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 °C and shows a low viscosity (18 cP) and a high ionic conductivity (1.8 × 10-2 S cm-1) at room temperature. This conductivity is less than that of [EMI][N(CN)2] salt (2.7 × 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 °C. In the crystal, the C−H···π interionic interactions between cations construct zigzag chains in the cationic two-dimensional layer. Close Ag··Ag interionic contacts of 3.226(1) Å 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 Ag···Ag interactions.