The direct evidence of confined water ("water pocket") inside hydrophilic room-temperature ionic liquids (RTILs) was obtained by complementary use of small-angle X-ray scattering and small-angle neutron scattering (SAXS and SANS). A large contrast in X-ray and neutron scattering cross-section of deuterons was used to distinguish the water pocket from the RTIL. In addition to nanoheterogeneity of pure RTILs, the water pocket formed in the water-rich region. Both water concentration and temperature dependence of the peaks in SANS profiles confirmed the existence of the hidden water pocket. The size of the water pocket was estimated to be ∼3 nm, and D2O aggregations were well-simulated on the basis of the observed SANS data.

Radical photocrosslinking polymerizations of functional acrylate derivatives are achieved in a chiral smectic C liquid crystal (SC *-LC) used as an asymmetric medium to synthesize helical network polymers (HNPs) with thermally and chemically stable chiroptical properties that are represented by circularly polarized luminescence (CPL). Two types of acrylate derivatives that bear an LC moiety and a fluorene moiety as luminophores are synthesized and used as functional monomers for photocrosslinking polymerizations. A trisubstituted acrylate derivative is used as a crosslinker to enhance the amount of photocrosslinking to produce a spatially linked network structure of polymers. The synthesized HNPs show a striated fan-shaped texture that is characteristic of the SC *-LC, and they exhibit notable Cotton effects owing to their circular dichroism in the absorption and luminescence processes. The CPL of the (R)- and (S)-HNP films shows considerably high dissymmetry factors (|g lum|) of 2.4 × 10–2 and 2.5 × 10–2, respectively. The CPL further increases in intensity by more than 4 times after heating the HNP film at 150 °C to provide |g lum| values of 1.0 × 10–1 and 1.1 × 10–1 for (R)- and (S)-HNP films, respectively. This increase in CPL intensity is ascribed to the thermally stimulated progress of the crosslinking between the monomers that still remain unreacted during photopolymerization at room temperature, thus leading to the completion of the helical network in the HNP film. The higher structural order of the HNP films prepared with the SC *-LC than those prepared with a chiral nematic LC (N*-LC) is confirmed through X-ray diffraction measurements. The present work is the first successful asymmetric polymerization using the SC *-LC as a chiral medium.

Ionic liquids bearing both liquid crystallinity and chirality are potentially applicable for chiral electrochemical syntheses and polymerizations. In this study, two types of chiral nematic liquid‐crystalline ionic liquids (N*‐LCILs) are developed to achieve asymmetric electrochemical polymerization without a supporting electrolyte and even a chiral dopant. N*‐LCILs are prepared i) by adding an axially chiral binaphthyl derivative as an external chiral dopant to imidazolium cation–based LCILs or ii) by incorporating a chiral binaphthyl phosphate as a counter anion in LCILs. Helical poly(3,4‐ethylenedioxythiophene) (H‐PEDOT) films are successfully synthesized through electrochemical polymerization of a dimer‐ or trimer‐type 3,4‐ethylenedioxythiophene (EDOT) monomer in an N*‐LCIL, where N*‐LCIL plays the role of both an asymmetric solvent and a supporting electrolyte. H‐PEDOT films have helically π‐stacked structures of conjugated chains and spiral morphologies consisting of one‐handed screwed fibril bundles. The plausible mechanism of the asymmetric electrochemical polymerization of EDOT in N*‐LCIL is proposed to elucidate the correlation of helical sense between the helically π‐stacked chains, screwed fibril bundles, and N*‐LCIL. The two present types of N*‐LCILs are the first to enable supporting electrolyte–free asymmetric electrochemical polymerization, and they have potential applications in various types of chiral electrochemical syntheses, expanding the potential utility of ionic liquids.

catalysts, and chiral liquid crystal (LC) solvents. [13-15] In particular, the third method using a chiral LC solvent as an asymmetric reaction field is facile and versatile because it requires neither chiral monomers nor chiral catalysts, and furthermore, the helicity of the resultant conjugated polymer is strictly controlled by the chirality of the LC reaction field. [8,16] The preparation of a chiral LC is achieved by adding the chiral compound to an achiral host LC. If the chirality of the LC is inverted and/or controlled by an external stimulus, such as temperature [17-24] or photoirradiation, [25-34] only one LC with a chiroptical configuration is required. This condition significantly reduces the synthesis time and reduces the cost of reagents. Very recently, thermally invertible chiral LCs have been developed and used for interfacial chemical polymerizations of acetylene to afford helicity-controlled helical polyacetylene films. [35] However, no photoinvertible chiral LC exhibiting the chemical stability needed to serve as a solvent for chemical or electrochemical polymerization has been reported to date. [36-39] Previously, we synthesized a photoresponsive chiral compound by substituting two axially chiral binaphthyl moieties at both terminal sites of a photochromic dithienylethene moiety and used it as a chiral dopant to prepare a photocontrollable N*-LC. [26] Although the helical sense of the N*-LC was inverted by irradiation with UV and visible light, the fatigue resistance and helical twisting power (HTP) of the N*-LC were insufficient for the use of asymmetric polymerization. Meanwhile, poly(3,4-ethylenedioxythiophene) (PEDOT) is regarded as a versatile functional conjugated polymer because of its high conductivity due to its low bandgap, optical transparency, and electrochemiluminescence. [40-47] It is of keen interest to introduce helicity into PEDOT to develop uncultivated chiroptical properties and functions. In fact, helical PEDOT (H-PEDOT) is useful as a carbonization precursor for helical carbon and graphite bearing spiral morphology. [11,48] We previously reported the synthesis of H-PEDOT by electrochemical polymerization of EDOT in N*-LCs or LC-based ionic liquids that include ordinary chiral compounds. [11,48-50] However, two types of chiral compounds with opposite helicity were needed because these chiral compounds had neither thermally invertible nor photoinvertible helical senses. Photoinvertible chiral compounds are synthesized by linking a photoresponsive bisbenzothienylethene moiety with an axially chiral binaphthyl moiety and used as chiral dopants to prepare a photoinvertible chiral nematic liquid crystal (N*-LC) field. Subsequently, electrochemical polymerizations of ethylenedioxythiophene (EDOT) in the N*-LC field to synthesize helical poly(ethylenedioxythiophene)s (H-PEDOTs) are achieved. The H-PEDOTs show not only spiral morphologies resembling the fingerprinted texture of N*-LC in polarizing optical microscope but also bisignate Cotton effects in circular dichroism spectra, in...

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