Vibrational study of the polymer electrolyte poly(ethylene oxide)(6): LiAsF6

A vibrational study of the polymer electrolyte compound poly(ethylene oxide )(6):LiAsF6 is reported. A symmetry-based factor group correlation method i s applied to interpret the observed bands. The Raman and infrared spectra o f the compound are consistent with the reported crystal structure. The nu ( 1) mode, which appears at 685 cm(-1), identifies the anions as being "spect roscopically free". Multiple bands in the nu (3) spectral region are interp reted as resulting from the dynamical coupling of the four AsF6- anions in the unit cell. The rho (CH2) region shows multiple bands that arise from th e complex conformations of the polymer backbone.