Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Heat capacities at 298.15 K of the extended [CnC1im][Ntf2] ionic liquid series

Rocha, M. A. A.[Marisa A.A.], Bastos, M.[Margarida], Coutinho, J. A. P.[Joao A. P.], Santos, L. M. N. B. F.[Luis M. N. B. F.]
J. Chem. Thermodyn. 2012, 53, 140-143
ABSTRACT
High-precision heat capacities at 298.15 K of the [CnC1im][Ntf2] ionic liquid series were measured with an uncertainty of less than +-0.3%, using a drop heat capacity apparatus that was recently updated. The dependence of the c_p values on the alkyl side chain length for the extended ionic liquid series [CnC1im][Ntf2] (with n = 2 to 8, 10, and 12) displays a trend shift at [C6C1im][Ntf2], which is taken as an evidence for percolation limit. Above this limit there is an increase in the methylene group contribution to the molar heat capacity which is in agreement with the higher molar absolute entropies change observed from the (liquid + vapor) equilibrium results. The obtained experimental results support the model that the ionic liquids tend to be segregated into a polar network and non-polar domains, being followed by an increase of the entropy contribution of the non-polar domains.
Compounds
# Formula Name
1 C18H31F6N3O4S2 1-dodecyl-3-methyl-1H-imidazolium bis(trifluoromethylsulfonyl)amide
2 C16H27F6N3O4S2 1-decyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide
3 C8H11F6N3O4S2 1-ethyl-3-methylimidazolium bis((trifluoromethyl)sulfonyl)imide
4 C9H13F6N3O4S2 1-methyl-3-propylimidazolium bis[(trifluoromethyl)sulfonyl]imide
5 C10H15F6N3O4S2 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide
6 C11H17F6N3O4S2 1-methyl-3-pentylimidazolium bis(trifluoromethylsulfonyl)imide
7 C12H19F6N3O4S2 1-hexyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide
8 C13H21F6N3O4S2 1-heptyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide
9 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 heat capacity at constant pressure, J/K/mol ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • High-precision drop calorimeter
  • 1
  • POMD
  • 2
  • Molar heat capacity at constant pressure, J/K/mol ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • High-precision drop calorimeter
  • 1
  • POMD
  • 3
  • Molar heat capacity at constant pressure, J/K/mol ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • High-precision drop calorimeter
  • 1
  • POMD
  • 4
  • Molar heat capacity at constant pressure, J/K/mol ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • High-precision drop calorimeter
  • 1
  • POMD
  • 5
  • Molar heat capacity at constant pressure, J/K/mol ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • High-precision drop calorimeter
  • 1
  • POMD
  • 6
  • Molar heat capacity at constant pressure, J/K/mol ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • High-precision drop calorimeter
  • 1
  • POMD
  • 7
  • Molar heat capacity at constant pressure, J/K/mol ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • High-precision drop calorimeter
  • 1
  • POMD
  • 8
  • Molar heat capacity at constant pressure, J/K/mol ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • High-precision drop calorimeter
  • 1
  • POMD
  • 9
  • Molar heat capacity at constant pressure, J/K/mol ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • High-precision drop calorimeter
  • 1