1-ethyl-3-methylimidazolium based ionic liquids containing cyano groups: Synthesis, characterization, and crystal structure

New 1-ethyl-3-methylimidazolium (EMI) salts [EMI][C(CN)(3)] and [EMI][Ag(CN)(2)] were prepared and characterized. The C(CN)(3) salt has a melting point at -11 degreesC and shows a low viscosity (18 cP) and a high ionic conductivity (1.8 x 10(-2) S cm(-1)) at room temperature. This conductivity is less than that of [EMI][N(CN)(2)] salt (2.7 x 10(-2) S cm(-1)), possibly due to the larger molecular weight of the anion. The first EMI salt containing Ag(I) complexes [EMI][Ag(CN)(2)] has a higher melting point of 73 degreesC. In the crystal, the C-H(...)pi interionic interactions between cations construct zigzag chains in the cationic two-dimensional layer. Close (AgAg)-Ag-.. interionic contacts of 3.226(1) Angstrom were observed in the one-dimensional anionic chain, and the relatively high melting point among the EMI salts with a monoanion appears to be governed essentially by these direct (AgAg)-Ag-... interactions.