Temperature and Alkyl Chain Dependence of Physicochemical Properties of Pyrrolidinium‑ and Imidazolium-Based Ionic Liquids

Influence of Temperature, Anions, and Alkyl Chain Length on the Density, Viscosity, Speed of Sound, Surface Tension, and Refractive Index of Imidazolium Hexafluorophosphate-Based Ionic Liquids

“…A comparative investigation of the physical properties of different combinations of anions and alkyl chains demonstrates that the anions have the dominant influence on the properties, which is consistent with previous studies. ,− , Figures S1–S5 in the Supporting Information file depict the alkyl chain effect on the density, viscosity, speed of sound, surface tension, and refractive index of 1-alkyl-3-methylimidazoulium hexafluorophosphate [C n C 1 im]­[PF 6 ] ( n = 4, 5, 6, 7, 8, and 9). As illustrated, as the length of the alkyl chain increases, the density, speed of sound, and surface tension decrease.…”

“…Tthe viscosity η and speed of sound c of [C 4 C 1 im]­[PF 6 ], [C 4 C 1 im]­[NTf 2 ], and [C 4 C 1 im]­[N­(CN) 2 ] at 298.15 K were compared to study the effect of the anion type on the properties. As aforementioned, it is clearly visible that the anions have greater influence on the properties than the effect of alkyl chain length where the influence is less significant, as shown in Figures S6–S10 in the Supporting Information file, for density, viscosity, speed of sound, surface tension, and refractive index, respectively.…”

“…The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.jced.4c00037. Influence of the chain length in the cation group on the density of [C n C 1 im]­[PF 6 ] at 298.15 K (Figure S1); influence of the chain length in the cation group on the viscosity of [C n C 1 im]­[PF 6 ] at 298.15 K (Figure S2); influence of the chain length in the cation group on the speed of sound of [C n C 1 im]­[PF 6 ] at 298.15 K (Figure S3); influence of the chain length in the cation group on the surface tension of [C n C 1 im]­[PF 6 ] at 298.15 K (Figure S4); influence of the chain length in the cation group on the refractive index of [C n C 1 im]­[PF 6 ] at 298.15 K (Figure S5); comparison of the density ρ of [C 4 C 1 im]­[PF 6 ], [C 4 C 1 im]­[NTf 2 ], and [C 4 C 1 im]­[N­(CN) 2 ] at 298.15 K (Figure S6); comparison of the viscosity ηof [C 4 C 1 im]­[PF6], [C 4 C 1 im]­[NTf 2 ], and [C 4 C 1 im]­[N­(CN) 2 ] at 298.15 K (Figure S7); comparison of the speed of sound c of [C 4 C 1 im]­[PF 6 ], [C 4 C 1 im]­[NTf 2 ], and [C 4 C 1 im]­[N­(CN) 2 ] at 298.15 K (Figure S8); comparison of the surface tension σ of [C 4 C 1 im]­[PF 6 ], [C 4 C 1 im]­[NTf 2 ], and [C 4 C 1 im]­[N­(CN) 2 ] at 298.15 K (Figure S9); and comparison of the refractive index n D of [C 4 C 1 im]­[PF 6 ], [C 4 C 1 im]­[NTf 2 ], and [C 4 C 1 im]­[N­(CN) 2 ] at 298.15 K (Figure S10) (PDF) …”