Coordination environment around the lithium cation in solid Li2(EMIm)(N(SO2CF3)2)3 (EMIm = 1-ethyl-3-methylimidazolium): Structural clue of ionic liquid electrolytes for lithium batteries

Crystal structure of Li2(EMIm)(N(SO2CF3)2)3 (EMIm = 1-ethyl-3-methylimidazolium cation) has been determined by single-crystal X-ray diffraction as a structural clue of ionic liquid electrolytes for lithium batteries. Li2(EMIm)(N(SO2CF3)2)3 crystallizes in the space group P21/cP21/c, a=15.184(3) Åa=15.184(3) Å, b=11.358(3) Åb=11.358(3) Å, c=21.249(5) Åc=21.249(5) Å, β=111.454(12)°β=111.454(12)°, Z=4Z=4, V=3561.18(14) Å3V=3561.18(14) Å3. Two of the three N(SO2CF3)2 anions have cis-conformations and the third anion shows a trans-conformation. The asymmetric unit contains two crystallographically independent lithium ions and both of them are trigonal-bipyramidally coordinated by five oxygen atoms of N(SO2CF3)2 anions, forming a two-dimensional network. EMIm cation occupies a space in the network, weakly interacting with the anions.

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