ABSTRACT

The enthalpies for dilution of solutions of 1,1,3,3-tetramethylurea (TMU), 1,3-dimethylethyleneurea (DMEU); 1,3-dimethylpropyleneurea (DMPU) and 2,4,6,8-tetramethyl-bis-urea (TMbU) in ordinary (H2O) and heavy (D2O) water were measured calorimetrically at 298.15 K. The enthalpy coefficients for pair (h22) and triplet (h222) interactions between hydrated solute molecules were estimated using the McMillan-Mayer formalism. The quantities of h22 as well as the corresponding solvent isotope effects were found to be positive for aqueous TMU, DMPU and DMEU and negative for aqueous TMbU. The correlation between h22 and standard enthalpies of solution of these compounds in H2O and D2O was established at the temperature in question

Compounds

#	Formula	Name
1	C5H12N2O	tetramethylurea
2	C5H10N2O	1,3-dimethyl-2-imidazolidinone
3	C6H12N2O	1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone
4	C8H14N4O2	1,3,4,6-tetramethylglycoluril
5	H2O	water
6	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 5	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 5	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	3 5	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	5 4	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 6	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 6	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	7
POMD	3 6	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	5
POMD	6 4	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	7

Thermodynamics Research Center / ThermoML | Thermochimica Acta

Enthalpy-related interaction parameters in H/D isotopically distinguishable aqueous solutions of tetramethylurea cyclic derivatives at 298.15 K

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

ABSTRACT