New guanidinium-based room-temperature ionic liquids. Substituent and anion effect on density and solubility in water

Article abstract of DOI:10.1515/znb-2010-0108

In order to examine the influence of the alkyl chain length on some physical properties of guanidinium salts, the synthesis of a homologous series of new N″-n-alkylsubstituted N,N-diethyl-N′,N′ - di-n-propyl-N″ -n-hexyl guanidinium ionic liquids (gILs), containing chloride (Cl), tetrafluoroborate (BF4), acesulfamate (Ace), saccharinate (Sac), and tosylate (Tos) as anions, is reported. C_n-gILAce, Cn-gILSac, and C_n-gILBF₄ were obtained by ion exchange reaction of the corresponding hexasubstituted guanidinium chlorides (C_n-gCl, n = 3, 4, 6, 8, 10), which were synthesized by a quaternization reaction of the pentaalkyl-substituted guanidine 3 and the corresponding alkylchloride in DMF. The tosylates gILs Cn-gTos (n = 1, 2, 4, 6, 8, 10) were synthesized by alkylation of 3 with the corresponding alkyltosylates. Some physical properties, such as solubility in water and organic solvents, refractive index and density, are considered as a function of the length of the n-alkyl substituent R and the nature of the anion.

Full text of DOI:10.1515/znb-2010-0108

New Guanidinium-based Room-temperature Ionic Liquids.
Substituent and Anion Effect on Density and Solubility in Water
Milen G. Bogdanova,c, Desislava Petkovaa,c, Stanimira Hristevaa,c, Ivan Svinyarova,c
,
and Willi Kantlehnerb,c
a Faculty of Chemistry, University of Sofia, 1, J. Bourchier Blvd., 1164 Sofia, Bulgaria
b Institut fu¨r Organische Chemie, Universita¨t Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart,
Germany
c Fakulta¨t Chemie/Organische Chemie, Hochschule Aalen, Beethovenstraße 1, 73430 Aalen,
Germany
Reprint requests to Dr. Milen G. Bogdanov. E-mail: mbogdanov@chem.uni-sofia.bg
Z. Naturforsch. 2010, 65b, 37 – 48; received October 28, 2009
Dedicated to Professor Klaus Peseke on the occasion of his 70th birthday
In order to examine the influence of the alkyl chain length on some physical properties of guani-
dinium salts, the synthesis of a homologous series of new Nꢀꢀ-n-alkylsubstituted N,N-diethyl-Nꢀ,Nꢀ-
di-n-propyl-Nꢀꢀ-n-hexyl guanidinium ionic liquids (gILs), containing chloride (Cl), tetrafluoroborate
(BF4), acesulfamate (Ace), saccharinate (Sac), and tosylate (Tos) as anions, is reported. Cn-gILAce,
Cn-gILSac, and Cn-gILBF4 were obtained by ion exchange reaction of the corresponding hexasub-
stituted guanidinium chlorides (Cn-gCl, n = 3, 4, 6, 8, 10), which were synthesized by a quaterniza-
tion reaction of the pentaalkyl-substituted guanidine 3 and the corresponding alkylchloride in DMF.
The tosylates gILs Cn-gTos (n = 1, 2, 4, 6, 8, 10) were synthesized by alkylation of 3 with the corre-
sponding alkyltosylates. Some physical properties, such as solubility in water and organic solvents,
refractive index and density, are considered as a function of the length of the n-alkyl substituent R
and the nature of the anion.
Key words: Ionic Liquids, Guanidinium Salts, Density, Quaternization Reaction, DMF
Introduction
sively studied. In contrast, the knowledge on the syn-
thesis, physical properties and potential application
of ILs based on the guanidinium ion is quite rare.
A retrospective view on guanidinium ILs (gILs) in
the last decade shows the availability of only a few
published reports: two examples of iodide and tri-
cyanomethanide (NC)3C− gILs were used for dye-
sensitized solar cells [2]; series of gILs, inc−luding
cyclic representatives, based on NO3−, ClO4 and
(NO2)2N− anions were synthesized as high-energy ILs
Room-temperature ionic liquids (RTILs) have at-
tracted enormously the attention of the scientific com-
munity in the last two decades. Consisting entirely of
ions (normally a small organic cation and an inorganic
or organic anion), they are liquids at ambient temper-
ature and display high thermal and chemical stability,
a large electrochemical window, high ionic conductiv-
ity, relatively low viscosity and negligible vapor pres-
sure. Furthermore, depending on the ion combination,
they can be soluble or insoluble in water or organic
solvents, respectively. These unique physico-chemical
properties favor their application in diverse fields such
as synthesis [1a], catalysis [1b], electrochemistry [1c],
nanotechnology [1d], separation technology, and ana-
lytical chemistry [1e], etc.
by Schreeve and coworkers [3]; several examples of
−
dimethyltetraalkyl g−ILs-based on BF4−, PF6−, NTf2
,
Sac−, and N(CN)2 anions have been reported as
a new generation of RTILs by Afonso and cowork-
ers [4a, b]; more than thirty hexaalkylguanidinium tri-
fluoromethanesulfonates (TfO−) have been reported
by Kunkel and Maas [5], and new chiral hexasub-
stituted RTgILs by Afonso and coworkers [4c] and
Shah and Liebscher [6]; very recently, a series of
(bis(trifluoromethylsulfonyl)imide)(Tf2N−) gILs have
been reported by Yang and coworkers [7a, b] as poten-
Along with ILs based on 1,3-dialkylimidazolium
cations, which seem to dominate the ILs area, ILs
based on tetraalkylammonium, sulfonium, phospho-
nium and pyrrolidinium cations have been exten-
c
0932–0776 / 10 / 0100–0037 $ 06.00 ꢀ 2010 Verlag der Zeitschrift fu¨r Naturforschung, Tu¨bingen · http://znaturforsch.com
Unauthenticated
Download Date | 3/5/16 5:27 AM

38
M. G. Bogdanov et al. · Guanidinium-based Room-temperature Ionic Liquids
Table 1. Structure and abbreviation of the synthesized RTILs based on Nꢀꢀ-n-alkyl-substituted N,N-diethyl-Nꢀ,Nꢀ-di-n-propyl-
Nꢀꢀ-n-hexyl guanidinium cations (Cn-g+).
Cn-g+
Cloride
Tetrafluoroborate
BF4
Saccharinate
Acesulfamate
Tosylate
Cl−
Sac−
Ace−
Tos−
−
R = CH3-
R = C2H5-
R = C3H7-
R = C4H9-
R = C5H13
R = C8H17
–
–
–
–
–
–
–
–
C1-gTos
C2-gTos
–
C4-gTos
C6-gTos
C8-gTos
C10-gTos
C3-gCl
C4-gCl
C6-gCl
C8-gCl
C10-gCl
C3-gBF4
C4-gBF4
C6-gBF4
C8-gBF4
C10-gBF4
C3-gSac
C4-gSac
C6-gSac
C8-gSac
C10-gSac
C3-gAce
C4-gAce
C6-gAce
C8-gAce
C10-gAce
-
-
R = C10H21
-
Scheme 1. Synthesis of guanidinium RTILs. Reagents and conditions: (i) COCl2/CH3CN, −25 ◦C to r. t., 24 h (yield 98 %);
◦
◦
(ii) 2 in CH3CN/H2NC6H13, −10 C to r. t., 16 h (yield 80 %); (i◦ii) RCl/DMF, 100 – 110 C, 10 – 13 h (yield 30 – 87 %);
2 – 4 h (yield 83 – 99 %).
◦
(iv) MeOH or water/K or Na salt of the corresponding anion, 60 C, 4 h (yield 82 – 99 %); (v) TosR/DMF, 100 – 110 C,
tial new electrolytes for lithium batteries, and a new
In this direction, in order to investigate the influ-
cyclic guanidinium ionic liquid OGI (1,3-dimethyl-2- ence of the anions and the chain length of the alkyl
Nꢀꢀ-methyl-Nꢀꢀ-octylimidazoguanidinium iodide) was substituents on some physical properties, here we re-
used as a quasi-solid-state electrolyte for dye- port the synthesis of a series of hydrophobicroom-tem-
sensitized solar cells by Li et al. [8]. It should further perature hexaalkylguanidinium ionic liquids (Cn-gX),
be mentioned that as a result of finding a new proto- containing chloride (Cl), tetrafluoroborate (BF4), ace-
col for the synthesis of hexasubstituted guanidinium sulfamate (Ace), saccharinate (Sac), and tosylate (Tos)
salts [9a – d], Kantlehner et al. in 1984 were able to as anions X (Table 1).
synthesize a large number (more than hundred) of hex-
aalkylguanidinium salts [9e], which in two cases have
been described as oils. Nevertheless, considering the
great versatility of the guanidinium cation (we have
calculated more than 105 possible combinations if one
Results and Discussion
Synthesis of compounds
The synthesis of the guanidinium salts is presented
varies the alkyl substituents from methyl to dodecyl in in Scheme 1. N,N-diethyl-Nꢀ,Nꢀ-di-n-propylurea 1, the
the guanidinium ion) the above contributions represent corresponding chloroformamidinium chloride 2 and
a “drop in the ocean” in the field of guanidinium-based guanidine 3 were synthesized as previously described
ILs, or in the ILs area in general. Having in mind this by Kantlehner and coworkers [2, 9a – e]. In order to
incredible number, a lot of work impends upon the de- synthesize guanidinium halides for anion metathesis
velopment of new synthetic methods for gILs and the reactions, guanidine 3 was further quaternized with
investigation of their properties and potential industrial chloroalkanes instead of bromo- or iodo-substituted
applications.
analogs. It is known [10] that the bromoalkanes re-
Unauthenticated
Download Date | 3/5/16 5:27 AM

M. G. Bogdanov et al. · Guanidinium-based Room-temperature Ionic Liquids
39
Table 2. Abbreviations, molecular weights, densities, water content, water uptake ability, and solubility in water and some
organic solvents of the synthesized RTgILs evaluated in this study.
a
Compound
Mw
(g mol−1
362.04
376.06
404.12
432.17
460.22
ρdried
(g mL−1
–
Water contentb
Water uptakec
(wt-%)
Solubilityd
)
)
(ppm)
670
690
–
720
600
immiscible
de, ch, bme
de, ch, bme
de, ch, bme
de, ch, bme
w, ch
miscible
C3-gCl
C4-gCl
C6-gCle
C8-gCl
C10-gCl
soluble
soluble
soluble
soluble
w, et, dcm, ac
w, et, dcm, ac
w, et, dcm, ac
w, et, dcm, ac
et, dcm, ac de, bme
0.949
–
0.931
0.929
soluble
C3-gBF4
C4-gBF4
C6-gBF4
C8-gBF4
C10-gBF4
413.39
427.41
455.77
483.52
511.57
1.011
1.009
0.997
0.990
0.981
370
330
350
330
300
5.21
4.36
3.19
3.03
2.88
w, de, ch, bme
w, de, ch, bme
w, de, ch, bme
w, de, ch, bme
w, de, ch, bme
et, dcm, ac
et, dcm, ac
et, dcm, ac
et, dcm, ac
et, dcm, ac
C3-gAce
C4-gAce
C6-gAce
C8-gAce
488.73
502.75
530.81
558.86
586.45
1.056
1.050
1.031
1.022
1.005
390
406
420
350
360
20.64
17.77
12.55
10.88
10.35
w, de, ch, bme
w, de, ch, bme
w, de, ch, bme
w, de, ch, bme
w, de, ch, bme
et, dcm, ac
et, dcm, ac
et, dcm, ac
et, dcm, ac
et, dcm, ac
C10-gAce
C3-gSac
C4-gSac
C6-gSac
C8-gSac
508.76
522.79
550.84
578.89
606.95
1.069
1.063
1.045
1.041
1.024
520
400
420
350
360
24.77
15.31
12.73
9.15
w, de, ch, bme
w, de, ch, bme
w, de, ch, bme
w, de, ch, bme
w, de, ch, bme
et, dcm, ac
et, dcm, ac
et, dcm, ac
et, dcm, ac
et, dcm, ac
C10-gSac
10.46
C1-gTos
C2-gTos
C4-gTos
C6-gTos
C8-gTos
C10-gTos
a
469.72
483.75
511.38
539.86
567.91
595.96
1.045
1.035
1.027
1.014
1.001
0.989
650
740
750
350
300
450
soluble
soluble
soluble
26.78
23.69
15.93
c
de, ch, bme
de, ch, bme
de, ch, bme
w, de, ch, bme
w, de, ch, bme
w, de
w,et, dcm, ac
w, et, dcm, ac
w, et, dcm, ac
et, dcm, ac
et, dcm, ac
et, dcm, ac, ch, bme
◦
b
◦
d
Measured at 25 C; water content estimated prior to the measurements; measured at 25 C; observed two phases (immiscible) and
complete solubilization (miscible), where: de – diethyl ether, ch – cyclohexane, bme – butyl methyl ether, w – water, et – ethanol, dcm –
dichloromethane, ac – acetone; e not liquid at r. t.
act strongly exothermic as the reaction rate increases, the rate of a stirred solvent-free reaction is almost
which is a disadvantage for large-scale experiments. the same as that in a single-phase system containing
The reaction with iodoalkanes can be often carried out 20 vol-% ethanol, which shows that there is no particu-
at room temperature, but the formed iodide salts are lar advantage in using solvents. On the other hand, it is
light-sensitive. Moreover, the solubility of many in- well known that the nucleophilic substitution reactions
organic salts M+X− in water decreases in the order (SN) are accelerated in more polar solvents in the case
Cl− < Br− < I−, which has a high impact on the anion of uncharged species reacting to charged ones [13]. On
exchange reaction. It seems that the only disadvantage this basis, it could be assumed that the use of rela-
of using chloroalkanes in this important step is the pro- tively highly polar DMF (dielectric constant = 38.3,
◦
longed reaction time of 2 – 3 d [11]. To overcome this b. p. 153 C) as solvent in the quaternizaton step will
problem, appropriate reaction conditions that can ac- accelerate the reaction. To prove the validity of this
celerate the reaction and increase the yields must be assumption, independent reactions between the pen-
found.
Although different solvents might be used in the
tasubstituted guanidine 3 and BuCl as reference com-
pounds were carried out on the 0.013 molar scale. Each
reaction mixture was heated at 110 ◦C (oil bath) for the
appropriate reaction time, worked up, and the yields
were estimated. Using this strategy we found that 3 re-
acts with BuCl in 89 % yield within 13 h. A prolon-
gation of the reaction time does not lead to a signif-
icant improvement in yield. Thus, the quaternization
quaternization step, the reaction for the ILs purpose
is normally carried out under solvent-free conditions,
i. e. the two reagents are mixed and heated to give two
phases. Furthermore, from the recently reported [12]
comparative study on the rate of single-phase and two-
phase synthesis of BumimCl it can be concluded that
Unauthenticated
Download Date | 3/5/16 5:27 AM

40
M. G. Bogdanov et al. · Guanidinium-based Room-temperature Ionic Liquids
Fig. 1. Solubility of water in
Cn-gILs as a function of the
nature of the anions and the
number of carbon atoms in the
alkyl chain n at room tempera-
ture.
reactions of guanidine 3 with butyl, hexyl, octyl, and ing sodium or potassium salt in methanol or water as
decyl chloride on a larger scale (0.1 mol) were carried solvents. The tosylate series was synthesized by alky-
out with a threefold molar excess of the correspond- lation of guanidine 3 with the corresponding tosylate.
◦
ing alkyl chloride at 100 – 110 C in DMF as solvent The reactions were carried out under the quaternization
for approximately 13 h. IR spectroscopy proved to be conditions described above, but with a smaller excess
a good method for monitoring the reaction in this case, (1.1 equiv.) of the tosyl ester. In all cases the reactions
since the disappearance of the C=N band of 3 at about proceeded quantitatively within 4.5 h. All synthesized
1610 cm−1 and the appearance of a C+–N band of compounds were characterized by spectroscopic meth-
Cn-gCl at about 1530 cm−1 can be easily observed. ods (1H, 13C NMR, IR), and the purity was established
Thus, Cn-gCl (n = 4, 6, 8, 10) were obtained in 80 – by elemental analysis. Furthermore, some properties
90 % yields. It should be mentioned that the successful of the synthesized gILs, such as miscibility with or-
progress of the reaction is limited to a certain tempera- ganic solvents, water uptake ability and density, were
ture range. A reaction temperature above 110 ◦C results assessed as a function of the anion and of the chain
in a reversion of the quaternization reaction (detected length of the alkyl substituent.
by IR spectroscopy), and the use of temperatures lower
than 80 ◦C results in significant prolongation of the re-
Properties
action time, and thus in lowering the yields. Limited
by the boiling point of propyl chloride (b. p. 46.7 ◦C),
Table 2 shows molecular weights, densities, water
the quaternization reaction in this case was carried out
at 60 ◦C and with a greater excess of the latter (added
portionwise), leading to the formation of C3-gCl in
30 % yield.
content, water uptake ability, and solubility in solvents
of the synthesized RTgILs. For water-insoluble gILs,
the water content prior to the property measurement
was estimated (by Karl-Fischer titration) to be in the
range 300 to 550 ppm and between 600 and 750 ppm
for the water soluble Cn-gCl (n = 3, 4, 6, 8, 10) and
Cn-gTos (n = 1, 2, 4). It is noteworthy that all Cn-gILs
are strongly hygroscopic. The capacity to absorb water
from the air was found to depend of course on the rel-
ative atmospheric humidity, but also on the length of
the alkyl substituent R. The absorbed water is readily
released by heating under vacuum, and thus, the syn-
thesized RTgILs might be considered as desiccants.
The compounds studied are, however, stable in the
air and in common organic solvents such as methanol,
As can be seen from Table 2, all of the synthesized
hexaalkylguanidinium chlorides are miscible with wa-
ter and immiscible with diethyl ether or cyclohexane.
This allows their isolation and purification by dissolv-
ing each product in a small quantity of water and sub-
sequent extraction of the residual volatile organic com-
ponents. This approach was very useful, especially in
the case of high-boiling alkyl chlorides. Except for C6-
gCl, which crystallized spontaneously after drying un-
der vacuum, the other guanidinium chlorides Cn-gCl
(n = 3, 4, 8, 10) are liquids at room temperature.
The synthesis of tetrafluoroborate (BF4), acesulfa- acetone, dichloromethane, chloroform, and acetoni-
mate (Ace) and saccharinate (Sac) gILs was achieved trile, in which they are completely soluble. Further-
by metathesis reactions of Cn-gCl with the correspond- more, they are insoluble (formation of two phases is
Unauthenticated
Download Date | 3/5/16 5:27 AM

M. G. Bogdanov et al. · Guanidinium-based Room-temperature Ionic Liquids
41
observed) in cyclohexane, diethyl ether and water, but cation, the density decreases as the number of car-
their miscibility with the latter depends not only on bon atoms n in the guanidinium ion Cn-g+ increases,
the hydrophobicity of the cation, but also on the na- which is typical for RTILs. Thus, the higher the mass
ture of the anion and the temperature. These excep- of the cation, the lower the density is in a given se-
tional solubility characteristics in general make them ries (see Table 2). Furthermore, the change of the butyl
good candidates for multiphasic reactions, liquid ex- substituent to decyl in the guanidinium ion leads to
traction and separation technology [14, 15]. To exam- a decrease in density for the tertafluoroborate series
ine the affinity for the absorption of water, equivalent Cn-gBF4 from 1.045 to 0.981 g cm−3, which is rather
quantities of the corresponding hydrophobic gIL and negligible compared to the methylimidazolium series
water were shaken vigorously in a closed tube, and Cn-mimBF4, with changes from 1.208 to 1.072 for
then the water content in the IL layer was estimated the same substituents. Considering the anion, when the
by Karl-Fischer titration. Fig. 1 presents the water con- cation is kept constant, the order of density decrease is
tent of the water-saturated Cn-gILs in wt-%. The ob- as follows: Sac− > Ace− > Tos− > BF4−, but just as in
served decrease in water uptake ability with increas- the case of the cation, the effect of the anion is negli-
ing number n of the carbon atoms in the alkyl chain gible, and thus, the densities for the C4-g+ series are:
clearly shows that the alkyl chain length corresponds 1.063 ≈ 1.050 ≈ 1.027 ≈ 1.009, following the anion
to the hydrophobicity. On the other hand, the nature of sequence considered above. These effects might be at-
the anion controls the hydrophobicity as well. Regard- tributed to the higher volume (mass respectively) of the
ing the influence of the anion, the water uptake abil- guanidinium ion compared to the volume of the coun-
ity decreases as follows: Cn-gTos > Cn-gAce ≈ Cn- terions. Consequently, it might be concluded that the
gSac > Cn-gBF4. This sequence can be rationalized density of a RTgIL can be determined by using the ap-
by taking into account the basicity of the correspond- propriate guanidinium ion, and at the same time other
ing anions. Furthermore, three immiscible liquid layers desirable properties may be varied by simply changing
were obtained by mixing water, cyclohexane or diethyl the substituents or counterions. This can be of a great
ether, and selected gILs. The formation of a sequence importance for the industrial application of RTILs.
water/gIL/diethyl ether depends clearly on the density
As we mentioned above, the density values of the
of the ILs under study. Thus, the less dense hydropho- gILs under study seem to be determined by the molec-
bic gILs are positioned between the water and the or- ular volume (mass) of the guanidinium ion. In spite of
ganic phases forming a third one. On the one hand, this the negligible differences in density in the separate se-
is due to the lower density value of the IL under study ries, we found this property to be further fine-tunable
compared to water, and on the other hand, due to the by using the Residual Volume Approach (RVA), a re-
partial miscibility of diethyl ether with the IL which cently developed method for predicting some physical
results in a further reduction of the density. Although properties of ILs by using simple correlations between
there are many examples of solubilization of organic the desired property and newly defined substituent pa-
solvents in hydrophobic ILs, most of the hydrophobic rameters βX [16, 17]. Plots of ρ = f(β) for the syn-
ILs are of high density (around 1.4 g cm−3) [15], and thesized RTgILs are shown in Fig. 2. As can be seen,
the density never is below 1.0 g cm−3. Thus, the be- the density decreases with βX, and each series follows
havior in layer sequence shown here is unique for the a very good linear relationship (R2 = 0.97 – 0.99). The
synthesized relatively “light” gILs and might be of in- results obtained from Fig. 2 show that the RVA can be
terest in novel reactions or in separation processes or applied successfully in the case of guanidinium-based
devices.
ILs as well, and can be used for predicting the density
values of the remaining members of the series by us-
ing the empirically obtained linear equation for a given
series and the substituent constants βX [16, 17].
It has recently been reported that the density of
some guanidinium-based RTILs is relatively low com-
pared to the imidazolium series [4b], and that the
guanidinium ion is more capable to suppress the ef-
fect of the anion than the other cations. In this direc-
tion, we found in the present study the same trend in
Conclusion
Several series of new homologous Nꢀꢀ-n-alkyl-
the density behavior, namely, the densities of all of substituted N,N-diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl
the five series under study are in the range 0.989– guanidinium salts with tetrafluoroborate, acesulfamate,
1.069 g cm−3, regardless of the anion. Considering the saccharinate, and tosylate anions were synthesized and
Unauthenticated
Download Date | 3/5/16 5:27 AM

42
M. G. Bogdanov et al. · Guanidinium-based Room-temperature Ionic Liquids
Fig. 2. Residual Volume Ap-
proach correlations of densities
at 25 ◦C:
gAce, ꢁ Cn-gTos, n = 1, 2, 4,
6, 8, 10 and × Cn-gBF4, n = 3,
4, 6, 8, 10.
Cn-gSac, ꢀ Cn-
characterized and their physical properties were evalu- Density
ated. All the salts are hydrophobicliquids at room tem-
The reported densities were determined by means of a pic-
nometer (1 cm3) at 25 ◦C. The mass of the volume of liquid
was taken on an analytical balance and each reported value
is the average of two measurements.
perature, allowing an investigation of their water up-
take ability and density. The behavior is unique for the
synthesized relatively “light” hydrophobic gILs, which
might be of interest in novel reactions or in separation
processes and devices.
Synthesis
Experimental Section
N,N-diethyl-Nꢀ,Nꢀ-di-n-propylurea (1), N,N-diethyl-Nꢀ,
Nꢀ-di-n-propylchloroformamidinium chloride (2) and the
pentasubstituted guanidine 3 were synthesized by protocols
published previously by Kantlehner and coworkers [2].
General remarks
Commercially available reagents were used as supplied.
All the other reagents used were dried and freshly distilled
prior to use. Distilled water was used for the preparation of
aqueous solutions. All glassware was oven-dried at 75 ◦C be-
fore using.
General procedure for the synthesis of guanidinium chlorides
Cn-gCl (n = 3, 4, 6, 8, 10)
The IR spectra were acquired from thin films on a Perkin-
Elmer FT-IR instrument Model Spectrum One and are re-
ported in reciprocal centimeters. The 1H and 13C NMR spec-
tra were obtained on a Bruker Avance DRX-250 NMR spec-
trometer operating at 250.13 and 62.9 Hz, respectively, in the
solvent given in parentheses. The chemical shifts are given in
ppm (δ) relative to tetramethylsilane as internal standard. El-
emental analyses were obtained in the laboratories at the In-
stitute of Organic Chemistry, University of Stuttgart. Prior to
their further manipulation (characterization or property mea-
surement), each RTIL was dried under vacuum (0.01 mbar)
at 90 ◦C for at least 6 h.
The reactions were carried out in round-bottom flasks
equipped with a reflux condenser and a calcium chloride
tube. The corresponding alkyl chlorides (3 equiv.) were
added to a solution of guanidine 3 in dry DMF, and the reac-
tion mixtures were stirred at 100 – 110 ◦C (oil bath) for an ap-
propriate time. The consumption of 3 was monitored by FT-
IR. After the end of the reaction the volatile ingredients were
evaporated under reduced pressure, the residue was dissolved
in distilled water and in order to remove any unreacted start-
ing material washed with cyclohexane (6 × 50 cm3). After-
wards, the main quantity of water was evaporated under re-
duced pressure (90 ◦C, 20 mbar), and the residual RTILs Cn-
gCl were further dried at high vacuum (90 ◦C, 0.01 mbar) for
6 – 8 h. Except C6-gCl, which solidified after drying, all the
Water contents
The water content of each RTgIL was determined by Karl- other guanidinium chlorides were obtained as slightly yellow
Fischer titration with a Metrohm 831 KF Coulometer.
liquids.
Unauthenticated
Download Date | 3/5/16 5:27 AM

M. G. Bogdanov et al. · Guanidinium-based Room-temperature Ionic Liquids
43
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-n-
propylguanidinium chloride (C3-gCl)
δ = 0.79 – 1.03 (m, 12 H, 2 × C2H4CH3, C5H10CH3,
C7H14CH3), 1.11 – 1.90 (m, 30 H, 12 × CH2, 2 × CH2CH3),
2.97 – 3.64 (m, 12 H, all CH2N). – 13C NMR (62.9 MHz,
CDCl3): δ = 11.3 (CH3), 11.4 (CH3), 13.1 (CH3), 13.2
(CH3), 13.9 (CH3), 14.0 (CH3), 21.0 (CH2), 21.1 (CH2),
22.6 (2 × CH2), 26.6 (CH2), 26.9 (CH2), 27.5 (2 × CH2),
29.1 (2 × CH2), 31.3 (CH2), 31.7 (CH2), 44.2 (CH2N),
44.3 (CH2N), 49.8 (2 × CH2N), 51.5 (CH2N), 51.6 (CH2N),
164.0 (CN3+).
This compound was obtained from 43.98 g (0.56 mol)
of n-propyl chloride and 39.66 g (0.14 mol) of guani-
dine 3. – Yield 15.21 g (30 %). – IR (film): ν = 1533
(CN3+) cm−1. – 1H NMR (250.13 MHz, CDCl3): δ =
0.78 – 1.02 (m, 12 H, 3 × C2H4CH3, C5H10CH3), 1.14 – 1.35
(m, 12 H, 3 × CH2, 2 × CH2CH3), 1.38 – 1.95 (m, 8 H,
NCH2CH2, 3 × NCH2CH2CH3), 2.96 – 3.55 (m, 12 H, all
CH2N). – 13C NMR (62.9 MHz, CDCl3): δ = 11.3 (2 ×
CH3), 11.4 (CH3), 13.0 (CH3), 13.1 (CH3), 13.7 (CH3), 21.0
(CH2), 22.5 (3 × CH2), 26.8 (CH2), 27.5 (CH2), 31.1 (CH2),
44.1 (2 × CH2N), 49.8 (CH2N), 51.4 (2 × CH2N), 51.5
(CH2N), 163.9 (CN3+).
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-n-
decylguanidinium chloride (C10-gCl)
This compound was obtained from 38.05 cm3 (33.11 g,
0.188 mol) of n-decyl chloride and 13.28 g (0.047 mol) of
guanidine 3. – Yield 51.4 g (74 %). – n2D0 = 1.4935. – IR
(film): ν = 1534 (CN3+) cm−1. – 1H NMR (250.13 MHz,
CDCl3): δ = 0.81 – 1.02 (m, 12 H, 2 × C2H4CH3,
C5H10CH3, C9H18CH3), 1.07 – 1.94 (m, 34 H, 14 × CH2,
2 × CH2CH3), 3.00 – 3.64 (m, 12 H, all CH2N). – 13C NMR
(62.9 MHz, CDCl3): δ = 11.3 (CH3), 11.4 (CH3), 13.1 (2 ×
CH3), 13.9 (CH3), 14.1 (CH3), 21.0 (CH2), 21.1 (CH2), 22.5
(CH2), 22.6 (CH2), 26.9 (CH2), 27.0 (CH2), 27.4 (2 × CH2),
29.2 (2 × CH2), 29.4 (2 × CH2), 31.3 (CH2), 31.8 (CH2),
44.2 (CH2N), 44.3 (CH2N), 49.8 (2 × CH2N), 51.5 (CH2N),
51.6 (CH2N), 163.9 (CN3+).
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-n-
butylguanidinium chloride (C4-gCl)
This compound was obtained from 58.55 cm3 (51.52 g,
0.56 mol) of n-butyl chloride and 39.66 g (0.14 mol) of
guanidine 3. – Yield 44.63 g (89 %). – n2D0 = 1.5007. – IR
(film): ν = 1532 (CN3+) cm−1. – 1H NMR (250.13 MHz,
CDCl3): δ = 0.80 – 1.03 (m, 12 H, 2 × C2H4CH3, C3H6CH3,
C5H10CH3), 1.12 – 1.95 (m, 22 H, 8 × CH2, 2 × CH2CH3),
2.92 – 3.56 (m, 12 H, all CH2N). – 13C NMR (62.9 MHz,
CDCl3): δ = 11.3 (CH3), 11.4 (CH3), 13.1 (CH3), 13.7
(CH3), 13.9 (2 × CH3), 20.1 (CH2), 21.0 (CH2), 22.5 (2 ×
CH2), 26.6 (CH2), 27.4 (CH2), 29.6 (CH2), 31.3 (CH2), 44.2
(2 × CH2N), 49.6 (CH2N), 49.8 (CH2N), 51.5 (2 × CH2N),
163.9 (CN3+).
General procedure for the synthesis of guanidinium
p-toluenesulfonates Cn-gTos (n = 1, 2, 4, 6, 8, 10)
In a round-bottom flask equipped with a reflux condenser,
the pentasubstituted guanidine 3 was added to a stirred so-
lution of the corresponding tosylate ester ◦in dry DMF. The
reaction mixture was then stirred at 110 C for 2 – 4.30 h.
The reaction was monitored by IR spectroscopy. At the end
of the reaction the volatile compounds were evaporated on a
rotary evaporator, and the residue was washed with diethyl
ether (5 × 50 cm3). The residue was further evaporated first
at 90 ◦C/23 mbar, and than at 0.01 mbar for 8 h.
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ,Nꢀꢀ-di-n-
hexylguanidinium chloride (C6-gCl)
This compound was obtained from 21.2 cm3 (23.88 g,
0.20 mol) of n-hexyl chloride and 14.0 g (0.05 mol) of guani-
dine 3. – Yield 17.4 g (87 %). – n2D0 = 1.4934. – IR (film):
ν = 1532 (CN3+) cm−1. – 1H NMR (250.13 MHz, CDCl3):
δ = 0.79 – 1.02 (m, 12 H, 2 × C2H4CH3, 2 × C5H10CH3),
1.16 – 1.95 (m, 26 H, 10 × CH2, 2 × CH2CH3), 2.96 – 3.57
(m, 12 H, all CH2N). – 13C NMR (62.9 MHz, CDCl3): δ =
11.3 (CH3), 11.4 (CH3), 13.1 (2 × CH3), 13.9 (2 × CH3),
21.0 (CH2), 21.1 (CH2), 22.5 (2 × CH2), 26.5 (CH2), 26.6
(CH2), 27.4 (CH2), 27.6 (CH2), 31.3 (2 × CH2), 44.2 (2 ×
CH2N), 49.8 (2 × CH2N), 51.5 (CH2N), 51.6 (CH2N), 163.9
(CN3+).
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-
methylguanidinium p-toluenesulfonate (C1-gTos)
This compound was obtained from 11.9 g (0.0639 mol)
of methyl tosylate and 16.5 g (0.0581 mol) of guanidine 3 in
DMF (110 cm3). – Yield: 27.02 g (99 %). – n2D0 = 1.5145. –
IR (film): ν = 1539 (CN+3 ), 1200 (SO3−), 677 (Ar) cm−1. –
1H NMR (250.13 MHz, CDCl3): δ = 0.75 – 1.02 (m, 9 H,
2 × C2H4CH3, C5H10CH3), 1.09 – 1.84 (m, 18 H, 6 × CH2,
2 × CH2CH3), 2.32 (s, 3 H, CH3–C6H4SO3−), 2.86 – 3.56
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-n-
octylguanidinium chloride (C8-gCl)
This compound was obtained from 47.5 cm3 (41.47 g, (m, 10 H, all CH2N), 3.03 (d, J = 3.1 Hz, 3 H, NCH3), 7.10
0.28 mol) of n-octyl chloride and 19.7 g (0.07 mol) of guani- (d, J = 7.9 Hz, 2 H, CH3C6H4SO3−), 7.79 (d, J = 8.1 Hz,
dine 3. – Yield 25.4 g (85 %). – nD20 = 1.4957. – IR (film): 2 H, CH3C6H4SO3−). – 13C NMR (62.9 MHz, CDCl3):
ν = 1533 (CN3+) cm−1. – 1H NMR (250.13 MHz, CDCl3): δ = 11.4 (CH3), 12.7 (CH3), 12.9 (CH3), 13.1 (CH3), 13.9
Unauthenticated
Download Date | 3/5/16 5:27 AM

44
M. G. Bogdanov et al. · Guanidinium-based Room-temperature Ionic Liquids
(CH3), 20.8 (CH2), 21.0 (CH2), 21.3 (CH3), 22.5 (CH2), 3 in DMF (95 cm3). – Yield: 20.36 g (88 %). – n2D0
=
26.5 (CH2), 27.2 (CH2), 31.3 (CH2), 38.6 and 38.9 (CH3N- 1.508. – IR (film): ν = 1535 (CN3+), 1202 (SO3−), 677
rotamers), 43.3 (CH2N), 43.7 (CH2N), 44.0 (CH2N), 51.3 (Ar). – 1H NMR (250.13 MHz, CDCl3): δ = 0.74 – 1.01
(CH2N), 52.9 (CH2N), 126.1 (2 × –CH=), 128.3 (2 × – (m, 12 H, 2 × C2H4CH3, 2 × C5H10CH3), 1.04 – 1.94
CH=), 138.5 (C-CH3), 144.5 (C-SO3), 164.0 (CN3+). – (m, 26 H, 10 × CH2, 2 × CH2CH3), 2.32 (s, 3 H, CH3–
Anal. for C25H47N3O3S (469.7) × H2O: calcd. C 61.56, C6H4SO3−), 2.90 – 3.57 (m, 12 H, all CH2N), 7.11 (d, J =
H 10.13, N 8.62; found C 61.55, H 9.95, N 8.53.
7.9 Hz, 2 H, CH3C6H4SO3−), 7.82 (d, J = 8.1 Hz, 2 H,
CH3C6H4SO3−). – 13C NMR (62.9 MHz, CDCl3): δ = 11.3
(CH3), 11.4 (CH3), 12.9 (CH3), 13.0 (CH3), 13.9 (CH3),
14.0 (CH3), 20.9 (CH2), 21.0 (CH2), 21.3 (CH3), 22.5 (2 ×
CH2), 26.5 (CH2), 26.7 (CH2), 27.4 (CH2), 27.5 (CH2), 31.3
(CH2), 31.4 (CH2), 44.0 (CH2N), 44.2 (CH2N), 49.6 (2 ×
CH2N), 51.3 (CH2N), 51.5 (CH2N), 126.2 (2 × –CH=),
128.3 (2 × –CH=), 138.4 (C-CH3), 144.5 (C-SO3), 164.0
(CN3+). – Anal. for C30H57N3O3S (539.9) × H2O: calcd.
C 64.59, H 10.66, N 7.53; found C 64.38, H 10.11, N 7.93.
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-
ethylguanidinium p-toluenesulfonate (C2-gTos)
This compound was obtained from 8.58 g (0.0428 mol)
of ethyl tosylate and 11.04 g (0.0390 mol) of guanidine 3 in
DMF (80 cm3). – Yield: 17.7 g (94 %). – n2D0 = 1.5136. –
IR (film): ν = 1535 (CN3+), 1201 (SO3−), 678 (Ar). –
1H NMR (250.13 MHz, CDCl3): δ = 0.74 – 1.02 (m, 9 H, 2 ×
C2H4CH3, C5H10CH3), 1.05 – 1.88 (m, 21 H, 6 × CH2, 3 ×
CH2CH3), 2.32 (s, 3 H, CH3–C6H4SO3−), 2.87 – 3.56 (m,
12 H, all CH2N), 7.10 (d, J = 7.9 Hz, 2 H, CH3C6H4SO3−),
7.81 (d, J = 8.1 Hz, 2 H, CH3C6H4SO3−). – 13C NMR
(62.9 MHz, CDCl3): δ = 11.4 (CH3), 12.9 (2 × CH3),
13.0 (2 × CH3), 13.9 (CH3), 20.9 (CH2), 21.3 (CH3), 22.5
(CH2), 26.6 (CH2), 27.3 (CH2), 27.4 (CH2), 31.3 (CH2),
44.0 (CH2N), 44.1 (CH2N), 44.6 (CH2N), 49.0 (CH2N),
51.3 (CH2N), 51.4 (CH2N), 126.2 (2 × –CH=), 128.2 (2 ×
–CH=), 138.4 (C-CH3), 144.7 (C-SO3), 163.8 (CN3+). –
Anal. for C26H49N3O3S (483.8) × H2O: calcd. C 62.24,
H 10.24, N 8.37; found C 62.65, H 9.86, N 8.58.
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-n-
octylguanidinium p-toluenesulfonate (C8-gTos)
This compound was obtained from 9.78 g (0.0344 mol)
of n-octyl tosylate and 8.86 g (0.0313 mol) of guani-
dine 3 in DMF (80 cm3). – Yield: 16.20 g (83 %). – n2D0
=
1.5034. – IR (film): ν = 1534 (CN+3 ), 1202 (SO3−), 677
(Ar). – 1H NMR (250.13 MHz, CDCl3): δ = 0.77 – 1.00
(m, 12 H, 2 × C2H4CH3, C7H14CH3, C5H10CH3), 1.04 –
1.91 (m, 30 H, 12 × CH2, 2 × CH2CH3), 2.32 (s, 3 H,
CH3–C6H4SO3−), 2.85 – 3.51 (m, 12 H, all CH2N), 7.10
(d, J = 7.9 Hz, 2 H, CH3C6H4SO3−), 7.82 (d, J = 8.1 Hz,
2 H, CH3C6H4SO3−). – 13C NMR (62.9 MHz, CDCl3):
δ = 11.3 (CH3), 11.4 (CH3), 12.9 (CH3), 13.0 (CH3), 13.9
(CH3), 14.1 (CH3), 20.9 (CH2), 21.0 (CH2), 21.2 (CH3),
22.5 (CH2), 22.6 (CH2), 26.5 (CH2), 26.6 (CH2), 26.8
(CH2), 26.9 (CH2), 27.4 (CH2), 29.1 (CH2), 31.3 (CH2),
31.7 (CH2), 44.0 (CH2N), 44.1 (CH2N), 49.7 (2 × CH2N),
51.4 (CH2N), 51.5 (CH2N), 126.2 (2 × –CH=), 128.2 (2 ×
–CH=), 138.3 (C-CH3), 144.8 (C-SO3), 163.9 (CN3+). –
Anal. for C32H61N3O3S (567.9) × 0.5 H2O: calcd. C 66.62,
H 10.83, N 7.28; found C 66.10, H 10.49, N 7.74.
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-n-
butylguanidinium p-toluenesulfonate (C4-gTos)
This compound was obtained from 12.17 g (0.0533 mol)
of n-butyl tosylate and 13.74 g (0.0485 mol) of guanidine
3 in DMF (100 cm3). – Yield: 22.1 g (89 %). – n2D0
=
1.5123. – IR (film): ν = 1535 (CN3+), 1202 (SO3−), 677
(Ar). – 1H NMR (250.13 MHz, CDCl3): δ = 0.74 – 1.02 (m,
12 H, 2 × C2H4CH3, C5H10CH3, C3H7CH3), 1.05 – 1.88
(m, 22 H, 8 × CH2, 2 × CH2CH3), 2.32 (s, 3 H, CH3–
C6H4SO3−), 2.87 – 3.56 (m, 12 H, all CH2N), 7.10 (d, J =
7.9 Hz, 2 H, CH3C6H4SO3−), 7.81 (d, J = 8.1 Hz, 2 H,
CH3C6H4SO3−). – 13C NMR (62.9 MHz, CDCl3): δ = 11.2
(CH3), 11.4 (CH3), 12.9 (2 × CH3), 13.7 (CH3), 13.9 (CH3),
20.0 (CH2), 20.9 (CH2), 21.0 (CH2), 21.3 (CH3), 22.5
(CH2), 26.6 (CH2), 27.4 (CH2), 29.5 (CH2), 31.3 (CH2),
44.0 (CH2N), 44.1 (CH2N), 49.6 (CH2N), 49.7 (CH2N),
51.3 (CH2N), 51.4 (CH2N), 126.2 (2 × –CH=), 128.2 (2 ×
–CH=), 138.4 (C-CH3), 144.7 (C-SO3), 163.8 (CN3+). –
Anal. for C28H53N3O3S (511.8) × H2O: calcd. C 63.47,
H 10.46, N 7.93; found C 63.55, H 10.11, N 8.39.
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-n-
decylguanidinium p-toluenesulfonate (C10-gTos)
This compound was obtained from 12.62 g (0.0468 mol)
of n-decyl tosylate and 12.06 g (0.0425 mol) of guani-
dine 3 in DMF (100 cm3). – Yield: 23.58 g (93 %). – n2D0
=
1.5007. – IR (film): ν = 1535 (CN3+), 1202 (SO3−), 678
(Ar). – 1H NMR (250.13 MHz, CDCl3): δ = 0.77 – 1.00
(m, 12 H, 2 × C2H4CH3, C9H18CH3, C5H10CH3), 1.07 –
1.92 (m, 34 H, 14 × CH2, 2 × CH2CH3), 2.31 (s, 3 H,
CH3–C6H4SO3−), 2.88 – 3.52 (m, 12 H, all CH2N), 7.09
(d, J = 7.1 Hz, 2 H, CH3C6H4SO3−), 7.82 (d, J = 8.1 Hz,
2 H, CH3C6H4SO3−). – 13C NMR (62.9 MHz, CDCl3):
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ,Nꢀꢀ-di-n-
hexylguanidinium p-toluenesulfonate (C6-gTos)
This compound was obtained from 12.09 g (0.0472 mol) δ = 11.3 (CH3), 11.4 (CH3), 12.9 (CH3), 13.0 (CH3), 13.9
of n-hexyl tosylate and 12.15 g (0.0429 mol) of guanidine (CH3), 14.1 (CH3), 20.9 (CH2), 21.0 (CH2), 21.3 (CH3),
Unauthenticated
Download Date | 3/5/16 5:27 AM

M. G. Bogdanov et al. · Guanidinium-based Room-temperature Ionic Liquids
45
22.5 (CH2), 22.6 (CH2), 26.5 (CH2), 26.6 (CH2), 26.8 NaBF4 in CH3OH (25 cm3). – Yield 7.7 g (98 %). – n2D0
=
(CH2), 26.9 (CH2), 27.4 (CH2), 27.5 (CH2), 29.2 (CH2), 1.4578. – IR (film): ν = 1534 (CN3+), 1034 and 1047 (B–
29.5 (CH2), 31.3 (CH2), 31.4 (CH2), 44.0 (CH2N), 44.1 F) cm−1. – 1H NMR (250.13 MHz, CDCl3): δ = 0.83 –
(CH2N), 50.0 (2 × CH2N), 51.4 (CH2N), 51.5 (CH2N), 1.01 (m, 12 H, 3 × C2H4CH3, C5H10CH3), 1.15 – 1.89 (m,
126.2 (2 × –CH=), 128.2 (2 × –CH=), 138.1 (C-CH3), 145.0 20 H, 7 × CH2, 2 × CH2CH3), 2.93 – 3.49 (m, 12 H, all
(C-SO3), 163.9 (CN3+). – Anal. for C34H65N3O3S (596.0) CH2N). – 13C NMR (62.9 MHz, CDCl3): δ = 11.2 (2 ×
× 0.5 H2O: calcd. C 67.50, H 11.00, N 6.95; found C 67.51, CH3), 11.3 (CH3), 12.7 (CH3), 13.9 (2 × CH3), 20.8 (CH2),
H 10.87, N 6.82.
22.5 (3 × CH2), 26.5 (CH2), 27.4 (CH2), 31.3 (CH2), 43.8
(2 × CH2N), 49.6 (CH2N), 51.3 (3 × CH2N), 164.1 (s,
CN3+). – Anal. for C20H44BF4N3 (413.4): calcd. C 58.11,
H 10.73, N 10.16; found C 57.52, H 10.49, N 10.29.
General procedure for anion metathesis reactions. Synthesis
of guanidinium tetrafluoroborates Cn-gBF4, acesulfamates
Cn-gAce, and saccharinates Cn-gSac (n = 3, 4, 6, 8, 10)
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-n-
Metathesis reaction in methanol
butylguanidinium tetrafluoroborate (C4-gBF4)
A methanol solution of the RTIL Cn-gCl was slowly
added dropwise to a stirred suspension of sodium tetrafluo-
roborate in methanol at 60 ◦C. The flask was equipped with
a magnetic stirrer, a dropping funnel, a reflux condenser and
a calcium chloride tube. The reaction mixture was stirred
for 4 h at reflux and cooled to r. t., and the formed white
precipitate of sodium chloride was removed by filtration.
The filtrate was distilled under reduced pressure giving the
crude product of the metathesis reaction. In order to remove
the residual sodium chloride, the residue was dissolved
in a small quantity of dry THF, filtered, and the solvent
was evaporated on a rotary evaporator. The residue was
further dissolved in a small quantity of dichloromethane
and washed with distilled water until the probe for chloride
anions (AgNO3 test) was negative. The dichloromethane
layer was dried with sodium sulfate and filtered, and
dichloromethane was evaporated on a rotary evaporator. The
resulting slight yellow RTILs Cn-gBF4 were further dried in
vacuo (90 ◦C/0.01 mbar) for 6 – 8 h.
This compound was obtained from 9.16 g (0.025 mol)
of C4-gCl in CH3OH (60 cm3) and 3.18 g (0.03 mol) of
NaBF4 in CH3OH (30 cm3). – Yield 10.2 g (96 %). – n2D0
=
1.4572. – IR (film): ν = 1534 (CN3+), 1033 and 1048 (B–
F) cm−1. – 1H NMR (250.13 MHz, CDCl3): δ = 0.81 – 1.02
(m, 12 H, 2 × C2H4CH3, C3H6CH3, C5H10CH3), 1.14 –
1.90 (m, 22 H, 8 × CH2, 2× CH2CH3), 2.92 – 3.51 (m,
12 H, all CH2N). – 13C NMR (62.9 MHz, CDCl3): δ = 11.3
(2 × CH3), 12.8 (CH3), 12.9 (CH3), 13.9 (2 × CH3), 20.1
(CH2), 20.8 (CH2), 22.5 (2 × CH2), 26.6 (CH2), 27.4 (CH2),
29.5 (CH2), 31.3 (CH2), 43.8 (2 × CH2N), 49.4 (CH2N),
49.6 (CH2N), 51.4 (2 × CH2N), 164.0 (CN3+). – Anal.
for C21H46BF4N3 (427.4) × H2O: calcd. C 57.79, H 10.85,
N 9.63; found C 58.19, H 10.62, N 10.07.
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ,Nꢀꢀ-di-n-
hexylguanidinium tetrafluoroborate (C6-gBF4)
This compound was obtained from 12.59 g (0.031 mol)
Metathesis reaction in water
of C6-gCl in CH3OH (80 cm3) and 4.1 g (0.037 mol) of
NaBF4 in CH3OH (40 cm3). – Yield 13.4 g (94 %). – n2D0
=
A solution of the RTIL Cn-gCl in water was slowly added
dropwise to a saturated stirred solution of the correspond-
ing sodium or potassium salt in water at 60 C. The flask
was equipped with a magnetic stirrer, a dropping funnel, a
reflux condenser, and a calcium chloride tube. The reaction
1.4597. – IR (film): ν = 1533 (CN3+), 1033 and 1047 (B–
F) cm−1. – 1H NMR (250.13 MHz, CDCl3): δ = 0.81 –
1.01 (m, 12 H, 2 × C2H4CH3, 2 × C5H10CH3), 1.15 –
1.89 (m, 26 H, 10 × CH2, 2 × CH2CH3), 2.91 – 3.53 (m,
12 H, all CH2N). – 13C NMR (62.9 MHz, CDCl3): δ =
11.2 (CH3), 11.3 (CH3), 12.7 (CH3), 12.8 (CH3), 13.9 (2 ×
CH3), 20.8 (CH2), 20.9 (CH2), 22.5 (2 × CH2), 26.5 (CH2),
26.6 (CH2), 27.3 (CH2), 27.4 (CH2), 31.3 (2 × CH2), 43.8
(CH2N), 43.9 (CH2N), 49.7 (2 × CH2N), 51.3 (CH2N), 51.4
(CH2N), 164.0 (CN3+). – Anal. for C23H50BF4N3 (455.5):
calcd. C 60.65, H 11.06, N 9.23; found C 60.48, H 10.91,
N 9.16.
◦
◦
mixture was stirred for 4 h at 60 C and then left to cool
over night. The resulting two layers were separated, and the
product of the metathesis reaction (the top layer) was dis-
solved in dichloromethane and washed with water until the
probe for chloride anions (AgNO3 test) was negative. The
dichloromethane layer was dried with sodium sulfate and fil-
tered, and dichloromethane was evaporated on a rotary evap-
orator. The resulting slightly yellow RTILs Cn-gX were fur-
ther dried in vacuo (90 ◦C/0.01 mbar) for 6 – 8 h.
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-n-
octylguanidinium tetrafluoroborate (C8-gBF4)
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-n-
propylguanidinium tetrafluoroborate (C3-gBF4)
This compound was obtained from 7.02 g (0.019 mol)
This compound was obtained from 17.9 g (0.041 mol)
of C3-gCl in CH3OH (45 cm3) and 2.52 g (0.023 mol) of of C8-gCl in CH3OH (110 cm3) and 5.45 g (0.049 mol)
Unauthenticated
Download Date | 3/5/16 5:27 AM

46
M. G. Bogdanov et al. · Guanidinium-based Room-temperature Ionic Liquids
NaBF4 in CH3OH (55 cm3). – Yield = 19.6 g (98 %). – N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-n-
n2D0 = 1.4580. – IR (film): ν = 1534 (CN3+), 1034 and 1048 butylguanidinium acesulfamate (C4-gAce)
(B–F) cm−1. – 1H NMR (250.13 MHz, CDCl3): δ = 0.79 –
This compound was obtained from 20.58 g (0.056 mol)
0.99 (m, 12 H, 2 × C2H4CH3, C5H10CH3, C7H14CH3),
of C4-gCl in H2O and 57.05 g (0.284 mol) acesulfame-K
1.17 – 1.84 (m, 30 H, 12 × CH2, 2 × CH2CH3), 2.93 – 3.52
(m, 12 H, all CH2N). – 13C NMR (62.9 MHz, CDCl3):
δ = 11.3 (2 × CH3), 12.7 (CH3), 12.8 (CH3), 14.0 (2 ×
CH3), 20.8 (CH2), 20.9 (CH2), 22.5 (CH2), 22.6 (CH2), 26.5
(CH2), 27.4 (CH2), 28.9 (CH2), 29.2 (CH2), 30.3 (2 × CH2),
31.3 (CH2), 31.7 (CH2), 43.8 (2 × CH2N), 43.9 (CH2N),
49.6 (CH2N), 51.4 (2 × CH2N), 164.0 (CN3+). – Anal. for
C25H54BF4N3 (483.5) × 0.5 H2O: calcd. C 60.96, H 11.26,
N 8.53; found C 61.00, H 11.11, N 9.11.
in H2O. – Yield = 26.2 g (92 %). – n2D0 = 1.5019. – IR
(film): ν = 1534 (CN3+), 1172 (SO2), 1602 (C=C), 1650
(C=O) cm−1. – 1H NMR (250.13 MHz, CDCl3): δ = 0.86 –
1.01 (m, 12 H, 2 × C2H4CH3, C3H6CH3, C5H10CH3), 1.12 –
1.90 (m, 22 H, 8 × CH2, 2 × CH2CH3), 1.99 (d, J = 1.0 Hz,
3 H, CH3/Ace), 2.95 – 3.51 (m, 12 H, all CH2N), 5.46 (d,
J = 1.0 Hz, 1 H, CH/Ace). – 13C NMR (62.9 MHz, CDCl3):
δ = 11.3 (CH3), 11.4 (CH3), 12.9 (CH3), 13.7 (CH3), 13.9
(2 × CH3), 20.1 (CH3/Ace), 20.9 (CH2), 21.0 (CH2), 22.5
(2 × CH2), 26.6 (CH2), 27.4 (CH2), 29.5 (CH2), 31.3 (CH2),
44.0 (2 × CH2N), 49.4 (CH2N), 49.7 (CH2N), 51.4 (2 ×
CH2N), 102.3 (CH/Ace), 160.3 (C–O/Ace), 163.9 (CN3+),
169.7 (C=O/Ace). – Anal. for C25H50N4O4S (502.8) × 0.5
H2O: calcd. C 58.67, H 10.04, N 10.95; found C 58.35,
H 9.88, N 11.19.
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-n-
decylguanidinium tetrafluoroborate (C10-gBF4)
This compound was obtained from 18.00 g (0.039 mol)
of C10-gCl in CH3OH (115 cm3) and 5.15 g (0.047 mol)
NaBF4 in CH3OH (52 cm3). – Yield = 19.4 g (97 %). –
n2D0 = 1.4567. – IR (film): ν = 1535 (CN3+), 1034 and 1048
(B–F) cm−1. – 1H NMR (250.13 MHz, CDCl3): δ = 0.79 –
1.01 (m, 12 H, 2 × C2H4CH3, C5H10CH3, C9H18CH3),
1.13 – 1.91 (m, 34 H, 14 × CH2, 2 × CH2CH3), 2.94 – 3.51
(m, 12 H, all CH2N). – 13C NMR (62.9 MHz, CDCl3):
δ = 11.2 (CH3), 11.3 (CH3), 12.7 (CH3), 12.8 (CH3), 14.0
(CH3), 14.1 (CH3), 20.8 (CH2), 20.9 (CH2), 22.5 (CH2),
22.6 (CH2), 26.5 (CH2), 27.3 (CH2), 27.4 (2 × CH2), 29.2
(2 × CH2), 29.5 (2 × CH2), 31.3 (CH2), 31.8 (CH2), 43.9
(2 × CH2N), 49.6 (CH2N), 49.7 (CH2N), 51.3 (2 × CH2N),
164.0 (CN3+). – Anal. for C27H58BF4N3 (511.6) × 0.5
H2O: calcd. C 62.29, H 11.42, N 8.07; found C 62.00,
H 11.33, N, 8.67.
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ,Nꢀꢀ-di-n-
hexylguanidinium acesulfamate (C6-gAce)
This compound was obtained from 22.84 g (0.0565 mol)
of C6-gCl in H2O and 22.74 g (0.113 mol) acesulfame-K
in H2O. – Yield = 26.5 g (88 %). – n2D0 = 1.4994. – IR
(film): ν = 1532 (CN3+), 1172 (SO2), 1603 (C=C), 1650
(C=O) cm−1. – 1H NMR (250.13 MHz, CDCl3): δ = 0.86 –
0.97 (m, 12 H, 2 × C2H4CH3, 2 × C5H10CH3), 1.13 – 1.89
(m, 26 H, 10 × CH2, 2 × CH2CH3), 1.99 (d, J = 1.0 Hz,
3 H, CH3/Ace), 2.94 – 3.51 (m, 12 H, all CH2N), 5.48 (d,
J = 1.0 Hz, 1 H, CH/Ace). – 13C NMR (62.9 MHz, CDCl3):
δ = 11.3 (CH3), 11.4 (CH3), 12.9 (2× CH3), 13.9 (2× CH3),
20.0 (CH3/Ace), 21.0 (2× CH2), 22.5 (2× CH2), 26.5 (2×
CH2), 27.4 (2× CH2), 31.3 (2× CH2), 44.1 (2× CH2N),
49.7 (2× CH2N), 51.4 (2× CH2N), 102.3 (CH/Ace), 160.3
(C–O/Ace), 163.9 (s, CN3+), 169.7 (C=O/Ace). – Anal. for
C27H54N4O4S (530.8) × H2O: calcd. C 59.09, H 10.28,
N 10.21; found C 59.47, H 10.16, N 10.25.
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-n-
propylguanidinium acesulfamate (C3-gAce)
This compound was obtained from 7.18 g (0.021 mol)
of C3-gCl in CH3OH (4.14 cm3) and 8.25 g (0.041 mol)
acesulfame-K in CH3OH (8 cm3). – Yield = 9.2 g (92 %). –
n2D0 = 1.5032. – IR (film): ν = 1533 (CN3+), 1171 (SO2),
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-n-
octylguanidinium acesulfamate (C8-gAce)
1
1602 (C=C), 1650 (C=O) cm−1. – H NMR (250.13 MHz,
CDCl3): δ = 0.80 – 1.01 (m, 12 H, 3 × C2H4CH3,
This compound was obtained from 12.37 g (0.028 mol)
C5H10CH3), 1.17 – 1.91 (m, 20 H, 7 × CH2, 2 × CH2CH3), of C8-gCl in H2O and 28.8 g (0.143 mol) acesulfame-K
2.00 (d, J = 1.0 Hz, 3H, CH3/Ace), 2.95 – 3.50 (m, 12 H, in H2O. – Yield = 15.9 g (99 %). – n2D0 = 1.4978. – IR
all CH2N), 5.46 (d, J = 1.0 Hz, 1 H, CH/Ace). – 13C NMR (film): ν = 1533 (CN3+), 1172 (SO2), 1601 (C=C), 1650
(62.9 MHz, CDCl3): δ = 11.3 (CH3), 11.4 (CH3), 12.8 (C=O) cm−1. – 1H NMR (250.13 MHz, CDCl3): δ = 0.77 –
(CH3), 12.9 (CH3), 13.9 (2 × CH3), 19.9 (CH3/Ace), 20.9 1.01 (m, 12 H, 2× C2H4CH3, C5H10CH3, C7H14CH3),
(CH2), 22.5 (3 × CH2), 26.6 (CH2), 27.5 (CH2), 31.3 (CH2), 1.08 – 1.91 (m, 30 H, 12 × CH2, 2 × CH2CH3), 1.99 (d,
44.0 (CH2N), 44.1 (CH2N), 49.7 (CH2N), 51.4 (3 × CH2N), J = 1.0 Hz, 3 H, CH3/Ace), 3.00 – 3.52 (m, 12 H, all CH2N),
102.4 (CH/Ace), 160.3 (C–O/Ace), 163.9 (CN3+), 169.8 5.46 (d, J = 1.0 Hz, 1 H, CH/Ace). – 13C NMR (62.9 MHz,
(C=O/Ace). – Anal. for C24H48N4O4S (488.7) × H2O: CDCl3): δ = 11.4 (2× CH3), 12.9 (CH3), 13.0 (CH3), 13.9
calcd. C 56.88, H 9.95, N 11.06; found C 57.70, H 9.89, (CH3), 14.1 (CH3), 19.9 (CH3/Ace), 20.9 (CH2), 21.0 (CH2),
N 11.39.
22.5 (CH2), 22.6 (CH2), 26.6 (CH2), 26.9 (CH2), 27.5 (2×
Unauthenticated
Download Date | 3/5/16 5:27 AM

M. G. Bogdanov et al. · Guanidinium-based Room-temperature Ionic Liquids
47
CH2), 29.2 (2× CH2), 31.3 (CH2), 31.7 (CH2), 44.0 (CH2N), 1.5274. – IR (film): ν = 1533 (CN+3 1), 1116 and 1142 (SO2),
1583 (C=C), 1637 (C=O) cm−1. – H NMR (250.13 MHz,
CDCl3): δ = 0.77 – 0.99 (m, 12 H, 2× C2H4CH3, C3H6CH3,
C5H10CH3), 1.09 – 1.91 (m, 22 H, 8 × CH2, 2 × CH2CH3),
2.93 – 3.55 (m, 12 H, all CH2N), 7.45 – 7.54 (m, 2 H, 2 ×
CH/Sac), 7.69 – 7.76 (m, 1 H, CH/Sac), 7.77 – 7.83 (m,
1 H, CH/Sac). – 13C NMR (62.9 MHz, CDCl3): δ = 11.3
(CH3), 11.4 (CH3), 12.9 (CH3), 13.7 (CH3), 13.9 (CH3),
14.0 (CH3), 20.1 (CH2), 20.9 (CH2), 22.5 (2 × CH2),
26.6 (CH2), 27.4 (CH2), 29.4 (CH2), 31.3 (CH2), 44.0
(CH2N), 44.1 (CH2N), 49.7 (CH2N), 50.9 (CH2N), 51.3
(CH2N), 52.4 (CH2N), 119.5 (CH/Sac), 123.1 (CH/Sac),
130.7 (CH/Sac), 131.6 (CH/Sac), 135.3 (C/Sac), 145.2
(C–S/Sac), 164.0 (CN3+), 169.9 (C=O/Sac). – Anal. for
C28H50N4O3S (522.8) × H2O: calcd. C 62.19, H 9.69,
N 10.36; found C 62.48, H 9.42, N 10.88.
44.1 (CH2N), 49.7 (2× CH2N), 51.4 (CH2N), 51.5 (CH2N),
102.3 (CH/Ace), 160.4 (C–O/Ace), 163.9 (CN3+), 169.8
(C=O/Ace). – Anal. for C29H58N4O4S (558.9) × H2O:
calcd. C 60.38, H 10.48, N 9.71; found C 60.38, H 10.27,
N 9.89.
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-n-
decylguanidinium acesulfamate (C10-gAce)
This compound was obtained from 15.62 g (0.034 mol)
of C10-gCl in H2O and 34.21 g (0.17 mol) of acesulfame-
K in H2O. – Yield = 19.4 g (97 %). – n2D0 = 1.4952. – IR
(film): ν = 1533 (CN3+), 1172 (SO2), 1603 (C=C), 1650
(C=O) cm−1. – 1H NMR (250.13 MHz, CDCl3): δ = 0.79 –
1.01 (m, 12 H, 2× C2H4CH3, C5H10CH3, C9H18CH3),
1.12 – 1.89 (m, 34 H, 14 × CH2, 2 × CH2CH3), 2.00
(d, J = 1.0 Hz, 3 H, CH3/Ace), 2.88 – 3.53 (m, 12 H, all
CH2N), 5.46 (d, J = 1.0 Hz, 1 H, CH/Ace). – 13C NMR
(62.9 MHz, CDCl3): δ = 11.3 (CH3), 11.4 (CH3), 12.9
(2× CH3), 13.9 (CH3), 14.1 (CH3), 19.9 (CH3/Ace), 20.9
(CH2), 22.6 (CH2), 26.5 (CH2), 26.6 (CH2), 26.9 (2× CH2),
27.4 (CH2), 27.5 (CH2), 29.2 (CH2), 29.3 (CH2), 29.5 (2×
CH2), 31.3 (CH2), 31.8 (CH2), 43.9 (CH2N), 44.0 (CH2N),
49.7 (2× CH2N), 51.4 (2× CH2N), 102.4 (CH/Ace), 160.4
(C–O/Ace), 163.9 (CN3+), 169.8 (C=O/Ace). – Anal. for
C31H62N4O4S (586.9): calcd. C 61.55, H 10.66, N 9.26;
found C 61.60, H 10.55, N 9.24.
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ,Nꢀꢀ-di-n-
hexylguanidinium saccharinate (C6-gSac)
This compound was obtained from 7.35 g (0.018 mol) of
C6-gCl in H2O and 22.0 g (0.091 mol) of sodium sacchar-
inate in H2O. – Yield = 9.4 g (94 %). – n2D0 = 1.5211. – IR
(film): ν = 1532 (CN3+1 ), 1116 and 1143 (SO2), 1583 (C=C),
1637 (C=O) cm−1. – H NMR (250.13 MHz, CDCl3): δ =
0.79 – 1.00 (m, 12 H, 2 × C2H4CH3, 2 × C5H10CH3), 1.14 –
1.88 (m, 26 H, 10 × CH2, 2 × CH2CH3), 2.93 – 3.54 (m,
12 H, all CH2N), 7.44 – 7.51 (m, 2 H, 2 × CH/Sac), 7.68 –
7.74 (m, 1 H, CH/Sac), 7.77 – 7.83 (m, 1 H, CH/Sac). –
13C NMR (62.9 MHz, CDCl3): δ = 11.3 (CH3), 11.4
(CH3), 13.0 (2 × CH3), 13.9 (2 × CH3), 20.9 (CH2),
21.0 (CH2), 22.5 (2 × CH2), 26.5 (CH2), 26.6 (CH2), 27.4
(CH2), 27.5 (CH2), 31.3 (2 × CH2), 44.0 (CH2N), 44.1
(CH2N), 49.7 (2 × CH2N), 51.4 (CH2N), 51.5 (CH2N),
119.4 (CH/Sac), 123.1 (CH/Sac), 130.5 (CH/Sac), 131.2
(CH/Sac), 135.6 (C/Sac), 145.4 (C–S/Sac), 164.0 (CN3+),
169.9 (C=O/Sac). – Anal. for C30H54N4O3S (550.8): calcd.
C 65.41, H 9.88, N 10.17; found C 65.22, H 9.85, N 10.13.
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-n-
propylguanidinium saccharinate (C3-gSac)
This compound was obtained from 8.86 g (0.025 mol) of
C3-gCl in H2O and 30.6 g (0.127 mol) of sodium sacchari-
nate in H2O. – Yield = 10.3 g (82 %). – n2D0 = 1.5304. – IR
(film): ν = 1534 (CN3+1 ), 1116 and 1142 (SO2), 1583 (C=C),
1637 (C=O) cm−1. – H NMR (250.13 MHz, CDCl3): δ =
0.78 – 0.98 (m, 12 H, 3× C2H4CH3, C5H10CH3), 1.09 – 1.90
(m, 20 H, 7 × CH2, 2 × CH2CH3), 2.89 – 3.55 (m, 12 H, all
CH2N), 7.46 – 7.53 (m, 2 H, 2 × CH/Sac), 7.66 – 7.75 (m,
1 H, CH/Sac), 7.76 – 7.83 (m, 1 H, CH/Sac). – 13C NMR
(62.9 MHz, CDCl3): δ = 11.3 (3 × CH3), 12.9 (CH3),
13.9 (2 × CH3), 20.9 (CH2), 22.5 (3 × CH2), 26.6 (CH2),
27.4 (CH2), 31.3 (CH2), 44.0 (2 × CH2N), 49.6 (CH2N),
51.3 (3 × CH2N), 119.4 (CH/Sac), 123.1 (CH/Sac), 130.6
(CH/Sac), 131.3 (CH/Sac), 135.4 (C/Sac), 145.3 (C–S/Sac),
163.9 (CN3+), 170.0 (C=O/Sac). – Anal. for C27H48N4O3S
(508.8) × 0.5 H2O: calcd. C 62.88, H 9.54, N 10.82; found
C 62.43, H 9.38, N 11.03.
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-n-
octylguanidinium saccharinate (C8-gSac)
This compound was obtained from 14.9 g (0.034 mol) of
C8-gCl in H2O and 41.7 g (0.173 mol) of sodium sacchari-
nate in H2O. – Yield = 19.8 g (99 %). – n2D0 = 1.5202. – IR
(film): ν = 1533 (CN3+), 1116 and 1143 (SO2), 1583 (C=C),
1637 (C=O) cm−1. – 1H NMR (250.13 MHz, CDCl3):
δ = 0.77 – 1.00 (m, 12 H, 2 × C2H4CH3, C5H10CH3,
C7H14CH3), 1.09 – 1.91 (m, 30 H, 12 × CH2, 2 × CH2CH3),
2.88 – 3.57 (m, 12 H, all CH2N), 7.46 – 7.53 (m, 2 H, 2 ×
CH/Sac), 7.68 – 7.75 (m, 1 H, CH/Sac), 7.76 – 7.84 (m, 1 H,
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-n-
butylguanidinium saccharinate (C4-gSac)
This compound was obtained from 14.2 g (0.039 mol) CH/Sac). – 13C NMR (62.9 MHz, CDCl3): δ = 11.3 (2 ×
of C4-gCl in H2O and 47.3 g (0.196 mol) of sodium CH3), 12.9 (2 × CH3), 13.9 (CH3), 14.1 (CH3), 20.9 (CH2),
saccharinate in H2O. – Yield = 19.0 g (95 %). – nD20
=
21.0 (CH2), 22.6 (2 × CH2), 26.6 (CH2), 26.8 (CH2), 27.4
Unauthenticated
Download Date | 3/5/16 5:27 AM

48
M. G. Bogdanov et al. · Guanidinium-based Room-temperature Ionic Liquids
(2 × CH2), 29.1 (2 × CH2), 31.2 (CH2), 31.7 (CH2), 44.0 1 H, CH/Sac). – 13C NMR (62.9 MHz, CDCl3): δ = 11.3
(2 × CH2N), 49.7 (2 × CH2N), 51.3 (CH2N), 51.4 (CH2N), (CH3), 11.4 (CH3), 13.0 (CH3), 13.9 (CH3), 14.1 (2 ×
119.4 (CH/Sac), 123.1 (CH/Sac), 130.6 (CH/Sac), 131.3 CH3), 20.9 (CH2), 21.0 (CH2), 22.5 (CH2), 22.6 (CH2), 26.6
(CH/Sac), 135.3 (C/Sac), 145.3 (C–S/Sac), 163.9 (CN3+), (CH2), 26.9 (CH2), 27.4 (2 × CH2), 29.3 (2 × CH2), 29.5
169.8 (C=O/Sac). – Anal. for C32H58N4O3S (578.9) × 1.5 (2 × CH2), 31.3 (CH2), 31.8 (CH2), 44.0 (CH2N), 44.2
H2O: calcd. C 63.43, H 10.15, N 9.25; found C 63.20, H 9.83, (CH2N), 49.7 (2 × CH2N), 51.4 (CH2N), 51.5 (CH2N),
N 9.30.
119.5 (CH/Sac), 123.1 (CH/Sac), 130.6 (CH/Sac), 131.3
(CH/Sac), 135.4 (C/Sac), 145.3 (C–S/Sac), 163.9 (CN3+),
170.0 (C=O/Sac). – Anal. for C34H62N4O3S (606.9) × H2O:
calcd. C 65.34, H 10.32, N 8.96; found C 65.17, H 10.07,
N 9.28.
N,N-Diethyl-Nꢀ,Nꢀ-di-n-propyl-Nꢀꢀ-n-hexyl-Nꢀꢀ-n-
decylguanidinium saccharinate (C10-gSac)
This compound was obtained from 7.58 g (0.016 mol) of
C10-gCl in H2O and 19.9 g (0.082 mol) of sodium saccha-
rinate in H2O. – Yield = 9.9 g (99 %). – n2D0 = 1.5184. – IR
(film): ν = 1533 (CN3+), 1116 and 1143 (SO2), 1583 (C=C),
1637 (C=O) cm−1. – 1H NMR (250.13 MHz, CDCl3):
δ = 0.78 – 0.98 (m, 12 H, 2 × C2H4CH3, C5H10CH3,
C9H18CH3), 1.11 – 1.91 (m, 34 H, 14 × CH2, 2 × CH2CH3),
2.91 – 3.56 (m, 12 H, all CH2N), 7.45 – 7.53 (m, 2 H, 2 ×
CH/Sac), 7.69 – 7.75 (m, 1 H, CH/Sac), 7.76 – 7.83 (m,
Acknowledgements
The present work was funded by the Bundesministeri-
um fu¨r Bildung und Forschung (Programm: Innovationen als
Schlu¨ssel fu¨r Nachhaltigkeit in der Wirtschaft. Verbundpro-
jekt: Neuartige ionische Flu¨ssigkeiten als innovative Reak-
tionsmedien fu¨r die Technische Organische Chemie. Fo¨rder-
kennzeichen 01RI05176). We are indebted to BASF SE, Lud-
wigshafen, for the gift of chemicals.
[1] a) F. Endres, S. Zein El Abedin, Phys. Chem.
Chem. Phys. 2006, 8, 2101 – 2116; b) P. Wasser-
scheid, A. Keim, Angew. Chem. 2000, 112, 3926 –
3945; Angew. Chem. Int. Ed. 2000, 39, 3772 – 3789;
c) S. A. Forsyth, J. M. Pringle, D. R. MacFarlane, Aust.
J. Chem. 2004, 57, 113 – 119; d) J. Dupont, P. A. Z.
Suarez, Phys. Chem. Chem. Phys. 2006, 8, 2441 –
2452; e) J. L. Anderson, D. W. Armstrong, Anal. Chem.
2003, 75, 4851 – 4858.
[2] P. Wang, S. M. Zakeeruddin, M. Gra¨tzel, W. Kant-
lehner, J. Mezger, E. V. Stoyanov, O. Scherr, Appl.
Phys. A: Mater. Sci. Process. 2004, A79, 73 – 77.
[3] Y. Gao, S. W. Arritt, B. Twamley, J. M. Shreeve, Inorg.
Chem. 2005, 44, 1704 – 1712.
[9] a) W. Kantlehner, H. Hagen, German Patent (DOS)
2716 477, BASF AG 1978; C. A. 90, 38 552
(1979); b) W. Kantlehner, H. Hagen, German Patent
(DOS) 2718 275, BASF AG 1978; C. A. 90, 86
777 (1979); c) W. Kantlehner, L. Kienitz, H. Jaus,
H. Bredereck, Liebigs Ann. Chem. 1979, 2089 – 2095;
d) W. Kantlehner, E. Haug, W. W. Mergen, P. Speh,
T. Maier, J. J. Kapassakalidis, H. J. Bra¨uner, H. Hagen,
Synthesis 1983, 904 – 905; e) W. Kantlehner, E. Haug,
W. W. Mergen, P. Speh, T. Maier, J. J. Kapassakalidis,
H. J. Bra¨uner, H. Hagen, Liebigs Ann. Chem. 1984,
108 – 126.
[10] S. V. Dzyuba, R. A. Bartsch, J. Heterocyclic Chem.
2001, 38, 265 – 268.
[4] a) N. M. M. Mateus, L. C. Branco, N. M. T. Lourenc¸o,
C. A. M. Afonso, Green Chem. 2003, 5, 347 – 352;
b) P. S. Kulkarni, L. C. Branco, J. G. Crespo, M. Cris-
tiana Nunes, A. Raymundo, C. A. M. Afonso, Chem.
Eur. J. 2007, 13, 8478 – 8488; c) L. C. Branco, P. M. P.
Gois, N. M. T. Lourenc, V. B. Kurteva and C. A. M.
Afonso, Chem. Commun. 2006, 2371 – 2372.
[11] C. M. Gordon, M. J. Muldoon in Ionic Liquids in Syn-
thesis, 2nd Ed. (Eds.: P. Wasserscheid, T. Welton),
Wiley-VCH, Weinheim, 2008, pp. 10.
[12] A. G. Bo¨wing, A. Jess, Green Chem. 2005, 7, 230 –
235.
[13] M. B. Smith, J. March, Marchꢀs advanced organic
chemistry: reactions, mechanisms, and structure, 5th
ed., John Wiley & Sons, New York, 2001, pp. 450.
[14] J. G. Huddleston, H. D. Willauer, R. P. Swatloski, A. E.
Visser, R. D. Rogers, Chem. Commun. 1998, 1765 –
1766.
[5] H. Kunkel, G. Maas, Eur. J. Org. Chem. 2007, 3746 –
3757.
[6] J. Shah, J. Liebscher, Synthesis 2008, 917 – 920.
[7] a) S. Fang, L. Yang, C. Wei, C. Jiang, K. Tachibana,
K. Kamijima, Electrochim. Acta 2009, 54, 1752 –
1756; b) S. Fang, L. Yang, J. Wang, H. Zhang, K. Ta-
chibana, K. Kamijima, J. Power Sour. 2009, 191, 619 –
622.
[15] H. Ohno, K. Fukumoto, Acc. Chem. Res. 2007, 40,
1122 – 1129.
[16] M. G. Bogdanov, W. Kantlehner, Z. Naturforsch. 2009,
64b, 215 – 222.
[8] D. Li, M. Wang, J. Wu, Q. Zhang, Y. Luo, Z. Yu,
Q. Meng, Z. Wu, Langmuir 2009, 25, 4808 – 4814.
[17] M. G. Bogdanov, B. Iliev, W. Kantlehner, Z. Natur-
forsch. 2009, 64b, 756 – 764.
Unauthenticated
Download Date | 3/5/16 5:27 AM