Thermodynamics Research Center / ThermoML | Thermochimica Acta

Standard enthalpies and heat capacities of solution of 2,4-dimethyl- and 2,4-diethylglycolurils in water at temperatures from (278.15 to 313.15) K

Ivanov, E. V.[Evgeniy V.], Batov, D. V.[Dmitriy V.], Baranov, V. V.[Vladimir V.], Kravchenko, A. N.[Angelina N.], Abrosimov, V. K.[Vladimir K.]
Thermochim. Acta 2014, 586, 72-4
ABSTRACT
The molar enthalpies of solution of 2,4-dimethyl- and 2,4-diethylglycolurils (2,4-DMGU and 2,4-DEGU) in water in the temperature range between (278.15 and 313.15) K were measured by microcalorimetry at ambient pressure. Experimental results were used to calculate the standard (at infinite dilution) molar enthalpies of these bicyclic compounds. The changes in molar heat capacities during the dissolution process were derived, too. The enthalpies of solution of both 2,4-DMGU and 2,4- DEGU are positive and increase with temperature. In the case of 2,4-DEGU, the temperature influence on the dissolution enthalpy was found to be more significant. Based on the data on the standard heat capacity of solution, a conclusion was drawn that the hydrophobic hydration of a solute is more pronounced in the aqueous medium containing 2,4-DEGU.
Compounds
# Formula Name
1 H2O water
2 C6H10N4O2 tetrahydro-1,3-dimethylimidazo[4,5-d]imidazole-2,5(1H,3H)-dione
3 C8H14N4O2 1,3-diethyltetrahydroimidazo[4,5-d]imidazole-2,5(1H,3H)-dione
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
  • 2
  • Normal melting temperature, K ; Crystal
  • Crystal
  • Liquid
  • Air at 1 atmosphere
  • VISOBS
  • 1
  • POMD
  • 3
  • Normal melting temperature, K ; Crystal
  • Crystal
  • Liquid
  • Air at 1 atmosphere
  • VISOBS
  • 1
  • POMD
  • 2
  • 1
  • Molar enthalpy of solution, kJ/mol ; Liquid
  • Temperature, K; Liquid
  • Molality, mol/kg - 2; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • ISOPERIBOL
  • 6
  • POMD
  • 1
  • 3
  • Molar enthalpy of solution, kJ/mol ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Molality, mol/kg - 3; Liquid
  • Liquid
  • ISOPERIBOL
  • 6