Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

High-Pressure Density of Bis(1-alkyl-3-methylimidazolium) Tetraisothiocyanatocobaltate Ionic Liquids: Experimental and PC-SAFT with Volume-Shift Modeling

Navarro, P.[Pablo], Palma, A. M.[Andre M.], Garcia, J.[Julian], Rodriguez, F.[Francisco], Coutinho, J. A. P.[Joao A. P.], Carvalho, P. J.[Pedro J.]
J. Chem. Eng. Data 2019, 64, 11, 4827-4833
ABSTRACT
Tetrathiocyanatocobaltate-based ionic liquids (ILs) have shown interesting thermophysical properties, mainly surprising low melting points and moderate viscosity. In addition, they have been tested to separate aromatics from aliphatics due to the high molar relation between cyano groups per molecule, with highlighted results. In this work, the high pressure density data (pT) were measured for bis(1-alkyl-3-methylimidazolium) tetrathiocyanatocobaltate ILs ([CnC1im]2[Co(SCN)4]) (n=1, 2) in wide range of temperature (283 - 363 K) and pressure (0.1 - 95 MPa). The new pT data and derivative properties, namely isothermal compressibility and isobaric expansivity, were successfully modeled with the Perturbed-Chain Statistical Association Fluid Theory (PC-SAFT) and using the so-called volume shift, allowing to propose a new molecular model and parameters for these solvents. The proposed model for tetrathiocyanatocobaltate-based ILs is shown to be robust enough for modeling the phase equilibria of this new class of compounds.
Compounds
# Formula Name
1 C16H22CoN8S4 bis(1-ethyl-3-methylimidazolium) tetrathiocyanatocobaltate
2 C20H30CoN8S4 bis(1-butyl-3-methylimidazolium) tetrathiocyanatocobaltate
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
  • 207
  • POMD
  • 2
  • Mass density, kg/m3 ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Vibrating tube method
  • 207