Tetraglyme−Li+ Cation Solvate Structures:  Models for Amorphous Concentrated Liquid and Polymer Electrolytes (II)

Three crystal structures of tetraglyme coordination complexes with lithium salts are reported(tetraglyme)1:LiAsF6, (tetraglyme)1/ 2:LiBF4, and (tetraglyme)2/5:LiCF3CO2. A novel form of six-coordinate Li+ cation coordination by the ether oxygens is found resembling double-helix dimers. Structural characterization of these materials provides insight into the molecular interactions which occur among the cations, anions, and ether oxygens. Such interactions are of interest for aiding in the understanding of the many factors which contribute to ionic conductivity mechanisms in amorphous concentrated liquid and solid poly(ethylene oxide) electrolytes.