ABSTRACT

The enthalpies of solution of 1,1,3,3-tetramethylurea in H2O and D2O were measured at 278.15, 288.15, 298.15, 308.15, and 318.15 K. Standard enthalpies and heat capacities of solution (hydration), along with D2O-H2O solvent isotope effects on the quantities studied, were computed. The enthalpies of the solute dissolution as well as corresponding solvent isotope effects were found to be negative in sign and decreasing in magnitude with increasing temperature. It was confirmed that hydrophobic hydration is the predominant type of the solute hydration and it is enhanced in D2O and weakened on going from 1,1,3,3-tetramethylurea to its cyclic derivative, 1,3-dimethyl-2-imidazolidinone.

Compounds

#	Formula	Name
1	C5H12N2O	tetramethylurea
2	H2O	water
3	D2O	water-d2

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	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Standard Abbe refractometry	1
POMD	1	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Pycnometric method	1
POMD	1 2	Molar enthalpy of solution, kJ/mol ; Liquid	Temperature, K; Liquid Molality, mol/kg - 1; Liquid	Pressure, kPa; Liquid	Liquid	ISOPERIBOL	5
POMD	1 3	Molar enthalpy of solution, kJ/mol ; Liquid	Temperature, K; Liquid Molality, mol/kg - 1; Liquid	Pressure, kPa; Liquid	Liquid	ISOPERIBOL	5

Thermodynamics Research Center / ThermoML | Thermochimica Acta

D2O-H2O solvent isotope effects on the enthalpy of 1,1,3,3-tetramethylurea hydration between 278.15 and 318.15 K

Batov, D. V.[Dmitriy V.], Ivanov, E. V.[Evgeniy V.]

ABSTRACT