ABSTRACT

The enthalpies of solution have been determined for L-phenylalanine in aqueous solutions of formamide, N-methylformamide, N, Ndimethylformamide and N, N-dimethylacetamide. The measurements were made at 298.15 K and mole fraction of amide x2 = (0 to 0.35) on the precise isothermic calorimeter. The results obtained have been used to calculate the standard enthalpies of solution and transfer of L-phenylalanine from a water into mixtures as well as the enthalpy coefficients of pairwise interaction (hxy) of the solute with amide in aqueous media. It is established the interrelation between enthalpy characteristics of dissolution (transfer) of L-phenylalanine and the composition of (water+amide) binary mixtures. Contributions of the amides properties (molar volume, dipolarity/polarizability, acidity and basicity) to the energy of pairwise interactions have been estimated quantitatively with assistance of a modified Kamlet-Taft equation

Compounds

#	Formula	Name
1	C9H11NO2	L-phenylalanine
2	CH3NO	formamide
3	C2H5NO	N-methylformamide
4	C3H7NO	dimethylformamide
5	C4H9NO	N,N-dimethylethanamide
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	2	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Standard Abbe refractometry	1
POMD	2	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Vibrating tube method	1
POMD	3	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Standard Abbe refractometry	1
POMD	3	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Vibrating tube method	1
POMD	4	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Standard Abbe refractometry	1
POMD	4	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Vibrating tube method	1
POMD	5	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Standard Abbe refractometry	1
POMD	5	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Vibrating tube method	1
POMD	1 2 6	Molar enthalpy of solution, kJ/mol ; Liquid	Solvent: Molality, mol/kg - 2; Liquid	Temperature, K; Liquid Molality, mol/kg - 1; Liquid Pressure, kPa; Liquid	Liquid	ISOPERIBOL	11
POMD	1 3 6	Molar enthalpy of solution, kJ/mol ; Liquid	Solvent: Molality, mol/kg - 3; Liquid	Temperature, K; Liquid Molality, mol/kg - 1; Liquid Pressure, kPa; Liquid	Liquid	ISOPERIBOL	11
POMD	1 4 6	Molar enthalpy of solution, kJ/mol ; Liquid	Solvent: Molality, mol/kg - 4; Liquid	Temperature, K; Liquid Molality, mol/kg - 1; Liquid Pressure, kPa; Liquid	Liquid	ISOPERIBOL	12
POMD	1 5 6	Molar enthalpy of solution, kJ/mol ; Liquid	Solvent: Molality, mol/kg - 5; Liquid	Temperature, K; Liquid Molality, mol/kg - 1; Liquid Pressure, kPa; Liquid	Liquid	ISOPERIBOL	11

Thermodynamics Research Center / ThermoML | Thermochimica Acta

Enthalpies of solution of L-phenylalanine in aqueous solution of amides at 298.15 K.

Smirnov, V. I.[Valeriy I.], Badelin, V. G.[Valentin G.]

ABSTRACT