Structural and Thermal Properties of Air‐Stable [Mg(1‐methylimidazole) 6 ][N(SO 2 CF 3 ) 2 ] 2

An air‐stable Mg salt, [Mg(MIm) 6 ][TFSA] 2 [MIm = 1‐methylimidazole; TFSA = bis(trifluoromethylsulfonyl)amide], was obtained by recrystallization from the MIm solution of Mg[TFSA] 2 . This compound melts at 481 K under sealed conditions, whereas it loses MIm at elevated temperatures (448 K, 5 % weight loss) under unsealed conditions. The crystal structure of [Mg(MIm) 6 ][TFSA] 2 was determined by X‐ray diffraction. The compound crystallizes in the monoclinic system (space group P 2 1 / c ) with a = 8.2062(7) Å, b = 11.3185(10) Å, c = 24.454(2) Å, β = 90.229(2)°, V = 2271.3(3) Å 3 , and Z = 2. The Mg 2+ cation is octahedrally surrounded by six non‐methylated N atoms of MIm ligands to form the [Mg(MIm) 6 ] 2+ complex cation, in which three imidazolium rings are crystallographically independent. The interplanar angles between two imidazolium rings, which are close to 90° in an ideal model, are 64.01(14), 72.86(18), and 81.91(17)° owing to the interaction of the [Mg(MIm) 6 ] 2+ cations with the TFSA – anions. The TFSA anion is completely isolated from the Mg 2+ core and adopts the energetically favorable trans conformation. Raman spectroscopic measurements revealed the octahedral coordination of MIm to Mg 2+ in crystalline [Mg(MIm) 6 ][TFSA] 2 and MIm solutions of Mg[TFSA] 2 .