ABSTRACT

The speed of sound was determined within the temperature and pressure intervals (283.15 343.15) K and (0.1 95) MPa for a set of ionic liquids with a common ion. The selected ionic liquids were composed by the bis(trifluomethylsulfonyl)imide anion with 1-butylmethylpiperidinium, 1-butylmethylpyrrolidinium, triethylsulfonium and 1-butylpyridinium cations, and by the 1-butyl-3- methylimidazolium cation with dicyanamide, hexafluoroantimonate, trifluoromethanesulfonate and methylsulfate anions. The analysis of the experimental data together with those available in literature reveals that changes in the chemical structure of anion have a much stronger influence over this magnitude than those in the cation. In addition, a clear inverse correlation between speed of sound and the ionic liquid molar mass was detected. Since data against temperature and pressure are available, the speed of sound derivatives against these variables were also determined; low values as compared with other liquids were obtained, with no clear correlation against chemical nature of the ionic compound.

Compounds

#	Formula	Name
1	C12H22F6N2O4S2	1-butyl-1-methylpiperidinium bis(trifluoromethanesulfonyl)imide
2	C11H20F6N2O4S2	1-butyl-1-methylpyrrolidinium bis[(trifluoromethyl)sulfonyl]imide
3	C8H15F6NO4S3	triethylsulfonium bis((trifluoromethyl)sulfonyl)imide
4	C11H14F6N2O4S2	1-butylpyridinium bis[(trifluoromethyl)sulfonyl]imide
5	C10H15N5	1-butyl-3-methylimidazolium dicyanamide
6	C8H15F6N2Sb	1-butyl-3-methylimidazolium hexafluoroantimonate
7	C9H15F3N2O3S	1-butyl-3-methylimidazolium trifluoromethanesulfonate
8	C9H18N2O4S	1-butyl-3-methylimidazolium methyl sulfate

Datasets

The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type	Compound-#	Property	Variable	Constraint	Phase	Method	#Points
POMD	1	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Standard Abbe refractometry	1
POMD	1	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	17
POMD	1	Speed of sound, m/s ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Frequency, MHz; Liquid	Liquid	Single path-length method	79
POMD	2	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Standard Abbe refractometry	1
POMD	2	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	13
POMD	2	Speed of sound, m/s ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Frequency, MHz; Liquid	Liquid	Single path-length method	84
POMD	3	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Standard Abbe refractometry	1
POMD	3	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	13
POMD	3	Speed of sound, m/s ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Frequency, MHz; Liquid	Liquid	Single path-length method	84
POMD	4	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Standard Abbe refractometry	1
POMD	4	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	13
POMD	4	Speed of sound, m/s ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Frequency, MHz; Liquid	Liquid	Single path-length method	83
POMD	5	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Standard Abbe refractometry	1
POMD	5	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	13
POMD	5	Speed of sound, m/s ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Frequency, MHz; Liquid	Liquid	Single path-length method	84
POMD	6	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Standard Abbe refractometry	1
POMD	6	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	13
POMD	6	Speed of sound, m/s ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Frequency, MHz; Liquid	Liquid	Single path-length method	84
POMD	7	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Standard Abbe refractometry	1
POMD	7	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	13
POMD	7	Speed of sound, m/s ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Frequency, MHz; Liquid	Liquid	Single path-length method	84
POMD	8	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Standard Abbe refractometry	1
POMD	8	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	13
POMD	8	Speed of sound, m/s ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Frequency, MHz; Liquid	Liquid	Single path-length method	84

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Speed of sound in ionic liquids with a common ion as a function of pressure and temperature

Yebra, Francisco, Zemankova, Katerina, Troncoso, Jacobo

ABSTRACT