ABSTRACT

Heat capacities in a range of temperatures of (5 to 370) K, enthalpies and temperatures of phase transitions for 1-ethyl-3-methylimidazolium bis(triflamide) ([C2mim][NTf2]) and 1-octyl-3-methylimidazolium bis(triflamide) ([C8mim][NTf2]) have been determined by adiabatic calorimetry. [C2mim][NTf2] has been found to form four crystalline phases with different fusion temperatures. Formation of the phases can be controlled by the temperature of annealing during crystallization. [C8mim][NTf2] forms three sequences of crystalline modifications, each including two polymorphs. Based on results of the measurements, thermodynamic functions for the compounds under study have been calculated. A heat-capacity anomaly near T = 230 K reported earlier for [C4mim][NTf2] and [C6mim][NTf2] have been found in some crystalline modifications of both the studied compounds. The position of the anomaly depends on the temperature of annealing of the crystals.

Compounds

#	Formula	Name
1	C8H11F6N3O4S2	1-ethyl-3-methylimidazolium bis((trifluoromethyl)sulfonyl)imide
2	C14H23F6N3O4S2	1-octyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]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	Molar enthalpy of transition or fusion, kJ/mol ; Metastable crystal			Metastable crystal Liquid Gas	Adiabatic calorimetry	1
POMD	1	Molar enthalpy of transition or fusion, kJ/mol ; Metastable crystal			Metastable crystal Liquid Gas	Adiabatic calorimetry	1
POMD	1	Molar enthalpy of transition or fusion, kJ/mol ; Crystal			Crystal Liquid Gas	Adiabatic calorimetry	1
POMD	1	Triple point temperature, K ; Metastable crystal			Metastable crystal Liquid Gas	Adiabatic calorimetry	1
POMD	1	Triple point temperature, K ; Metastable crystal			Metastable crystal Liquid Gas	Adiabatic calorimetry	1
POMD	1	Triple point temperature, K ; Metastable crystal			Metastable crystal Liquid Gas	Adiabatic calorimetry	1
POMD	1	Triple point temperature, K ; Crystal			Crystal Liquid Gas	Adiabatic calorimetry	1
POMD	1	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	VADIAC:UFactor:4	34
POMD	1	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	VADIAC:UFactor:2	16
POMD	1	Molar heat capacity at saturation pressure, J/K/mol ; Liquid	Temperature, K; Liquid		Liquid Gas	VADIAC:UFactor:2	75
POMD	1	Molar heat capacity at saturation pressure, J/K/mol ; Crystal	Temperature, K; Crystal		Crystal Gas	VADIAC:UFactor:4	201
POMD	1	Molar heat capacity at saturation pressure, J/K/mol ; Metastable crystal	Temperature, K; Metastable crystal		Metastable crystal Gas	VADIAC:UFactor:4	6
POMD	1	Molar heat capacity at saturation pressure, J/K/mol ; Metastable crystal	Temperature, K; Metastable crystal		Metastable crystal Gas	VADIAC:UFactor:4	97
POMD	1	Molar heat capacity at saturation pressure, J/K/mol ; Metastable crystal	Temperature, K; Metastable crystal		Metastable crystal Gas	VADIAC:UFactor:4	328
POMD	1	Molar enthalpy, kJ/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	VADIAC:UFactor:4	34
POMD	1	Molar enthalpy, kJ/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	VADIAC:UFactor:4	16
POMD	1	Molar entropy, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	VADIAC:UFactor:4	34
POMD	1	Molar entropy, J/K/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	VADIAC:UFactor:4	16
POMD	2	Molar enthalpy of transition or fusion, kJ/mol ; Metastable crystal			Metastable crystal Liquid Gas	Adiabatic calorimetry	1
POMD	2	Molar enthalpy of transition or fusion, kJ/mol ; Metastable crystal			Metastable crystal Liquid Gas	Adiabatic calorimetry	1
POMD	2	Molar enthalpy of transition or fusion, kJ/mol ; Metastable crystal			Metastable crystal Crystal 1 Gas	Adiabatic calorimetry	1
POMD	2	Molar enthalpy of transition or fusion, kJ/mol ; Crystal 1			Crystal 1 Liquid Gas	Adiabatic calorimetry	1
POMD	2	Triple point temperature, K ; Metastable crystal			Metastable crystal Crystal of unknown type Gas	Adiabatic calorimetry	1
POMD	2	Triple point temperature, K ; Metastable crystal			Metastable crystal Liquid Gas	Adiabatic calorimetry	1
POMD	2	Triple point temperature, K ; Metastable crystal			Metastable crystal Crystal of unknown type Gas	Adiabatic calorimetry	1
POMD	2	Triple point temperature, K ; Metastable crystal			Metastable crystal Liquid Gas	Adiabatic calorimetry	1
POMD	2	Triple point temperature, K ; Metastable crystal			Metastable crystal Crystal 1 Gas	Adiabatic calorimetry	1
POMD	2	Triple point temperature, K ; Crystal 1			Crystal 1 Liquid Gas	Adiabatic calorimetry	1
POMD	2	Molar heat capacity at saturation pressure, J/K/mol ; Liquid	Temperature, K; Liquid		Liquid Gas	VADIAC:UFactor:2	86
POMD	2	Molar heat capacity at saturation pressure, J/K/mol ; Metastable crystal	Temperature, K; Metastable crystal		Metastable crystal Gas	VADIAC:UFactor:4	40
POMD	2	Molar heat capacity at saturation pressure, J/K/mol ; Metastable crystal	Temperature, K; Metastable crystal		Metastable crystal Gas	VADIAC:UFactor:4	63
POMD	2	Molar heat capacity at saturation pressure, J/K/mol ; Metastable crystal	Temperature, K; Metastable crystal		Metastable crystal Gas	VADIAC:UFactor:4	104
POMD	2	Molar heat capacity at saturation pressure, J/K/mol ; Metastable crystal	Temperature, K; Metastable crystal		Metastable crystal Gas	VADIAC:UFactor:4	4
POMD	2	Molar heat capacity at saturation pressure, J/K/mol ; Metastable crystal	Temperature, K; Metastable crystal		Metastable crystal Gas	VADIAC:UFactor:4	145
POMD	2	Molar heat capacity at saturation pressure, J/K/mol ; Metastable crystal	Temperature, K; Metastable crystal		Metastable crystal Gas	VADIAC:UFactor:4	4
POMD	2	Molar heat capacity at saturation pressure, J/K/mol ; Glass	Temperature, K; Glass		Glass Gas	VADIAC:UFactor:4	116

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Thermodynamic properties and polymorphism of 1-alkyl-3-methylimidazolium bis(triflamides)

Paulechka, Y. U.[Yauheni U.], Blokhin, A. V.[Andrey V.], Kabo, G. J., Strechan, A. A.[Aliaksei A.]

ABSTRACT