A symmetry-based study of vibrational decoupling in the crystalline phases of CH3(OCH2CH2)2OCH3LiCF3SO3 and P(EO)3LiCF3SO3

A symmetry-based analysis of vibrational modes in the crystalline phases of CH3(OCH2CH2)2OCH3LiCF3SO3 (diglyme–LiTf) and P(EO)3LiCF3SO3 is presented. Raman and infrared vibrational spectra suggest that the intramolecular triflate ion vibrations in the diglyme–LiTf crystal can be appropriately described in terms of a single diglyme–LiTf dimer. By contrast, the diglyme modes can be adequately represented by the vibrations of an individual diglyme molecule. These approximations are extended to consider vibrational modes of the high molecular weight P(EO)3LiCF3SO3 crystalline compound.