Vapor pressures and enthalpies of vaporization of a series of the symmetric linear n -alkyl esters of dicarboxylic acids

Article abstract of DOI:10.1021/je100231g

Vapor pressures and the molar enthalpies of vaporization of the linear aliphatic alkyl esters of dicarboxylic acids R-CO₂-(CH ₂)_n-CO₂-R with n = (0 to 4) with R = C ₂H₅, n-C₃H₇, and n-C ₄H₉ have been determined using the transpiration method. A linear correlation of enthalpies of vaporization (at T = 298.15 K) of the esters with the number n and with Kovat's indices has been found, proving the internal consistency of measured data.

Full text of DOI:10.1021/je100231g

ARTICLE
pubs.acs.org/jced
Vapor Pressures and Enthalpies of Vaporization of a Series of the
Symmetric Linear n-Alkyl Esters of Dicarboxylic Acids
Svetlana V. Lipp and Eugenii L. Krasnykh
Samara State Technical University, Samara 443100, Russia
Sergey P. Verevkin*
Department of Physical Chemistry, University of Rostock, Dr-Lorenz-Weg 1, D-18059, Rostock, Germany
S Supporting Information
b
ABSTRACT: Vapor pressures and the molar enthalpies of vaporization of the linear aliphatic alkyl esters of dicarboxylic acids R-
CO2-(CH2)n-CO2-R with n = (0 to 4) with R = C2H5, n-C3H7, and n-C4H9 have been determined using the transpiration
method. A linear correlation of enthalpies of vaporization (at T = 298.15 K) of the esters with the number n and with Kovat’s indices
has been found, proving the internal consistency of measured data.
’ INTRODUCTION
was used with a column length of 30 m, an inside diameter of 0.32
mm, and a film thickness of 0.25 mm. The standard temperature
program of the GC was T = 333.15 K for 180 s followed by a
Linear alkyl esters of dicarboxylic acids can be used as green
solvents to extract carboxylic acids, as plasticizers in polymers, as
an additive in fragrance formulation, and even as an additive for
biodiesel.1 In addition, esters are intermediates in the polymer
production, for example, polybutylene succinate polymers.2 The
reliable data on vapor pressures and enthalpies of vaporization
are required for the optimization of technological processes and
for the assessment of the environmental fate of chemicals.
Thermodynamic properties of dimethyl esters of dicarboxylic
acids have been studied recently.3 Vapor pressure and vaporiza-
tion enthalpy data of esters of dicarboxylic acid with a longer alkyl
chain are scarce and contradicting. This paper extends our
previous3-9 studies on the esters with the systematic study of
heating rate of 0.167 K s-1 to T = 523.15 K. No total impurities
3
(greater than mass fraction 0.003) could be detected in the
samples used for the vapor pressure measurements.
Measurements of the Enthalpies of Vaporization Using the
Transpiration Method. Vapor pressures were determined using
the method of transpiration in a saturated nitrogen stream,11,12 and
enthalpies of dialkyl esters of dicarboxylic acids were obtained
applying the Clausius-Clapeyron equation. About 0.5 g of the
sample was mixed with glass beads and placed in a thermostatted
U-shaped tube having a length of 20 cm and a diameter of 0.5 cm.
Glass beads with diameter of 1 mm provided a surface which was
sufficient for the vapor-liquid equilibration. At constant tempera-
ture (( 0.1 K), a nitrogen stream was passed through the U-tube,
and the transported amount of gaseous material was collected in a
cooling trap. The flow rate of the nitrogen stream was measured
using a soap bubble flow meter and optimized to reach the
saturation equilibrium of the transporting gas at each temperature
under study. On one hand, the flow rate of the nitrogen stream in
the saturation tube should be not too slow to avoid the transport of
material from the U-tube due to diffusion. On the other hand, the
flow rate should be not too fast to reach the saturation of the
nitrogen stream with a compound. We tested our apparatus at
different flow rates of the carrier gas to check the lower boundary of
the flow below which the contribution of the vapor condensed in
the trap by diffusion becomes comparable to the transpired one. In
our apparatus, the contribution due to diffusion was negligible at a
the linear aliphatic n-alkyl esters of dicarboxylic acids CmH2mþ1
-
CO2-(CH2)n-CO2-CmH2mþ1 with n = (0 to 4) and m = (2 to
4). The enthalpies of vaporization, Δgl Hm, have been obtained
from the temperature dependence of the vapor pressures mea-
sured by the transpiration method. These data together with
those available from the literature were used to establish the
general regularities in the Δgl Hm and the vapor pressures within
this homologous series.
’ EXPERIMENTAL SECTION
Materials. The sample of diethyl ester of oxalic acid was of
commercial origin (Aldrich). Other samples of alkyl esters of
dicarboxylic acids were synthesized by the esterification of an
appropriate dicarboxylic acid with the alcohol of the desired alkyl
chain length.10 Phosphoric acid was used as a catalyst. Samples
were purified by repeated vacuum distillation. The degree of
purity of the samples was determined using a Hewlett-Packard
gas chromatograph 5890 Series II equipped with a flame ioniza-
tion detector and a Hewlett-Packard 3390A integrator. The
flow rate up to 0.11 cm3 s-1. The upper limit for our apparatus
3
where the speed of nitrogen could already disturb the equilibration
Special Issue: John M. Prausnitz Festschrift
Received: March 11, 2010
Accepted: May 28, 2010
Published: June 10, 2010
carrier gas (nitrogen) flow was 12.1 cm3 s-1. A capillary column
HP-5 (stationary phase cross-linked 5 % phenyl methyl silicone)
3
r
2010 American Chemical Society
800
dx.doi.org/10.1021/je100231g J. Chem. Eng. Data 2011, 56, 800–810
|

Journal of Chemical & Engineering Data
ARTICLE
Table 1. Vapor Pressures, p, and Vaporization Enthalpy, ΔlgHm, Obtained by the Transpiration Method
Ta
mb
mg
V(N2)
gas flow
pd
Pa
(pexp - pcalc
)
Δgl Hm
Ta
mb
mg
V(N2)
gas flow
pd
Pa
(pexp - pcalc
)
Δgl Hm
c
c
K
dm3
dm3 h-1
Pa
kJ mol-1
K
dm3
dm3 h-1
Pa
kJ mol-1
3
3
3
3
diethyl oxalate; Δgl Hm(298.15 K) = (57.80 ( 0.36) kJ mol-1
3
ꢀ
ꢁ
305:6 81119:36 78:2
T=K
lnðp=PaÞ ¼
-
-
ln
ðÞ
R
RðT=KÞ
R
298:15
283.6
288.5
293.4
298.3
303.3
308.4
311.3
5.75
5.58
5.71
5.73
4.82
5.31
6.30
6.07
3.74
2.48
1.70
1.00
0.711
0.704
5.09
5.16
2.78
2.80
2.80
2.84
2.82
16.4
25.6
-0.4
0.0
58.95
58.56
58.18
57.80
57.41
57.01
56.78
313.5
7.42 0.711 2.84
175.0
207.5
243.4
297.2
383.4
483.2
627.5
1.1
-4.7
2.3
56.61
56.38
56.23
55.99
55.68
55.36
55.04
316.4
8.80 0.711 2.84
39.2
0.8
318.3 10.33 0.711 2.84
57.1
0.3
321.4
325.4
329.5
333.5
5.58 0.319 1.13
6.41 0.284 1.10
6.51 0.229 1.10
6.77 0.183 1.10
1.4
81.4
-1.9
4.1
0.9
125.4
150.9
-10.6
-1.3
1.7
diethyl malonate; ΔlgHm(298.15 K) = (61.70 ( 0.25) kJ mol-1
3
ꢀ
ꢁ
320:15 87489:79 86:5
T=K
lnðp=PaÞ ¼
-
-
ln
R
RðT=KÞ
R
298:15
283.8
286.2
289.2
292.3
295.2
298.2
301.3
1.26
1.46
1.85
2.20
1.49
3.00
2.61
2.85
2.65
2.50
2.26
1.19
1.85
1.25
3.14
3.57
3.57
3.57
3.57
3.57
3.57
6.89
8.58
11.5
-0.04
-0.1
0.1
62.95
62.74
62.48
62.21
61.96
61.70
61.43
304.2
304.7
307.3
310.2
313.3
316.3
2.66 1.01 3.57
4.87 1.75 3.14
2.58 0.774 3.57
2.63 0.625 3.57
2.36 0.446 3.57
2.33 0.357 3.57
40.5
42.8
51.3
64.6
81.4
100.5
0.0
0.6
61.18
61.14
60.91
60.66
60.39
60.13
-0.4
0.1
15.0
19.3
25.1
32.1
0.0
0.0
0.0
0.2
-0.9
0.1
diethyl succinate; ΔlgHm(298.15 K) = (65.07 ( 0.25) kJ mol-1
3
ꢀ
ꢁ
332:36 93334:78 94:8
T=K
lnðp=PaÞ ¼
-
-
ln
R
RðT=KÞ
R
298:15
290.2
290.5
293.5
296.4
301.4
306.4
311.4
313.4
316.4
318.4
321.4
9.22
1.77
3.78
3.61
4.05
4.26
4.81
1.77
4.30
2.54
4.28
26.6
8.65
8.56
8.56
8.54
8.54
8.70
8.70
2.83
2.67
2.83
2.74
4.95
0.02
-0.03
0.1
65.83
65.80
65.52
65.24
64.77
64.29
63.82
63.63
63.34
63.16
62.87
323.5
326.5
326.5
328.5
331.4
331.6
333.6
336.5
339.4
342.4
345.5
3.92 0.708 2.83
4.65 0.695 2.78
4.16 0.608 1.46
5.56 0.695 2.78
4.25 0.450 1.46
6.90 0.718 2.78
7.50 0.695 2.78
4.81 0.364 1.46
5.73 0.364 1.46
6.86 0.364 1.46
8.69 0.359 1.44
77.7
94.1
1.0
-0.8
1.3
62.67
62.39
62.39
62.20
61.92
61.90
61.71
61.44
61.16
60.88
60.59
4.99
7.99
5.98
4.27
2.90
2.18
0.708
1.34
0.708
0.914
5.04
6.78
8.61
96.3
-0.1
0.0
112.5
133.0
135.1
151.7
186.4
222.1
265.8
342.5
3.4
13.4
-0.2
0.1
20.8
31.3
35.0
45.5
50.3
66.1
0.3
0.6
-2.7
-0.6
-3.3
-6.7
12.5
-0.9
0.2
-2.4
0.3
diethyl glutarate; ΔlgHm(298.15 K) = (69.76 ( 0.38) kJ mol-1
3
ꢀ
ꢁ
347:220 100503:36 103:1
T=K
lnðp=PaÞ ¼
-
-
ln
R
RðT=KÞ
R
298:15
298.3
303.4
308.6
311.2
313.5
316.2
318.2
318.5
3.52
3.90
4.27
2.90
3.37
4.58
2.78
9.06
13.06
8.84
6.29
3.52
3.30
3.68
1.95
5.86
8.29
8.29
8.29
7.81
7.91
8.18
7.82
8.18
3.52
0.1
0.3
69.75
69.23
68.69
68.42
68.19
67.91
67.70
67.67
322.2
323.3
328.2
333.2
338.2
2.63 1.35 4.05
8.00 3.73 8.29
3.15 1.01 4.05
5.29 1.15 4.05
6.79 1.01 4.05
25.4
27.7
-1.1
-1.2
-1.4
-0.4
1.5
67.29
67.18
66.67
66.16
65.64
65.12
64.64
5.75
8.77
0.1
40.5
10.8
-0.1
0.2
60.1
13.4
16.1
18.5
20.0
87.4
-0.4
-0.8
0.2
343.2 10.24 1.08 4.05
347.9 98.33 7.36 8.18
123.6
172.5
3.0
8.6
diethyl adipate; Δgl Hm(298.15 K) = (74.03 ( 0.27) kJ mol-1
3
ꢀ
ꢁ
361:74 107240:52 111:4
T=K
lnðp=PaÞ ¼
-
-
ln
R
RðT=KÞ
R
298:15
801
dx.doi.org/10.1021/je100231g |J. Chem. Eng. Data 2011, 56, 800–810

Journal of Chemical & Engineering Data
ARTICLE
Table 1. Continued
c
c
Ta
mb
V(N2)
gas flow
pd
Pa
(pexp - pcalc
)
Δgl Hm
Ta
mb
mg
V(N2)
gas flow
pd
Pa
(pexp - pcalc
)
Δgl Hm
K
mg
dm3
dm3 h-1
Pa
kJ mol-1
K
dm3
dm3 h-1
Pa
kJ mol-1
3
3
3
3
303.5
308.2
313.3
318.2
323.1
328.2
329.6
333.2
2.63
2.07
1.82
1.33
3.05
3.72
3.05
4.59
14.58
7.36
4.22
2.04
3.13
2.45
1.78
2.04
8.18
8.18
8.18
8.18
8.18
8.18
2.11
8.18
2.20
3.43
5.23
7.93
0.04
0.1
73.44
72.91
72.34
71.80
71.25
70.68
70.53
70.13
335.2
338.2
340.2
343.2
346.2
349.1
352.2
3.00 1.13
7.43 2.32
2.06
8.18
2.06
2.06
2.06
2.06
2.06
32.3
39.0
46.2
56.1
69.8
85.1
106.1
0.6
-0.5
0.5
69.90
69.57
69.35
69.01
68.68
68.36
68.01
-0.1
-0.2
-0.4
0.0
2.60 0.685
3.48 0.754
4.32 0.754
3.83 0.548
4.48 0.514
-0.5
0.0
11.8
18.5
20.9
27.3
0.0
0.3
1.5
0.1
dipropyl oxalate; ΔlgHm(298.15 K) = (61.40 ( 0.49) kJ mol-1
3
ꢀ
ꢁ
322:28 89666:99 94:8
T=K
lnðp=PaÞ ¼
-
-
ln
ðÞ
R
RðT=KÞ
R
298:15
293.6
298.5
301.4
306.4
308.4
311.4
313.4
316.3
5.01
5.01
4.65
4.65
1.60
4.83
2.18
2.82
7.58
7.58
7.58
7.58
7.58
2.99
7.58
2.99
3.08
9.43
0.4
0.3
61.84
61.37
61.10
60.63
60.44
60.15
59.96
59.69
318.6
321.4
323.3
326.3
328.3
330.4
333.5
3.40 0.771
4.02 0.771
4.90 0.771
5.89 0.771
6.79 0.771
7.73 0.771
9.78 0.771
3.08
3.08
3.08
3.08
3.08
3.08
3.08
62.6
74.1
-1.0
-3.1
2.3
59.47
59.20
59.02
58.74
58.55
58.35
58.06
5.12
13.9
17.5
25.5
30.4
36.2
41.3
52.0
3.79
0.1
90.3
2.59
-0.2
0.3
108.5
124.8
142.3
180.1
0.8
0.746
1.90
2.2
-1.5
-2.4
-2.0
1.6
0.746
0.771
8.8
dipropyl malonate; ΔlgHm (298.15 K) = (66.18 ( 0.40) kJ mol-1
3
ꢀ
ꢁ
339:6 96922:69 103:1
T=K
lnðp=PaÞ ¼
-
-
ln
R
RðT=KÞ
R
298:15
293.3
298.3
299.4
303.2
307.3
308.2
311.3
313.3
2.63
2.69
3.03
3.25
3.13
0.77
3.28
1.13
9.88
6.16
6.20
4.81
3.24
0.75
2.45
0.75
9.26
9.36
7.59
9.47
9.47
3.00
9.47
3.00
3.56
5.82
6.52
8.97
-0.1
0.03
0.1
66.69
66.17
66.06
65.67
65.25
65.15
64.83
64.63
315.3
318.5
319.4
323.4
328.5
333.5
336.4
338.5
4.06 2.21
2.30 1.03
5.51 2.21
3.23 1.00
3.54 0.75
5.07 0.75
6.23 0.75
7.40 0.75
9.47
3.00
9.47
3.00
3.00
3.00
3.00
3.00
24.5
29.6
0.5
-1.1
0.4
64.42
64.09
64.00
63.59
63.06
62.54
62.25
62.03
33.2
0.1
42.6
-1.5
-1.5
-0.8
0.5
12.9
0.3
62.2
13.5
17.8
19.9
0.0
89.0
0.4
109.5
130.0
-0.5
4.8
dipropyl succinate; ΔlgHm(298.15 K) = (70.98 ( 0.32) kJ mol-1
3
ꢀ
ꢁ
354:66 104193:73 111:4
T=K
lnðp=PaÞ ¼
-
-
ln
R
RðT=KÞ
R
298:15
308.3
312.4
316.4
318.5
321.5
323.5
326.4
6.17
3.80
4.89
0.96
2.38
1.41
3.60
15.50
6.73
6.30
1.04
2.06
1.04
2.07
7.78
7.34
7.34
4.15
4.05
4.15
4.14
4.87
6.85
9.36
0.1
0.1
69.85
69.40
68.95
68.72
68.38
68.16
67.84
328.6
331.3
333.4
336.5
338.5
341.5
343.5
2.90 1.38
3.48 1.38
3.13 1.04
3.82 1.04
4.40 1.04
5.33 1.03
6.17 1.03
4.15
4.14
4.15
4.14
4.15
4.11
4.11
25.2
30.3
36.2
44.3
50.9
62.5
72.3
0.3
-0.1
0.8
67.59
67.29
67.06
66.71
66.49
66.16
65.93
-0.1
-0.1
-0.4
-0.5
-0.1
11.1
0.1
13.9
16.3
20.9
0.0
-0.2
0.6
dipropyl glutarate; ΔlgHm(298.15 K) = (75.48 ( 0.31) kJ mol-1
3
ꢀ
ꢁ
369:20 111167:48 119:7
T=K
lnðp=PaÞ ¼
-
-
ln
R
RðT=KÞ
R
298:15
313.3
316.4
318.5
319.4
322.5
323.5
3.41
3.13
0.53
2.53
2.42
0.78
14.09
9.86
1.33
6.02
4.46
1.37
8.80
8.83
4.00
8.80
8.92
4.00
2.76
3.59
4.44
4.78
6.09
6.37
0.01
-0.03
0.1
73.67
73.30
73.05
72.94
72.57
72.45
333.6
336.4
338.5
341.4
343.6
346.4
2.66 2.00
2.80 1.72
2.60 1.33
2.37 0.986
2.75 0.997
3.37 0.986
4.00
6.87
3.99
3.95
3.99
3.95
14.9
18.4
22.0
27.1
31.0
38.5
-0.1
-0.1
0.4
71.24
70.91
70.66
70.31
70.04
69.71
0.1
0.3
-0.09
-0.3
-0.4
0.3
802
dx.doi.org/10.1021/je100231g |J. Chem. Eng. Data 2011, 56, 800–810

Journal of Chemical & Engineering Data
ARTICLE
Table 1. Continued
c
c
Ta
mb
V(N2)
gas flow
pd
(pexp - pcalc
)
Δgl Hm
Ta
mb
mg
V(N2)
gas flow
pd
Pa
(pexp - pcalc
)
Δgl Hm
K
mg
dm3
dm3 h-1
Pa
7.78
10.0
Pa
kJ mol-1
K
dm3
dm3 h-1
Pa
kJ mol-1
3
3
3
3
325.4
328.5
329.5
331.4
2.63
1.19
2.93
2.58
3.79
1.33
3.01
2.29
8.92
4.00
8.81
6.87
-0.01
0.0
72.22
71.85
71.73
71.50
348.4
350.5
353.5
3.83 0.997
4.56 1.02
5.57 0.997
3.99
3.95
3.99
43.2
50.4
62.8
-0.7
-0.3
0.8
69.47
69.22
68.86
10.9
12.8
0.1
0.2
dipropyl adipate; ΔlgHm(298.15 K) = (80.97 ( 0.31) kJ mol-1
3
ꢀ
ꢁ
386:62 1191102:74 127:9
T=K
lnðp=PaÞ ¼
-
-
ln
ðÞ
R
RðT=KÞ
R
298:15
318.8
321.7
323.5
327.4
333.2
336.1
339.1
342.1
1.33
1.73
0.64
2.25
2.79
2.24
1.98
2.49
8.30
8.41
2.63
6.54
4.94
3.13
2.18
2.18
8.89
8.77
8.78
8.72
8.72
8.72
8.72
8.72
1.73
0.03
0.00
78.33
77.96
77.73
77.23
76.49
76.12
75.74
75.35
345.5
348.3
351.5
354.2
357.1
361.2
365.3
4.26 3.00
4.03 2.19
2.94 1.24
2.93 1.02
8.77
8.77
2.01
2.04
2.04
2.04
2.04
15.2
19.6
25.3
30.6
37.3
48.5
63.9
-0.7
0.0
0.5
0.5
0.4
0.2
0.0
74.92
74.56
74.15
73.81
73.44
72.91
72.39
2.22
2.60
3.67
6.02
7.65
9.72
-0.01
-0.01
0.01
2.42 0.698
2.46 0.545
3.14 0.528
0.02
0.02
12.2
-0.1
dibutyl oxalate; Δgl Hm(298.15 K) = (71.37 ( 0.21) kJ mol-1
3
ꢀ
ꢁ
355:36 104587:61 111:4
T=K
lnðp=PaÞ ¼
-
-
ln
R
RðT=KÞ
R
298:15
291.4
293.4
295.7
298.8
300.4
302.3
302.8
303.3
305.2
305.3
308.2
308.3
308.4
311.3
312.3
313.2
314.3
315.5
317.4
317.8
318.2
319.9
320.2
322.5
323.2
323.4
325.3
1.54
1.66
2.04
1.64
1.66
2.26
1.76
2.17
2.72
2.13
2.19
2.05
2.29
2.17
1.70
2.26
2.41
4.30
2.44
1.79
2.32
1.52
2.24
2.09
2.64
1.667
1.46
21.91
18.65
17.61
11.09
9.78
11.13
7.83
9.33
9.78
7.84
6.00
5.73
6.27
4.70
3.32
4.13
4.00
6.13
3.14
2.09
2.67
1.50
2.35
1.71
2.00
1.35
1.01
7.83
7.83
7.83
7.83
7.83
9.41
7.83
8.00
7.82
9.40
7.82
8.00
9.40
9.40
7.96
8.00
9.40
7.82
9.40
7.82
8.00
5.62
9.40
3.95
8.00
4.03
4.04
0.87
1.10
1.43
1.82
2.09
2.49
2.76
2.83
3.40
3.34
4.46
4.33
4.48
5.65
6.24
6.60
7.37
8.55
9.37
-0.01
0.02
0.1
72.13
71.91
71.65
71.31
71.13
70.92
70.86
70.81
70.59
70.58
70.26
70.25
70.24
69.91
69.80
69.70
69.58
69.45
69.23
69.19
69.15
68.96
68.92
68.67
68.59
68.57
68.35
325.3
326.4
327.5
328.2
328.5
330.3
331.1
331.4
333.2
333.5
333.5
335.2
336.3
337.0
338.1
338.6
340.2
340.8
341.4
343.2
343.4
343.5
345.2
348.3
351.2
2.47 1.67
2.12 1.34
1.55 0.879
3.89 2.12
2.50 1.35
2.09 1.00
2.01 0.848
2.41 1.00
4.80 1.75
3.27 1.15
3.69 1.35
3.10 1.00
3.41 1.00
1.73 0.485
4.15 1.06
3.94 1.01
4.48 1.00
3.69 0.766
4.68 1.00
4.27 0.794
2.72 0.479
5.54 1.04
3.34 0.545
8.40 1.06
3.84 0.409
4.00
4.01
1.82
3.17
4.03
4.00
1.81
4.01
3.17
1.81
4.03
4.00
4.01
1.81
3.17
4.03
4.00
1.91
4.01
3.17
1.91
4.03
1.63
3.17
1.63
3.17
1.63
18.0
19.3
21.5
22.3
22.6
25.4
28.9
29.2
33.9
34.6
33.3
37.5
41.4
43.4
47.5
47.5
54.3
58.6
56.8
65.1
69.3
64.5
74.1
96.2
113.7
133.2
181.1
-0.2
-0.4
0.0
68.35
68.23
68.11
68.03
68.00
67.80
67.71
67.68
67.47
67.44
67.44
67.25
67.13
67.05
66.93
66.87
66.69
66.63
66.56
66.36
66.34
66.33
66.14
65.79
65.47
65.26
64.69
-0.02
-0.1
-0.1
0.1
-0.5
-0.7
-1.2
0.7
0.02
0.1
0.4
0.3
-0.03
0.1
0.9
-0.4
-0.6
0.2
-0.1
0.02
-0.1
-0.03
-0.2
-0.1
0.3
0.0
0.6
-1.1
0.0
2.0
-0.3
0.5
-2.1
-1.5
1.7
10.5
10.5
12.4
11.5
14.9
15.9
15.1
17.6
0.2
0.5
-3.5
-2.1
2.6
-0.7
0.3
0.5
0.9
-0.6
-0.6
353.1 11.06 1.01
358.2 6.11 0.409
6.0
6.8
dibutyl malonate; ΔlgHm(298.15 K) = (75.28 ( 0.39) kJ mol-1
3
ꢀ
ꢁ
370:83 110964:14 119:7
T=K
lnðp=PaÞ ¼
-
-
ln
R
RðT=KÞ
R
298:15
303.2
308.3
0.96
1.41
7.97
7.24
8.69
8.69
1.38
2.23
-0.02
-0.1
74.68
74.07
338.2
340.2
2.88 1.23
2.78 0.976
4.92
2.93
26.7
32.5
-1.0
70.49
70.25
0.4
803
dx.doi.org/10.1021/je100231g |J. Chem. Eng. Data 2011, 56, 800–810

Journal of Chemical & Engineering Data
ARTICLE
Table 1. Continued
c
c
Ta
mb
V(N2)
gas flow
pd
Pa
(pexp - pcalc
)
Δgl Hm
Ta
mb
mg
V(N2)
gas flow
pd
Pa
(pexp - pcalc
)
Δgl Hm
K
mg
dm3
dm3 h-1
Pa
kJ mol-1
K
dm3
dm3 h-1
Pa
kJ mol-1
3
3
3
3
313.3
318.3
323.2
325.1
328.2
330.2
333.2
335.2
2.08
2.11
1.90
1.93
2.83
2.28
3.20
2.31
6.52
4.35
2.46
2.20
2.46
1.71
1.88
1.22
8.69
8.69
4.92
2.93
4.92
2.93
4.92
2.93
3.66
5.57
8.78
0.04
-0.1
0.3
73.47
72.87
72.28
72.06
71.68
71.45
71.09
70.85
343.2
345.2
349.1
353.1
357.2
361.2
365.2
369.2
2.98 0.839
3.20 0.805
1.33 0.259
1.84 0.267
2.62 0.293
3.04 0.259
3.79 0.259
4.92 0.259
3.35
2.93
1.04
1.04
1.04
1.04
1.04
1.04
40.7
45.4
0.8
-0.5
-1.6
0.1
69.89
69.65
69.18
68.70
68.21
67.73
67.26
66.78
58.6
10.1
0.1
78.8
13.1
15.2
19.3
21.7
0.3
102.2
134.3
167.2
217.4
-0.7
1.7
0.2
0.4
-2.4
2.0
-0.4
dibutyl succinate; ΔlgHm(298.15 K) = (79.11 ( 0.38) kJ mol-1
3
ꢀ
ꢁ
382:77 117236:9 127:9
T=K
lnðp=PaÞ ¼
-
-
ln
ðÞ
R
RðT=KÞ
R
298:15
313.3
316.2
318.3
320.2
323.2
325.2
328.2
330.2
333.2
0.83
1.33
0.96
1.77
0.76
2.24
1.72
2.02
2.03
6.73
8.31
5.03
7.62
2.52
6.23
3.78
3.74
2.94
8.78
8.31
5.03
8.31
5.03
8.31
5.03
8.31
5.03
1.32
0.02
0.00
77.17
76.80
76.54
76.29
75.91
75.65
75.27
75.01
74.63
335.4
338.2
340.1
343.2
346.2
349.2
352.1
355.1
358.2
1.71 2.08
2.40 2.35
2.54 2.23
1.92 1.26
1.53 0.830
1.48 0.638
1.43 0.479
2.02 0.559
2.12 0.479
8.31
5.03
8.93
5.03
1.92
1.92
1.92
1.92
1.92
8.77
-0.1
-0.1
-0.6
0.2
74.35
73.99
73.75
73.35
72.97
72.58
72.21
71.83
71.43
1.70
2.05
2.48
3.25
3.83
4.89
5.77
7.43
11.0
12.1
16.4
19.7
24.7
31.9
38.7
47.3
-0.02
0.03
0.1
-0.5
-0.4
1.1
0.03
-0.02
-0.04
0.01
0.8
0.6
dibutyl glutarate; ΔlgHm(298.15 K) = (83.07 ( 0.21) kJ mol-1
3
ꢀ
ꢁ
394:44 123673:84 136:2
T=K
lnðp=PaÞ ¼
-
-
ln
R
RðT=KÞ
R
298:15
317.5
318.3
322.4
323.4
323.4
325.4
326.5
328.4
328.4
330.6
331.5
333.5
334.6
334.7
1.36
2.18
1.43
1.28
1.89
1.21
1.34
0.62
1.48
1.38
1.46
1.37
1.52
2.38
21.26
31.32
14.00
11.24
16.93
9.26
7.97
8.47
7.96
8.43
8.47
7.93
7.96
8.43
8.60
7.95
8.60
8.43
8.60
7.90
0.64
0.70
1.03
1.14
1.13
1.32
1.45
1.79
1.73
2.10
2.29
2.73
3.06
2.98
0.00
0.01
80.44
80.33
79.77
79.63
79.63
79.36
79.21
78.95
78.95
78.65
78.53
78.26
78.11
78.09
337.6
338.6
340.5
343.3
346.6
349.6
350.3
352.5
354.7
357.5
360.6
363.4
366.4
369.5
1.33 3.58
1.80 4.50
1.02 2.15
1.20 2.02
1.41 1.82
1.30 1.35
1.54 1.51
1.21 1.01
1.46 1.02
1.48 0.845
1.43 0.676
1.31 0.507
1.59 0.504
2.02 0.504
8.60
8.43
8.61
2.02
2.02
2.02
2.02
2.02
2.03
2.03
2.03
2.03
2.02
2.02
3.75
-0.1
-0.1
-0.1
-0.04
0.02
-0.1
0.1
77.70
77.56
77.30
76.92
76.47
76.07
75.97
75.67
75.37
74.99
74.57
74.19
73.78
73.35
4.04
4.75
6.00
7.82
9.73
0.01
0.03
0.01
-0.02
-0.02
0.04
9.28
10.3
3.51
12.1
14.5
17.7
21.3
26.0
31.8
40.3
0.0
8.60
-0.02
-0.02
0.00
0.3
6.63
0.3
6.45
-0.3
-0.2
-0.1
1.2
5.06
0.02
5.02
0.1
8.03
-0.02
dibutyl adipate; Δgl Hm(298.15 K) = (88.51 ( 0.51) kJ mol-1
3
ꢀ
ꢁ
413:05 131594:6 144:5
T=K
lnðp=PaÞ ¼
-
-
ln
R
RðT=KÞ
R
298:15
313.2
318.2
323.2
328.2
333.3
338.4
343.1
2.58
0.55
1.08
1.07
1.20
1.07
0.97
135.7
17.2
21.7
13.1
9.0
8.61
8.61
8.61
8.61
8.61
8.61
8.65
0.18
0.30
0.48
0.79
1.27
2.02
3.04
0.00
0.00
86.34
85.62
84.90
84.18
83.44
82.70
82.02
348.2
353.2
358.2
363.2
368.2
373.2
1.92 3.9
2.15 2.9
2.26 2.1
2.44 1.6
2.79 1.3
3.39 1.1
8.65
8.65
4.50
4.50
4.50
4.50
4.67
7.05
10.2
0.1
0.2
81.29
80.56
79.84
79.12
78.40
77.67
-0.02
-0.02
-0.01
0.00
0.2
14.3
20.1
28.5
-0.1
-0.4
-0.4
5.0
3.0
0.03
a Temperature of saturation. b Mass of transferred sample condensed at T = 243.15 K. c Volume of nitrogen used to transfer mass m of sample. d Vapor
pressure at temperature T calculated from m and the residual vapor pressure at the cooling temperature T = 243.15 K.
804
dx.doi.org/10.1021/je100231g |J. Chem. Eng. Data 2011, 56, 800–810

Journal of Chemical & Engineering Data
ARTICLE
was at a flow rate of 10 cm3 s-1. Thus, we carried out the
experimental p-T data available from the literature8,16-25 using
eq 2 and eq 3, in the same way as our own results, and calculated
Δgl Hm(298.15 K) for the sake of comparison. The handbook by
Stephenson and Malanowski16 as well as a review article by
Stull18 contain vapor pressure data for some alkyl esters of
dicarboxylic acids. The origin of the data presented there is
unclear, and methods of measurements, errors of measurements,
and purities of compounds are unknown. However, we also
treated the results from Stephenson and Malanowski16 using eq 2
and eq 3 and calculated Δgl Hm(298.15 K), but the agreement or
disagreement with other data in each case should be
questionable3 (see Table 2). Antoine equation coefficients for
some alkyl esters of dicarboxylic acid were found in the compila-
tion by Dikyi et al.,19 and we also used this data for estimation of
Δgl Hm(298.15 K) using eq 2 and eq 3 (see Table 2). Vapor
pressures of some diethyl esters were measured by Heiber et al.17
using the static method in 1940; however, the purities of esters
were not reported. Their results are generally in agreement with
the available data (see Figure 1 to 3), but the vaporization
enthalpies derived from their data are systematically lower than
those measured in this work.
3
experiments in the flow rate interval of (1 to 9) cm3 s-1 which
3
has ensured that transporting gas was in saturated equilibrium with
the coexisting liquid phase in the saturation tube. The mass of the
compound collected within a certain time interval was determined
by dissolving it in a suitable solvent with a certain amount of
external standard (n-decane, n-undecane, n-dodecane). This solu-
tion was analyzed using a gas chromatograph equipped with an
autosampler. The peak area of the compound related to the peak of
the external standard (hydrocarbon n-CnH2nþ2) is a directmeasure
of the mass of the compound condensed into the cooling trap,
provided that a calibration of the system has been made. The
saturation vapor pressure pisat at each temperature Ti (maintained
and measured ( 0.1 K) was calculated from the amount of product
collected within a definite period of time. Assuming that Dalton’s
law of partial pressures applied to the nitrogen stream saturated
with the substance i of interest is valid, values of pisat were calculated
pisat ¼ miRTa=VMi; V ¼ VN2 þ Vi; ðVN2 . ViÞ ð1Þ
where R = 8.314472 J K-1 mol-1; mi is the mass of transported
3
3
compound; Mi is the molar mass of the compound; and Vi is its
volume contribution to the gaseous phase. VN2 is the volume of
transporting gas, and Ta is the temperature of the soap bubble
meter. The volume of transporting gas VN2 was determined from
the flow rate and time measurements. Data of pisat have been
obtained as a function of temperature and were fitted using the
following equation11
Diethyl Oxalate. Vapor pressures of diethyl oxalate available
from the literature are very consistent (see Figure 1) except for
data from Stull18 and some of the lower points by by Heiber
et al.17 Enthalpies of vaporization calculated from the vapor
pressures measured using ebulliometry20,21 are about 1 kJ mol-1
3
higher than value measured in the current work. Such a difference
could be explained due long extrapolation of data in refs 20 and
21 to 298.15 K.
ꢀ
ꢁ
b
T
R ln pisat ¼ a þ þ ΔgCp ln
ð2Þ
l
Diethyl Malonate. Vapor pressures (Figure 2) and enthalpies
of vaporization of diethyl malonate (Table 2) are in disarray. The
vapor pressures measured close to the boiling point agree well,
but the lower temperatures reported by Stull18 and Heiber et al.17
are in disagreement with the trend obtained in this temperature
range by our new result. Vapor pressures reported in our earlier
work8 most probably were affected by water traces, and these
data should be disregarded. In this study, we used a sample of
impeccable quality (purity 99.99 % and water content 100
ppm according to the Karl Fisher titration). The spread of
vaporization enthalpies listed in the Table 2 for diethyl malonate
T
T0
where a and b are adjustable parameters and Δgl Cp is the difference
of the molar heat capacities of the gaseous and the liquid phase,
respectively. T0 appearing in eq 2 is an arbitrarily chosen reference
temperature (which has been chosen to be 298.15 K). Conse-
quently, from eq 2 the expression for the vaporization enthalpy at
temperature T is derived
Δgl HmðTÞ=J mol-1 ¼ - b þ ðΔlgCp=J mol-1 K-1ÞT ð3Þ
3
3
3
Values of Δgl Cp have been calculated according to a procedure
developed by Chickos.13-15 Our own experimental results and
parametersa and b are listed in Table 1. The errors in the enthalpies
of vaporization are calculated from eq 2 by using the method of
least-squares, and uncertainties in values of Δgl Cp are not taken into
account. We have checked the experimental and calculation
procedure with measurements of vapor pressures of n-alcohols.12
The uncertainty of the GC analysis of transported mass of the
material, δmi = (1 to 3) %, was the main contributor to the total
experimental error of vapor pressure data, δpi = (1 to 3) %,
measured by the transpiration method.
ranges from (60.5 to 71.0) kJ mol-1, but our new value ΔlgHm-
3
(298.15 K) = (61.7 ( 0.3) kJ mol-1 measured in this work
3
around the reference temperature is not affected by extrapolation
as another data set.
Diethyl Succinate. In contrast to diethyl malonate, vapor
pressures of diethyl succinate are remarkably consistent
(Figure S1, Supporting Information), and as a consequence,
vaporization enthalpies derived from these vapor pressures are
generally close to ΔlgHm(298.15 K) = (65.1 ( 0.3) kJ mol-1
3
measured in this work.
Diethyl Glutarate. Vapor pressures (Figure S2, Supporting
Information) and enthalpies of vaporization of diethyl glutarate
(Table 2) are generally consistent (again, except for data
from Stull18 and some of the lower points by Heiber et al.17).
’ RESULTS AND DISCUSSION
Vapor Pressures and Enthalpies of Vaporization. Vapor
pressures and vaporization enthalpies of the dimethyl esters of
dicarboxylic acids were studied in our lab recently.3 Compilation
of the molar vaporization enthalpies is given in Table S1,
Supporting Information. In this work, we have investigated
dialkyl esters of dicarboxylic acids with the longer alkyl chain
length. A compilation of vaporization enthalpies of alkyl esters of
dicarboxylic acids available from the literature and our new own
values is presented in Table 2. We treated the original
However, our value ΔlgHm(298.15 K) = (69.8 ( 0.4) kJ mol-1 is
3
noticeably (2 to 3) kJ mol-1 higher in comparison with the
literature data.
3
Diethyl Adipate. Vapor pressures (Figure 3) for this com-
pound are in agreement (except for ref 25), but the spread of
vaporization enthalpies inspected is large, from (65 to 74)
kJ mol-1. Our new value ΔlgHm(298.15 K) = (74.0 ( 0.3)
3
3
kJ mol-1 isagainthe highest one in comparison withotherresults.
805
dx.doi.org/10.1021/je100231g |J. Chem. Eng. Data 2011, 56, 800–810

Journal of Chemical & Engineering Data
ARTICLE
Table 2. Compilation of Data on Enthalpies of Vaporization Δgl Hm(298.15 K) of the Linear Symmetric Alkyl Esters of
Dicarboxylic Acids R-CO2-(CH2)n-CO2-R with n = (0 to 4)
T-range
Clp (Δgl Cp)c
Δgl Hm (Tav)
Δgl Hm(298.15 K)d
compounds
na
techniqueb
E
K
J mol-1 K-1
kJ mol-1
kJ mol-1
ref
3
3
3
3
diethyl oxalate
95-92-1
0
320.5 to 458.8
343.0 to 457.0
320.0 to 459.0
303.8 to 447.5
339.0 to 392.2
353.5 to 499.4
283.6 to 333.5
386.2 to 491.0
288.2 to 318.3
313.0 to 472.0
314.7 to 463.8
298.2
260.0 (-78.2)
58.6
53.9
62.3
49.5
54.1
49.2
57.1
56.9
64.7
51.2
51.2
65.2
18
61.9
16
69.4
16
S
E
55.3 ( 0.2
59.3
17
20
E
58.6 ( 0.3
57.8 ( 0.4
67.2 ( 0.5
65.1 ( 0.2
60.5
21
T
this work
diethyl malonate
105-53-3
1
E
291.9 (-86.5)
22
T
8
E
18
S
58.7 ( 0.2
58.4 ( 0.6
63.9
17
GC
23
293.0 to 318.0
384.0 to 468.0
313.0 to 472.0
283.8 to 316.3
356.6 to 488.0
327.7 to 489.6
298.2
63.3
59.9
51.2
61.6
56.8
54.7
16
71.0
16
59.4
16
T
E
61.7 ( 0.3
67.0 ( 0.3
64.5
this work
diethyl succinate
123-25-1
2
323.8 (-94.8)
24
E
18
GC
S
60.6 ( 0.6
63.8 ( 0.1
60.1
23
335.2 to 465.1
298.2
54.7
17
16
327.0 to 490.0
378.0 to 533.7
290.2 to 345.5
338.7 to 510.0
338.0 to 510.0
339.7 to 473.0
298.3 to 347.9
299.6 to 334.5
298.2
55.1
52.6
63.5
55.5
55.3
54.9
67.3
56.0
64.5
16
E
T
E
66.9 ( 0.3
65.1 ( 0.3
67.6
21
this work
diethyl glutarate
818-38-2
3
4
355.7 (-103.0)
387.6 (-111.4)
18
67.0
16
S
T
65.9 ( 0.1
69.8 ( 0.4
58.0 ( 1.2
64.7 ( 0.7
73.0
17
this work
diethyl adipate
141-28-6
TE
GC
E
25
23
350.6 to 523.9
350.8 to 469.9
298.2
58.4
58.4
18
S
70.5 ( 0.3
64.6
17
16
T
303.5 to 352.5
326.0 to 487.0
326.5 to 486.6
293.6 to 333.5
293.3 to 338.5
70.8
55.1
54.6
60.0
64.4
74.0 ( 0.3
64.4
this work
16
dipropyl oxalate
615-98-5
0
323.8 (-94.8)
E
T
T
64.0
18
61.4 ( 0.5
66.2 ( 0.4
this work
this work
dipropyl malonate
1117-19-7
1
2
355.7 (-103.1)
387.6 (-111.4)
dipropyl succinate
925-15-5
350.0 to 524.0
350.6 to 523.9
308.3 to 343.5
313.3 to 353.5
58.1
58.4
67.9
71.3
72.4
16
E
T
T
73.0
18
71.0 ( 0.3
75.5 ( 0.3
this work
this work
dipropyl glutarate
1724-48-7
3
4
419.5 (-119.7)
451.4 (-127.9)
dipropyl adipate
106-19-4
413 to 540
63.6
85.8
19
413.0 to 540.0
318.8 to 365.3
291.4 to 358.2
85.7
16
T
T
75.5
68.8
81.0 ( 0.3
71.4 ( 0.2
this work
this work
dibutyl oxalate
2050-60-4
0
1
387.6 (-111.4)
419.5 (-119.7)
dibutyl malonate
1190-39-2
T
303.2 to 369.2
70.9
75.3 ( 0.4
this work
806
dx.doi.org/10.1021/je100231g |J. Chem. Eng. Data 2011, 56, 800–810

Journal of Chemical & Engineering Data
ARTICLE
Table 2. Continued
T-range
Clp (Δgl Cp)c
Δgl Hm (Tav)
Δgl Hm(298.15 K)d
compounds
na
techniqueb
K
J mol-1 K-1
kJ mol-1
kJ mol-1
ref
3
3
3
3
dibutyl succinate
141-03-07
2
E
E
451.4 (-127.9)
67.4
18
397.8 to 475.5
313.2 to 358.2
317.5 to 369.5
69.1
74.4
77.2
86.3 ( 0.2
79.1 ( 0.3
83.1 ( 0.2
25
T
T
this work
this work
dibutyl glutarate
6624-57-3
3
4
483.3 (-136.2)
515.2 (-144.5)
dibutyl adipate
435.2 to 563.2
313.2 to 373.2
68.7
84.2
96.9
19
105-99-7
T
88.5 ( 0.5
this work
a n is the number of CH2 groups in the linear aliphatic esters of dicarboxylic acids R-CO2-(CH2)n-CO2-R with n = 0 to 4. b Techniques: E =
ebulliometry; S = static method; T = transpiration; TE = torsion-effusion method; GC = gas-liquid chromatographic correlation method. c Values of
Δgl Cp have been derived from the isobaric molar heat capacity of the liquid esters Cpl according to the procedure developed by Chickos et al.13-15 d Vapor
pressure data available in the literature were treated using eq 2 and eq 3 to evaluate enthalpy of vaporization at T = 298.15 K in the same way as our own
results in Table 1.
Figure 2. Plot of vapor pressure against reciprocal temperature for
diethyl malonate. O, ref 18; ], ref 22; /, ref 8; 2, ref 17; 4, this work.
Figure 1. Plot of vapor pressure against reciprocal temperature for
diethyl oxalate. O, ref 17; 9, ref 18; /, ref 20; ], ref 21; 2, this work.
vaporization with the number of C-atoms in the series of
homologues is a valuable test to check the internal consistency
of the experimental results. Vaporization enthalpies, Δgl Hm,
linearly depended on the number of carbon atoms of the methyl
ester of dicarboxylic acid.3 The plot of ΔlgHm(298.15 K) against
the number of C-atoms in the linear aliphatic alkyl esters of
dicarboxylic acids R-CO2-(CH2)n-CO2-R with n = (0 to 4)
is presented in Figure 4. The dependence of vaporization
enthalpy on the number of C-atoms is described by the following
equations for diethyl, dipropyl, and dibutyl esters correspond-
ingly
Available vapor pressure data for dipropyl oxalate (Figure S3,
Supporting Information), dipropyl succinate (Figure S4, Sup-
porting Information), dipropyl adipate (Figure S5, Supporting
Information), dibutyl succinate (Figure S6, Supporting In-
formation), and dibutyl adipate (Figure S7, Supporting In-
formation) seem to be consistent, and they are presented
graphically in figures given in the Supporting Information.
Enthalpies of vaporization of some alkyl esters of dicarboxylic
acid were assessed by Chickos et al.24 using correlation gas
chromatography. Their vaporization enthalpies for the diethyl
malonate, succinate, and adipate are (3 to 9) kJ mol-1 lower
3
Δgl Hmð298:15 KÞ=kJ mol-1
than our results (Table 2). As a matter of fact, for the correlation
gas chromatography method, Chicoks et al.24 considered a
system of reference vaporization enthalpies based on data
compiled in the handbook by Stephenson and Malanowski,16
which according to Table 2 were not always reliable. However, it
is possible to recalculate the data reported by Chicoks et al.24
using their primary retention data and the reliable vaporization
enthalpies from Table 2.
3
¼ ð57:5 ( 0:2Þ þ ð4:09 ( 0:08Þn
ðR2 ¼ 0:9989Þ
ð4Þ
Δgl Hmð298:15 KÞ=kJ mol-1
3
¼ ð61:3 ( 0:2Þ þ ð4:87 ( 0:08Þn
Correlation of Enthalpies of Vaporization with the Num-
ber of C-Atoms in Esters. The correlation of enthalpies of
ðR2 ¼ 0:9991Þ
ð5Þ
807
dx.doi.org/10.1021/je100231g |J. Chem. Eng. Data 2011, 56, 800–810

Journal of Chemical & Engineering Data
ARTICLE
standards, and logarithmic interpolation is utilized defined by
lgðtxÞ - lgðtNÞ
Jx ¼
100 þ 100 N
ð7Þ
3
3
lgðtN þ 1Þ - lgðtNÞ
where x refers to the adjusted retention time; N is the number of
carbon atoms of the n-alkane eluting before; and (N þ 1) is the
number of carbon atoms of the n-alkane eluting after the peak of
interest. According to the established GC procedure, all reten-
tion times are corrected for the “dead” retention time adjusted
from the retention times of the homologous n-hydrocarbons.26,27
There are some comprehensive libraries containing Jx values
available from the literature, which are generally standardized for
the common stationary phases. In this work, we used the data for
stationary phases OV-101.10
The vaporization enthalpy Δgl Hm appears to be a linear
function of Kovat’s indices in homologous series of methyl esters
Figure 3. Plot of vapor pressure against reciprocal temperature for
diethyl adipate. O, ref 18; Δ, ref 25; 2, ref 17; [, this work.
Figure 5. Plot of experimental vaporization enthalpies Δgl Hm(298.15
K) against Kovat’s index J (OV-101 at 423.15 K) for dipropyl esters of
dicarboxylic acids (Pr-CO2-(CH2)n-CO2-Pr) with n = 0, 1, 2,
3, and 4.
Figure 4. Plot of experimental vaporization enthalpies Δgl Hm(298.15
K) against the number of CH2 groups in the linear aliphatic esters of
dicarboxylic acids R-CO2-(CH2)n-CO2-R (R = CH3-, C2H5-,
C3H7-, C4H9-): [, ethyl; b, propyl; Δ, butyl.
Δgl Hmð298:15 KÞ=kJ mol-1
3
¼ ð71:1 ( 0:4Þ þ ð4:20 ( 0:18Þn
ðR2 ¼ 0:9946Þ
ð6Þ
from which enthalpy of vaporization Δgl Hm(298.15 K) for other
representatives of this series with n > 4 can be calculated.
Correlation of Enthalpies of Vaporization with Kovat’s
Indices. The correlation of the enthalpies of vaporization with
Kovat’s indices of the organic compounds is another valuable
method to study the systematic behavior in homologous series.
Kovat’s index is the retention characteristics acknowledged among
analytic chemists for the identification of the individual compounds
in diverse mixtures. In Kovat’s index, n-alkanes serve as the
Figure 6. Plot of experimental vaporization enthalpies Δgl Hm(298.15
K) against Kovat’s index (OV-101 at 423.15 K) for diethyl and dibutyl
esters of dicarboxylic acids: R-CO2-(CH2)n-CO2-R with n = 0, 1, 2,
3, and 4. Δ, ethyl; b, butyl.
808
dx.doi.org/10.1021/je100231g |J. Chem. Eng. Data 2011, 56, 800–810

Journal of Chemical & Engineering Data
ARTICLE
Table 3. Vapor Pressure Coefficients of Equation 2 for
Dialkyl Esters of Dicarboxylic Acids
NK_149 P (GC-P1660), Scientists and Educators of Innovative
Russia (2009-2013).
compounds
temperature range, K
a
b
Δgl Cp
’ REFERENCES
diethyl oxalate
283.5 to 458.8
283.7 to 472.0
290.1 to 489.6
298.3 to 510.0
303.4 to 523.9
293.5 to 486.6
308.2 to 523.9
318.7 to 540.0
313.2 to 457.7
313.1 to 563.1
307.57
321.86
333.19
-81385.52
-87949.79
-93562.27
78.2
86.5
94.8
(1) Zeikus, J.; Jain, M.; Elankovan, P. Biotechnology of succinic acid
production and markets for derived industrial products. Appl. Microbiol.
Biotechnol. 1999, 51, 545–552.
diethyl malonate
diethyl succinate
diethyl glutarate
diethyl adipate
dipropyl oxalate
dipropyl succinate
dipropyl adipate
dibutyl succinate
dibutyl adipate
(2) Wolf, O.; Crank, M.; Patel, M.; Marscheider-Weidemann, F.;
Schleich, J.; H€using, B.; Angerer, G. Techno-economic feasibility of
large-scale production of Bio-based polymers in Europe. European
Science and Technology Observatory. 2005, EUR 22103 42 EN.
(3) Verevkin, S.; Kozlova, S.; Emel’yanenko, V.; Nikitin, E.; Popov,
A.; Krasnykh, E. Vapor pressures, enthalpies of vaporization, and critical
parameters of a series of the linear aliphatic dimethyl esters of dicar-
boxylic acids. J. Chem. Eng. Data 2006, 51, 1896–1905.
348.03 -100716.15 103.1
364.39 -108100.31 111.4
332.37
-92817.18
94.8
359.27 -105719.28 111.4
400.00 -123641.37 127.9
389.01 -119340.17 127.9
430.12 -137398.93 144.5
(4) Verevkin, S. P.; Beckhaus, H.-D.; Belen’kaja, R. S.; Rakus, K.;
R€uchardt, C. Geminal Substituent Effects. 9. Enthalpies of Formation
and Strain Free Increments of Branched Esters and Ethers. Thermochim.
Acta 1996, 279, 47–64.
(5) Verevkin, S. P.; Heintz, A. Determination of Vaporization
Enthalpies of the Branched Esters from Correlation Gas-Chromatogra-
phy and Transpiration Methods. J. Chem. Eng. Data 1999,
44, 1240–1244.
of dicarboxylic acids.3 We have used Kovat’s indices obtained in
our previous work10 and own results for ΔlgHm(298.15 K) for
alkyl esters of dicarboxylic acids (see Table 2) to test how the
results fit into a systematic dependence on Kovat’s indices.
Experimental Jx values for alkyl esters of dicarboxylic acids with
n = 0 to 4, used in this work, are given in Table S2, Supporting
Information. It is apparently from Figures 5 and 6 that the data
for Δgl Hm(298.15 K) fit very well in the linear correlation. This
fact could serve as evidence of the internal consistency of our
experimental results for vaporization enthalpies.
Vapor Pressure Correlations for Dialkyl Esters of Dicar-
boxylic Acids. Taking the generally good agreement between
vapor pressure data reported in this work and the literature into
account, the experimental data (if it has been possible) were
regressed together to develop correlations accurately describing
the vapor pressure of dialkyl esters of dicarboxylic acids over a
temperature range from ambient to the normal boiling point.
Table 3 summarizes coefficients of the vapor pressure correlation
(eq 3) for dialkyl esters of dicarboxylic acids, which could be used
for thermochemical and technical calculations.
(6) Krasnykh, E. L.; Verevkin, S. P.; Koutek, B.; Doubsky, J. Vapor
Pressures and Enthalpies of Vaporization of a Series of the n-Alkyl
Acetates. J. Chem. Thermodyn. 2006, 38, 717–723.
(7) Verevkin, S. P.; Dogan, B.; Beckhaus, H.-D.; R€uchardt, C.
Synergic destabilization bei geminal ester groups. Angew. Chem. 1990,
102, 693-694; Angew. Chem., Int. Ed. Engl. 1990, 29, 674.
(8) Verevkin, S. P.; Beckhaus, H.-D.; R€uchardt, C. Geminal Substituent
Effects. V. Enthalpies of Formation of Alkylsubstituted Malonic Acid and
Aminocarboxylic Acid Esters. Thermochim. Acta 1992, 197, 27–39.
(9) Rakus, K.; Verevkin, S. P.; Keller, M.; Beckhaus, H.-D.; R€uchardt,
C. Substituent Effects on the Strength of C-C Bonds. 19. Geminal
Substituent Effects. 10. Radical Stabilisation Enthalpies of Bis-
(methoxycarbonyl)alkyl- and Tris(methoxycarbonyl)methyl Radikals.
Liebigs Ann. 1995, 1, 1483–1493.
(10) Lipp, S. V.; Krasnykh, E. L.; Levanova, S. V. Retention indices
of symmetric dicarboxylic acid esters. J. Anal. Chem. 2008, 63, 349–352.
(11) Verevkin, S. P. Pure Component Phase Changes Liquid and
Gas. In Experimental Thermodynamics: Measurement of the thermody-
namic properties of multiple phases; Weir, R. D., De Loss, Th. W., Eds.;
Elsevier: New York, 2005; Vol. 7, Chapter 1, pp 6-30.
’ ASSOCIATED CONTENT
(12) Kulikov, D. V.; Verevkin, S. P.; Heintz, A. Enthalpies of
vaporization of a series of linear aliphatic alcohols. Experimental
measurements and application of the ERAS-model for their prediction.
Fluid Phase Equilib. 2001, 192, 187–202.
(13) Chickos, J. S.; Hesse, D. G.; Liebman, J. F. A Group Additivity
Approach for the Estimation of Heat Capacities of Organic Liquids and
Solids. Struct. Chem. 1993, 4, 261–269.
(14) Chickos, J. S.; Acree, W. E., Jr. Enthalpies of Vaporization of
Organic and Organometallic Compounds, 1880-2002. J. Phys. Chem.
Ref. Data 2003, 32, 519–878.
(15) Chickos, J. S.; Acree, W. E., Jr. Enthalpies of Sublimation of
Organic and Organometallic Compounds, 1910-2001. J. Phys. Chem.
Ref. Data 2002, 31, 537–698.
(16) Stephenson, R. M.; Malanowski, S. Handbook of the Thermo-
dynamics of Organic Compounds; Elsevier: New York, 1987.
(17) Heiber, W.; Reindl, E. Bildungsw€armen und constitution von
molek€ulverbindungen des zinntetrachlorids. Ztschr. Elektrochem. 1940,
10, 559–570.
(18) Stull, D. R. Vapor Pressure of Pure Substances Organic
Compounds. Ind. Eng. Chem. 1947, 39, 517–540.
(19) Dykyj, J.; Svoboda, J.; Wilhoit, R. C.; Frenkel, M.; Hall, K. R.
Vapour Pressure of chemicals. Subvolume B. Vapour Pressure and Antoine
Coefficient for Oxygen-Containing Organic Compaunds. Thermodynamics
Research Center. The Texas A&M University system, 1998.
S
Supporting Information. Experimental data on enthal-
b
pies of vaporization of the methyl esters of dicarboxylic acids
(Table S1); Kovat’s indices on the OV-101 phase at 423.15 K of
the linear symmetric alkyl esters of dicarboxylic acids (Table S2);
comparison of the vapor pressures available for alkyl esters of
dicarboxylic acids (Figures S1 to S7). This material is available
free of charge via the Internet at http://pubs.acs.org.
’ AUTHOR INFORMATION
Corresponding Author
*Telephone: þ49 381 498 6508). Fax: þ49 381 498 6524.
E-mail: sergey.verevkin@uni-rostock.de.
Funding Sources
Svetlana Lipp acknowledges gratefully a research scholarship
from the DAAD (Deutscher Akademischer Austauschdienst).
Sergey P. Verevkin acknowledges gratefully financial support
from the Research Training Group 1213 “New Methods for
Sustainability in Catalysis and Technique” of the German
Science Foundation (DFG). Eugen L. Krasnykh acknowledges
gratefully financial support from the Federal Target Program
809
dx.doi.org/10.1021/je100231g |J. Chem. Eng. Data 2011, 56, 800–810

Journal of Chemical & Engineering Data
ARTICLE
(20) Matsuda, A.; Tanaka, Y.; Munakata, T. Measurement of phy-
sical properties of diethyl oxalate-methyl salicylate. Kyushu Univ.,
Fukuoka, Japan. Kogaku Shuho-Kyushu Daigaku 1970, 43 (6), 834–41.
(21) Steele, W. V.; Chirico, R. D.; Hossenlopp, I. A.; Knipmeyer,
S. E.; Nguyen, A.; Smith, N. K. Determination of ideal-gas enthalpies of
formation for key compounds. DIPPR project 871, Experimental Results
for DIPPR 1990-91 Projects on Phase Equilibria and Pure Component
Properties; DIPPR: Barlesville, OK, 1994; pp 188-215.
(22) Smirnova, G. E.; Zel’venski, Ya. D.; Shalygin, V. A.; Sukhor-
ukova, G. A.; Dzhekseneva, T. Z. Vapor pressure of some derivatives of
malonic esters. Mosk. Khim.-Tekhnol. Inst., Mockow, USSR. Avali. VINITI.
Deposited Doc. 1978, (VINITI 3298-78), 9.
(23) Katayama, H. Measurement and estimation of vapor pressures
of dimethyl, diethyl, diisopropyl and dibutyl succinates at reduced
pressure. J. Chem. Eng. Jpn. 1992, 25, 366–372.
(24) Chickos, J. S.; Sabbah, R.; Hosseini, S.; Liebman, J. F. The
sublimation enthalpy of dimethyl oxalate. Struct. Chem. 1996,
7, 391–395.
(25) Chen, J.; Liang, Y.; Ma, P. Determination of extremely-low
vapor pressure of five esters by using torsion-effusion method. Huagong
Xuebao (Chin. Ed.) 1997, 48, 622–625.
(26) Pacakova, V.; Feltl, K. Chromatographic Retention Indices; An
Aid to the Identfication of Organic Compounds; Ellis Horwood: London,
1992.
(27) Emel’yanenko, V. N.; Verevkin, S. P.; Koutek, B.; Doubsky, J.
Vapor Pressures and Enthalpies of Vaporization of a Series of the Linear
Aliphatic Nitriles. J. Chem. Thermodyn. 2005, 37, 73–81.
810
dx.doi.org/10.1021/je100231g |J. Chem. Eng. Data 2011, 56, 800–810