Pk. Muhuri et al., IONIC ASSOCIATION OF SOME LITHIUM-SALTS IN 1,2-DIMETHOXYETHANE - A RAMAN-SPECTROSCOPIC AND CONDUCTIVITY STUDY, JOURNAL OF PHYSICAL CHEMISTRY B, 101(17), 1997, pp. 3329-3332
Precise measurements on electrical conductances as well as laser Raman
spectra in the wavenumber range 3500-100 cm(-1) of five lithium salts
in 1,2-dimethoxyethane (DME) have been reported. The conductance data
are interpreted by the Fuoss-Kraus theory, yielding values for the io
n-pair and triple-ion formation constants. The Raman spectra suggest t
he presence of ''spectroscopically free'' ClO4-, BF4-, and AsF6-, ions
in solutions, whereas there is no such evidence for either the Cl- or
Br- ion, thus substantiating the very high ion-pair formation constan
ts for LiCl and LiBr as obtained from conductance measurements. The ob
served processes have been interpreted by an Eigen multistep mechanism
. Changes in the Raman bands at ca. 867, 1147, 1452, and 2805 cm(-1) s
uggest that the solvation of Li+ ion in DME occurs through the etherea
l oxygen atom of the solvent molecule.