2
0
2009
zho
liu
0
journal
Original
Zhou, L.[Li]
Liu, C.[Chunli]
Thermochim. Acta
2009
2020-09-29
Enthalpies of transfer of amino acids from water to aqueous solutions of N-methylacetamide and N,N-dimethylacetamide at T=298.15K
Enthalpies of solution of glycine, l-alanine and l-serine in aqueous solutions of N-methylacetamide and N,N-dimethylacetamide were measured at 298.15 K. Enthalpies of transfer ( trH) of amino acids from water to aqueous solutions of amides were derived. It has been show that the enthalpies of transfer of amino acids are positive and increase with the increasing concentration of amides. The relative order of trH of amino acids in the same concentration of NMA or DMA is l-serine less than glycine less than l-alanine. The influence of side group of l-alanine and l-serine on trH has been discussed in terms of structural interaction. The results were compared with those in aqueous formamide, N-methylformamide and N,N-dimethylformamide solutions.
Amino acid
Enthalpy of transfer
N-Methylacetamide
N
N-Dimethylacetamide
10.1016/j.tca.2008.10.011
1-2
482
72-74
1
InChI=1S/C2H5NO2/c3-1-2(4)5/h1,3H2,(H,4,5)
DHMQDGOQFOQNFH-UHFFFAOYSA-N
2-aminoacetic acid
aminoacetic acid
aminoethanoic acid
glycine
C2H5NO2
1
Commercial source
1
99
2
Stated by supplier
2
Crystallization from solution
Dried by vacuum heating
Crystallization from solution
Dried by vacuum heating
3
99
2
Estimated by the compiler
2
InChI=1S/C3H7NO2/c1-2(4)3(5)6/h2H,4H2,1H3,(H,5,6)/t2-/m0/s1
QNAYBMKLOCPYGJ-REOHCLBHSA-N
(S)-2-aminopropanoic acid
(S)-(+)-alanine
.alpha.-alanine
L-.alpha.-aminopropionic acid
L-2-aminopropanoic acid
L-alanine
C3H7NO2
1
Commercial source
1
99
2
Stated by supplier
2
Crystallization from solution
Dried by vacuum heating
Crystallization from solution
Dried by vacuum heating
3
99
2
Estimated by the compiler
3
InChI=1S/C3H7NO3/c4-2(1-5)3(6)7/h2,5H,1,4H2,(H,6,7)/t2-/m0/s1
MTCFGRXMJLQNBG-REOHCLBHSA-N
L-serine
(S)-(+)-serine
(S)-2-amino-3-hydroxypropanoic acid
(S)-serine
.alpha.-amino-.beta.-hydroxypropionic acid
.beta.-hydroxyalanine
C3H7NO3
1
Commercial source
1
99
2
Stated by supplier
2
Crystallization from solution
Dried by vacuum heating
Crystallization from solution
Dried by vacuum heating
3
99
2
Estimated by the compiler
4
InChI=1S/C3H7NO/c1-3(5)4-2/h1-2H3,(H,4,5)
OHLUUHNLEMFGTQ-UHFFFAOYSA-N
N-methylacetamide
N-methylethanamide
methylacetamide
C3H7NO
1
Commercial source
1
99
2
Stated by supplier
2
Molecular sieve treatment
5
InChI=1S/C4H9NO/c1-4(6)5(2)3/h1-3H3
FXHOOIRPVKKKFG-UHFFFAOYSA-N
N,N-dimethylethanamide
N,N-dimethylacetamide
N,N-dimethylacetamide [DMA]
C4H9NO
1
Commercial source
1
Molecular sieve treatment
6
InChI=1S/H2O/h1H2
XLYOFNOQVPJJNP-UHFFFAOYSA-N
water
H2O
1
Commercial source
1
99.5
3
Estimated by the compiler
1
1
1
4
1
6
1
Principal objective of the work
VN
TRC
6/17/2009
1
Molar enthalpy of solution, kJ/mol
Calvet calorimetry
Liquid
Difference with the reference state, X-X(REF)
Pure solute at the same temperature and pressure
Crystal
4
6
1
Data file compiler
Propagation of evaluated standard uncertainties
95
Liquid
1
Temperature, K
Liquid
298.15
5
2
Pressure, kPa
Liquid
101
3
3
Mole fraction
1
Liquid
0
1
1
Solvent: Molality, mol/kg
4
Liquid
1
0
2
1
14.15
4
1
0.35
1
0.5001
4
1
14.55
4
1
0.36
1
0.9997
4
1
15.05
4
1
0.37
1
1.4991
5
1
15.41
4
1
0.38
1
1.9993
5
1
15.71
4
1
0.39
1
2.5
5
1
16.02
4
1
0.39
1
2.9981
5
1
16.42
4
1
0.4
1
3.4962
5
1
16.71
4
1
0.41
1
3.9957
5
1
16.98
4
1
0.42
2
2
1
4
1
6
1
Principal objective of the work
VN
TRC
6/17/2009
1
Molar enthalpy of solution, kJ/mol
Calvet calorimetry
Liquid
Difference with the reference state, X-X(REF)
Pure solute at the same temperature and pressure
Crystal
4
6
1
Data file compiler
Propagation of evaluated standard uncertainties
95
Liquid
1
Temperature, K
Liquid
298.15
5
2
Pressure, kPa
Liquid
101
3
3
Mole fraction
2
Liquid
0
1
1
Solvent: Molality, mol/kg
4
Liquid
1
0
2
1
7.57
3
1
0.19
1
0.4998
4
1
8.24
3
1
0.2
1
0.9998
4
1
8.67
3
1
0.21
1
1.4985
5
1
9.12
3
1
0.22
1
1.9998
5
1
9.62
3
1
0.24
1
2.4993
5
1
10.04
4
1
0.25
1
2.9991
5
1
10.57
4
1
0.26
1
3.4987
5
1
10.96
4
1
0.27
1
3.9989
5
1
11.35
4
1
0.28
3
3
1
4
1
6
1
Principal objective of the work
VN
TRC
6/17/2009
1
Molar enthalpy of solution, kJ/mol
Calvet calorimetry
Liquid
Difference with the reference state, X-X(REF)
Pure solute at the same temperature and pressure
Crystal
4
6
1
Data file compiler
Propagation of evaluated standard uncertainties
95
Liquid
1
Temperature, K
Liquid
298.15
5
2
Pressure, kPa
Liquid
101
3
3
Mole fraction
3
Liquid
0
1
1
Solvent: Molality, mol/kg
4
Liquid
1
0
2
1
11.34
4
1
0.28
1
0.4998
4
1
11.56
4
1
0.28
1
0.9998
4
1
11.85
4
1
0.29
1
1.4985
5
1
12.34
4
1
0.3
1
1.9998
5
1
12.71
4
1
0.31
1
2.4993
5
1
13.05
4
1
0.32
1
2.9991
5
1
13.4
4
1
0.33
1
3.4987
5
1
13.62
4
1
0.33
1
3.9989
5
1
13.98
4
1
0.34
4
1
1
5
1
6
1
Principal objective of the work
VN
TRC
6/17/2009
1
Molar enthalpy of solution, kJ/mol
Calvet calorimetry
Liquid
Difference with the reference state, X-X(REF)
Pure solute at the same temperature and pressure
Crystal
5
6
1
Data file compiler
Propagation of evaluated standard uncertainties
95
Liquid
1
Temperature, K
Liquid
298.15
5
2
Pressure, kPa
Liquid
101
3
3
Mole fraction
1
Liquid
0
1
1
Solvent: Molality, mol/kg
5
Liquid
1
0.4999
4
1
14.76
4
1
0.36
1
0.9988
4
1
15.15
4
1
0.37
1
1.5002
5
1
15.64
4
1
0.38
1
2.0004
5
1
15.93
4
1
0.39
1
2.4983
5
1
16.25
4
1
0.4
1
3.0005
5
1
16.67
4
1
0.41
1
3.5017
5
1
16.94
4
1
0.42
1
4.0005
5
1
17.33
4
1
0.43
5
2
1
5
1
6
1
Principal objective of the work
VN
TRC
6/17/2009
1
Molar enthalpy of solution, kJ/mol
Calvet calorimetry
Liquid
Difference with the reference state, X-X(REF)
Pure solute at the same temperature and pressure
Crystal
5
6
1
Data file compiler
Propagation of evaluated standard uncertainties
95
Liquid
1
Temperature, K
Liquid
298.15
5
2
Pressure, kPa
Liquid
101
3
3
Mole fraction
2
Liquid
0
1
1
Solvent: Molality, mol/kg
5
Liquid
1
0.5
4
1
8.43
3
1
0.21
1
1.0001
5
1
8.91
3
1
0.22
1
1.4995
5
1
9.5
3
1
0.23
1
2.0004
5
1
10.05
4
1
0.25
1
2.4999
5
1
10.65
4
1
0.26
1
2.9874
5
1
11.3
4
1
0.28
1
3.4988
5
1
11.72
4
1
0.29
1
4.0006
5
1
12.27
4
1
0.3
6
3
1
5
1
6
1
Principal objective of the work
VN
TRC
6/17/2009
1
Molar enthalpy of solution, kJ/mol
Calvet calorimetry
Liquid
Difference with the reference state, X-X(REF)
Pure solute at the same temperature and pressure
Crystal
5
6
1
Data file compiler
Propagation of evaluated standard uncertainties
95
Liquid
1
Temperature, K
Liquid
298.15
5
2
Pressure, kPa
Liquid
101
3
3
Mole fraction
3
Liquid
0
1
1
Solvent: Molality, mol/kg
5
Liquid
1
0.5002
4
1
11.71
4
1
0.29
1
0.9995
4
1
12.02
4
1
0.3
1
1.5012
5
1
12.57
4
1
0.31
1
1.9988
5
1
12.96
4
1
0.32
1
2.5002
5
1
13.3
4
1
0.33
1
2.9997
5
1
13.72
4
1
0.34
1
3.4989
5
1
14.01
4
1
0.34
1
4.0005
5
1
14.35
4
1
0.35