Apparent molar volumes and expansivities of ionic liquids based on N -Alkyl- N -methylmorpholinium cations in acetonitrile

Article abstract of DOI:10.1021/je400790d

Densities of some acetonitrile solutions of ionic liquids based on N-alkyl-N-methyl-morpholinium cations, N-ethyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide, N-butyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide, N-methyl-N-octylmorpholinium bis(trifluoromethanesulfonyl)imide and N-decyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide were measured at T = (298.15-318.15) K and at atmospheric pressure. From density data the apparent molar volumes and partial molar volumes of the ILs at infinite dilution as well as the limiting apparent molar expansibilities and the Hepler's constant values have been evaluated. The results have been discussed in terms of the effect that alkyl chain length of the ILs and experimental temperature have on the ionic liquid-acetonitrile interactions occurring in the studied solutions.

Full text of DOI:10.1021/je400790d

Article
pubs.acs.org/jced
Apparent Molar Volumes and Expansivities of Ionic Liquids Based on
N‑Alkyl‑N‑methylmorpholinium Cations in Acetonitrile
Łukasz Marcinkowski, Teresa Olszewska, Adam Kloskowski, and Dorota Warmins
́
ka*,†
†
‡
†
†
‡
Department of Physical Chemistry and Department of Organic Chemistry, Chemical Faculty, Gdan
0-233 Gdansk, Poland
́
sk University of Technology,
8
́
ABSTRACT: Densities of some acetonitrile solutions of ionic liquids
based on N-alkyl-N-methyl-morpholinium cations, N-ethyl-N-methylmor-
pholinium bis(trifluoromethanesulfonyl)imide, N-butyl-N-methylmorpholi-
nium bis(trifluoromethanesulfonyl)imide, N-methyl-N-octylmorpholinium
bis(trifluoromethanesulfonyl)imide and N-decyl-N-methylmorpholinium
bis(trifluoromethanesulfonyl)imide were measured at T = (298.15−
318.15) K and at atmospheric pressure. From density data the apparent
molar volumes and partial molar volumes of the ILs at infinite dilution as
well as the limiting apparent molar expansibilities and the Hepler’s constant
values have been evaluated. The results have been discussed in terms of the
effect that alkyl chain length of the ILs and experimental temperature have
on the ionic liquid−acetonitrile interactions occurring in the studied
solutions.
1
. INTRODUCTION
have been used for the computation of excess molar volumes
and interpreted in terms of ion−dipole interactions as well as
the structural aspects of the ionic liquid and the investigated
organic solvents. Only a few papers are focused on limiting
molar quantities which may be determined by studying highly
Over the past years ionic liquids have received much attention
as potential green solvents or as materials for a wide range of
applications in engineering. The main benefits of ionic liquids
are their extremely low vapor pressure, nonflammability, high
thermal and electrochemical stabilities, and wide liquid
temperature range. Nowadays ILs are widely used in organic
synthesis, biocatalysis, nanotechnology, electrochemistry, and
32−35
diluted solutions of ionic liquids.
Hence, in the present
1
−3
work we report the volumetric properties of some ionic liquids
based on N-alkyl-N-methylmorpholinium cations in acetonitrile
(AN) solutions. It is worth noting that so far the interactions of
morpholinium cation-based ILs with nonpolar and dipolar
4
−7
separation technologies, etc.
Because of a growing interest in industrial applications of
ionic liquids, various ILs have been subjected to studies of their
structure−property relationships. Most of these studies
concerned ionic liquids containing alkylimidazolium, alkyl
pyrrolidinium, alkylpyridinium, phosphonium, and quaternary
ammonium cations.
reported on the synthesis, thermal, electrochemical, and
physicochemical characterization of morpholinium cation
3
6,37
solutes have been studied by Khara et al.
using the time-
resolved fluorescence anisotropy measurements. Our interest in
systems containing acetonitrile is due to the report of Chaban
3
8
et al. They found that acetonitrile decreases in an
unprecedented way the viscosity of ILs and increases their
ionic conductivity, which is not without significance for the
application of IL/AN binary systems as advanced electrolyte
solutions in electrochemistry. In our study, data on the
densities of acetonitrile solutions of N-ethyl-N-methylmorpho-
linium bis(trifluoromethanesulfonyl)imide, N-butyl-N-methyl-
morpholinium bis(trifluoromethanesulfonyl)imide, N-methyl-
N-octylmorpholinium bis(trifluoromethanesulfonyl)imide, and
N-decyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)-
imide obtained at T = 298.15, 303.15, 308.15, 313.15, and
8
−12
Recently, some work has been
1
3−17
based ILs.
These ionic liquids can be conveniently
synthesized because of their good product reproducibility,
easy purification process, low cost, and short processing time.
Morpholinium based ILs have been applied as catalysts, heat
stabilizers, antioxidants for lubricating oils and as corrosion
1
8−20
inhibitors.
Moreover, they have been considered as
21
electrolytes for conventional lithium batteries.
3
18.15 K are reported. From the experimental data, the
Despite its importance for process design, detailed knowl-
edge of the thermodynamic and transport properties of
mixtures of ionic liquids with other molecular solvents is
limited. Existing studies mainly concern the density, viscosity,
and speed of sound of mixtures of water or alcohols and ILs
apparent molar volumes and partial molar volumes of the ILs at
infinite dilution as well as the limiting apparent molar
expansibilities and the Hepler’s constant values have been
estimated. The results have been discussed in terms of the
22−26
based on alkylimidazolium or alkylpyridinium cations.
However, in recent times data on the volumetric properties of
systems involving ionic liquids with aprotic organic solvent
Received: September 3, 2013
Accepted: February 19, 2014
Published: March 3, 2014
27−31
have been published.
The results of density measurements
©
2014 American Chemical Society
718
dx.doi.org/10.1021/je400790d | J. Chem. Eng. Data 2014, 59, 718−725

Journal of Chemical & Engineering Data
Article
1
3
effect that alkyl chain length of the ILs and experimental
temperature have on the ionic liquid−acetonitrile interactions
occurring in the studied solutions.
7.3 Hz, 3H). C NMR (CDCl ) δ 119.72 (q, J = 321.0 Hz),
3
CF
61.23, 60.23, 59.35, 45.77, 6.62.
N - B u t y l - N - m e t h y l m o r p h o l i n i u m B i s -
trifluoromethanesulfonyl)imide [Mor ][TFSI]. H NMR
1
(
1
,4
2. EXPERIMENTAL SECTION
(
DMSO-d , δ/ppm relative to TMS): δ 3.89 (brs, 4H), 3.38
6
2
.1. Chemicals. Acetonitrile (AN) (purity > 99.9 % and
(m, 6H), 3.09 (s, 3H), 1.64 (m, 2H), 1.30 (m, 2H), 0.93 (t, J =
−
4
13
mass fraction of H O < 2.10 ), N-methylmorpholine
ReagentPlus, 99 %), bromoethane (reagent grade, 98 %), 1-
bromobutane (ReagentPlus, 99 %), 1-bromooctane (99 %), 1-
bromodecane (98 %), lithium bis(trifluoromethylsulfonyl)-
imide (99.95 % trace metals basis) were obtained from
Sigma-Aldrich. Dichloromethane (>99.9 %) and acetone
7.4, Hz, 3H). C NMR (CDCl ) δ 119.99 (q, JCF = 321.1 Hz),
3
2
(
66.29, 60.60, 60.09, 46.54, 23.40, 19.46, 13.32.
N - M e t h y l - N - o c t y l m o r p h o l i n i u m B i s -
1
(trifluoromethanesulfonyl)imide [Mor1,8][TFSI]. H NMR
(CDCl , δ/ppm relative to TMS): δ 3.96 (dd, J = 6.6 and
3
3.3 Hz, 4H), 3.41 (m, 4H), 3.34 (m, 2H), 3.15 (s, 3H), 1.72
(
>99.9 %) were purchased from POCH. All solvent and
reagents were used without further purification.
.2. Synthesis of Ionic Liquid. Figure 1 presents the
(m, 2H), 1.34 (m, 4H), 1.27 (m, 5H), 0.87 (t, J = 6.8 Hz, 2H).
13
C NMR (CDCl ) δ 119.95 (q, JCF = 321.1 Hz), 66.79, 60.73,
3
2
60.18, 46.76, 31.75, 29.10, 29.07, 26.19, 22.72, 21.69, 14.20.
molecular structures of the studied ionic liquids. All of them
N - D e c y l - N - m e t h y l m o r p h o l i n i u m B i s -
trifluoromethanesulfonyl)imide [Mor1,10][TFSI]. H NMR
1
(
(
3
CDCl δ/ppm relative to TMS): δ 3.96 (t, J = 4.8 Hz, 4H),
3
.42 (m, 4H), 3.35 (m, 2H), 3.16 (s, 3H), 1.75 (m, 2H), 1.34
1
3
(
(
4
1
m, 4H), 1.27 (m, 9H), 0.87 (t, J = 6.9 Hz, 2H). C NMR
CDCl ) δ 119.99 (q, J = 321.2 Hz), 66.82, 60.75, 60.20,
3
CF
6.79, 32.02, 29.54, 29.48, 29.40, 29.15, 26.23, 22.84, 21.73,
4.28.
−
The possible presence of residual of Br in the prepared ionic
liquids was examined by ionic chromatography measurements
Figure 1. Molecular structures of the studied ionic liquids.
(
ICS 3000 ion-exchange chromatography apparatus from
Dionex, equipped in electrochemical detector operated in the
conductivity mode). Determinations were performed using
Dionex AS22 IonPac column. Ionic liquid samples were
prepared by dissolution of the 0.10 g of the given IL in 10
mL of the 40% acetonitrile in water solutions. Thus the final
concentrations of the samples were equal 1% w/v. Chromato-
graphic system was calibrated using standard solutions prepared
using analytical grade potassium bromide (concentrations
were prepared according to the procedure described for the first
time by Kim et al., which was modified in terms of the reaction
length and workup. The sequence of reactions leading to the
formation of the required ionic liquid is shown in Scheme 1. In
39
Scheme 1. The Sequence of Reactions Leading to the
a
Formation of Required Ionic Liquid
varied from 1 μg·g− to 50 μg·g ). All samples, as well as
1
−1
chromatographic eluent were prepared using deionized water
(
Milli-Q water system, Bedford, MA, USA). Eluent contained
4
.5 mM Na CO and 1.4 mM NaHCO was delivered in the
2 3 3
−1
−
0
,3 mL·min rate. The Br content for [Mor1,2] [TFSI],
[Mor1,4] [TFSI], [Mor1,8] [TFSI] and [Mor1,10] [TFSI] was
−1
found to be equal 65, 190, 55, and 530 μg·g , respectively.).
Taking in to account low content of water and bromide, as
well as the high purity of the reagents used for synthesis, we
assumed that overall purity of investigated ionic liquids was
higher than 99 %. Before measurements the ionic liquids were
a
Reagents and conditions: (i) RBr, CH CN, 65 °C, 48 h; (ii)
3
(
CF SO ) NLi, CH Cl , 48 h, room temp.
3 2 2 2 2
dried by purging them with a neutral gas (N ) at 323 K for
2
the synthesis, commercially available N-methylmorpholine was
used as a starting substrate which, upon treatment with
bromoethane, 1-bromobutane, 1-bromooctane, or 1-bromode-
cane in acetonitrile, gives the resepective quaternary
morpholinium salts. In the next step the obtained bromide
salts were converted into the corresponding [TFSI] products
by treatment with lithium bis(trifluoromethylsulfonyl)imide in
dichloromethane in an anion exchange reaction. It is note-
worthy that one of the synthesized ionic liquids, namely
more than 72 h. The water content in the ILs, measured by the
Karl Fischer titration method (831 KF Coulometer apparatus
from Metrohm), for [Mor1,2] [TFSI], [Mor1,4] [TFSI],
[Mor1,8] [TFSI], and [Mor1,10] [TFSI] was found to be equal
to (192, 187, 204, and 210) μg·g− mass fraction, respectively.
2.3. Apparatus and Procedure. Stock solutions of the ILs
were prepared by mass and then diluted by acetonitrile to get
the test samples. All the preparations and manipulations
involving anhydrous materials were performed in a drybox.
Densities of the solutions were measured using an Anton
Paar DMA 5000 density meter with a thermostat system based
1
[
Mor1,10][TFSI], is a new compound which has been
synthesized for the first time. The prepared ionic liquids were
1
13
−3
−3
characterized using H and C NMR (Varian Unity Plus
spectrometer operating at 500 and 125 MHz, respectively).
on a Peltier unit with a repeatability of 5.0·10 kg m and an
2
standard uncertainty equal 1.0·10− kg m . The temperature
was kept constant between 298.15 K and 318.15 K with an
accuracy of 0.01 K. Before each measurement series, the
accuracy of the density measurements and solvent purity were
verified by measuring the density of pure acetonitrile at T =
−3
N - E t h y l - N - m e t h y l m o r p h o l i n i u m B i s -
1
(
trifluoromethanesulfonyl)imide [Mor ][TFSI]. H NMR
1
,2
(
3
CDCl , δ/ppm relative to TMS): δ 3.92 (t, J = 4.7 Hz, 4H),
.45 (q, J = 7.2 Hz, 2H), 3.34 (m, 4H), 3.06 (s, 3H), 1,35 (t, J =
3
7
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dx.doi.org/10.1021/je400790d | J. Chem. Eng. Data 2014, 59, 718−725

Journal of Chemical & Engineering Data
Article
Table 1. Densities, d and Apparent Molar Volumes, Vφ of Solutions of Ionic Liquids in Acetonitrile at T = (298.15 to 318.15) K
(
Pressure p = 0.1 MPa)
T = 298.15 K
10−3d 106VΦ
T = 303.15 K
T = 308.15 K
T = 313.15 K
T = 318.15 K
mS
m
10−3
d
106VΦ
10−3
d
106VΦ
10−3
d
106VΦ
10−3
d
106VΦ
mol·kg−
1
mol·kg−1
kg·m−3
m ·mol
3
−1
kg·m−3
m ·mol
3
−1
kg·m−3
m ·mol
3
−1
kg·m−3
m ·mol
3
−1
kg·m−3
m ·mol
3
−1
[
Mor1,2][TFSI]
0
0
0
0
0
0
0
0
0
0
.00940
0.009434
0.01654
0.02652
0.03788
0.05256
0.06858
0.08695
0.1078
0.778145
0.779333
0.780985
0.782850
0.785240
0.787810
0.790740
0.794037
0.797714
0.802540
248.26
248.98
249.89
250.74
251.62
252.58
253.25
253.70
254.83
256.14
0.772716
0.773905
0.77556
247.85
248.56
249.37
250.15
251.26
252.31
252.96
253.52
254.71
256.10
0.767263
0.768452
0.770110
0.771974
0.774365
0.776944
0.779877
0.783146
0.786836
0.791661
246.85
247.89
248.68
249.84
250.86
251.73
252.48
253.50
254.50
255.90
0.761774
0.762964
0.764619
0.766483
0.768876
0.771442
0.774373
0.777657
0.781334
0.786155
246.17
247.28
248.39
249.58
250.55
251.79
252.54
253.29
254.49
255.94
0.756247
0.75744
245.44
246.41
247.23
248.26
249.44
250.72
252.09
252.59
253.95
255.55
.01643
.02623
.03729
.05146
.06670
.08395
.1032
0.759113
0.760976
0.763372
0.765945
0.768855
0.772158
0.775832
0.780648
0.777429
0.779815
0.782385
0.785318
0.788611
0.792286
0.797108
.1249
0.1316
.1531
0.1634
[
Mor1,4][TFSI]
0
0
0
0
0
0
0
0
0
0
.00876
.01641
.02727
.0374
0.00879
0.01653
0.02761
0.03802
0.05226
0.06737
0.08642
0.1101
0.778005
0.779272
0.781074
0.782759
0.785036
0.787436
0.790427
0.794115
0.797144
0.802019
290.27
290.92
291.33
291.61
292.23
292.58
293.11
293.54
0.772575
0.773845
0.775647
0.777331
0.779607
0.781999
0.784994
0.788679
0.791717
0.796577
290.37
290.73
291.28
291.66
292.35
292.92
293.34
293.82
294.18
295.09
0.767120
0.768390
0.770192
0.771873
0.774153
0.776549
0.779543
0.783226
0.786253
0.791135
290.06
290.61
291.25
291.81
292.37
292.88
293.37
293.92
294.45
295.14
0.761631
0.762901
0.764703
0.766385
0.768667
0.771064
0.774057
0.777740
0.780771
0.785644
289.71
290.46
291.19
291.76
292.30
292.83
293.39
293.98
294.48
295.32
0.756103
0.757375
0.759178
0.760862
0.763147
0.765551
0.768552
0.772235
0.775257
0.780136
289.52
290.16
290.98
291.53
292.06
292.49
293.00
293.72
294.41
295.24
.05109
.06543
.08326
.1051
.1229
0.1300
294.013
294.75
.1515
0.1623
[
Mor1,8][TFSI]
0
0
0
0
0
0
0
0
0
0
.00860
.01582
.02493
.03657
.04938
.06357
.08323
.09874
.1214
0.00864
0.01594
0.02524
0.03724
0.05062
0.06563
0.08680
0.1038
0.778032
0.779270
0.780834
0.782840
0.785053
0.787516
0.790942
0.793660
0.797655
0.802048
352.47
353.04
353.64
354.04
354.50
354.82
355.34
355.72
356.22
356.79
0.772604
0.773845
0.775414
0.777423
0.779637
0.782098
0.785532
0.788255
0.792260
0.796655
352.55
353.00
353.47
353.96
354.55
355.04
355.50
355.87
356.34
356.98
0.767150
0.768392
0.769962
0.771972
0.774191
0.776655
0.780089
0.782815
0.786817
0.791206
352.40
353.02
353.59
354.16
354.67
355.18
355.74
356.12
356.70
357.46
0.761661
0.762906
0.764479
0.766490
0.768712
0.771180
0.774615
0.777346
0.781350
0.785752
352.42
352.91
353.49
354.19
354.72
355.23
355.90
356.26
356.91
357.60
0.756135
0.757382
0.758957
0.760974
0.763200
0.765666
0.769109
0.771842
0.775861
0.780271
352.19
352.75
353.41
354.00
354.57
355.29
355.90
356.33
356.86
357.59
0.1292
.1462
0.1576
[
Mor1,10][TFSI]
0
0
0
0
0
0
0
0
0
0
.00834
.01551
.02440
.03643
.04973
.06430
.08140
.09973
.1212
0.00838
0.01564
0.02472
0.03714
0.05106
0.06653
0.08502
0.1052
0.777974
0.779195
0.780710
0.782766
0.785044
0.787549
0.790507
0.793696
0.797448
0.802250
391.20
391.57
392.02
392.40
392.92
393.32
393.71
394.05
394.45
395.08
0.772547
0.773770
0.775289
0.777348
0.779630
0.782140
0.785101
0.788290
0.792039
0.796850
391.35
391.80
392.19
392.65
393.19
393.60
394.06
394.50
395.03
395.63
0.767094
0.768318
0.769839
0.771899
0.774185
0.776698
0.779664
0.782856
0.786610
0.791423
391.28
392.00
392.46
393.05
393.57
394.01
394.46
394.95
395.50
396.17
0.761606
0.762833
0.764357
0.766421
0.768710
0.771222
0.774189
0.777385
0.781149
0.785970
391.37
392.06
392.56
393.19
393.79
394.39
394.93
395.42
395.92
0.756080
0.757311
0.758838
0.760906
0.763198
0.765716
0.768695
0.771901
0.775667
0.780493
391.43
391.98
392.57
393.26
393.95
394.54
394.97
395.45
396.08
396.86
0.1294
.1484
0.1609
396.60
−3
−1
Standard uncertainties u are u(T) = 0.01 K, u(d) = 0.08 kg·m , standard uncertainty of molinity u(m ) = 0.001 mol·kg and standard uncertainty of
molality u(m) = 0.001 mol·kg
S
−1
−
3
2
98.15 K. A density of 776.554 kg·m with standard
where V is the volume of the solution, n and n denote the
1 2
−3
0
uncertainty 0.08 kg·m was found, whereas the literature
values vary from 775.9 kg·m to 776.93 kg·m .
number of moles of the solvent and solute, respectively, and V
is the molar volume of the solvent.
1
−3
−3 40,41
The values of the apparent molar volumes V of the studied
Φ
3
. RESULTS AND DISCUSSION
solutions of ionic liquids were calculated from experimental
density data using the following equation:
The apparent molar volume VΦ is defined as the difference
between the volume of the solution and the volume of pure
solvent per mole of solute and is given by the equation:
V = (d − d)/(m dd ) + M /d
(2)
Φ
0
S
0
2
0
where m denotes the number of moles of the solute per
0
1
s
V = (V − n V )n
(1)
Φ
1
2
kilogram of solution (molinity); d and d are the densities of
0
7
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Journal of Chemical & Engineering Data
Article
solution and solvent, respectively; and M is the molar mass of
the solute. Equations based on molarity, c, or molality, m, have
somewhat different forms. Equation 2 was preferred because
Table 2. The Coefficients of the Redlich, Rosenfeld, and
Meyer (RRM) Equation, the Corresponding Standard
Deviations σ and the Limiting Apparent Molar Volumes for
Ionic Liquids in Acetonitrile Obtained by Using Masson
Equation at 298.15 K
2
the value m is a direct experimental quantity characterizing the
s
solution. It obvious that the calculation of molar concentration
is possible using the equation:
Redlich, Rosenfeld, and Meyer (RRM)
equation
Masson
equation
c = mSd
(3)
1
06V0
109bv
106σ
106V0
Φ
Φ
The density data and apparent molar volumes obtained for
the solutions of [Mor ][TFSI], [Mor ][TFSI], [Mor ]-
3
−1
6
−2
3
−1
3
−1
ionic liquid
m ·mol
m ·mol
m ·mol
m ·mol
1
,2
1,4
1,8
[
TFSI], and [Mor1,10][TFSI] in acetonitrile at temperatures
[Mor1,2
]
247.26 ± 0.36
289.05 ± 0.11
351.55 ± 0.13
390.14 ± 0.10
35.6 ± 5.5
3.1 ± 1.4
6.4 ± 2.1
2.87 ± 0.98
0.28
245.75
[
TFSI]
Mor1,4
TFSI]
Mor1,8
[TFSI]
[Mor1,10
TFSI]
between 298.15 K and 318.15 K are collected in Table 1. As
seen, the apparent molar volume of all the studied ionic liquids
is found to be increasing with concentration at all temperatures
investigated. At low molarities of IL, the ions are surrounded by
the solvent molecules, indicating strong ion−solvent inter-
action, an increase in the IL molarity increases the ion−ion
[
[
]
0.085
0.10
288.95
[
]
351.282
390.019
]
0.049
[
interactions resulting in greater V values.
Φ
To provide a more complete discussion of the effect of alkyl
chain length of the ILs and experimental temperature on the
ionic liquid−acetonitrile interactions, the apparent molar
volumes at infinite dilution were estimated. At this limit, each
Moreover, analysis at 298.15 K on the basis of eq 8 has been
attempted. The obtained values of empirical slopes S , the
V
apparent molar volumes of ionic liquids at infinite dilution at
experimental temperatures, and their standard deviations σ are
collected in Table 3. As seen from Table 2, the values of the
limiting apparent molar volumes obtained using RRM and
Masson equation agree generally. Moreover, standard devia-
ion is surrounded only by the solvent molecules and therefore
0
Φ
V is unaffected by ion−ion interactions and is a measure only
of the ion−solvent interactions.
The extrapolation of the experimental apparent molar
volumes to infinite dilution to obtain the limiting apparent
molar volumes at 298.15 K was based on the Redlich,
tions of the empirical slope S of the Masson equation are
V
significantly smaller than those obtained for the RRM equation.
Thus, we based further calculations and the discussion on the
42
Rosenfeld, and Meyer (RRM) equation:
values of V0 obtained from the Massson equation. Figure 2
Φ
0
DH
V = V + S
c + bVc
(4)
Φ
Φ
V
Table 3. The Coefficients of Masson Equation and the
where S DV H denotes the theoretical Debye−Hu
volumes and b is an empirical term. For the ionic liquids
ckel slope for the
̈
Corresponding Standard Deviations σ for [Mor ][TFSI],
1,2
[Mor ][TFSI], [Mor ][TFSI], and [Mor1,10][TFSI] in
Acetonitrile from (298.15 to 318.15) K
V
1,4
1,8
studied, that is, type 1−1 electrolytes, the slope equal in
3
3/2
−3/2
acetonitrile to 13.17 cm dm mol
expression:
was calculated from the
Masson equation
DH
T
106V0
106SV
(m ·mol−3)1/2
106σ
Φ
S
= 6RTA [(∂ ln ε/∂P) − κ /3]
(5)
V
Φ
T
T
3
−1
9
3
−1
K
m ·mol
m ·mol
where R is the gas constant, T is the temperature, κ is the
isothermal compressibility of acetonitrile, ε is its dielectric
constant and (∂ ln ε/∂P) is its pressure dependence The
Debye−Hu
A was obtained by
T
[
Mor1,2][TFSI]
43
2
3
3
3
98.15
03.15
08.15
13.15
245.75 ± 0.15
245.06 ± 0.17
244.03 ± 0.11
243.25 ± 0.15
241.95 ± 0.20
[
288.95 ± 0.10
288.77 ± 0.11
288.51 ± 0.10
288.15 ± 0.10
287.84 ± 0.11
0.92 ± 0.020
0.98 ± 0.028
1.06 ± 0.015
1.15 ± 0.021
1.22 ± 0.028
0.17
0.19
0.12
0.18
0.23
4
4
43
T
̈
ckel slope for molarity-based osmotic coefficients
Φ
1
/2
2
3/2
318.15
A
= (1/3)(2πNA) [e /4πεε kT]
(6)
Φ
0
Mor1,4][TFSI]
where N is Avogadro’s number, e is the unit charge, ε is the
298.15
303.15
308.15
313.15
318.15
0.51 ± 0.015
0.56 ± 0.017
0.61 ± 0.011
0.65 ± 0.010
0.67 ± 0.017
0.10
0.12
0.10
0.10
0.12
A
0
permittivity of free space, and k is the Boltzmann constant.
To estimate the apparent molar volumes of ionic liquids at
infinite dilution in acetonitrile the appropriate RRM equation
was rearranged into a linear form:
[
Mor1,8][TFSI]
DH
0
VΦ − SV c = V + b c
(7)
Φ
V
2
3
3
3
98.15
03.15
08.15
13.15
351.282 ± 0.066
351.142 ± 0.052
350.923 ± 0.055
350.764 ± 0.046
350.506 ± 0.061
0.506 ± 0.0096
0.538 ± 0.0073
0.599 ± 0.0077
0.635 ± 0.0065
0.666 ± 0.0086
0.076
0.060
0.063
0.053
0.070
The parameters of eq 7 and the standard deviations σ are given
in Table 2.
Because of the lack or poor quality of data required for
calculating the theoretical Debye−Huckel slopes SV , (i.e.,
̈
dielectric constant, isothermal compressibility, and the pressure
derivative of solvent permittivity) at temperatures different than
98.15 K, the purely empirical Masson-type equation was used
DH
318.15
[
Mor1,10][TFSI]
2
98.15
03.15
390.019 ± 0.036
389.989 ± 0.042
389.967 ± 0.060
389.871 ± 0.054
389.793 ± 0.071
0.460 ± 0.0057
0.513 ± 0.0059
0.570 ± 0.0084
0.629 ± 0.0076
0.655 ± 0.0099
0.042
0.049
0.069
0.063
0.082
3
2
0
Φ
45
308.15
13.15
318.15
to obtain the V over the temperature range studied:
3
0
V = V + S
c
V
(8)
Φ
Φ
7
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Journal of Chemical & Engineering Data
Article
Figure 2. The concentration dependencies of the apparent molar
volume for [Mor ][TFSI] (◆), [Mor ][TFSI] (■), [Mor ][TFSI]
(
Figure 3. The limiting values of V against the alkyl chain length of the
cation of ionic liquid at T = 298.15 K.
φ
1
,2
1,4
1,8
▲), and [Mor1,10][TFSI] (●) in acetonitrile solutions at T = 298.15
K.
of larger cations. Thus, the apparent molar volumes at infinite
dilution of ionic liquids based on morpholinium cations in
acetonitrile result mainly from the cation size which determines
not only the intrinsic volume but also the volume of
electrostriction and the structural contribution to the volume.
Figure 4 presents the influence of temperature on the
obtained limiting molar volumes of ILs. For better visualization,
shows the apparent molar volumes against the square root of
molarities for [Mor ][TFSI], [Mor ][TFSI], [Mor ][TFSI],
and [Mor1,10][TFSI] in acetonitrile at T = 298.15 K.
1
,2
1,4
1,8
Figure 2, as well as the data collected in Table 3, show that
the values of empirical slope S are positive, suggesting that
V
ion−ion interactions are one of the factors controlling the
properties of the studied systems. Furthermore, Figure 2 shows
that the values of slope decrease with the increase in the alkyl
chain length of the cation constituent of the ionic liquid and
increase with growing temperature. It should be noted that
highest values of S were observed for acetonitrile solution of
V
[
Mor ][TFSI] while the lowest values for [Mor1,10][TFSI]
1,2
solutions. Apparently, this variation is related to the increasing
size of the cation which seems to be the most important factor
controlling ion−ion as well as ion−solvent interactions. The
latter are quantified by the apparent molar volume at infinite
dilution.
As seen from Table 3, the apparent molar volumes at infinite
dilution for the morpholinium based ionic liquids in acetonitrile
increase with the increase in the cation size at all temperatures
investigated. This effect is presented in Figure 3 as plots of the
limiting values of V against the alkyl chain length of the cation.
φ
Similar results were reported for some ionic liquids based on
32,33
imidazolium cations in dimethylsulfoxide and water.
The limiting values of the apparent molar volumes of a solute
0
0
0
V can be expressed as the sum of the three contributions:
Figure 4. The difference [V (IL) − V
(IL)] calculated for
Φ
Φ
Φ,298.15K
[
Mor ][TFSI] (◆), [Mor ][TFSI] (■), [Mor ][TFSI] (▲), and
0
0
0
0
1,2 1,4 1,8
V (IL) = V + V + V
(10)
[Mor1,10][TFSI] ( ) in acetonitrile solutions against temperature.
●
Φ
int
elec
str
where V0 represents the intrinsic volume of solute molecules,
int
0
Φ
0
0
plots of the difference [V (IL) − V
(IL)] calculated for
V
denotes the volume change related to electrostriction
Φ,298.15K
elec
the ionic liquids against temperature are shown. The temper-
(
decrease of the solution volume due to electrostatic attraction
ature dependence of V0 is not linear, and the best curve
0
between solute and surrounding solvent molecules), and V is
Φ
str
description is obtained using the second-order polynomial:
the volume contribution reflecting all the structural volume
changes in the surrounding solvent (negative effect). The
electrostriction volume is the most significant factor controlling
the volumetric properties of smaller cations while the structural
contribution is the factor determining the partial molar volume
0
Φ
2
V = A + B(T/K) + C(T/K)
where A, B, and C are empirical parameters whose values
(11)
obtained by regression analysis along with the respective values
7
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Journal of Chemical & Engineering Data
Article
Table 4. The Coefficients of eq 11 and the Corresponding Standard Deviations σ for [Mor ][TFSI], [Mor ][TFSI],
1
,2
1,4
[
Mor ][TFSI], and [Mor1,10][TFSI] in Acetonitrile
1,8
1
06A
106B
106C
106σ
3
−1
3
−1
3
−1
3
−1
ionic liquid
m ·mol
m ·mol
m ·mol
m ·mol
[
Mor1,2][TFSI]
Mor1,4][TFSI]
Mor1,8][TFSI]
Mor1,10][TFSI]
247.3 ± 1.3
0.006 ± 0.075
0.011 ± 0.019
−0.002 ± 0.012
0.024 ± 0.011
−0.0028 ± 0.0011
−0.00097 ± 0.00028
−0.00051 ± 0.00018
−0.00051 ± 0.00015
0.099
0.025
0.016
0.014
[
[
[
289.29 ± 0.32
351.66 ± 0.21
389.73 ± 0.17
6
0
Φ
3
−1
Table 5. The Infinite Dilution Apparent Molar Expansibility, 10 E /(m ·mol ·K) Values Derived from eq 12 at Different
Temperatures
ionic liquid
T/K = 298.15
T/K = 303.15
T/K = 308.15
T/K = 313.15
T/K = 318.15
[Mor1,2][TFSI]
[Mor1,4][TFSI]
[Mor1,8][TFSI]
[Mor1,10][TFSI]
−0.1328
−0.0374
−0.0281
−0.0013
−0.1605
−0.0471
−0.0333
−0.0064
−0.1882
−0.0568
−0.0384
−0.0116
−0.2159
−0.0665
−0.0435
−0.0167
−0.2436
−0.0762
−0.0487
−0.0219
2
0
2
of the residual variance are listed in Table 4. In general, an
increase in temperature causes a decrease in the values of the
apparent molar volumes of all the investigated ionic liquids. A
significantly higher decrease in the limiting apparent molar
volume with temperature is observed for [Mor ][TFSI], for
It has been shown that the sign of (∂ V /∂ T) is a better
Φ P
criterion in characterizing the long-range structure making and
breaking capacity of electrolytes in solution. The values of the
46
second derivative obtained for [Mor ][TFSI] (−0.0056),
1
,2
[Mor ][TFSI] (−0.002), [Mor ][TFSI] (−0.0012), and
1
,2
1,4
1,8
example, the ionic liquid with the shortest alkyl chain. In the
[Mor1 ][TFSI] (−0.0012) in acetonitrile are small and
,10
case of the other ionic liquids the influence of temperature on
negative for all the studied systems. Therefore, the ionic liquids
under study act as structure breakers in acetonitrile. It is worth
noting that similar results for the acetonitrile solution of 1,3-
dimethylimidazolium methyl sulfate were reported by Shekaari
0
Φ
V is relatively small, and it changes according to the sequence:
[
Mor ][TFSI] > [Mor ][TFSI] > [Mor1,10][TFSI]. One
1,4 1,8
might suspect that the observed result is the effect of
electrostriction and the ability of the alkyl chains of the N-
alkyl-N-methylmorpholinium cations to penetrate the solvent.
It is well-known that the increase of temperature weakens the
solvent structure, thereby increasing the electrostriction and
penetration effects. As these two different effects lead to
decreasing the limiting molar volume, the obtained sequence of
47
et al.
4. CONCLUSIONS
Densities of acetonitrile solutions of N-ethyl-N-methylmorpho-
linium bis(trifluoromethanesulfonyl)imide, N-butyl-N-methyl-
morpholinium bis(trifluoromethanesulfonyl)imide, N-methyl-
N-octylmorpholinium bis(trifluoromethanesulfonyl)imide and
N-decyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)-
imide have been measured at several temperatures. Because of
solute−solvent interactions, the apparent molar volumes of all
the studied ionic liquids increase with increasing concentration
at all investigated temperatures. The values of the apparent
molar volumes at infinite dilution obtained using Redlich,
Rosenfeld, and Meyer (RRM) and Masson equations were
found to be in good agreement, and they increase with
increasing cation size at all temperatures investigated. The
values of the limiting apparent molar expansibilities as well as
the sequence of the influence of temperature on the limiting
molar volumes ([Mor ][TFSI] ≫ [Mor ][TFSI] > [Mor ]-
0
the influence of temperature on VΦ indicates that the most
significant factor controlling the volumetric properties of the
studied ILs is electrostriction. When considering ionic liquids,
one should keep in mind that the longer is the alkyl chain, the
weaker is the electrostatic ion−solvent interactions because of
the increasing masking of the cation positive charge and
stronger “solvofobic” interactions between the solvent mole-
cules and the −CH units of the cations. The particularly strong
2
temperature effect observed for [Mor ][TFSI] and the weak
1
,2
temperature effect observed for the other ILs indicates that the
penetration effect is much less important than the electro-
striction effect. This conclusion is supported by the almost
constant values of limiting molar volumes for solutions of
1,2
1,4
1,8
[
Mor1,10][TFSI] across the temperature range investigated.
Limiting apparent molar expansibility is a quantitative
[TFSI] > [Mor1 ][TFSI]) indicate that the most significant
,10
factor controlling the volumetric properties of the studied ILs is
2
0
Φ
2
measure of the variation of limiting apparent molar volume
with temperature. Its temperature dependence can be described
by the equation:
electrostriction. The obtained sign of (∂ V /∂ T) for the ionic
P
liquids investigated indicates that ionic liquids based on
morpholinium cations act as structure breakers in acetonitrile.
0
0
E = (∂V /∂T) = B + 2CT
(12)
Φ
Φ
P
AUTHOR INFORMATION
Corresponding Author
dorota@chem.pg.gda.pl.
Notes
■
*
The values of limiting apparent molar expansibility for the
studied ILs are listed in Table 5 as a function of experimental
temperature. In the light of the discussion presented above, it is
0
not surprising that at each temperature EΦ values for ionic
The authors declare no competing financial interest.
liquids based on morpholinium cations in acetonitrile are
negative and decrease with rising temperature. As the
temperature increases the effects connected with the weakening
of the solvent structure are enhanced.
REFERENCES
■
(1) Earle, M. J.; Seddon, K. R. Ionic liquids. Green Solvents for the
Future. Pure Appl. Chem. 2000, 72, 1391−1398.
7
23
dx.doi.org/10.1021/je400790d | J. Chem. Eng. Data 2014, 59, 718−725

Journal of Chemical & Engineering Data
Article
(
2) Carda-Broch, S.; Berthod, A.; Armstrong, D. W. Solvent
Liquids with Primary and Secondary Alcohols. Thermochim. Acta 2012,
549, 49−56.
Properties of the 1-Butyl-3-Methylimidazolium Hexafluorophosphate
Ionic Liquid. Anal. Bioanal. Chem. 2003, 375, 191−199.
(23) Rilo, E.; Varea, L. M.; Cabeza, O. Density and Derived
Thermodynamic Properties of 1-Ethyl-3-methylimidazolium Alkyl
Sulfate Ionic Liquid Binary Mixtures with Water and with Ethanol
from 288 K to 318 K. J. Chem. Eng. Data 2012, 57 (8), 2136−2142.
(
3) Takeshi, E.; Kazuhiko, M.; Rika, H. Properties of Fluorosulfate-
−
Based Ionic Liquids and Geometries of (FO SOH)OSO F and
2
2
−
(
FO SOH) O SOF . Dalton Trans. 2011, 40, 12491−12499.
2
2
2
(
4) Hallett, J. P.; Welton, T. Room-Temperature Ionic Liquids:
Solvents for Synthesis and Catalysis. 2. Chem. Rev. 2011, 111, 3508−
576.
5) Plechkova, N. V.; Seddon, K. R. Applications of Ionic Liquids in
the Chemical Industry. Chem. Soc. Rev. 2008, 37 (1), 123−150.
6) Seiler, M.; Jork, C.; Kavarnou, A.; Arlt, W.; Hirsch, R. Separation
(24) Garcia-Mardones, M.; Barros, A.; Bandres, I.; Artigas, H.;
Lafuente, C. Thermodynamic Properties of Binary Mixtures
Combining Two Pyridinium-Based Ionic Liquids and Two Alkanols.
J. Chem. Thermodyn. 2012, 51, 17−24.
3
(
(
25) Arce, A.; Rodil, E.; Soto, A. Physical and Excess Properties for
Binary Mixtures of 1-Methyl-3-Octylimidazolium Tetrafluoroborate,
Omim][BF4], Ionic Liquid with Different Alcohols. J. Solution Chem.
006, 35, 63−78.
26) Domanska, U.; Laskowska, M. Effect of Temperature and
(
of Azeotropic Mixtures Using Hyperbranched Polymers or Ionic
[
2
Liquids. AIChE J. 2004, 50, 2439−2454.
(
7) Kubisa, P. Ionic Liquids in the Synthesis and Modification of
(
́
Polymers. J. Polym. Sci. A: Polym. Chem. 2005, 43, 4675−4683.
Composition on the Density and Viscosity of Binary Mixtures of Ionic
(
8) Tan, Z.; Welz-Biermann, U.; Yan, P.; Liu, Q.; Fang, D.
Liquid with Alcohols. J. Solution Chem. 2009, 38 (6), 779−799.
Thermodynamic Properties of Ionic Liquids−Measurements and
Predictions 2011Ionic Liquids: Theory, Properties, New Approaches;
Kokorin, A., Ed.; InTech: Rijeka, Croatia, 2011; pp 3−36.
(27) Vranes, M. B.; Dozic, S.; Djeric, V.; Gadzuric, S. B. Volumetric
Properties of Binary Mixtures of 1-Butyl-1-methylpyrrolidinium
Bis(trifluoromethylsulfonyl)imide with N-Methylformamide and
N,N-Dimethylformamide from (293.15 to 323.15) K. J. Chem. Eng.
Data 2013, 58 (5), 1092−1102.
(
9) Fredlake, C. P.; Crosthwaite, J. M.; Hert, D. G.; Aki, S. N. V. K.;
Brennecke, J. F. Thermophysical Properties of Imidazolium-Based
Ionic Liquids. J. Chem. Eng. Data 2004, 49, 954−964.
(28) Iulian, O.; Ciocirlan, O. Volumetric Properties of Binary
(
10) Jacquemin, J.; Husson, P.; Padua, A. A. H.; Majer, V. Density
Mixtures of Two 1-Alkyl-3-Methylimidazolium Tetrafluoroborate
Ionic Liquids with Molecular Solvents. J. Chem. Eng. Data 2012, 57
and Viscosity of Several Pure and Water-Saturated Ionic Liquids. Green
Chem. 2006, 8, 172−180.
(
(
10), 2640−2646.
11) Gardas, R. L.; Freire, M. G.; Carvalho, P. J.; Marrucho, I. M.;
(
29) Juarez-Camacho, E. P.; Manriquez-Ramirez, M. E.; German, C.;
Fonseca, I. M. A.; Ferreira, A. G. M.; Coutinho, J. A. P. High-Pressure
Densities and Derived Thermodynamic Properties of Imidazolium-
Based Ionic Liquids. J. Chem. Eng. Data 2006, 52 (1), 80−88.
Zuniga-Moreno, A. Volumetric Properties of the Binary System
Trihexyltetradecylphosphonium Bromide (CYPHOS IL 102) + N,N-
Dimethylformamide (DMF) at Temperatures from T=293.15 to
313.15 K at Atmospheric Pressure. J. Solution Chem. 2012, 41 (9),
1575−1586.
(30) Zhu, A. L.; Wang, J. J.; Liu, R. X. A Volumetric and Viscosity
Study for the Binary Mixtures of 1-Hexyl-3-Methylimidazolium
Tetrafluoroborate with some Molecular Solvents. J. Chem. Thermodyn.
2011, 43 (5), 796−799.
(
12) Gardas, R. L.; Cost, H. F.; Freire, M. G.; Carvalho, P. J.; M., I.
M.; Fonseca, I. M. A.; Ferreira, A. G. M.; Coutinho, J. A. P. Densities
and Derived Thermodynamic Properties of Imidazolium-, Pyridinium-,
Pyrrolidinium-, and Piperdinum-Based Ionic Liquids. J. Chem. Eng.
Data 2008, 53, 805−811.
(
13) Brigouleix, C.; Anouti, M.; Jacquemin, J.; Caillon-Caravanier,
M.; Galiano, H.; Lemordant, D. Physicochemical Characterization of
Morpholinium Cation Based Protic Ionic Liquids Used As Electro-
lytes. J. Phys. Chem. B 2010, 114, 1757−1766.
(31) Geppert-Rybczynska, M.; Heintz, A.; Lehmann, J. K.; Golus, A.
Volumetric Properties of Binary Mixtures Containing Ionic Liquids
and Some Aprotic Solvents. J. Chem. Eng. Data 2010, 55 (9), 4114−
(
14) Choi, S.; Kim, K.-S.; Cha, J.-H.; Lee, H.; Oh, J.; Lee, B.-B.
Thermal and Electrochemical Properties of Ionic Liquids Based on N-
Methyl-N-Alkyl Morpholinium Cations. Korean J. Chem. Eng. 2006, 23
4
(
120.
32) Wang, H. Y.; Wang, J. J.; Zhang, S. B. Apparent Molar Volumes
(
5), 795−799.
and Expansivities of Ionic Liquids [C(n)mim]Br (n = 4, 8, 10, 12) in
Dimethyl Sulfoxide. J. Chem. Eng. Data 2012, 57 (7), 1939−1944.
(
15) Zhang, Q. S.; Liu, A. X.; Guo, B. N.; Wu, F. Synthesis of Ionic
Liquids Based on the N-Methyl-N-Allyl Morpholinium Cation. Chem.
J. Chin. Univ.-Chin. 2005, 26 (2), 340−342.
(33) Shekaari, H.; Armanfar, E. Apparent Molar Volumes and
Expansivities of Aqueous Solutions of Ionic Liquids, 1-Alkyl-3-
Methylimidazolium Alkyl Sulfate at T = (298.15−328.15) K. Fluid
Phase Equilib. 2011, 303 (2), 120−125.
(
16) Wang, L. M.; Xia, C. Theory Study on Structure Property of N-
Ethyl Morpholinium Ionic Liquid of Different Alkyl Length. In
Advanced Measurement and Test, Pts 1−3; Trans Tech Publications
Ltd: Stafa-Zurich, 2011; Vol: 301−303, pp 170−174.
(
34) Wang, J. J.; Zhang, S. B.; Wang, H. Y.; Pei, Y. C. Apparent Molar
Volumes and Electrical Conductance of Ionic Liquids [C(n)mim]Br
n = 8, 10, 12) in Ethylene Glycol, N,N-Dimethylformamide, and
Dimethylsulfoxide at 298.15 K. J. Chem. Eng. Data 2009, 54 (12),
252−3258.
35) Zafarani-Moattar, M. T.; Shekaari, H. Apparent Molar Volume
(
17) Lava, K.; Binnemans, K.; Cardinaels, T. Piperidinium,
(
Piperazinium and Morpholinium Ionic Liquid Crystals. J. Phys.
Chem. B 2009, 113 (28), 9506−9511.
3
(
(
18) Galinski, M.; Stepniak, I. Morpholinium-Based Ionic Liquid
Mixtures as Electrolytes in Electrochemical Double Layer Capacitors.
and Isentropic Compressibility of Ionic Liquid 1-Butyl-3-Methylimi-
dazolium Bromide in Water, Methanol, and Ethanol at T = (298.15 To
J. Appl. Electrochem. 2009, 39 (10), 1949−1953.
(
19) Hajipour, A. R.; Nasreesfahani, Z.; Ruoho, A. E. An Efficient and
3
(
18.15) K. J. Chem. Thermodyn. 2005, 37 (10), 1029−1035.
Chemoselective Synthesis of Aldehyde 1,1-Diacetates Using Morpho-
linium Bisulfate as a Bronsted Acidic Ionic Liquid Under Solvent-Free
Conditions. Org. Prep. Proced. Int. 2008, 40 (4), 385−391.
36) Khara, D. C.; Kumar, J. P.; Mondal, N.; Samanta, A. Effect of the
Alkyl Chain Length on the Rotational Dynamics of Nonpolar and
Dipolar Solutes in a Series of N-Alkyl-N-methylmorpholinium Ionic
Liquids. J. Phys. Chem. B 2013, 117 (17), 5156−64.
(
20) Cha, J. H.; Kim, K. S.; Choi, S.; Yeon, S. H.; Lee, H.; Lee, C. S.;
Shim, J. J. Size-Controlled Electrochemical Synthesis of Palladium
Nanoparticles Using Morpholinium Ionic Liquid. Korean J. Chem. Eng.
(37) Khara, D. C.; Samanta, A. Fluorescence Response of Coumarin-
1
53 in N-Alkyl-N-methylmorpholinium Ionic Liquids: Are These
2
(
007, 24 (6), 1089−1094.
21) Kim, K. S.; Park, S. Y.; Choi, S.; Lee, H. Ionic Liquid-Polymer
Media More Structured Than the Imidazolium Ionic Liquids? J. Phys.
Chem. B 2012, 116 (45), 13430−8.
(38) Chaban, V. V.; Voroshyloya, I. V.; Kalugin, O. N.; Prezhdo, O.
V. Acetonitrile Boosts Conductivity of Imidazolium Ionic Liquids. J.
Phys. Chem. B 2012, 116 (26), 7719−7727.
Gel Electrolytes Based on Morpholinium Salt and Pvdf(HFP)
Copolymer. J. Power Sources 2006, 155 (2), 385−390.
(
22) Calvar, N.; Gomez, E.; Dominguez, A.; Macedo, E. A.
Thermodynamic Behavior of Binary Mixtures C(N)Mpyntf(2) Ionic
7
24
dx.doi.org/10.1021/je400790d | J. Chem. Eng. Data 2014, 59, 718−725

Journal of Chemical & Engineering Data
Article
(
39) Kim, K. S.; Choi, S.; Demberelnyamba, D.; Lee, H.; Oh, J.; Lee,
B.; Mun, S. Ionic Liquids Based on N-Alkyl-N-methylmorpholinium
Salts as Potential Electrolytes. Chem. Commun. 2004, 828−829.
(
40) Martins, F.; Leitao, R. E.; Ventura, M. C.; Pinheiro, L.; Nunes,
N. Densities and Refractive Indices for the Ternary Mixture
Methanol/Propan-1-Ol/Acetonitrile. J. Mol. Liq. 2012, 170, 30−36.
(
41) Huo, Y.; Xia, S. Q.; Ma, P. S. Densities of Ionic Liquids, 1-Butyl-
3-Methylimidazolium Hexafluorophosphate and 1-Butyl-3-Methylimi-
dazolium Tetrafluoroborate, with Benzene, Acetonitrile, and 1-
Propanol at T = (293.15 To 343.15) K. J. Chem. Eng. Data 2007,
5
2 (5), 2077−2082.
42) Redlich, O.; Meyer, D. M. The Molal Volumes of Electrolytes.
Chem. Rev. 1964, 64 (3), 221−227.
43) Marcus, Y. Electrostriction, Ion Solvation, and Solvent Release
on Ion Pairing. J. Phys. Chem. B 2005, 109 (39), 18541−18549.
44) Marcus, Y. The Properties of Solvents; John Wiley & Sons:
London, 1998.
45) Masson, D. O. Solute Molecular Volumes in Relation to
Solvation and Ionization. Philos. Mag. 1929, 8, 218−235.
46) Hepler, L. G. Studies on Viscosities and Densities of R NX In
(
(
(
(
(
4
ME + Water Mixtures of Different Temperatures. Can. J. Chem. 1969,
7, 4613−4616.
47) Shekaari, H.; Mousavi, S. Volumetric Properties of Ionic Liquid
,3-Dimethlimidazolium Methyl Sulfate+Molecular Solvents at T =
298.15−328.15)K. Fluid Phase Equilib. 2010, 291, 201−207.
4
(
1
(
7
25
dx.doi.org/10.1021/je400790d | J. Chem. Eng. Data 2014, 59, 718−725