CATION-POLYMER INTERACTION AND IONIC ASSOCIATION IN DIGLYME-LICF3SO3 AND DIGLYME-PROPYLENE CARBONATE-LICF3SO3 COMPLEXES

Cation-polymer interaction and ionic association in diglyme-LiCF3SO3 and diglyme-propylene carbonate-LiCF3SO3 complexes were studied using vibrational spectroscopy. The diglyme molecules form mainly a 1:1 complex with lithium cations (diglyme.Li) and most of the triflate ions are associated with lithium cations in the diglyme-LiCF3SO3 solutions at room temperature. At low temperatures (-80 degrees C) the diglyme molecules form only a 2:1 complex with lithium cations (diglyme.Li) and all triflate ions exist as ''free'' ions when the O:Li ratio greater than or equal to 6:1. However in a more highly concentrated sample (eg O:Li = 4:1) at low temperatures (-80 degrees C) the 1:1 diglyme.Li complex and aggregated triflate species also exist in addition to the 2:1 complex and ''free'' triflate ions. Addition of propylene carbonate to the diglyme-LiCF3SO3 complexes does not affect the coordination of the lithium cations with diglyme molecules to any significant extent and increases the relative concentration of ''free'' triflate species only in samples with low salt content.