ABSTRACT

The knowledge of the physical properties of ionic liquids is of high importance in order to evaluate their potential applicability for a given purpose. In the last few years, ionic liquids have been proposed as promising solvents for extractive desulfurization of fuels. Among them, recent studies have shown that ionic liquids derived from pyridinium affords excellent S-compounds removal capacity. In this work, the thermal analysis of five ionic liquids derived from pyridinium cation polysubstituted with different alkyl chains was carried out by Differencial Scanning Calorimetry (DSC) and Thermal Gravimetric Analysis (TGA). Furthermore, the density, speed of sound, refractive index and dynamic viscosity for all the pure ionic liquids were also measured from T = (298.15 to 343.15) K. The effect of the number of cation alkyl chains, their length, and their position on the pyridinium ring, on the ionic liquid physical properties is also analyzed and discussed.

Compounds

#	Formula	Name
1	C16H24F6N2O4S2	1-ethyl-3,5-dimethyl-2-pentylpyridinium bis(trifluoromethylsulfonyl)imide
2	C18H28F6N2O4S2	1-butyl-3,5-dimethyl-2-pentylpyridinium bis(trifluoromethylsulfonyl)imide
3	C16H24F6N2O4S2	1-hexyl-2,3,5-trimethylpyridinium bis(trifluoromethylsulfonyl)imide
4	C17H26F6N2O4S2	1-hexyl-2-ethyl-3,5-dimethylpyridinium 1,1,1-trifluoro-N-[(trifluoromethyl)sulfonyl]methanesulfonamide
5	C20H32F6N2O4S2	1-hexyl-3,5-dimethyl-2-pentylpyridinium bis(trifluoromethylsulfonyl)imide

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	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	10
POMD	1	Viscosity, Pa*s ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Capillary tube (Ostwald; Ubbelohde) method	10
POMD	1	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Standard Abbe refractometry	10
POMD	1	Speed of sound, m/s ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	10
POMD	2	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	10
POMD	2	Viscosity, Pa*s ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Capillary tube (Ostwald; Ubbelohde) method	10
POMD	2	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Standard Abbe refractometry	10
POMD	2	Speed of sound, m/s ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	10
POMD	3	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	10
POMD	3	Viscosity, Pa*s ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Capillary tube (Ostwald; Ubbelohde) method	10
POMD	3	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Standard Abbe refractometry	10
POMD	3	Speed of sound, m/s ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	10
POMD	4	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	10
POMD	4	Viscosity, Pa*s ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Capillary tube (Ostwald; Ubbelohde) method	10
POMD	4	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Standard Abbe refractometry	10
POMD	4	Speed of sound, m/s ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	10
POMD	5	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	10
POMD	5	Viscosity, Pa*s ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Capillary tube (Ostwald; Ubbelohde) method	10
POMD	5	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Standard Abbe refractometry	10
POMD	5	Speed of sound, m/s ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	10

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Effect of the number, position and length of alkyl chains on the physical properties of polysubstituted pyridinium ionic liquids

Verdia, P.[Pedro], Hernaiz, M.[Marta], Gonzalez, E. J.[Emilio J.], Macedo, E. A.[Eugenia A.], Salgado, J.[Josefa], Tojo, E.[Emilia]

ABSTRACT