ABSTRACT

The enthalpies of solution of N-acetyl-N -methylglycinamide, N-acetyl-N -methyl-l- -alaninamide, N-acetyl-N -methyl-l- -leucinamide and N-acetyl-N -methyl-l- -serinamide have been measured in water and in aqueous urea solutions with molalities from 0.25 to 3.0 mol kg-1 at 298.15 K. From these data the standard dissolution enthalpies of amides in aqueous urea solutions have been determined. The results have been treated according to McMillan Mayer s theory in order to obtain the enthalpic coefficients of the interactions between amino acid derivatives and urea molecules. The obtained parameters were compared with the hydrophobic scale for the amino acid side chains.

Compounds

#	Formula	Name
1	C5H10N2O2	2-acetamido-N-methylacetamide
2	C6H12N2O2	2-acetamido-N-methylpropanamide
3	C9H18N2O2	(S)-2-acetamido-N,4-dimethylpentanamide
4	C6H12N2O3	N-acetyl-N'-methyl-l-alpha-serinamide
5	CH4N2O	urea
6	H2O	water

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 6	Molar enthalpy of solution, kJ/mol ; Liquid	Amount concentration (molarity), mol/dm3 - 1; Liquid Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	ISOPERIBOL	1
POMD	6 2	Molar enthalpy of solution, kJ/mol ; Liquid	Molality, mol/kg - 2; Liquid Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	ISOPERIBOL	1
POMD	6 3	Molar enthalpy of solution, kJ/mol ; Liquid	Molality, mol/kg - 3; Liquid Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	ISOPERIBOL	1
POMD	6 4	Molar enthalpy of solution, kJ/mol ; Liquid	Molality, mol/kg - 4; Liquid Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	ISOPERIBOL	1
POMD	5 1 6	Molar enthalpy of solution, kJ/mol ; Liquid	Solvent: Molality, mol/kg - 5; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid Molality, mol/kg - 1; Liquid	Liquid	ISOPERIBOL	6
POMD	5 6 2	Molar enthalpy of solution, kJ/mol ; Liquid	Solvent: Molality, mol/kg - 5; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid Molality, mol/kg - 2; Liquid	Liquid	ISOPERIBOL	6
POMD	5 6 3	Molar enthalpy of solution, kJ/mol ; Liquid	Solvent: Molality, mol/kg - 5; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid Molality, mol/kg - 3; Liquid	Liquid	ISOPERIBOL	6
POMD	5 6 4	Molar enthalpy of solution, kJ/mol ; Liquid	Solvent: Molality, mol/kg - 5; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid Molality, mol/kg - 4; Liquid	Liquid	ISOPERIBOL	7

Thermodynamics Research Center / ThermoML | Thermochimica Acta

The interactions between some N-acetyl-N -methyl-l- -amino acid amides and urea in water at 298.15K

Nowicka, B., Palecz, B.[Bartlomiej], Belica, S., Piekarski, H.[Henryk]

ABSTRACT