Structural Studies of Lithium 4,5-Dicyanoimidazolate–Glyme Solvates. 1. From Isolated Free Ions to Conductive Aggregated Systems

We present complementary series of crystal structures of lithium salts containing 4,5-dicyanoimidazolato anions substituted with perfluoroalkyl groups. Single-crystal X-ray analysis of 10 adducts with aprotic solvents, glymes (dimethyl ethers of poly­(ethylene glycols)) and crown ethers, have been performed to correlate their molecular structures and properties with spectroscopic and thermal data. Comprehensive structure analysis of crystalline materials reveals valuable information about the coordination ability of substituted 4,5-dicyanoimidazolato anions and provides the basis for developing the model of poly­(ethylene oxide) electrolytes and liquid systems. Presented results reveal new aggregation modes at high concentrations of lithium salts involving the release of cations by self-assembly of an anionic subnetwork and provide some insight into the electrochemical performance of TDI anions.