POSS Ionic Liquid

Tanaka, Kazuo; Ishiguro, Fumiyasu; Chujo, Yoshiki

doi:10.1021/ja105631j

Cited by 158 publications

(146 citation statements)

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“…25,26 Thus, it is likely that the molecular distribution of the ion pairs that are tethered to the POSS core in the crystals remain the same after melting, meaning that a star-shaped structure might be maintained before and after melting. Based on these presumptions, we aimed to align the POSS molecules to form regular structures in the liquid phase.…”

Section: Resultsmentioning

confidence: 99%

“…During anion exchange, the 1-alkyl-3-methylimidazolium bromides were transformed to the hydroxide form, and the desired products were prepared via neutralization with POSS-(COOH) 8 . 25 After lyophilization, the products obtained were either colorless and transparent liquids or white solids. To prohibit coloration, all procedures were carried out without heating.…”

Section: Resultsmentioning

confidence: 99%

“…[10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] We recently reported the synthesis of POSS-based ILs, and we investigated their thermal properties. 25,26 By tethering multiple ion pairs composed of imidazolium cations and carboxylates to the vertices of POSS cores or by simply adding POSS molecules with acid groups, the melting temperatures of the ion pairs decreased and their thermal stabilities increased. [25][26][27][28] In the crystalline state, the POSS core can isolate each ion pair.…”

Section: Introductionmentioning

confidence: 99%

“…25,26 By tethering multiple ion pairs composed of imidazolium cations and carboxylates to the vertices of POSS cores or by simply adding POSS molecules with acid groups, the melting temperatures of the ion pairs decreased and their thermal stabilities increased. [25][26][27][28] In the crystalline state, the POSS core can isolate each ion pair. As a result, the intermolecular interactions are reduced, and thus the melting temperatures are decreased.…”

Section: Introductionmentioning

confidence: 99%

“…Finally, we reported on the synthesis of room temperature ILs using POSS. 25 Our interests have shifted, and we would like to exploit the thermal properties of POSS for realizing optical materials. In particular, we aim to construct unique optical materials based on SILP materials that utilize the structural features of POSS.…”

Section: Introductionmentioning

confidence: 99%

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POSS ionic liquid crystals

et al. 2015

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Here we report the use of unique organic − inorganic hybrid materials composed of octa-substituted polyhedral oligomeric silsesquioxane (POSS) cores as ionic liquid (IL) crystals. These materials have a wide temperature range in which they exist in liquid crystal (LC) phase because of the stabilizing effect of the POSS core. We synthesized ion pairs composed of alkyl chainsubstituted imidazolium and carboxylates of various lengths that were or were not connected to the POSS core; then the thermal properties of these materials were investigated. It was found that both ion salts and the octadecyl-substituted imidazolium ion pairs with or without connection to POSS could form LCs. Interestingly, the LC phase of the POSS-tethered ion salts was maintained until decomposition. In contrast, the octadecyl-substituted imidazolium ion salts that were not tethered to the POSS core showed a clearance point during heating. The highly symmetric structure of POSS contributes not only to the suppression of the molecular motion of the ion salts, but also results in the formation of regular structures, leading to thermally stable, thermotropic IL crystals. In addition, by using electrostatic interactions originating among ionic moieties, robust chiral structures can be produced. 3,4 Even a small quantity of chiral ionic sources can efficiently induce enantiomeric structures in a bulk sample, and ionic moieties can be assembled to form regularly ordered structures. 5,6 These well-ordered ionic moieties are expected to work as efficient cation carriers and scaffolds for ordering cations. These materials, which comprise closely assembled ionic species, can exhibit interesting optical and magnetic properties. Thus, new molecular designs for preparing thermally stable LCs composed of ionic species are needed to produce advanced functional materials.The concept of supported IL phases (SILPs) has been recently proposed. Several materials based on SILPs have exhibited important characteristics such as high ion conductivity and compatibility with organic reaction media; these materials have been used as templates for the formation of nanostructures. 1 Silica supports improve the thermal stability of LCs. 7,8 Carmichael et al. 9 have synthesized and explored silicon wafer-assisted SILP materials. They created layers with thicknesses between 10 and 21 nm of an ionic LC with [C 18 C 1 Im] [PF 6 ] on the planar wafer surface and found that the ionic LC formed a mesophase. Inspired by their work, Wasserscheid et al. 7 fabricated SILP materials using silicon nanoparticles and used them as supports for preparing mesoporous structures that could act as effective gasphase catalysts. 8 To construct advanced materials based on the concept of SILP materials, their properties must be fine-tuned according to preprogramed designs at the molecular level. A wide variety of

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%