ABSTRACT

Dilution enthalpies of six a-amino acid enantiomers (l-alanine vs d-alanine, l-serine vs d-serine, and l-proline vs d-proline) in pure water were determined at T = (288.15 to 323.15) K by isothermal titration calorimetry (ITC). Homochiral enthalpic pairwise interaction coefficients (hxx) at each temperature were evaluated according to the McMillan Mayer theory. The hxx values of a-alanine and a-proline enantiomers are all positive (hLL greater than hDD greater than 0), while those of a-serine enantiomers are all negative (hLL less than hDD less than 0). In both cases, the hxx values increase uniformly and gradually with elevating temperatures. A slight but significant enthalpic discrimination effect is found in the homochiral pairwise interactions of these a-amino acid enantiomers. The positive growth of hxx values indicates that increasing temperature promotes the predominance of hydrophobic interactions in the binary aqueous solutions studied.

Compounds

#	Formula	Name
1	C3H7NO2	(S)-2-aminopropanoic acid
2	C3H7NO2	(R)-2-aminopropanoic acid
3	C3H7NO3	L-serine
4	C3H7NO3	(R)-(-)-serine
5	C5H9NO2	L-proline
6	C5H9NO2	D-proline
7	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 7	Molar enthalpy of dilution, kJ/mol ; Liquid	Temperature, K; Liquid Initial molality of solute, mol/kg; Liquid Final molality of solute, mol/kg; Liquid	Pressure, kPa; Liquid	Liquid	ISOPERIBOL	152
POMD	2 7	Molar enthalpy of dilution, kJ/mol ; Liquid	Temperature, K; Liquid Initial molality of solute, mol/kg; Liquid Final molality of solute, mol/kg; Liquid	Pressure, kPa; Liquid	Liquid	ISOPERIBOL	152
POMD	3 7	Molar enthalpy of dilution, kJ/mol ; Liquid	Temperature, K; Liquid Initial molality of solute, mol/kg; Liquid Final molality of solute, mol/kg; Liquid	Pressure, kPa; Liquid	Liquid	ISOPERIBOL	152
POMD	4 7	Molar enthalpy of dilution, kJ/mol ; Liquid	Temperature, K; Liquid Initial molality of solute, mol/kg; Liquid Final molality of solute, mol/kg; Liquid	Pressure, kPa; Liquid	Liquid	ISOPERIBOL	152
POMD	5 7	Molar enthalpy of dilution, kJ/mol ; Liquid	Temperature, K; Liquid Initial molality of solute, mol/kg; Liquid Final molality of solute, mol/kg; Liquid	Pressure, kPa; Liquid	Liquid	ISOPERIBOL	152
POMD	6 7	Molar enthalpy of dilution, kJ/mol ; Liquid	Temperature, K; Liquid Initial molality of solute, mol/kg; Liquid Final molality of solute, mol/kg; Liquid	Pressure, kPa; Liquid	Liquid	ISOPERIBOL	152

Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

Temperature Dependences and Enthalpic Discrimination of Homochiral Pairwise Interactions of Six a-Amino Acid Enantiomers in Pure Water

Liu, J.[Jiamin], Zhu, L.[Liyuan], Wang, H.[Huaqin], Chen, N.[Nan], Hu, X.-G.[Xin-Gen]

ABSTRACT