Polymerizable ionic liquids and polymeric ionic liquids: Facile synthesis of ionic liquids containing ethylene oxide repeating unit: Via methanesulfonate and their electrochemical properties

Article abstract of DOI:10.1039/c6ra26459j

Polymeric ionic liquids have shown great potential in numerous application fields, and an easy access to polymerizable monomer is the key to the polymerized ionic liquids. The polymerizable monomer is usually synthesized via the quaternization of a corresponding bromide, which is usually prepared from bromination of the corresponding alcohol but with a low yield. In this study, a polymerizable monomer was prepared by quaternization of a mesylate, derived from the corresponding alcohol, followed by an ion exchange reaction. The polymerizable ILs M1-M4 showed ionic conductivity as high as 10^-3 S cm^-1, and the oxygen effect was observed with the lithium salt. Polymeric ionic liquids P1 and P2 were prepared via radical polymerization on M1 and M2, and the ionic conductivity of polymeric ionic liquid P2 was as high as 2.2 × 10^-4 S cm^-1 with electrochemical stability exceeding 7 V (vs. Li/Li⁺).

Full text of DOI:10.1039/c6ra26459j

RSC Advances
View Article Online
View Journal | View Issue
PAPER
Polymerizable ionic liquids and polymeric ionic
liquids: facile synthesis of ionic liquids containing
ethylene oxide repeating unit via methanesulfonate
and their electrochemical properties†
Cite this: RSC Adv., 2017, 7, 5394
abcde
a
a
d
Borong Wu,
Zhen-Wei Zhang, Mu-Hua Huang* and Yiyuan Peng
Polymeric ionic liquids have shown great potential in numerous application fields, and an easy access to
polymerizable monomer is the key to the polymerized ionic liquids. The polymerizable monomer is
usually synthesized via the quaternization of a corresponding bromide, which is usually prepared from
bromination of the corresponding alcohol but with a low yield. In this study, a polymerizable monomer
was prepared by quaternization of a mesylate, derived from the corresponding alcohol, followed by an
Received 7th November 2016
Accepted 20th December 2016
ꢀ3
ꢀ1
ion exchange reaction. The polymerizable ILs M1–M4 showed ionic conductivity as high as 10 S cm
,
and the oxygen effect was observed with the lithium salt. Polymeric ionic liquids P1 and P2 were
DOI: 10.1039/c6ra26459j
prepared via radical polymerization on M1 and M2, and the ionic conductivity of polymeric ionic liquid P2
was as high as 2.2 ꢁ 10ꢀ S cm with electrochemical stability exceeding 7 V (vs. Li/Li ).
4
ꢀ1
+
www.rsc.org/advances
conductivity, which hardly meets the requirement for LIBs, and
Introduction
the addition of carbonate ester makes the leakage of carbonate
4
With the fast development of electric vehicles and mobile ester a possibility. Ionic liquid has numerous advantages: low
electric devices, rechargeable batteries with high performance vapor pressure, non-ammability, and good ion conduction,
are highly required. Lithium ion batteries (LIBs) have been and these properties make it a better candidate for application
improved rapidly and possess high energy density and excellent in LIBs.
5
cyclic stability. However, several safety problems have been
Solid or quasi-solid electrolytes, such as polymer electro-
encountered and numerous accidents have occurred due to lytes, usually have good mechanical stability and simple pro-
6
–8
LIBs. To solve the safety issue of LIBs, electrolytes are the main cessing. Among them, polymeric ionic liquids (PILs) are the
components that could be improved, which function as the most promising solid electrolyte candidates, since they
charge carriers between electrodes. Traditionally, organic liquid combine the advantages of ionic liquids and polymers. Plenty of
1
electrolytes, such as carbonate ester, were widely used, which pioneering studies have been directed at obtaining high ionic
3
,9–26
have drawbacks such as volatility, leakage, ammability, and conductivity PILs.
Since the rst PIL synthesized by the
27
toxicity. Thus, the synthesis of solvent-free electrolytes has Ohno group, several attempts have been made to investigate
2
8,29
attracted the attention from materials scientists.
the tether effect
between the charge center and backbone on
2,3
Solid polymer electrolyte (SPE) is a popular concept used the ionic conductivity improvement of the PILs. The introduc-
by people to reconstruct old electronic device systems. Poly- tion of oxygen atom in the spacer was found to decrease the
ethylene oxide (PEO)-based SPE has particularly been paid ionic conductivity of PILs
30,31
since the oxygen trapped the
attention to for application in LIBs. Pure PEO has poor ionic mobile cation was different from that in the traditional SPE. The
Vidal group researched the nitrogen element in the spacer and
ꢀ
4
ꢀ1
ꢂ
an ionic conductivity as high as 6.5 ꢁ 10 S cm at 20 C was
a
32
School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, achieved. From the reported study, it was strongly suggested
1
00081, China. E-mail: mhhuang@bit.edu.cn
that the tether effect played an important role in determining
the ionic conductivity. However, a systematic study on the
tether effect as well as the heteroatom effect on ionic conduc-
tivity of ILs as well as PILs was not available.
b
Beijing Key Laboratory of Environment Science and Engineering, Beijing 100081,
China
c
Collaborative Innovation Center of Electric Vehicles in Beijing, Beijing 100081, China
d
Beijing Higher Institution Engineering Research Center of Power Battery and Chemical
Moreover, an easy access to polymerizable ILs is highly
Key Laboratory of Small Functional Organic Molecule, Ministry of Education, Jiangxi required in order to accelerate the development of high
Energy Materials, Beijing 100081, China
e
Normal University, Nanchang 330022, China
performance PILs suitable for battery applications. In this
sense, the synthetic method towards ionic liquid monomers is
†
Electronic supplementary information (ESI) available. See DOI:
0.1039/c6ra26459j
1
5394 | RSC Adv., 2017, 7, 5394–5401
This journal is © The Royal Society of Chemistry 2017

View Article Online
Paper
RSC Advances
Fig. 1 Structure of some polymerizable ionic liquids and polymeric
ionic liquids in this study.
very important as well as is study on the structure–property
relationship of ILs and PILs. In this study, the design and
synthesis of polymerizable ionic liquid monomer M1 to M4 as Fig. 2 H-NMR spectrum of ionic liquid monomer M1 in DMSO-D6.
well as PILs P1 and P2 is presented (Fig. 1) towards developing
1
a highly efficient synthetic procedure. In addition, the ionic
conductivity of the synthesized ILs and PILs was investigated.
Results and discussion
Synthesis and characterization of polymerizable ionic liquid
monomer M1 to M4
Our study initiated with the synthesis of polymerizable ionic
liquid M1. According to the reported procedure, we tried the
quaternization reaction between bromide 1 and N-vinyl-
Fig. 3 Mass spectrum of cation of ionic liquid monomer M1.
imidazole 2 in organic solvents, such as methanol and chloro-
form, and the imidazolium bromide was obtained as
a precipitate from acetonitrile. In order to make the synthetic
procedure greener and with higher economic efficiency, the
ꢂ
solvent-free quaternization reaction was carried out at 80 C.
The reaction was effective and gave the target product in 96%
isolated yield, which was transferred into polymerizable ionic
liquid M1 by exchange with LiTFSI in 90% isolated yield
(Scheme 1).
The chemical structure of M1 was determined by examining
1
its H-NMR spectrum (Fig. 2), which was very similar to that of Fig. 4 Mass spectrum of anion of ionic liquid monomer M1.
its corresponding bromide (Fig. S1†).
The structure was further conrmed by high-resolution mass
spectroscopy (Fig. 3 and 4).
With M1 prepared, we moved to the synthesis of M2 using
dibromide 3 (Scheme 2).
The commercially available dibromide
substituted by methacrylic acid in the presence of Cs
3
was mono-
CO . It
2
3
was found that the monoester reaction outcome strongly
depended on the reaction conditions. Using excess dibromide
and adding acid into the dibromide solution, monoester 4 was
isolated in 45% yield aer ash column chromatography.
Bromide 4 was transferred into polymerizable ionic liquid M2 in
Scheme 2 Synthesis of ionic liquid M2 via alkylbromide 3.
95% yield by treating 4 with N-ethylimidazole, 5 followed by ion
exchange with LiTFSI.
The chemical structure of M2 was determined by examining
1
its H-NMR spectrum (Fig. 5), which was very similar to that of
its corresponding bromide (Fig. S2†). This was further
conrmed via high-resolution mass spectroscopy (Fig. 6).
Scheme 1 Synthesis of ionic liquid M1 via alkylbromide 1.
This journal is © The Royal Society of Chemistry 2017
RSC Adv., 2017, 7, 5394–5401 | 5395

View Article Online
RSC Advances
Paper
1
Fig. 7 H-NMR spectrum of ionic liquid monomer M3.
1
Fig. 5 H-NMR spectrum of ionic liquid monomer M2.
The monosubstitution of dimesylate 10 was achieved using
methacrylic acid in basic conditions to give monoester 11
(Fig. S5†) in 45% isolated yield. Finally, ionic liquid M4 was
obtained in 94% yield by the quaternization reaction between
mesylate 11 and N-ethylimidazole 5, followed by ion exchange
reaction with LiTFSI (Scheme 4).
ꢀ
The mesylate anion of IL 12 was transferred into TFSI by
exchange with LiTFSI in water, and M4 was obtained. This was
1
conrmed via the H NMR spectrum of M4 (Fig. 8).
Fig. 6 Mass spectrum of anion of ionic liquid monomer M2.
Synthesis of polymeric ionic liquid P1 and P2
With the experience of quaternization reaction and ion
exchange reaction obtained from the synthesis of M1 and M2,
we began with the synthesis of M3 and M4 following the same
procedure. However, the bromination of alcohol 6 did not work
With polymerizable ionic liquid monomer M1 and M2 in hand,
we conducted the radical polymerization reaction. M1 was rst
polymerized in the presence of AIBN in DMF with heating to
1
give P1 as a rubber-like solid; its H-NMR spectrum showed the
using either HBr or PBr . As an alternative, alcohol 6 was
3
complete disappearance of vinyl group between 5–6 ppm
transformed into mesylate 7 (Fig. S3†) in 99% isolated yield by
treating 6 with methanesulfonyl chloride (MsCl) in the presence
of Et N. To our delight, the quaternization reaction between
3
mesylate 7 and N-vinylimidazole 2 worked nicely to give imi-
dazolium mesylate 8 in 97% yield, which was transferred into
M3 in 100% yield (Scheme 3).
(Fig. 9).
Similarly, M2 was polymerized to give P2 with AIBN as the
initiator. The structure of P2 was characterized by examining its
1
H-NMR spectrum (Fig. 10).
Molecular weight determinations were attempted using
GPC, but unfortunately no peak could be observed despite
several attempts. As an alternative, we carried out the molecular
The chemical structure of M3 was determined by examining
1
its H-NMR spectrum (Fig. 7).
1
weight measurement via H-NMR observations according to
It was further conrmed by high-resolution mass spectros-
copy of M3 (Fig. S6†).
Encouraged by success on the synthesis of M3, we moved to
the synthesis of M4 starting from diol 9. Diol 9 was transformed
into dimesylate 10 (Fig. S4†) in 99% isolated yield by treating 6
33
known methods, which gave molecular weights of 16 588 g
ꢀ
1
ꢀ1
mol for P1 and 15 782 g mol for P2.
3
with methanesulfonyl chloride (MsCl) in the presence of Et N.
Scheme 3 Synthesis of ionic liquid M3 via mesylate.
Scheme 4 Synthesis of ionic liquid M4 via mesylate.
5396 | RSC Adv., 2017, 7, 5394–5401
This journal is © The Royal Society of Chemistry 2017

View Article Online
Paper
RSC Advances
1
Fig. 8 H-NMR spectrum of ionic liquid monomer M4.
Fig. 11 Temperature dependence of polymer P1 and P2.
The ionic conductivity of P1 and P2 was dependent on the
temperature, as shown in Fig. 11.
It was shown that P1 and P2 have higher ionic conductivity at
higher temperatures, which arises from the movement
improvement of the polymer chains and free volume. It also
showed a nearly linear relationship between log s and T. The
activation energies of P1 and P2 were calculated to be 58.58 kJ
ꢀ
1
ꢀ1
mol and 48.73 kJ mol , respectively. The ionic conductivity
ꢀ
6
ꢀ1
of P1 and P2 was measured to be 1.1 ꢁ 10 S cm and 2.2 ꢁ
ꢀ
4
ꢀ1
ꢂ
10
S cm , respectively, at 30 C. Ionic conductivity of P1
decreased to one thousandth of M1 aer polymerization of M1,
which was observed for most of the PILs. However, P2 decreased
to one tenth of M2 aer M2 polymerization. This 100-fold
difference of ionic conductivity denitely comes from the
structural differences between P1 and P2. The long alkyl chain
between the polymer backbone and charge centre keeps the
1
Fig. 9 H-NMR spectrum of polymeric ionic liquid P1.
ꢀ
TSFI ions moving more freely compared with the case charge
centre attached to the polymer backbone. Essentially, the large
difference of ionic conductivity also corresponds to the big
ꢂ
ꢂ
difference of T between P1 and P2, at ꢀ22 C vs. ꢀ67 C.
g
Lithium salt concentration dependence of M1 to M4 and P1 to
P2
In order to evaluate the potential of ILs and PILs in LIBs, the
interaction between ILs (PILs) and lithium salt was
investigated.
As shown in Fig. 12, with the increase of the ILs M1–M4
content, the ionic conductivity of the LiTFSI and ILs composites
went up. Pure LiTFSI had ionic conductivity that was too low to
be measured. When 94 wt% M1 was added into LiTFSI, the ionic
1
Fig. 10 H-NMR spectrum of polymeric ionic liquid P2.
ꢀ
4
ꢀ1
ꢂ
conductivity increased to 8 ꢁ 10 S cm at 30 C; similarly,
ꢀ
4
ꢀ1
ꢀ3
ꢀ1
Ionic conductivity of ionic liquid monomer M1 to M4 and
polymer P1 and P2
9
ꢁ
.6 ꢁ 10 S cm for M2, 1.17 ꢁ 10 S cm for M3, and 1.43
ꢀ
3
ꢀ1
10 S cm for M4 was observed. Clearly, oxygen-containing
ionic liquids M3 and M4 showed higher ionic conductivity than
all-carbon chain ionic liquids M1 and M2. This may be the
result of dissociation ability of the ethylene oxide chain with the
lithium salt. M2 had higher ionic conductivity than M1 and M4
The ionic conductivity of pure ionic liquids M1 to M4 was
ꢀ
3
ꢀ1
ꢀ3
ꢀ1
measured to be 1.36 ꢁ 10 S cm , 1.3 ꢁ 10 S cm , 1.79 ꢁ
ꢀ3
ꢀ1
ꢀ3
ꢀ1
ꢂ
10
S cm and 1.89 ꢁ 10 S cm , respectively, at 30 C.
This journal is © The Royal Society of Chemistry 2017
RSC Adv., 2017, 7, 5394–5401 | 5397

View Article Online
RSC Advances
Paper
ꢂ
Fig. 12 IL helps lithium salt ionic conductivity at 30 C.
Fig. 14 Electrochemical stability of P2.
higher than M3 under the same conditions. This may be caused
by the longer chain of M2 and M4 than that of M1 and M3 as
well as the plasticizing effect of the ester moiety.
Thermal stability
In the case of PILs, P2 was investigated towards LiTFSI due
to its high ionic conductivity. When LiTFSI was introduced
into P2 during the polymerization process, the ionic conduc-
tivity of the composite decreased. The addition of LiTFSI to P2
An ideal solid electrolyte for lithium batteries will have high
thermal stability. The decomposition temperature of P1 and P2
was measured by TGA (Fig. S7†).
P1 lost 5% weight at 369 C, whereas P2 at 234 C, but P2 has
higher maximum decomposed temperature, and decomposed
more completely than P1.
ꢂ
ꢂ
ꢀ
may make a dimer of TFSI formed, which will have bigger ion
volume corresponding to the poor mobility, and thus provides
lower ionic conductivity than pure P2. Higher Li-salt concen-
tration resulted in higher dimer concentration in the system
and lower ionic conductivity (Fig. 13).
Experimental
Materials
Electrochemical stability
1-Vinyl-1H-imidazole, 1-bromoundecane, azodiisobutyronitrile
(
AIBN), 1,12-dibromo dodecane, N-ethylimidazole, 2,5,8,11-
For further application of P2 as solid electrolyte, it is very
important to know its electrochemical stability. Generally, the
point corresponding to the irreversible change is dened to be
the decomposition voltage, which, in other words, means the
stability boundary or so-called window.
0
tetraoxatridecan-13-ol,
methanesulfonyl
chloride,
2,2 -
((oxybis(ethane-2,1-diyl))bis(oxy))diethanol, cesium carbonate,
methanesulfonyl
chloride,
lithiumbis((triuoromethyl)
sulfonyl)-amide (LiTFSI) and methanol were purchased from
Tianjin Baiheng technology Co., Ltd. Dichloromethane, tri-
chloromethane, and ethylacetate were purchased from Beijing
Chemical Works. Anhydrous ether, and N,N-dimethylforma-
mide were purchased from Beijing Tong Guang Fine Chemical
Co., Ltd. All reagents were used as received.
As shown in Fig. 14, non-oxidizable electrochemical stability
+
of P2 exceeded 7 V (vs. Li/Li ), whereas anti-reductive electro-
chemical stability was about 2.5 V. This demonstrated high
potential for applications in high-voltage systems.
Characterisation method
1
The H-NMR spectrum of sample dissolved in either CDCl
3
or
DMSO-D6 was recorded on a Varian Mercury plus 400 M nuclear
magnetic resonance spectrometer. The molecular weight of
ionic liquid monomers was obtained through the Fourier
transform ion cyclotron resonance mass spectrometer, a Bruker
APEX IV. The ionic conductivity was measured as follows:
s ¼ d/(RꢁA)
where, d is the lm thickness, and R is the resistance value,
which is obtained from the AC impedance measurement. A is
the area of the lm in contact with the blocking electrode. In the
0
AC impedance spectrum, the value of R was obtained from Z
0
0
Fig. 13 Lithium salt concentration dependence of P2.
value when ꢀZ reached minimum. In this study, the structure
5398 | RSC Adv., 2017, 7, 5394–5401
This journal is © The Royal Society of Chemistry 2017

View Article Online
Paper
RSC Advances
of the substrate for the AC impedance measurement was dichloromethane into the above mixture. Aer being shaken 3–
ss|PIL|ss (ss means stainless steel). Electrochemical stability 4 times, the down layer was collected. The organics were dried
was measured via linear sweep voltammetry or cyclic voltam- with anhydrous sodium sulfate, ltered, and concentrated to
metry. Aer the establishment of Pt/PIL/Pt, the cyclic voltam- give a light yellow oil (1.50 g, 2.76 mmol, 95%).
ꢀ
1
metry test was carried out with the scan speed of 0.1 mV s and
voltage range between 2 V and 7 V.
1H NMR (400 MHz, DMSO-D6): d ¼ 1.23 (m, 23H), 1.86 (s,
3H), 3.50 (s, 2H), 4.19 (dd, J ¼ 13.9 Hz, 2H), 5.66 (s,
¼ 6.6 Hz, J
H), 5.99 (s, 1H), 7.85 (s, 3H), 9.34 (s, 1H).
Synthesis of M3. To a solution of alcohol 6 (1 ml, 5.11 mmol)
in dichloromethane (30 ml) was added triethylamine (2.14 ml)
1
2
1
Synthetic procedures
Synthesis of M1. To 1-bromoundecane (1 ml, 4.17 mmol) in and methanesufonyl chloride (0.585 g, 5.11 mmol) dropwise at
ꢂ
ꢂ
methanol (30 ml), 1-vinyl-1H-imidazole (0.4 ml, 4.17 mmol) was 0 C. The resulting mixture was stirred at 0 C for 45 min and then
added at room temperature. The mixture was vigorously stirred at room temperature for 10 h. The reaction was then quenched by
ꢂ
at 100 C (oil bath) for 10 h, and the solvents were removed by adding HCl (0.1 M, 20 ml) and extracted with DCM (2 ꢁ 30 ml).
distillation. The residue was washed using ethyl acetate to give The combined organics were dried over anhydrous sodium
imidazolium bromide as a white precipitate (1.37 g, 4.0 mmol, sulfate, ltered and then concentrated under reduced pressure to
1
9
6%), which was pure enough based on its H-NMR spectrum to give the mesylate 7 as an oil (1.448 g, 5.059 mmol, 99%).
1
be used directly for the next step.
H NMR (400 MHz, DMSO-D6): d ¼ 3.03 (s, 3H), 3.33 (s, 3H),
H NMR (400 MHz, DMSO-D6): d 0.85 (s, 3H), 1.23 (m, 18H), 3.50 (m, 2H), 3.61 (m, 10H), 3.74 (m, 2H), 4.34 (m, 2H).
To the mesylate 7 (1 g, 3.492 mmol) was added 1-vinyl-1H-
1
1
1
7
.82 (s, 2H), 4.20 (s, 2H), 5.42 (d, J ¼ 6.3 Hz, 1H), 5.97 (d, J ¼
5.5 Hz, 1H), 7.32 (m, 1H), 7.96 (s, 1H), 8.23 (s, 1H), 9.59 (d, J ¼ imidazole (0.34 ml, 3.492 mmol), the resulting mixture was
ꢂ
.2 Hz, 1H).
stirred at 100 C for 10 h. The resulting reaction mixture was
To a suspension of imidazolium bromide (2 g, 5.84 mmol) in washed with ethyl acetate to give the imidazolium mesylate 8 as
deionized water (30 ml), LiTFSI (1.68 g, 5.84 mmol) in one an oil (1.288 g, 3.387 mmol, 97%).
1
portion was added, and the mixture was shaken vigorously in
H NMR (400 MHz, DMSO-D6): d ¼ 3.00 (s, 3H), 3.55 (s, 3H),
a separation funnel, followed by addition of dichloromethane 3.75 (m, 2H), 3.85 (m, 10H), 4.11 (t, J
1
¼ 4.3 Hz, J
2
¼ 4.5 Hz, 2H),
¼ 8.6 Hz, J
¼ 2.5 Hz, 1H), 7.5 (m, 1H),
into the abovementioned mixture. Aer being shaken 3–4 4.80 (t, J
times, the lower layer was collected. The organics were dried 2.5 Hz, 1H), 6.10 (dd, J
with anhydrous sodium sulfate, ltered, and concentrated to 7.9 (s, 1H), 8.0 (s, 1H), 10.3 (s, 1H).
give a light yellow oil (2.85 g, 5.256 mmol, 90%).
To a suspension of mesylate 8 (1 g, 2.630 mmol) in deionized
¼ 4.2 Hz, J
¼ 4.4 Hz, 2H), 5.60 (dd, J
¼
1
2
1
2
¼ 15.6 Hz, J
1
2
1
H NMR (400 MHz, DMSO-D6): d ¼ 0.85 (s, 3H), 1.23 (m, water (30 ml) was added LiTFSI (0.755 g, 2.630 mmol, 1 eq.), and
8H), 1.82 (s, 2H), 4.20 (s, 2H), 5.42 (d, J ¼ 6.3 Hz, 1H), 5.97 (d, J the mixture was shaken vigorously in a separation funnel fol-
1
¼
15.5 Hz, 1H), 7.32 (m, 1H), 7.96 (s, 1H), 8.23 (s, 1H), 9.59 (d, J lowed by dichloromethane addition into the above mixture.
¼
7.2 Hz, 1H).
Aer being shaken 3–4 times, the bottom layer was collected.
Synthesis of bromide 4. To a solution of 1,12-dibromo- The organics were dried with anhydrous sodium sulfate,
dodecane (1 ml, 3.95 mmol, 2 equiv.) in DMF (5 ml) was ltered, and concentrated to give M3 as a light yellow oil
added methacrylic acid (0.17 ml, 1.975 mmol, 1 eq.), cesium (1.487 g, 2.630 mmol, 100%).
1
carbonate (0.643 g, 1.975 mmol, 1 equiv.) and hydroquinone (1
H NMR (400 MHz, DMSO-D6): d 3.24 (s, 3H), 3.44 (dd, J
1
¼
wt% of methacrylic acid). The resulting mixture was stirred at 5.7 Hz, J
2
¼ 3.4 Hz, 2H), 3.52 (dd, J
1
¼ 6.7 Hz, J
¼ 8.7 Hz, J
¼ 2.4 Hz, 1H), 7.3 (dd, J
puried via ash column chromatography to give the title 8.7 Hz, 1H), 7.9 (s, 1H), 8.2 (s, 1H), 9.4 (s, 1H).
compound as a yellow oil (0.59 g, 1.77 mmol, 45%).
Synthesis of M4. To a solution of diol 9 (1 ml, 5.81 mmol) in
2
¼ 4.1 Hz, 10H),
¼ 2.3 Hz, 1H),
¼ 15.6 Hz, J
ꢂ
32
C for 48 h to give a clear solution. The solvents were 3.83 (m, 2H), 4.4 (m, 2H), 5.45 (dd, J
¼ 15.6 Hz, J
1
2
removed with reduced pressure and the resulting residue was 6.0 (dd, J
1
2
1
2
¼
1
H NMR (400 MHz, DMSO-D6): d ¼ 1.33 (m, 20H), 1.95 (s, dichloromethane (30 ml) was added triethylamine (2.43 ml) and
ꢂ
3
¼
H), 3.58 (t, J
1
¼ 6.72 Hz, J
2
¼ 6.71 Hz, 2H), 4.15 (t, J
1
¼ 6.5 Hz, J
2
methanesufonyl chloride (1.33 g, 11.62 mmol) dropwise at 0 C.
ꢂ
6.6 Hz, 2H), 5.73 (d, J ¼ 1.40 Hz, 1H), 6.08 (s, 1H).
The resulting reaction mixture was stirred at 0 C for 45 min,
Synthesis of M2. To bromide 4, (1 g, 2.99 mmol) 1-ethyl-1H- and then at room temperature for 10 h. The reaction mixture
imidazole (0.34 ml, 2.99 mmol) was added, and the resulting was diluted with dichloromethane (30 ml) and washed with HCl
ꢂ
mixture was stirred at 90 C to give the imidazolium bromide as (0.1 M, 30 ml). The organic layer was washed with pure water
a white precipitate (0.985 g, 2.87 mmol, 96%), which was pure and then dried with anhydrous sodium sulfate. Aer elimina-
enough for the next step.
tion of solvents under reduced pressure, the dimesylate 10 was
1
H NMR (400 MHz, DMSO-D6): d ¼ 1.23 (m, 23H), 1.86 (s, obtained as an oil (2.01 g, 5.75 mmol, 99%).
1
3H), 3.50 (s, 2H), 4.19 (dd, J
1
¼ 6.6 Hz, J
2
¼ 13.9 Hz, 2H), 5.66 (s,
H NMR (400 MHz, DMSO-D6): d 3.07 (d, J ¼ 0.8 Hz, 3H), 3.65
(m, 8H), 3.76 (m, 4H), 4.37 (dd, J ¼ 4.70 Hz, 4H).
¼ 3.70 Hz, J
To a solution of dimesylate 10 (1 g, 2.853 mmol, 2 equiv.) in
1H), 5.99 (s, 1H), 7.85 (s, 3H), 9.34 (s, 1H).
1
2
To a suspension of the above imidazolium bromide (1 g,
2.912 mmol) in deionized water (30 ml) was added LiTFSI DMF (30 ml) was added methacrylic acid (0.13 ml, 1.427 mmol, 1
(0.842 g, 2.912 mmol) in one portion, and the mixture was equiv.), cesium carbonate (0.465 g, 1.427 mmol, 1 equiv.) and
shaken vigorously in a separation funnel followed by addition of hydroquinone (1 wt% of methacrylic acid). The resulting reaction
This journal is © The Royal Society of Chemistry 2017
RSC Adv., 2017, 7, 5394–5401 | 5399

View Article Online
RSC Advances
Paper
ꢂ
mixture was stirred at 32 C for 48 h to give a clear solution. The 2162039), Jiangxi Provincial Department of Science and Tech-
solvents were removed under reduced pressure, and the residue nology (No. 20133BBE50014) and the Science Foundation of the
was puried by ash column chromatography to give the title Education Department of Jiangxi province (No. KJLD13020) for
monoester 11 as a yellow oil (0.437 g, 1.283 mmol, yield 45%).
generous support.
1
H NMR (400 MHz, DMSO-D6): d 1.95 (m, 3H), 3.08 (d, 3H),
3
1
.65 (m, 6H), 3.76 (m, 4H), 4.30 (m, 2H), 4.38 (m, 4H), 5.58 (m,
Notes and references
H), 6.13 (dd, J
1
¼ 0.93 Hz, J
2
¼ 1.44 Hz, 1H).
To mesylate 11 (1 g, 2.936 mmol) was added 1-ethyl-1H-
1 M. Armand, F. Endres, D. R. MacFarlane, H. Ohno and
B. Scrosati, Nat. Mater., 2009, 8, 621–629.
2 W. H. Meyer, Adv. Mater., 1998, 10, 439–448.
3 A. S. Shaplov, R. Marcilla and D. Mecerreyes, Electrochim.
Acta, 2015, 175, 18–34.
4 N. V. Plechkova and K. R. Seddon, Chem. Soc. Rev., 2008, 37,
123–150.
5 X. Chen, J. Zhao, J. Zhang, L. Qiu, D. Xu, H. Zhang, X. Han,
B. Sun, G. Fu, Y. Zhang and F. Yan, J. Mater. Chem., 2012,
22, 18018–18024.
imidazole (0.33 ml, 2.936 mmol), and the resulting mixture was
stirred at 100 C for 10 h. The resulting reaction mixture was
washed with ethyl acetate to give imidazolium mesylate 12 as an
oil (1.217 g, 2.789 mmol, 95%).
ꢂ
1
H NMR (400 MHz, DMSO-D6): d 1.57 (m, 3H), 1.94 (s, 3H),
2
1
.75 (s, 3H), 3.64 (m, 12H), 4.32 (m, 4H), 4.52 (m, 2H), 5.59 (s,
H), 6.11 (s, 1H), 7.34 (s, 1H), 7.65 (s, 1H), 9.77 (s, 1H).
To a suspension of imidazolium mesylate 12 (1 g, 2.291
mmol) in deionized water (30 ml) was added LiTFSI (0.658 g,
.291 mmol 1 eq.), and the mixture was shaken vigorously in
2
6 J. Yuan, D. Mecerreyes and M. Antonietti, Prog. Polym. Sci.,
2013, 38, 1009–1036.
a separation funnel, followed by addition of dichloromethane
into the abovementioned mixture. Aer being shaken 3–4
times, the bottom layer was collected. The organics were dried
with anhydrous sodium sulfate, ltered, and concentrated to
7 J. Yuan and M. Antonietti, Polymer, 2011, 52, 1469–1482.
8 D. Mecerreyes, Prog. Polym. Sci., 2011, 36, 1629–1648.
9 N. Nishimura and H. Ohno, Polymer, 2014, 55, 3289–3297.
10 Z. Jia, W. Yuan, C. Sheng, H. Zhao, H. Hu and G. L. Baker, J.
Polym. Sci., Part A: Polym. Chem., 2015, 53, 1339–1350.
give M3 as a light yellow oil (1.351 g, 2.176 mmol, 95%).
1
H NMR (400 MHz, DMSO-D6): d 1.44 (t, J
1
¼ 7.2 Hz, J ¼ 6.2 Hz,
2
3
H), 1.89 (s, 3H), 3.63 (m, 12H), 4.23 (d, J ¼ 5.9 Hz, 4H), 4.35 (m, 11 Y. S. Vygodskii, A. S. Shaplov, E. I. Lozinskaya,
2H), 5.70 (s, 1H), 6.04 (s, 1H), 7.76 (s, 1H), 7.81 (s, 1H), 9.14 (s, 1H).
K. A. Lyssenko, D. G. Golovanov, I. A. Malyshkina,
N. D. Gavrilova and M. R. Buchmeiser, Macromol. Chem.
Phys., 2008, 209, 40–51.
Synthesis of P1. A mixture of M1 (1 g, 1.84 mmol) and AIBN
ꢂ
(10 mg, 1 wt%) was heated at 90 C under nitrogen for 1 h to give
P1 as a rubber-like solid.
12 A. S. Shaplov, L. Goujon, F. Vidal, E. I. Lozinskaya, F. Meyer,
I. A. Malyshkina, C. Chevrot, D. Teyssie, I. L. Odinets and
Y. S. Vygodskii, J. Polym. Sci., Part A: Polym. Chem., 2009,
47, 4245–4266.
1
H NMR (400 MHz, DMSO-D6): d 0.80 (s, 3H), 1.23 (m, 18H),
1
9
.82 (s, 2H), 4.20 (s, 2H), 7.32 (m, 1H), 7.96 (s, 1H), 8.23 (s, 1H),
.59 (d, J ¼ 7.2 Hz, 1H).
Synthesis of P2. A mixture of M2 (1 g, 1.59 mmol) and AIBN 13 A. S. Shaplov, P. S. Vlasov, E. I. Lozinskaya, D. O. Ponkratov,
ꢂ
(10 mg, 1 wt%) was heated at 90 C under nitrogen for 1 h to give
I. A. Malyshkina, F. Vidal, O. V. Okatova, G. M. Pavlov,
C. Wandrey, A. Bhide, M. Schonhoff and Y. S. Vygodskii,
Macromolecules, 2011, 44, 9792–9803.
P1 as a rubber-like solid.
1
H NMR (400 MHz, DMSO-D6): d ¼ 1.24 (m, 23H), 1.87 (s,
3
H), 3.51 (s, 2H), 4.19 (dd, J
1
¼ 6.6 Hz, J
2
¼ 13.9 Hz, 2H), 7.79 (s, 14 A. S. Shaplov, E. I. Lozinskaya, D. O. Ponkratov,
I. A. Malyshkina, F. Vidal, P. Aubert, O. V. Okatova,
G. M. Pavlov, L. I. Komarova, C. Wandrey and
Y. S. Vygodskii, Electrochim. Acta, 2011, 57, 74–90.
3H), 9.17 (s, 1H).
Conclusion
1
5 M. Dobbelin, I. Azcune, M. Bedu, A. Ruiz De Luzuriaga,
A. Genua, V. Jovanovski, G. Cabanero and I. Odriozola,
Chem. Mater., 2012, 24, 1583–1590.
Ionic liquid monomer M1 to M4 and polymeric ionic liquid P1
to P2 were designed and synthesized in high yield. It is worth
noting that the mesylate of ethylene oxide-containing alcohol 16 A. S. Shaplov, D. O. Ponkratov, P. Aubert, E. I. Lozinskaya,
could be synthesized in perfect yield and it could be transferred
C. Plesse, A. Maziz, P. S. Vlasov, F. Vidal and
into imidazolium mesylate with high efficiency. M1 to M4 had
Y. S. Vygodskii, Polymer, 2014, 55, 3385–3396.
ꢀ
3
ꢀ1
ionic conductivity around 1–2 ꢁ 10 S cm . P2 showed ionic 17 Z. Jia, W. Yuan, H. Zhao, H. Hu and G. L. Baker, RSC Adv.,
ꢀ4
ꢀ1
conductivity of 2.2 ꢁ 10 S cm , which was 200 times that of
P1 due to the long alkyl chain tether separated polymer back- 18 H. Hu, W. Yuan, L. Lu, H. Zhao, Z. Jia and G. L. Baker, J.
bone and charge centre. Further systematic study of electro- Polym. Sci., Part A: Polym. Chem., 2014, 52, 2104–2110.
chemical properties of M1 to M4 and their corresponding PILs 19 A. S. Shaplov, D. O. Ponkratov, P. S. Vlasov, E. I. Lozinskaya,
2014, 4, 41087–41098.
is ongoing and will be reported in due course.
L. V. Gumileva, C. Surcin, M. Morcrette, M. Armand,
P. Aubert, F. Vidal and Y. S. Vygodskii, J. Mater. Chem. A,
2
015, 3, 2188–2198.
Acknowledgements
2
0 M. A. Aboudzadeh, A. S. Shaplov, G. Hernandez, P. S. Vlasov,
E. I. Lozinskaya, C. Pozo-Gonzalo, M. Forsyth, Y. S. Vygodskii
and D. Mecerreyes, J. Mater. Chem. A, 2015, 3, 2338–2343.
The authors thank the National Natural Science Foundation of
China (No. 21202008), Beijing Natural Science Foundation (No.
5400 | RSC Adv., 2017, 7, 5394–5401
This journal is © The Royal Society of Chemistry 2017

View Article Online
Paper
RSC Advances
2
2
1 M. A. Aboudzadeh, H. Zhu, C. Pozo-Gonzalo, A. S. Shaplov, 26 L. Porcarelli, A. S. Shaplov, F. Bella, J. R. Nair, D. Mecerreyes
D. Mecerreyes and M. Forsyth, Electrochim. Acta, 2015, 175, 74–79. and C. Gerbaldi, ACS Energy Lett., 2016, 1, 678–682.
2 A. S. Shaplov, E. I. Lozinskaya, P. S. Vlasov, S. M. Morozova, 27 H. Ohno and K. Ito, Chem. Lett., 1998, 751–752.
D. Y. Antonov, P. Aubert, M. Armand and Y. S. Vygodskii, 28 M. D. Green and T. E. Long, Polym. Rev., 2009, 49, 291–314.
Electrochim. Acta, 2015, 175, 254–260.
29 H. Ohno, Macromol. Symp., 2007, 249–250, 551–556.
2
2
2
3 G. Colliat-Dangus, M. M. Obadia, Y. S. Vygodskii, A. Serghei, 30 H. Ohno, M. Yoshizawa and W. Ogihara, Electrochim. Acta,
A. S. Shaplov and E. Drockenmuller, Polym. Chem., 2015, 6,
299–4308.
4 L. Porcarelli, J. R. Nair, C. Gerbaldi, A. S. Shaplov,
2004, 50, 255–261.
31 W. Ogihara, S. Washiro, H. Nakajima and H. Ohno,
Electrochim. Acta, 2006, 51, 2614–2619.
4
Y. S. Vygodskii, M. Salsamendi and D. Mecerreyes, ACS 32 J. Juger, F. Meyer, F. Vidal, C. Chevrot and D. Teyssie,
Appl. Mater. Interfaces, 2016, 8, 10350–10359. Tetrahedron Lett., 2009, 50, 128–131.
5 Y. V. Nelyubina, A. S. Shaplov, E. I. Lozinskaya, M. I. Buzin 33 H. He, M. Zhong, B. Adzima, D. Luebke, H. Nulwala and
and Y. S. Vygodskii, J. Am. Chem. Soc., 2016, 138, 10076– K. Matyjaszewski, J. Am. Chem. Soc., 2013, 135, 4227–4230.
0079.
1
This journal is © The Royal Society of Chemistry 2017
RSC Adv., 2017, 7, 5394–5401 | 5401