ABSTRACT

The molar enthalpies of solution of bicaret (2,4,6,8-tetraethylglycoluril) in ordinary (H2O) and heavy (D2O) water at (278.15, 288.15, 298.15, 308.15, and 318.15) K as well as the enthalpies for dilution of its H/D isotopically distinguishable aqueous solutions at 298.15 K were measured calorimetrically. The standard (at infinite dilution) molar enthalpies and heat capacities of solution, and the enthalpic coefficients for pair (h22) and triplet (h222) interactions between hydrated solute molecules, along with D2O-H2O solvent isotope effects (IEs) on the studied quantities were computed. The enthalpic effects of bicaret dissolution and corresponding IEs were found to be negative and decreasing in magnitude with increasing temperature. On the contrary, the h22 and h222 values as well as IEs on them were found to be positive. These facts indicate that the bicaret hydration being predominantly hydrophobic is enhanced in the D2O medium. The hydration behavior of the solute was discussed in comparison with that for mebicar (2,4,6,8-tetramethylglycoluril) using the previously obtained data.

Compounds

#	Formula	Name
1	H2O	water
2	D2O	water-d2
3	C12H22N4O2	bicaret

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	3	Normal melting temperature, K ; Crystal			Crystal Liquid Air at 1 atmosphere	VISOBS	1
POMD	1 3	Molar enthalpy of dilution, kJ/mol ; Liquid	Initial molality of solute, mol/kg; Liquid Final molality of solute, mol/kg; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid	ISOPERIBOL	6
POMD	1 3	Molar enthalpy of solution, kJ/mol ; Liquid	Temperature, K; Liquid Molality, mol/kg - 3; Liquid	Pressure, kPa; Liquid	Liquid	ISOPERIBOL	5
POMD	2 3	Molar enthalpy of dilution, kJ/mol ; Liquid	Initial molality of solute, mol/kg; Liquid Final molality of solute, mol/kg; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid	Liquid	ISOPERIBOL	6
POMD	2 3	Molar enthalpy of solution, kJ/mol ; Liquid	Temperature, K; Liquid Molality, mol/kg - 3; Liquid	Pressure, kPa; Liquid	Liquid	ISOPERIBOL	5

Thermodynamics Research Center / ThermoML | Thermochimica Acta

D2O-H2O solvent isotope effects on the enthalpies of bicaret (tetraethylglycoluril) hydration and dilution of its aqueous solutions at different temperatures

Ivanov, E. V.[Evgeniy V.], Batov, D. V.[Dmitriy V.], Gazieva, G. A.[Galina A.], Kravchenko, A. N.[Angelina N.], Abrosimov, V. K.[Vladimir K.]

ABSTRACT