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Article

Conductive Supramolecular Architecture Constructed from Polyoxovanadate Cluster and Heterocyclic Surfactant

by
Toshiyuki Misawa
,
Minako Taira
,
Katsuhiko Fujio
and
Takeru Ito
*
Department of Chemistry, School of Science, Tokai University, 4-1-1 Kitakaname, Hiratsuka 259-1292, Japan
*
Author to whom correspondence should be addressed.
Crystals 2018, 8(2), 57; https://doi.org/10.3390/cryst8020057
Submission received: 30 December 2017 / Revised: 12 January 2018 / Accepted: 22 January 2018 / Published: 25 January 2018
(This article belongs to the Special Issue Crystal Structure Analysis of Supramolecular and Porous Solids)
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Abstract

:
Proton-conductive solid electrolytes are significant for fuel-cell battery technology. Especially for use in motor vehicles, proton conductors which work at intermediate temperatures (373–673 K) under an anhydrous atmosphere are desired to improve the fuel cell stability and efficiency. Inorganic–organic hybrid supramolecular architectures are a promising option for the realization of highly conductive proton conductors. Here, a hybrid layered crystal was synthesized for the first time by using an proton-containing decavanadate (V10) anion and a heterocyclic surfactant cation. A simple ion-exchange reaction led to the formation of an inorganic–organic hybrid of V10 by using dodecylpyridazinium (C12pda) as the heterocyclic surfactant. Single crystal X-ray analyses revealed that four C12pda cations were associated with one V10 anion, which was a diprotonated species forming a one-dimensional infinite chain structure through hydrogen bonds. Anhydrous proton conductivity was investigated by alternating current (AC) impedance spectroscopy in the range of 313–393 K, exhibiting a maximum value of 1.7 × 10−5 S cm−1 at 373 K.

1. Introduction

Supramolecular chemistry enables the production of a variety of self-organized architectures from the artificial to the biological [1], which include static and dynamic systems [2]. In addition, supramolecular chemistry can produce inorganic–organic hybrid materials which exhibit characteristic functions derived from the synergy of inorganic and organic components [3,4,5]. Recently, toward the application to fuel-cell batteries [6], crystalline inorganic–organic hybrids such as MOFs (metal–organic frameworks) or PCPs (porous coordination polymers) have been widely investigated as a possible substitution for the present polymer proton conductors [7,8,9,10,11,12].
As for inorganic components, polyoxometalate (POM) clusters are promising due to their unique redox properties [13,14,15,16,17,18,19]. Heteropolyacids, Keggin-type POMs with a proton as counter cation, have been investigated as high proton conductors [20,21,22,23,24,25,26]. Such POMs have been successfully hybridized by surfactant cations to form inorganic–organic hybrids [27,28,29,30,31,32,33,34,35] and single crystals [36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55]. These polyoxometalate–surfactant hybrids allow various combinations of the ionic components, leading to precise engineering of the structure and function.
Among several POMs, a polyoxovanadate such as decavanadate ([V10O28]6−, V10, Figure 1), tends to be associated with protons [56,57,58,59,60,61]. Therefore, polyoxovanadate–surfactant hybrid crystals are promising as proton-conducting materials, and anhydrous proton conductivity has been evaluated for the V10 hybrid crystals comprising decyltrimethylammonium ([(C10H21)N(CH3)3]+, C10) surfactant [47]. The anhydrous proton conductivity could be enhanced by the delocalized π–electrons in the heterocyclic moiety of the hybridized surfactant. However, no V10 hybrid crystal comprising the surfactant with a heterocyclic moiety has been reported.
Here we demonstrate the first syntheses and structural analyses of V10-heterocyclic surfactant hybrid crystals. Dodecylpyridazinium ([C4H4N2(C12H25)]+ (C12pda), Figure 1) cation was employed as the heterocyclic surfactant. The C12pda cation has been rarely reported to form hybrid crystals with POMs [44]. In the crystal structure, the V10 anion formed a diprotonated species, and anhydrous proton conductivity was elucidated.

2. Materials and Methods

2.1. Materials and Genaral Methods

All chemical reagents were purchased from Wako Pure Chemical Industries, Ltd. (Wako, Osaka, Japan) and Tokyo Chemical Industry Co., Ltd. (TCI, Tokyo, Japan). [C4H4N2(C12H25)]Br (C12pda·Br) was synthesized by using pyridazine and 1-bromododecane based on the literature [62].
Infrared (IR) spectra (as 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. Diffuse reflectance ultraviolet-visible (UV-vis) spectra were collected with a Jasco V-670 spectrometer (JASCO Corporation, Tokyo, Japan).
Conductivity measurements were carried out by alternating current (AC) impedance method in a frequency range from 20 to 1.0 × 107 Hz using a Wayne Kerr 6510P inductance-capacitance-resistance (LCR) meter. Pelletized powder samples (10 mm in diameter, 0.81 mm in thickness) were sandwiched with Pt electrodes, and the impedance was measured under a dry N2 atmosphere at 313–393 K.

2.2. Synthesis

C12pda-V10 hybrids were synthesized as follows: solid V2O5 (0.40 g, 2.2 mmol) was dispersed in 15 mL of water, and dissolved by adding LiOH·H2O (0.24 g, 5.7 mmol). The solution was adjusted to pH 6.0 or 4.0 with 6M HCl, and the resulting orange solution was added at room temperature to an ethanol solution (15 mL) of C12pda·Br (0.30 g, 0.91 mmol) with stirring for 60 min. Obtained dark green (pH 6.0) or yellow (pH 4.0) precipitates were filtered off, and washed with 10 mL of ethanol to obtain as-prepared product of C12pda-V10 (0.377 g (56% yield) for pH 6.0; 0.179 g (34% yield) for pH 4.0).
Yellow plate crystals suitable for X-ray diffraction measurements were obtained from the filtrate of the synthesis at pH 6.0 kept at 279 K for 4–5 months. The yellow plate crystals were also obtained from the filtrate of the synthesis at pH 4.0 kept at 293 K for two weeks. Anal.: Calcd for C66H126N8V10O30: C: 39.22, H: 6.28, N: 5.54%. Found: C: 38.22, H: 6.18, N: 5.48%. IR (KBr disk): 959 (s), 827 (m), 755 (m), 721 (m), 607 (m), 446 (w), 407 (w) cm−1.

2.3. X-ray Crystallography

Single crystal X-ray diffraction data for the C12pda-V10 crystals were recorded with an ADSC Q210 CCD area detector with a synchrotron radiation at the 2D beamline in Pohang Accelerator Laboratory (PAL). The diffraction images were processed by using HKL3000 [63], and absorption correction was also performed with HKL3000. The structure was solved by the direct method using SHELXT Version 2014/5 [64] and refined by the full-matrix least-squares method on F2 using SHELXL Version 2014/7 [65]. All calculations were performed using the CrystalStructure software package [66]. All non-hydrogen atoms were refined anisotropically. The H atoms attached to the O atoms of V10 were found in the difference Fourier synthesis and their positional and isotropic displacement parameters were refined. The hydrogen atoms of C12pda surfactants and ethanol molecule of crystallization were refined using the riding model. 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: [email protected] (CCDC 1813634).

3. Results

3.1. Syntheses of C12pda-V10 hybrids

C12pda-V10 hybrids were obtained as insoluble precipitates from aqueous solution of solid V2O5, the pH of which was adjusted at 6.0 or 4.0. The C12pda-V10 hybrids synthesized at pH 6.0 were dark green, while the C12pda-V10 hybrids synthesized at pH 4.0 were yellow. In this pH range, the V10 anions or their protonated species are the main species in the solution [67]. Figure 2a,b shows Infrared (IR) spectra of these dark green and yellow C12pda-V10 hybrids, in which the characteristic peaks for the V10 anion were observed in the range of 400–1000 cm−1. This means that both C12pda-V10 hybrids synthesized at pH 6.0 and 4.0 contained the V10 anion, although the sample colors were different (dark green and yellow). The dark green color will be derived from the reduced V10 species. On the other hand, the C12pda-V10 hybrids synthesized at pH 6.0 and 4.0 exhibited different powder X-ray diffraction (XRD) patterns (Figure 3a,b), indicating that these hybrids had different bulk structures.
The yellow-colored C12pda-V10 crystals were obtained from the synthetic filtrate at pH 6.0. The C12pda-V10 crystals were identified to possess the same molecular and crystal structure as the yellow C12pda-V10 hybrids synthesized at pH 4.0, which was revealed by the IR spectrum (Figure 2b,c) and powder XRD pattern (Figure 3b,c). The yellow crystalline hybrids were employed for the conductivity measurements (see below). The XRD pattern of the C12pda-V10 crystals was different in peak positions from that calculated from the results of single crystal X-ray analyses (Figure 3d). This may be due to the difference in the measurement temperature (powder: ambient temperature, single crystal: 100 K) and the desolvation of solvent molecules of the crystals during the XRD measurements.

3.2. Crystal Structure of C12pda-V10

The X-ray structure and elemental analyses revealed the formula of the C12pda-V10 crystals to be [C4H4N2(C12H25)]4[H2V10O28]·H2O·C2H5OH (Table 1, Figure 4). The crystal consisted of the V10 anion, being consistent with the IR spectrum (Figure 2c). Four C12pda cations (1+ charge) were associated with one V10 anion (6- charge) due to the charge compensation, suggesting the presence of two protons as counter cation in the C12pda-V10 crystals. The protons were connected to the V10 anion to form [H2V10O28]4− (H2V10) as observed in the hybrid crystals of the V10 anion and C10 cation (C10-V10) [47] (see below).
The crystal packing of C12pda-V10 was composed of alternating V10 inorganic monolayers and C12pda organic bilayers parallel to the bc plane with an interlayer distance of 25.5 Å (Figure 4a). The dodecyl chains of C12pda were interdigitated straightly with each other. The solvent molecules (water and ethanol) of crystallization were placed at the interface between the V10 and C12pda layers (Figure 4a).
The V10 anion in the C12pda-V10 crystals was clearly identified as a diprotonated species by the X-ray structure analyses (Figure 4b). This result was confirmed by the bond valence sum (BVS) calculations [68] giving values of 1.37 (O15) and 1.24 (O24), while the BVS values were within the range 1.63–2.03 for other oxygen atoms. Each diprotonated V10 anion was related by the two-fold screw axis, and connected by the O–H···O hydrogen bond to form a one-dimensional infinite chain structure (Figure 4c). The O···O distances were 2.740(2) Å for O15–H66···O17i (symmetry code i: 1 − x, −0.5 + y, 0.5 − z) and 2.766(2) Å for O24–H67···O9i, respectively. The C12pda-V10 crystals had a zigzag infinite chain structure of V10 different from the chain structure observed in the C10-V10 crystals [47], which would be caused by the different manner of the protonation. In the C12pda-V10 crystals, one protonated oxygen site (O15) was different from the case of the C10-V10 hybrid crystals, resulting in a different arrangement of the V10 anions from that in the C10-V10 crystals. These hydrogen-bonded V10 chains were formed in the inorganic layers, and isolated by the pyridazinium moieties of the C12pda cations.
The structural features of the C12pda cations were then investigated. Although most C–C bonds of the dodecyl chains of C12pda had an anti conformation, three C–C bonds (C22–C23, C40–C41, C56–C57) had a gauche conformation (Figure 5a), two of which (C40–C41, C56–C57) were located some methylene groups away from the hydrophilic head, which was similar to the C12pda conformation in the hybrid crystal comprising decatungstate ([W10O32]4−, W10) anion (C12pda-W10) [44]. The hydrophilic heads of C12pda penetrated into the V10 inorganic layers as mentioned above. The penetrated pyridazine rings of C12pda had short contacts between the heterocyclic moiety due to the C–H···π interactions (Figure 5b), being different from the C12pda-W10 hybrid crystal [44]. The C12pda cation interacted with the V10 anions by C–H···O hydrogen bonds [69] with C···O distances ranging from 2.82 to 3.92 Å (mean value: 3.33 Å), most of which were formed between the V10 anion and pyridazine rings of the C12pda cations.

3.3. Anhydrous Proton Conductivity of C12pda-V10

The anhydrous proton conductivity was investigated for the yellow C12pda-V10 hybrids by alternating current (AC) impedance spectroscopy. Figure 6a shows a typical Nyquist spectrum, which was measured at 373 K under a dry N2 atmosphere. The spectrum showed a suppressed half circle in the high- and medium-frequency regions and a slightly inclined line in the low-frequency region. The Nyquist spectrum was fitted based on an equivalent circuit shown in Figure 6a (inset) [45,46,47]. The red line represents simulated data with the equivalent circuit, which successfully reproduced the measured Nyquist spectrum. The estimated value of the bulk resistance, Rb, was 6.05 × 103 Ω at 373 K, from which the conductivity of the yellow C12pda-V10 hybrids was calculated to be 1.7 × 10−5 S cm−1. This anhydrous conductivity will be owing to the protons which were connected to the V10 anions.
Figure 6b shows the temperature dependence of the conductivity for the yellow C12pda-V10 hybrids at 313−393 K (40−120 °C). The conductivity at 313 K (40 °C) was 1.1 × 10−8 S cm−1, increased with the increasing temperature, and reached 1.7 × 10−5 S cm−1 at 373 K (100 °C). The proton conductivity jumped by three orders of magnitude from that at 313 K to 373 K. However, the conductivity dropped to 9.8 × 10−6 S cm−1 at 393 K (120 °C), plausibly due to the removal of water molecules of crystallization by the heating.
The activation energy of the proton conductivity was estimated from the Arrhenius plot as shown in Figure 6c. The value of the slope was obtained by the conductivities except for that at 393 K, where the conduction mechanism would have changed. An obtained value of the activation energy was 1.3 eV (125 kJ/mol), suggesting that the proton conduction mechanism in the yellow C12pda-V10 hybrids was more similar to the vehicle mechanism rather than the Grotthuss mechanism [11]. However, the detailed mechanism is unclear and under investigation.

4. Discussion

Here, the successful crystallization was realized to obtain the single crystals of C12pda-V10. Surfactant-V10 hybrid crystals have often been obtained from the synthetic filtrates [36,47,48]. The recrystallization with organic solvents was usually unsuccessful, leading to difficulty in the crystallization of hybrid crystals comprising hydrophobic heterocyclic surfactants. In the case reported here, the different pH values (6.0 and 4.0) were tried to obtain the C12pda-V10 hybrids, and suitable single crystals were obtained from the dark green C12pda-V10 hybrids obtained at pH 6.0. The dark green C12pda-V10 hybrids seemed to contain reduced V10 species (Figure 2a), since the dark green color was plausibly derived from the presence of reduced V atoms [16]. The ultraviolet-visible (UV-vis) spectrum of the dark green C12pda-V10 hybrids (Figure 7a) suggests the presence of intervalence charge transfers between reduced and fully-oxidized V atoms (ex. VIV and VV), while the yellow C12pda-V10 hybrids comprising the fully-oxidized V atoms (BVS values: 5.02–5.07) exhibited no distinct absorption (Figure 7b). However, the detailed oxidation states are unclear. The reduced V10 species in the filtrate were gradually oxidized to cause the slow crystallization of the C12pda-V10 crystals comprising oxidized and yellow-colored V10 species, which had the same molecular and bulk structures as the yellow C12pda-V10 hybrids.
The C12pda-V10 crystals contained the diprotonated V10 species, and formed a one-dimensional infinite chain structure by the O–H···O hydrogen bonds, which possibly contributed to the emergence of proton-conductivity. In fact, the yellow C12pda-V10 hybrids exhibited anhydrous proton conductivity at 313–393 K. The highest value was 1.7 × 10−5 S cm−1 at 373 K, but lower than other systems (10−3–10−2 S cm−1 order for higher conductivity) [7,8,9,10]. However, a promising strategy utilizing the proton-containing V10 anion and stable heterocyclic surfactants was verified for the emergence of anhydrous proton conductivity. The selection of the surfactants and optimization of the synthetic conditions would pave the way to another class of anhydrous proton conductors.

Supplementary Materials

The following are available online at https://www.mdpi.com/2073-4352/8/2/57/s1, cif file of C12pda-V10.

Acknowledgments

This work was financially supported in part by JSPS KAKENHI Grant Number JP26410245, and Research and Study Program of Tokai University Educational System General Research Organization. X-ray diffraction measurements with synchrotron radiation were performed at the Pohang Accelerator Laboratory (Beamline 2D) supported by Pohang University of Science and Technology (POSTECH).

Author Contributions

Toshiyuki Misawa, Minako Taira and Takeru Ito conceived and designed the experiments; Toshiyuki Misawa and Minako Taira performed the experiments; Toshiyuki Misawa and Takeru Ito analyzed the data; Katsuhiko Fujio contributed materials; Toshiyuki Misawa and Takeru Ito wrote the paper.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Lehn, J.-M. Supramolecular Chemistry: Concepts and Perspectives; VCH: Weinheim, Germany, 1995. [Google Scholar]
  2. Sauvage, J.-P. Transition metal-complexed catenanes and rotaxanes as molecular machine prototypes. Chem. Commun. 2005, 12, 1507–1510. [Google Scholar] [CrossRef] [PubMed]
  3. Kato, T.; Mizoshita, N.; Kishimoto, K. Functional liquid-crystalline assemblies: Self-organized soft materials. Angew. Chem. Int. Ed. 2006, 45, 38–68. [Google Scholar] [CrossRef] [PubMed]
  4. Coronado, E.; Gómez-García, C.J. Polyoxometalate-based molecular materials. Chem. Rev. 1998, 98, 273–296. [Google Scholar] [CrossRef] [PubMed]
  5. Coronado, E.; Giménez-Saiz, C.; Gómez-García, C.J. Recent advances in polyoxometalate-containing molecular conductors. Coord. Chem. Rev. 2005, 249, 1776–1796. [Google Scholar] [CrossRef]
  6. Steele, B.C.H.; Heinzel, A. Materials for fuel-cell technologies. Nature 2001, 414, 345–352. [Google Scholar] [CrossRef] [PubMed]
  7. Horike, S.; Umeyama, D.; Kitagawa, S. Ion conductivity and transport by porous coordination polymers and metal-organic frameworks. Acc. Chem. Res. 2013, 46, 2376–2384. [Google Scholar] [CrossRef] [PubMed]
  8. Yoon, M.; Suh, K.; Natarajan, S.; Kim, K. Proton conduction in metal-organic frameworks and related modularly built porous solids. Angew. Chem. Int. Ed. 2013, 52, 2688–2700. [Google Scholar] [CrossRef] [PubMed]
  9. Ramaswamy, P.; Wong, N.E.; Shimizu, G.K.H. MOFs as proton conductors–challenges and opportunities. Chem. Soc. Rev. 2014, 43, 5913–5932. [Google Scholar] [CrossRef] [PubMed]
  10. Tang, Q.; Liu, Y.; Liu, S.; He, D.; Miao, J.; Wang, X.; Yang, G.; Shi, Z.; Zheng, Z. High proton conduction at above 100 °C mediated by hydrogen bonding in a lanthanide metal−organic framework. J. Am. Chem. Soc. 2014, 136, 12444–12449. [Google Scholar] [CrossRef] [PubMed]
  11. Yamada, T.; Sadakiyo, M.; Kitagawa, H. High proton conductivity of one-dimensional ferrous oxalate dihydrate. J. Am. Chem. Soc. 2009, 131, 3144–3145. [Google Scholar] [CrossRef] [PubMed]
  12. Colodrero, R.M.P.; Olivera-Pastor, P.; Losilla, E.R.; Hernández-Alonso, D.; Aranda, M.A.G.; Leon-Reina, L.; Rius, J.; Demadis, K.D.; Moreau, B.; Villemin, D.; et al. High proton conductivity in a flexible, cross-linked, ultramicroporous magnesium tetraphosphonate hybrid framework. Inorg. Chem. 2012, 51, 7689–7698. [Google Scholar] [CrossRef] [PubMed]
  13. Long, D.-L.; Burkholder, E.; Cronin, L. Polyoxometalate clusters, nanostructures and materials: From self assembly to designer materials and devices. Chem. Soc. Rev. 2007, 36, 105–121. [Google Scholar] [CrossRef] [PubMed]
  14. Nyman, M. Polyoxoniobate chemistry in the 21st century. Dalton Trans. 2011, 40, 8049–8058. [Google Scholar] [CrossRef] [PubMed]
  15. Proust, A.; Matt, B.; Villanneau, R.; Guillemot, G.; Gouzerh, P.; Izzet, G. Functionalization and post-functionalization: A step towards polyoxometalate-based materials. Chem. Soc. Rev. 2012, 41, 7605–7622. [Google Scholar] [CrossRef] [PubMed]
  16. Monakhov, K.Y.; Bensch, W.; Kögerler, P. Semimetal-functionalised polyoxovanadates. Chem. Soc. Rev. 2015, 44, 8443–8483. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  17. Okuhara, T.; Mizuno, N.; Misono, M. Catalytic chemistry of heteropoly compounds. Adv. Catal. 1996, 41, 113–252. [Google Scholar]
  18. Yamase, T. Photo- and electrochromism of polyoxometalates and related materials. Chem. Rev. 1998, 98, 307–325. [Google Scholar] [CrossRef] [PubMed]
  19. Sadakane, M.; Steckhan, E. Electrochemical properties of polyoxometalates as electrocatalysts. Chem. Rev. 1998, 98, 219–237. [Google Scholar] [CrossRef] [PubMed]
  20. Nakamura, O.; Kodama, T.; Ogino, I.; Miyake, Y. High-conductivity solid proton conductors: Dodecamolybdophosphoric acid and dodecatungstophosphoric acid crystals. Chem. Lett. 1979, 8, 17–18. [Google Scholar]
  21. Honma, I.; Yamada, M. Bio-inspired membranes for advanced polymer electrolyte fuel cells. Anhydrous proton-conducting membrane via molecular self-assembly. Bull. Chem. Soc. Jpn. 2007, 80, 2110–2123. [Google Scholar] [CrossRef]
  22. Oh, S.-Y.; Yoshida, T.; Kawamura, G.; Muto, H.; Sakai, M.; Matsuda, A. Inorganic-organic composite electrolytes consisting of polybenzimidazole and Cs-substituted heteropoly acids and their application for medium temperature fuel cells. J. Mater. Chem. 2010, 20, 6359–6366. [Google Scholar] [CrossRef]
  23. Kukino, T.; Kikuchi, R.; Takeguchi, T.; Matsui, T.; Eguchi, K. Proton conductivity and stability of Cs2HPW12O40 electrolyte at intermediate temperatures. Solid State Ion. 2005, 176, 1845–1848. [Google Scholar] [CrossRef]
  24. Wu, X.; Tong, X.; Wu, Q.; Ding, H.; Yan, W. Reversible phase transformation-type electrolyte based on layered shape polyoxometalate. J. Mater. Chem. A 2014, 2, 5780–5784. [Google Scholar] [CrossRef]
  25. Tsuboi, M.; Hibino, M.; Mizuno, N.; Uchida, S. Crystalline polyoxometalate (POM)–polyethylene glycol (PEG) composites aimed as non-humidified intermediate-temperature proton conductors. J. Solid State Chem. 2016, 234, 9–14. [Google Scholar] [CrossRef]
  26. Klaiber, A.; Landsmann, S.; Löffler, T.; Polarz, S. Fourfold action of surfactants with superacid head groups: Polyoxometalate–silicone nanocomposites as promising candidates for proton-conducting materials. New J. Chem. 2016, 40, 919–922. [Google Scholar] [CrossRef]
  27. Song, Y.-F.; Long, D.-L.; Ritchie, C.; Cronin, L. Nanoscale polyoxometalate-based inorganic/organic hybrids. Chem. Rec. 2011, 11, 158–171. [Google Scholar] [CrossRef] [PubMed]
  28. Yin, P.; Li, D.; Liu, T. Solution behaviors and self-assembly of polyoxometalates as models of macroions and amphiphilic polyoxometalate-organic hybrids as novel surfactants. Chem. Soc. Rev. 2012, 41, 7368–7383. [Google Scholar] [CrossRef] [PubMed]
  29. Polarz, S.; Landsmann, S.; Klaiber, A. Hybrid surfactant systems with inorganic constituents. Angew. Chem. Int. Ed. 2014, 53, 946–954. [Google Scholar] [CrossRef] [PubMed]
  30. Clemente-León, M.; Coronado, E.; Soriano-Portillo, A.; Mingotaud, C.; Dominguez-Vera, J.M. Langmuir-Blodgett films based on inorganic molecular complexes with magnetic or optical properties? Adv. Colloid Interface Sci. 2005, 116, 193–203. [Google Scholar] [CrossRef] [PubMed]
  31. Nisar, A.; Wang, X. Surfactant-encapsulated polyoxometalate building blocks: Controlled assembly and their catalytic properties. Dalton Trans. 2012, 41, 9832–9845. [Google Scholar] [CrossRef] [PubMed]
  32. Zhang, T.; Liu, S.; Kurth, D.G.; Faul, C.F.J. Organized nanostructured complexes of polyoxometalates and surfactants that exhibit photoluminescence and electrochromism. Adv. Funct. Mater. 2009, 19, 642–652. [Google Scholar] [CrossRef]
  33. Qi, W.; Wu, L. Polyoxometalate/polymer hybrid materials: Fabrication and properties. Polym. Int. 2009, 58, 1217–1225. [Google Scholar] [CrossRef]
  34. Ito, T. Polyoxometalate-surfactant hybrids as building strategy for two-dimensional molecular arrays. Polyoxometalate Chem. 2012, 1, 6–14. [Google Scholar]
  35. Zhang, G.; Ke, H.; He, T.; Xiao, D.; Chen, Z.; Yang, W.; Yao, J. Synthesis and characterization of new layered polyoxometallates-1,10-decanediamine intercalative nanocomposites. J. Mater. Res. 2004, 19, 496–500. [Google Scholar] [CrossRef]
  36. Janauer, G.G.; Dobley, A.D.; Zavalij, P.Y.; Whittingham, M.S. Evidence for decavanadate clusters in the lamellar surfactant ion phase. Chem. Mater. 1997, 9, 647–649. [Google Scholar] [CrossRef]
  37. Spahr, M.E.; Nesper, R. Anhydrous octamolybdate with trimethyl hexadecyl ammonium cations. Z. Anorg. Allg. Chem. 2001, 627, 2133–2138. [Google Scholar] [CrossRef]
  38. Ito, T. Inorganic-organic hybrid surfactant crystals: Structural aspects and functions. Crystals 2016, 6, 24. [Google Scholar] [CrossRef]
  39. Ito, T.; Sawada, K.; Yamase, T. Crystal structure of bis(dimethyldioctadecylammonium) hexamolybdate: A molecular model of Langmuir-Blodgett films. Chem. Lett. 2003, 32, 938–939. [Google Scholar] [CrossRef]
  40. Ito, T.; Yamase, T. Inorganic-organic hybrid layered crystal composed of polyoxomolybdate and surfactant with π electrons. Chem. Lett. 2009, 38, 370–371. [Google Scholar] [CrossRef]
  41. Ito, T.; Mikurube, K.; Abe, Y.; Koroki, T.; Saito, M.; Iijima, J.; Naruke, H.; Ozeki, T. Hybrid inorganic-organic crystals composed of octamolybdate isomers and pyridinium surfactant. Chem. Lett. 2010, 39, 1323–1325. [Google Scholar] [CrossRef]
  42. Mikurube, K.; Hasegawa, K.; Naruke, H.; Ito, T. Hybrid layered crystal comprising polyoxometalate and surfactant synthesized from reduced Mo-blue species. J. Chem. 2013, 2013, 6. [Google Scholar] [CrossRef]
  43. Mikurube, K.; Hasegawa, K.; Matsumoto, T.; Kobayashi, J.; Naruke, H.; Ito, T. Isomerization-induced introduction of metal cations into polyoxomolybdate-surfactant hybrid crystals. Inorg. Chem. Commun. 2016, 73, 45–48. [Google Scholar] [CrossRef]
  44. Otobe, S.; Fujioka, N.; Hirano, T.; Ishikawa, E.; Naruke, H.; Fujio, K.; Ito, T. Decisive interactions between the heterocyclic moiety and the cluster observed in polyoxometalate-surfactant hybrid crystals. Int. J. Mol. Sci. 2015, 16, 8505–8516. [Google Scholar] [CrossRef] [PubMed]
  45. Ito, T.; Fujimoto, N.; Uchida, S.; Iijima, J.; Naruke, H.; Mizuno, N. Polyoxotungstate-surfactant layered crystal toward conductive inorganic-organic hybrid. Crystals 2012, 2, 362–373. [Google Scholar] [CrossRef]
  46. Kobayashi, J.; Kawahara, R.; Uchida, S.; Koguchi, S.; Ito, T. Conductive Hybrid Crystal Composed from Polyoxomolybdate and Deprotonatable Ionic-Liquid Surfactant. Int. J. Mol. Sci. 2016, 17, 994. [Google Scholar] [CrossRef] [PubMed]
  47. Ito, T.; Taira, M.; Fukumoto, K.; Yamamoto, K.; Naruke, H.; Tomita, K. Polyoxovanadate-surfactant hybrid layered crystal containing one-dimensional hydrogen-bonded cluster chain. Bull. Chem. Soc. Jpn. 2012, 85, 1222–1224. [Google Scholar] [CrossRef]
  48. Kiyota, Y.; Taira, M.; Otobe, S.; Hanyuda, K.; Naruke, H.; Ito, T. Compositional introduction of lithium ions into conductive polyoxovanadate-surfactant hybrid crystals. CrystEngComm 2017, 19, 3037–3043. [Google Scholar] [CrossRef]
  49. Nyman, M.; Ingersoll, D.; Singh, S.; Bonhomme, F.; Alam, T.M.; Brinker, C.J.; Rodriguez, M.A. Comparative study of inorganic cluster-surfactant arrays. Chem. Mater. 2005, 17, 2885–2895. [Google Scholar] [CrossRef]
  50. Nyman, M.; Rodriguez, M.A.; Anderson, T.M.; Ingersoll, D. Two structures toward understanding evolution from surfactant-polyoxometalate lamellae to surfactant-encapsulated polyoxometalates. Cryst. Growth Des. 2009, 9, 3590–3597. [Google Scholar] [CrossRef]
  51. Du, H.-J.; Mi, L.-W.; Yue, Z.-C.; Niu, Y.-Y.; Hou, H.-W. Templated fabrication, isomer recognition of series of 1,10-(alkane-1, ω-diyl)-bis(3-methylimidazolium)-induced polyoxometalates (ω = 1–11). Inorg. Chim. Acta 2014, 409, 418–426. [Google Scholar] [CrossRef]
  52. Yue, Z.-C.; Du, H.-J.; Li, L.; Zhang, W.-L.; Niu, Y.-Y.; Hou, H.-W. Construction and isomer recognition of polyoxometalates functionalized by 1,2-dimethylimidazole alkane templates. Inorg. Chim. Acta 2014, 410, 136–143. [Google Scholar] [CrossRef]
  53. Jiang, Y.; Liu, S.; Li, S.; Miao, J.; Zhang, J.; Wu, L. Anisotropic ionic liquids built from nonmesogenic cation surfactants and Keggin-type polyoxoanions. Chem. Commun. 2011, 47, 10287–10289. [Google Scholar] [CrossRef] [PubMed]
  54. Yin, P.; Wu, P.; Xiao, Z.; Li, D.; Bitterlich, E.; Zhang, J.; Cheng, P.; Vezenov, D.V.; Liu, T.; Wei, Y. A double-tailed fluorescent surfactant with a hexavanadate cluster as the head group. Angew. Chem. Int. Ed. 2011, 50, 2521–2525. [Google Scholar] [CrossRef] [PubMed]
  55. Zhu, L.; Chen, K.; Hao, J.; Wei, Z.; Zhang, H.; Yin, P.; Wei, Y. Synthesis and crystallization behavior of surfactants with hexamolybdate as the polar headgroup. Inorg. Chem. 2015, 54, 6075–6077. [Google Scholar] [CrossRef] [PubMed]
  56. Day, V.W.; Klemperer, W.G.; Maltbie, D.J. Where are the protons in H3Vl0O283−? J. Am. Chem. Soc. 1987, 109, 2991–3002. [Google Scholar] [CrossRef]
  57. Ferreira da Silva, J.L.; Minas da Piedade, M.F.; Duarte, M.T. Decavanadates: A building-block for supramolecular assemblies. Inorg. Chim. Acta 2003, 356, 222–242. [Google Scholar] [CrossRef]
  58. Nakamura, S.; Ozeki, T. Hydrogen-bonded aggregates of protonated decavanadate anions in their tetraalkylammonium salts. J. Chem. Soc. Dalton Trans. 2001, 472–480. [Google Scholar] [CrossRef]
  59. Nakamura, S.; Ozeki, T. Guest driven rearrangements of protonation and hydrogen bonding in decavanadate anions as their tetraalkylammonium salts. Dalton Trans. 2008, 6135–6140. [Google Scholar] [CrossRef] [PubMed]
  60. Kojima, T.; Antonio, M.R.; Ozeki, T. Solvent-driven association and dissociation of the hydrogen-bonded protonated decavanadates. J. Am. Chem. Soc. 2011, 133, 7248–7251. [Google Scholar] [CrossRef] [PubMed]
  61. Román, P.; Aranzabe, A.; Luque, A.; Gutiérrez-Zorrilla, J.M.; Martinez-Ripoll, M. Effects of protonation in decavanadates: Crystal structure of tetrakis(n-hexylammonium) dihydrogendecavanadate(V). J. Chem. Soc. Danton Trans. 1995, 2225–2231. [Google Scholar] [CrossRef]
  62. Fujio, K.; Ikeda, S. Size of spherical micelles of dodecylpyridinium bromide in aqueous NaBr solutions. Langmuir 1991, 7, 2899–2903. [Google Scholar] [CrossRef]
  63. Otwinowski, Z.; Minor, W. Processing of X-ray diffraction data collected in oscillation mode. Methods Enzymol. 1997, 276, 307–326. [Google Scholar] [PubMed]
  64. Sheldrick, G.M. SHELXT—Integrated space-group and crystal structure determination. Acta Crystallogr. Sect. A 2015, 71, 3–8. [Google Scholar] [CrossRef] [PubMed]
  65. Sheldrick, G.M. A short history of SHELX. Acta Crystallogr. Sect. A 2008, 64, 112–122. [Google Scholar] [CrossRef] [PubMed]
  66. CrystalStructure 4.2; Rigaku Corporation: Tokyo, Japan, 2017.
  67. Cruywagen, J.J. Protonation, oligomerization, and condensation reactions of vanadate(V), molybdate(VI), and tungstate(VI). Adv. Inorg. Chem. 1999, 49, 127–182. [Google Scholar]
  68. Brown, I.D.; Altermatt, D. Bond-valence parameters obtained from a systematic analysis of the inorganic crystal structure database. Acta Crystallogr. Sect. B 1985, 41, 244–247. [Google Scholar] [CrossRef]
  69. Desiraju, G.R.; Steiner, T. The Weak Hydrogen Bond. In Structural Chemistry and Biology; Oxford University Press: New York, NY, USA, 1999; pp. 12–16. [Google Scholar]
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Figure 1. Molecular structures of dodecylpyridazinium (C12pda) cation (left) and decavanadate (V10) anion (right).
Figure 1. Molecular structures of dodecylpyridazinium (C12pda) cation (left) and decavanadate (V10) anion (right).
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Figure 2. IR spectra of C12pda-V10 hybrids: (a) dark green C12pda-V10 hybrids synthesized at pH 6.0; (b) yellow C12pda-V10 hybrids synthesized at pH 4.0; (c) C12pda-V10 crystals obtained from the filtrate of the synthesis at pH 6.0.
Figure 2. IR spectra of C12pda-V10 hybrids: (a) dark green C12pda-V10 hybrids synthesized at pH 6.0; (b) yellow C12pda-V10 hybrids synthesized at pH 4.0; (c) C12pda-V10 crystals obtained from the filtrate of the synthesis at pH 6.0.
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Figure 3. Powder X-ray diffraction patterns of C12pda-V10 hybrids: (a) dark green C12pda-V10 hybrids synthesized at pH 6.0; (b) yellow C12pda-V10 hybrids synthesized at pH 4.0; (c) C12pda-V10 crystals obtained from the filtrate of the synthesis at pH 6.0; (d) Calculated pattern of C12pda-V10 crystals using the structure obtained by single-crystal X-ray diffraction.
Figure 3. Powder X-ray diffraction patterns of C12pda-V10 hybrids: (a) dark green C12pda-V10 hybrids synthesized at pH 6.0; (b) yellow C12pda-V10 hybrids synthesized at pH 4.0; (c) C12pda-V10 crystals obtained from the filtrate of the synthesis at pH 6.0; (d) Calculated pattern of C12pda-V10 crystals using the structure obtained by single-crystal X-ray diffraction.
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Figure 4. Crystal structure of C12pda-V10 (C: gray, N: blue, O: red, H: white); (a) packing diagram along b axis (upper) and c axis (lower). V10 anions in polyhedral representation. H atoms of C12pda and ethanol of crystallization are omitted for clarity. Some solvent molecules are highlighted; (b) molecular structure of diprotonated V10 anion. Another V10 anion is generated by the symmetry operation (1 − x, −0.5 + y, 0.5 − z). Symmetry code: (i) 1 − x, −0.5 + y, 0.5 − z; (c) molecular arrangements in the inorganic layers. V10 anions in polyhedral representation. The short contacts derived from O-H···O hydrogen bonds are represented in red broken lines. The C12pda cations and solvents of crystallization are omitted for clarity.
Figure 4. Crystal structure of C12pda-V10 (C: gray, N: blue, O: red, H: white); (a) packing diagram along b axis (upper) and c axis (lower). V10 anions in polyhedral representation. H atoms of C12pda and ethanol of crystallization are omitted for clarity. Some solvent molecules are highlighted; (b) molecular structure of diprotonated V10 anion. Another V10 anion is generated by the symmetry operation (1 − x, −0.5 + y, 0.5 − z). Symmetry code: (i) 1 − x, −0.5 + y, 0.5 − z; (c) molecular arrangements in the inorganic layers. V10 anions in polyhedral representation. The short contacts derived from O-H···O hydrogen bonds are represented in red broken lines. The C12pda cations and solvents of crystallization are omitted for clarity.
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Figure 5. View of crystallographically-independent surfactant molecules; (a) whole C12pda cations in the asymmetric unit together with V10 anion; (b) pyridazinium moieties of the C12pda cations in the vicinity of the V10 anions. The distances of short contacts are represented in Å unit. Symmetry code: (ii) 1 − x, 1 − y, 1 − z; (iii) x, 1.5 − y, 0.5 + z.
Figure 5. View of crystallographically-independent surfactant molecules; (a) whole C12pda cations in the asymmetric unit together with V10 anion; (b) pyridazinium moieties of the C12pda cations in the vicinity of the V10 anions. The distances of short contacts are represented in Å unit. Symmetry code: (ii) 1 − x, 1 − y, 1 − z; (iii) x, 1.5 − y, 0.5 + z.
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Figure 6. Conductive properties of the yellow C12pda-V10 hybrids; (a) Nyquist spectrum (open circles) at 373 K and simulated spectrum (red line) based on an equivalent electronic circuit in the figure. The parameters obtained by the fitting: Rb = 6.05 × 103 Ω, Rgb = 9.65 × 103 Ω, Rct = 1.1 × 103 Ω, Cb = 2.5 × 10−8 F, Cgb = 5.0 × 10−8 F, Cdl = 2.0 × 10−4 F, σ = 2.0 × 103 Ω s−1/2 (Zw = (1 − j)σ/(ω−1/2)); (b) temperature dependence of the conductivity; (c) Arrhenius plot of the conductivity. Least-squares fit is shown as a broken line. The fitted results are in the figure.
Figure 6. Conductive properties of the yellow C12pda-V10 hybrids; (a) Nyquist spectrum (open circles) at 373 K and simulated spectrum (red line) based on an equivalent electronic circuit in the figure. The parameters obtained by the fitting: Rb = 6.05 × 103 Ω, Rgb = 9.65 × 103 Ω, Rct = 1.1 × 103 Ω, Cb = 2.5 × 10−8 F, Cgb = 5.0 × 10−8 F, Cdl = 2.0 × 10−4 F, σ = 2.0 × 103 Ω s−1/2 (Zw = (1 − j)σ/(ω−1/2)); (b) temperature dependence of the conductivity; (c) Arrhenius plot of the conductivity. Least-squares fit is shown as a broken line. The fitted results are in the figure.
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Figure 7. Diffuse reflectance UV-vis spectra of C12pda-V10 hybrids: (a) dark green C12pda-V10 hybrids synthesized at pH 6.0; (b) yellow C12pda-V10 hybrids synthesized at pH 4.0.
Figure 7. Diffuse reflectance UV-vis spectra of C12pda-V10 hybrids: (a) dark green C12pda-V10 hybrids synthesized at pH 6.0; (b) yellow C12pda-V10 hybrids synthesized at pH 4.0.
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Table
Table 1. Crystallographic data of C12pda-V10 crystal.
Table 1. Crystallographic data of C12pda-V10 crystal.
CompoundC12pda-V10
Chemical formulaC66H124N8V10O30
Formula weight2019.16
Crystal systemMonoclinic
Space groupP21/c (No. 14)
a (Å)26.183(2)
b (Å)15.828(2)
c (Å)21.891(2)
α (°)90.0000
β (°)103.094(2)
γ (°)90.0000
V (Å3)8836.3(15)
Z4
ρcalcd (g cm−3)1.518
T (K)100(2)
Wavelength (Å)0.63000
μ (mm−1)1.045
No. of reflections measured249,472
No. of independent reflections35,308
Rint0.0740
No. of parameters1041
R1 (I > 2σ(I))0.0565
wR2 (all data)0.1652

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Misawa, T.; Taira, M.; Fujio, K.; Ito, T. Conductive Supramolecular Architecture Constructed from Polyoxovanadate Cluster and Heterocyclic Surfactant. Crystals 2018, 8, 57. https://doi.org/10.3390/cryst8020057

AMA Style

Misawa T, Taira M, Fujio K, Ito T. Conductive Supramolecular Architecture Constructed from Polyoxovanadate Cluster and Heterocyclic Surfactant. Crystals. 2018; 8(2):57. https://doi.org/10.3390/cryst8020057

Chicago/Turabian Style

Misawa, Toshiyuki, Minako Taira, Katsuhiko Fujio, and Takeru Ito. 2018. "Conductive Supramolecular Architecture Constructed from Polyoxovanadate Cluster and Heterocyclic Surfactant" Crystals 8, no. 2: 57. https://doi.org/10.3390/cryst8020057

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