains. The addition of salt causes a marked increase of the long-r ange conformational disorder. The frequency shift of the D-LAM combine d with changes in the asymmetric CH2 stretching bands indicate that th e increasing long-range conformational disorder is connected with an i ncreasing short-range conformational disorder of oligomer chains in a linear relationship.