Polymerizable Ionic Liquid Crystals Comprising Polyoxometalate Clusters toward Inorganic-Organic Hybrid Solid Electrolytes

Solid electrolytes are crucial materials for lithium-ion or fuel-cell battery technology due to their structural stability and easiness for handling. Emergence of high conductivity in solid electrolytes requires precise control of the composition and structure. A promising strategy toward highly-conductive solid electrolytes is employing a thermally-stable inorganic component and a structurally-flexible organic moiety to construct inorganic-organic hybrid materials. Ionic liquids as the organic component will be advantageous for the emergence of high conductivity, and polyoxometalate, such as heteropolyacids, are well-known as inorganic proton conductors. Here, newly-designed ionic liquid imidazolium cations, having a polymerizable methacryl group (denoted as MAImC1), were successfully hybridized with heteropolyanions of [PW12O40]3− (PW12) to form inorganic-organic hybrid monomers of MAImC1-PW12. The synthetic procedure of MAImC1-PW12 was a simple ion-exchange reaction, being generally applicable to several polyoxometalates, in principle. MAImC1-PW12 was obtained as single crystals, and its molecular and crystal structures were clearly revealed. Additionally, the hybrid monomer of MAImC1-PW12 was polymerized by a radical polymerization using AIBN as an initiator. Some of the resulting inorganic-organic hybrid polymers exhibited conductivity of 10−4 S·cm−1 order under humidified conditions at 313 K.


Introduction
The development of highly-conductive solid electrolytes is crucial for innovative battery technology, such as lithium-ion and fuel-cell batteries [1][2][3][4], which are now being applied to power sources of motor vehicles working at intermediate temperature of 373 to 573 K. However, they demand highly-conductive solid electrolyte to overcome some drawbacks when used at intermediate temperatures. In most lithium-ion batteries, flammable organic-liquid electrolytes are used, which should be substituted for safer solid electrolytes. Polymer electrolyte membrane fuel cells (PEMFC) use proton-conducting fluorocarbon polymers (Nafion) exhibiting high conductivity only under humidified conditions below 373 K, and highly-conductive solid electrolytes working at intermediate temperatures without humidity are demanded. However, present solid electrolytes, to date, are insufficient in their conductivities.
Polymers 2017, 9,290 2 of 13 should be substituted for safer solid electrolytes. Polymer electrolyte membrane fuel cells (PEMFC) use proton-conducting fluorocarbon polymers (Nafion) exhibiting high conductivity only under humidified conditions below 373 K, and highly-conductive solid electrolytes working at intermediate temperatures without humidity are demanded. However, present solid electrolytes, to date, are insufficient in their conductivities. A promising option toward highly-conductive solid electrolytes is to employ a thermally-stable inorganic component and a structurally-flexible organic moiety to construct inorganic-organic hybrid conductors [5,6]. Ionic liquids exhibit characteristic conductive properties [7][8][9], and enable the construction of conductive materials [10][11][12][13].

Genaral Methods for Characterization
IR spectra (as a KBr pellet) were recorded on a Jasco FT/IR-4200ST spectrometer (JASCO Corporation, Tokyo, Japan). Powder X-ray diffraction (XRD) patterns were measured with a Rigaku

Genaral Methods for Characterization
IR spectra (as a KBr pellet) were recorded on a Jasco FT/IR-4200ST spectrometer (JASCO Corporation, Tokyo, Japan). Powder X-ray diffraction (XRD) patterns were measured with a Rigaku MiniFlex300 diffractometer (Rigaku Corporation, Tokyo, Japan) by using Cu Kα radiation (λ = 1.54056 Å) at ambient temperature. CHN elemental analyses were performed with a PerkinElmer 2400II elemental analyzer.
Solution 1 H NMR spectroscopy was conducted with a Bruker AVANCE-500 NMR spectrometer (Bruker Corporation, Yokohama, Japan) (500 MHz) at room temperature. Gel permeation chromatography (GPC) was carried out to determine the number-average (M n ) and weight-average (M w ) molecular weights with a Tosoh GPC system (Tosoh Corporation, Tokyo, Japan) equipped with four columns of TSK gels, Multipore HXL-M, and a Tosoh RI-8010 detector (Tosoh Corporation, Tokyo, Japan) with a Tosoh CCPD pump (Tosoh Corporation, Tokyo, Japan), using DMF solution containing 20 mM LiBr as an eluent at a flow rate of 1.0 mL min −1 . GPC was also conducted for THF-soluble polymers with a Tosoh HLC-8320GPC (Tosoh Corporation, Tokyo, Japan) equipped with four columns of TSK gels, and a Super-Multipore HZ-H, using THF as an eluent at a flow rate of 1.0 mL min −1 . Standard polystyrenes were used to calibrate the molecular weights. Differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) were carried out on a Seiko Instruments DSC-6200 (Seiko Instruments Inc., Chiba, Japan) and TG/DTA-6200 (Seiko Instruments Inc., Chiba, Japan), respectively, at a heating rate of 10 K·min −1 under a nitrogen atmosphere.

Syntheses of P-MAImC 1 -PW 12 Hybrid Homopolymers
In a 50 mL eggplant flask, 1.00 g (0.297 mmol) of MAImC 1 -PW 12 and 24.4 mg (0.149 mmol) of 2,2 -azobis(isobutyronitrile) (AIBN; Wako, recrystallized) were dissolved in 4.3 mL of DMF. After degassing the flask, it was sealed by a three-way cock, and the mixture was stirred at 353 K for 20 h. Then, the reaction mixture was poured into 100 mL of methanol to precipitate the polymer. The obtained polymer was filtered and dried in vacuo to afford 0.852 g of P-MAImC 1 -PW 12 (Yield: 85.2%).

Syntheses of CP-MAImC 1 -PW 12 /BMA Hybrid Copolymers
The radical copolymerizations were carried out for the mixtures of MAImC 1 -PW 12 and butyl methacrylate (BMA; TCI (Tokyo, Japan), purity > 99.0%) to prepare copolymers with different compositions of monomer units. The typical procedure of copolymerization is described below.
In a 50 mL eggplant flask, 0.536 g (0.152 mmol) of MAImC 1 -PW 12 , 0.536 g (3.77 mmol) of BMA, and 12.7 mg (0.0773 mmol) of AIBN were dissolved in 4.5 mL of DMF. After degassing the flask, it was sealed by a three-way cock, and the mixture was stirred at 353 K for 20 h. Then, the reaction mixture was poured into 120 mL of methanol to precipitate the polymer. The obtained polymer was filtered and dried in vacuo to afford 0.659 g of CP-MAImC 1 -PW 12 /BMA (1:1) (Yield: 61.4%). The similar radical copolymerizations were carried out for the mixtures of MAImC 1 -PW 12 and MAImC 8 Br to prepare copolymers with different compositions. The typical procedure of copolymerization is described below.
In a 50 mL eggplant flask, 0.805 g (0.239 mmol) of MAImC 1 -PW 12 , 0.805 g (2.16 mmol) of MAImC 8 -Br, and 8.0 mg (0.049 mmol) of AIBN were dissolved in 6.8 mL of DMF. After degassing the flask, it was sealed by a three-way cock, and the mixture was stirred at 353 K for 20 h. Then, the reaction mixture was poured into 150 mL of ethyl acetate to precipitate the polymer. The obtained polymer was filtered and dried in vacuo to afford 1.06 g of CP-MAImC 1 -PW 12 /MAImC 8 Br (1:1) (Yield: 65.8%).

X-ray Crystallography
Single crystal X-ray diffraction data for hybrid monomer of MAImC 1 -PW 12 was recorded with an ADSC Q210 CCD area detector (Area Detector Systems Corporation, Poway, CA, USA) with synchrotron radiation at the 2D beamline at the Pohang Accelerator Laboratory (PAL). The diffraction images were processed by using HKL3000 (HKL Research, Inc., Charlottesville, VA, USA) [39]. Absorption correction was performed with the program PLATON [40]. The structure was solved by the direct methods using SHELXT version 2014/5 [41] and refined by the full-matrix least-squares method on F 2 using SHELXL version 2014/7 [42]. Further details of the crystal structure investigation may be obtained free of charge from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; Fax: (+44) 1223 336 033; or E-Mail: deposit@ccdc.cam.ac.uk (CCDC 1555936).

Synthesis and Structure of MAImC 1 -PW 12 Hybrid Monomer
Synthesis of starting polymerizable ionic liquid of MAImC 1 was obtained as iodide salt according to Scheme 1 (see the Materials and Methods section).

X-ray Crystallography
Single crystal X-ray diffraction data for hybrid monomer of MAImC1-PW12 was recorded with an ADSC Q210 CCD area detector (Area Detector Systems Corporation, Poway, CA, USA) with synchrotron radiation at the 2D beamline at the Pohang Accelerator Laboratory (PAL). The diffraction images were processed by using HKL3000 (HKL Research, Inc., Charlottesville, VA, USA) [39]. Absorption correction was performed with the program PLATON [40]. The structure was solved by the direct methods using SHELXT version 2014/5 [41] and refined by the full-matrix least-squares method on F 2 using SHELXL version 2014/7 [42]. Further details of the crystal structure investigation may be obtained free of charge from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; Fax: (+44) 1223 336 033; or E-Mail: deposit@ccdc.cam.ac.uk (CCDC 1555936).

Synthesis and Structure of MAImC1-PW12 Hybrid Monomer
Synthesis of starting polymerizable ionic liquid of MAImC1 was obtained as iodide salt according to Scheme 1 (see the Materials and Methods section). The colorless precipitate of the MAImC1-PW12 hybrid monomer was successfully obtained by a cation exchange reaction of dodecatungstophosphoric acid (H-PW12) by MAImC1, as reported for the syntheses of ionic liquid surfactant-polyoxometalate hybrid crystals [43][44][45]. As shown in Figure 2a, IR spectrum of the MAImC1-PW12 hybrid monomer exhibited characteristic peaks of dodecatungstophosphate (PW12) anion in the range of 400-1100 cm −1 [17,46], as well as peaks derived from MAImC1 (methylene groups in 2800-3000 cm −1 and methacryl group in 1200-1800 cm −1 ). This indicates the successful hybridization of polymerizable MAImC1 cations and PW12 anions. The XRD pattern of the MAImC1-PW12 hybrid monomer obtained as the initial precipitate was almost the same as the pattern calculated from the results of the single crystal X-ray analysis (Figure 2b), indicating that the as-prepared precipitate and single crystals of MAImC1-PW12 had the same composition and structure. Differences in the peak intensity and position of the patterns may be due to the difference in the measurement temperature (powder: ambient temperature, single crystal: 100 K). The colorless precipitate of the MAImC 1 -PW 12 hybrid monomer was successfully obtained by a cation exchange reaction of dodecatungstophosphoric acid (H-PW 12 ) by MAImC 1 , as reported for the syntheses of ionic liquid surfactant-polyoxometalate hybrid crystals [43][44][45]. As shown in Figure 2a, IR spectrum of the MAImC 1 -PW 12 hybrid monomer exhibited characteristic peaks of dodecatungstophosphate (PW 12 ) anion in the range of 400-1100 cm −1 [17,46], as well as peaks derived from MAImC 1 (methylene groups in 2800-3000 cm −1 and methacryl group in 1200-1800 cm −1 ). This indicates the successful hybridization of polymerizable MAImC 1 cations and PW 12 anions. The XRD pattern of the MAImC 1 -PW 12 hybrid monomer obtained as the initial precipitate was almost the same as the pattern calculated from the results of the single crystal X-ray analysis (Figure 2b), indicating that the as-prepared precipitate and single crystals of MAImC 1 -PW 12 had the same composition and structure. Differences in the peak intensity and position of the patterns may be due to the difference in the measurement temperature (powder: ambient temperature, single crystal: 100 K).
indicates the successful hybridization of polymerizable MAImC1 cations and PW12 anions. The XRD pattern of the MAImC1-PW12 hybrid monomer obtained as the initial precipitate was almost the same as the pattern calculated from the results of the single crystal X-ray analysis (Figure 2b), indicating that the as-prepared precipitate and single crystals of MAImC1-PW12 had the same composition and structure. Differences in the peak intensity and position of the patterns may be due to the difference in the measurement temperature (powder: ambient temperature, single crystal: 100 K).  The molecular structure was clearly revealed by single-crystal X-ray structure analysis (Table 1, Figure 3)

. The chemical formula was [{CH 2 =C(CH 3 )COO(CH 2 ) 2 }C 3 H 3 N 2 (CH 3 )] 3 [PW 12 O 40 ]
(MAImC 1 -PW 12 ), and three protons of H-PW 12 were completely exchanged by three MAImC 1 cations. As shown in Figure 3a, there were two crystallographically-independent MAImC 1 cations, one of which was disordered near the two-fold axis with a site occupancy of 0.5. The PW 12 anion lay on the inversion center, and exhibited a common type of disorder for the Keggin anion noted previously [47,48].

Synthesis of MAImC1-PW12 Hybrid Homo-and Copolymers
The radical polymerization of the obtained MAImC1-PW12 hybrid monomer and the copolymerizations with vinyl monomers, butyl methacrylate (BMA), and MAImC8-Br were carried

Synthesis of MAImC 1 -PW 12 Hybrid Homo-and Copolymers
The radical polymerization of the obtained MAImC 1 -PW 12 hybrid monomer and the copolymerizations with vinyl monomers, butyl methacrylate (BMA), and MAImC 8 -Br were carried out by using AIBN as an initiator as shown in Scheme 2. The yields and the molecular weights of the obtained polymers are shown in Table 2. MAImC 1 -PW 12 hybrid monomer was successfully polymerized by using about a half equivalent of AIBN against the monomer, where the homopolymer was soluble in some organic solvents and the weight-average molecular weight was 7960. The homopolymer, P-MAImC 1 -PW 12 , was soluble in DMF, DMSO, and NMP, but insoluble in methanol, chloroform, and THF. On the other hand, the copolymerization of the MAImC 1 -PW 12 hybrid monomer with BMA and MAImC 8 -Br were conducted using a 1/50 equivalent amount of AIBN against the monomers to yield high molecular weight copolymers. The copolymers of MAImC 1 -PW 12 with BMA, CP-MAImC 1 -PW 12 /BMA, were widely soluble in chloroform, THF, DMF, and NMP, however, the copolymers of MAImC 1 -PW 12 Table 2. MAImC1-PW12 hybrid monomer was successfully polymerized by using about a half equivalent of AIBN against the monomer, where the homopolymer was soluble in some organic solvents and the weight-average molecular weight was 7960. The homopolymer, P-MAImC1-PW12, was soluble in DMF, DMSO, and NMP, but insoluble in methanol, chloroform, and THF. On the other hand, the copolymerization of the MAImC1-PW12 hybrid monomer with BMA and MAImC8-Br were conducted using a 1/50 equivalent amount of AIBN against the monomers to yield high molecular weight copolymers. The copolymers of MAImC1-PW12 with BMA, CP-MAImC1-PW12/BMA, were widely soluble in chloroform, THF, DMF, and NMP, however, the copolymers of MAImC1-PW12 with MAImC8-Br, CP-MAImC1-PW12/MAImC8Br, were only soluble in NMP. Therefore, GPC measurement of CP-MAImC1-PW12/MAImC8Br could not be conducted.
The thermal stability of these hybrid polymers was evaluated by thermogravimetric analysis (TGA), and compared with poly(butyl methacrylate) (PBMA) as shown in Figure 5. It was found from the TGA curves that the thermal degradation of the hybrid homo-and copolymers of MAImC 1 -PW 12 mainly occurred at around 503-553 K, whereas that of PBMA occurred at just over 473 K. Probably, the thermal degradation of the hybrid polymers would be induced by a decomposition of the organic components, imidazolium groups, at ca. 500 K, whereas the starting temperatures of degradation for all the hybrid polymers were higher than that of purely-organic PBMA polymer. Notably, CP-MAImC 1 -PW 12 /MAImC 8 Br hybrid copolymer exhibiting moderate conductivity (see below) was much more stable than PBMA. It was considered that the weight loss of these hybrid polymers would be derived from the degradation of the polymer side chain. These results indicated that the hybridization with the PW 12 inorganic anions enhanced the thermal stability of the organic polymers.    Figure 6 shows powder XRD patterns of the MAImC 1 -PW 12 hybrid homo-and copolymers. As shown in Figure 6a, MAImC 1 -PW 12 hybrid homopolymer prepared with DMSO exhibited an XRD pattern similar to that of crystalline MAImC 1 -PW 12 hybrid monomer (Figure 2b). This indicates that the polymerization did not proceed sufficiently, being consistent with the molecular weight estimated by GPC (Table 2). On the contrary, the XRD pattern of the MAImC 1 -PW 12 hybrid homopolymer prepared with DMF (Figure 6b) did not show any peak except for halo patterns typical for amorphous polymer phase, suggesting that the MAImC 1 -PW 12 hybrid monomer was successfully polymerized. Both XRD patterns of MAImC 1 -PW 12 hybrid copolymers (Figure 6c,d) showed halo peaks typical for an amorphous polymer phase, supported by the GPC results (Table 2).   Figure 6 shows powder XRD patterns of the MAImC1-PW12 hybrid homo-and copolymers. As shown in Figure 6a, MAImC1-PW12 hybrid homopolymer prepared with DMSO exhibited an XRD pattern similar to that of crystalline MAImC1-PW12 hybrid monomer (Figure 2b). This indicates that the polymerization did not proceed sufficiently, being consistent with the molecular weight estimated by GPC (Table 2). On the contrary, the XRD pattern of the MAImC1-PW12 hybrid homopolymer prepared with DMF ( Figure 6b) did not show any peak except for halo patterns typical for amorphous polymer phase, suggesting that the MAImC1-PW12 hybrid monomer was successfully polymerized. Both XRD patterns of MAImC1-PW12 hybrid copolymers (Figure 6c,d) showed halo peaks typical for an amorphous polymer phase, supported by the GPC results (Table 2).  Table 3 shows conductivity values of MAImC1-PW12 hybrid monomer and polymers measured under less-or fully-humidified conditions. Most samples, unfortunately, exhibited rather low conductivity below the order of 10 −7 S·cm −1 despite the degree of polymerization and/or presence of humidity. However, the copolymer of MAImC1-PW12 with MAImC8-Br (CP-MAImC1-PW12/MAImC8Br (1:1)) exhibited much better conductivity. The Nyquist plots (Figure 7) changed drastically with or without additional humidification, and the conductivities were estimated by the resistance (R1) simulated by the equivalent circuits depicted in Figure 7. Table 4 shows estimated parameters with these equivalent circuits. The conductivity under relative humidity (denoted as RH) of 95% was 5.7 × 10 −4 S·cm −1 , which was a moderate value at the lower temperature (313 K). The conductivity of the CP-MAImC1-PW12/MAImC8Br hybrid copolymer depended on the ratio of MAImC1-PW12 hybrid monomer and MAImC8-Br comonomer. The higher the ratio of MAImC1-PW12 hybrid monomer to MAImC8-Br comonomer, the lower the conductivity was: the conductivity of CP-MAImC1-PW12/MAImC8Br (3:1) with additional humidity (3.5 × 10 −6 S·cm −1 ) was two orders of magnitude lower than that of CP-MAImC1-PW12/MAImC8Br (1:1) (Table 3). Therefore, the moderate conductivity of CP-MAImC1-PW12/MAImC8Br under humidified conditions was derived from polymerized MAImC8-Br moiety, which was confirmed by high conductivity (3.2 × 10 −3 S·cm −1 ) of homopolymer of MAImC8-Br (P-MAImC8Br) as shown in Table 3. However, P-MAImC8Br  Table 3 shows conductivity values of MAImC 1 -PW 12 hybrid monomer and polymers measured under less-or fully-humidified conditions. Most samples, unfortunately, exhibited rather low conductivity below the order of 10 −7 S·cm −1 despite the degree of polymerization and/or presence of humidity. However, the copolymer of MAImC 1 -PW 12 with MAImC 8 -Br (CP-MAImC 1 -PW 12 /MAImC 8 Br (1:1)) exhibited much better conductivity. The Nyquist plots (Figure 7) changed drastically with or without additional humidification, and the conductivities were estimated by the resistance (R 1 ) simulated by the equivalent circuits depicted in Figure 7. Table 4 shows estimated parameters with these equivalent circuits. The conductivity under relative humidity (denoted as RH) of 95% was 5.7 × 10 −4 S·cm −1 , which was a moderate value at the lower temperature (313 K). The conductivity of the CP-MAImC 1 -PW 12 /MAImC 8 Br hybrid copolymer depended on the ratio of MAImC 1 -PW 12 hybrid monomer and MAImC 8 -Br comonomer. The higher the ratio of MAImC 1 -PW 12 hybrid monomer to MAImC 8 -Br comonomer, the lower the conductivity was: the conductivity of CP-MAImC 1 -PW 12 /MAImC 8 Br (3:1) with additional humidity (3.5 × 10 −6 S·cm −1 ) was two orders of magnitude lower than that of CP-MAImC 1 -PW 12 /MAImC 8 Br (1:1) (Table 3). Therefore, the moderate conductivity of CP-MAImC 1 -PW 12 /MAImC 8 Br under humidified conditions was derived from polymerized MAImC 8 -Br moiety, which was confirmed by high conductivity (3.2 × 10 −3 S·cm −1 ) of homopolymer of MAImC 8 -Br (P-MAImC 8 Br) as shown in Table 3. However, P-MAImC 8 Br irreversibly expanded under humidified conditions to result in a gel-like material, and the durability of P-MAImC 8 Br against humidity was quite low, and the conductivity measurement was able only one time. On the other hand, CP-MAImC 1 -PW 12 /MAImC 8 Br hybrid copolymers endured the presence of humidity, and the conductivity measurements were carried out repeatedly. Therefore, the hybridization of MAImC 1 -PW 12 with MAImC 8 Br seems crucial for the increase in durability of P-MAImC 8 Br homopolymer and the emergence of moderate conductivity.

Discussion
The newly-designed polymerizable ionic liquid cation of MAImC 1 was successfully hybridized with heteropolyanion of dodecatungstophosphate (PW 12 ). The inorganic-organic hybrid momomer of MAImC 1 -PW 12 was revealed to be polymerized by a radical polymerization using AIBN as an initiator. Both hybrid monomer and polymers contained imidazolium moieties, and were expected to work as ionic or proton conductors [10][11][12][13]23].
These MAImC 1 -PW 12 hybrid monomer and polymers have an advantage to the generality on the selection of polyoxometalate anions and ionic liquid cations. In our compounds, the polymerizable ionic liquid moiety is a cationic species and interacts with heteropolyanions to form ionic hybrid monomer compounds [37,38]. In principle, the organic ionic liquid moiety can be flexibly designed in terms of organic syntheses, and the inorganic polyoxometalate anions can be variously selected, indicating more versatility than other polyoxometalate-polymer systems using polyoxometalate with the organic moiety grafted by covalent bonding [25][26][27][28][29][30][31][32][33][34][35][36]. Additionally, the MAImC 1 -PW 12 hybrid monomer can be obtained as single crystals [28][29][30][31][32], which enabled unambiguous characterization of the key starting material. Other combinations of the polymerizable ionic liquid moiety and polyoxometalate are now investigated.
The carrier for the conduction of CP-MAImC 1 -PW 12 /MAImC 8 Br is unclear. The conductivity increased under the presence of water vapor, indicating the water molecules may assist the moving of carriers. The proton conductivity often increases under the presence of water vapor [3]. Therefore, the carrier in CP-MAImC 1 -PW 12 /MAImC 8 Br is suggested to be proton. The proton may be derived from water molecules, since the MAImC 1 -PW 12 hybrid monomer and polymers have no residual protons, as revealed by single-crystal structure analysis. As mentioned above, the moderate conductivity of CP-MAImC 1 -PW 12 /MAImC 8 Br (1:1) (5.7 × 10 −4 S·cm −1 at 313 K) was derived from the MAImC 8 -Br moiety ( Table 3). The water molecules may loosen the polymer chain of the polymerized MAImC 8 -Br moiety, and the carrier species could move more easily under the presence of humidity. The CP-MAImC 1 -PW 12 /MAImC 8 Br hybrid copolymer had good durability against water vapor, while the purely organic P-MAImC 8 Br polymer was quite sensitive against humidity. The increase in the durability against humidity will be derived from the introduction of PW 12 anions into P-MAImC 8 Br, and the hybridization with the inorganic moiety has been revealed to be effective for possible inorganic-organic hybrid solid electrolyte [49].

Conclusions
Polymerizable ionic liquid (MAImC 1 ) was utilized to construct the inorganic-organic hybrid monomer with heteropolyanions (PW 12 ). The hybrid monomer was synthesized by a cation exchange reaction, and obtained as single crystals. This new hybrid monomer was successfully polymerized by a radical polymerization to form several types of homo-and copolymers. Copolymerization of MAImC 1 -PW 12 with MAImC 8 -Br resulted in the formation of a possible solid