Crystal structures of glyme solvates with LiTFSI and LiBETI (TFSI -) bis(trifluoromethanesulfonyl)imide, BETI -) bis(perfluoroethanesulfonyl)imide) have been determined including (monoglyme) 1 : LiBETI, (diglyme) 2 :LiTFSI, (diglyme) 1/2 :LiTFSI, and low-temperature (triglyme) 1 :LiBETI. These solvates, combined with the phase behavior of the salts with various glymes from DSC analysis, provide insight into the molecular interactions of lithium salts in ethoxy solvents commonly used for solid polymer and liquid electrolytes. Many of the solvates appear to undergo order-disorder solid phase transitions. These are the first reported crystal structures containing the BETIanion.

Crystalline phases of (triglyme) 1 :LiX (X ) CF 3 SO 3 -, BF 4 -, ClO 4 -, and AsF 6 -) have been isolated and structurally characterized. The phases are isostructural and represent a novel form of Li + cation coordination not observed in crystalline poly(ethylene oxide) (PEO)-salt phases. The crystal structure of a (triglyme) 1 :LiBPh 4 phase has also been determined, which differs markedly from those found with the smaller anions. In addition, a more concentrated (triglyme) 2/3 :LiCF 3 SO 3 phase has been characterized, which also displays a novel form of Li + cation coordination. Such solvates represent models for interchain cation transport transition states in concentrated liquid and amorphous PEO electrolytes.

Three crystal structures of tetraglyme coordination complexes with lithium salts are reporteds(tetraglyme) 1 :LiAsF 6 , (tetraglyme) 1/2 :LiBF 4 , and (tetraglyme) 2/5 :LiCF 3 CO 2 . 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.

A deep-eutectic solvent with the properties of an ionic liquid is formed when choline chloride is mixed with copper(II) chloride dihydrate in a 1:2 molar ratio. EXAFS and UV-vis-near-IR optical absorption spectroscopy have been used to compare the coordination sphere of the cupric ion in this ionic liquid with that of the cupric ion in solutions of 0.1 M of CuCl(2)·2H(2)O in solvents with varying molar ratios of choline chloride and water. The EXAFS data show that species with three chloride ions and one water molecule coordinated to the cupric ion as well as species with two chloride molecules and two water molecules coordinated to the cupric ion are present in the ionic liquid. On the other hand, a fully hydrated copper(II) ion is formed in an aqueous solution free of choline chloride, and the tetrachlorocuprate(II) complex forms in aqueous choline chloride solutions with more than 50 wt % of choline chloride. In solutions with between 0 and 50 wt % of choline chloride, mixed chloro-aquo complexes occur. Upon standing at room temperature, crystals of CuCl(2)·2H(2)O and of Cu(choline)Cl(3) formed in the ionic liquid. Cu(choline)Cl(3) is the first example of a choline cation coordinating to a transition-metal ion. Crystals of [choline](3)[CuCl(4)][Cl] and of [choline](4)[Cu(4)Cl(10)O] were also synthesized from molecular or ionic liquid solvents, and their crystal structures were determined.