Ionic Liquid-Supported Photocatalysts: A Reusable Environmentally Friendly Oxidation Reaction System That Uses Air and Light.

Ionic liquids are used in various fields due to their unique physical properties and are widely utilized as reaction solvents in the field of synthetic organic chemistry. We have previously proposed a new organic synthetic method in which the catalyst and reaction reagents are supported on ionic liquids. This method has various advantages, such as the ability to reuse the reaction solvent and catalyst and its facile post-reaction treatment. In this paper, we describe the synthesis of an ionic liquid-supported anthraquinone photocatalyst and the synthesis of benzoic acid derivatives using this system. This synthesis of benzoic acid derivatives via the cleavage of vicinal diols by an ionic liquid-supported anthraquinone photocatalyst is an environmentally friendly process, and furthermore, it has a simple post-reaction process, and the catalyst and solvent can both be reused. To the best of our knowledge, this is the first report on the synthesis of benzoic-acid derivatives via the cleavage of vicinal diols using light and an ionic-liquid-supported catalyst.

Epoxidation of olefins using diaryltellurium dicarboxylates.

This paper reports an efficient method for the epoxidation of a variety of functionalized olefins using diaryltellurium dicarboxylates as hypervalent tellurium compounds. This method is able to efficiently convert olefins into epoxides using catalytic amounts of tellurium and urea hydrogen peroxide. Furthermore, we propose that this reaction proceeds via the formation of peroxides of phenol, carboxylic acid, and tellurium peroxide when diaryltellurium dicarboxylates and hydrogen peroxide react. This is the first example of an epoxidation reaction using hypervalent tellurium compounds.

Bis(2,6-diisopropylphenyl) tellurone: a well-defined monomeric diorganotellurone without cocrystallized solvents and without stabilizing intramolecular contacts.

Only two crystal structures of diorganotellurones have been reported to date, both of which contain cocrystallized solvents and one of which is stabilized by intramolecular Te-N secondary bonding interactions. This work describes the crystal structure of bis(2,6-diisopropylphenyl) tellurone, (C12H17)2TeO2 or C24H34O2Te, the first well-defined diorganotellurone without cocrystallized solvents and without stabilizing intramolecular contacts. The molecule has crystallographic twofold symmetry, with half the molecule as the asymmetric unit. The molecular structure is compared to previously reported tellurones and those computed at the density functional theory DFT/B3PW91 level. The molecules form two-dimensional layers as a result of a weak intermolecular hydrogen-bonding network. The layers are then stacked in an antiparallel manner to form the crystal packing structure. The Hirshfeld surface analysis was employed to visualize and quantify the intermolecular contacts in the molecular crystal structure, and the contribution of O...H and H...H interactions was found to be the dominating factor.

One-pot synthesis, structural analysis, and oxidation applications of a series of diaryltellurium dicarboxylates.

This paper presents a concise and efficient one-pot synthesis of a variety of functionalized diaryltellurium dicarboxylates. The method is based on a mild photosensitized oxygenation of cheap and readily available carboxylic acids. The molecular structures of the diaryltellurium dicarboxylates were determined unambiguously using single-crystal X-ray diffraction analysis. The thus obtained diaryltellurium dicarboxylates were used to study the oxidation of benzoin derivatives.

Dimensional Control in Polyoxometalate Crystals Hybridized with Amphiphilic Polymerizable Ionic Liquids.

Ionic liquids are an important component for constructing functional materials, and polyxometalate cluster anion is a promising partner for building inorganic-organic hybrid materials comprising ionic liquids. In such hybrid materials, the precise control of the molecular arrangement in the bulk structures is crucial for the emergence of characteristic functions, which can be realized by introducing an amphiphilic moiety into the ionic liquids. Here, an amphiphilic polymerizable imidazolium ionic liquid with a methacryloyl group was firstly hybridized with polyoxometalate anions of octamolybdate ([Mo8O26]4-, Mo8) and silicotungstate ([SiW12O40]4-, SiW12) to obtain inorganic-organic hybrid crystals. The polymerizable ionic liquid with a octyl chain (denoted as MAImC8) resulted in the formation of anisotropic molecular arrangements in the bulk crystal structure, which was compared with the hybrid crystals composed from the polymerizable ionic liquid without a long alkyl chain (denoted as MAIm). Rather densely packed isotropic molecular arrangements were observed in the hybrid crystals of MAIm-Mo8 and MAIm-SiW12 due to the lack of the amphiphilic moiety. On the other hand, using the amphiphilic MAImC8 cation gave rise to a honeycomb-like structure with the Mo8 anion and a layered structure with the SiW12 anion, respectively.

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.

Conductive Hybrid Crystal Composed from Polyoxomolybdate and Deprotonatable Ionic-Liquid Surfactant.

A polyoxomolybdate inorganic-organic hybrid crystal was synthesized with deprotonatable ionic-liquid surfactant. 1-dodecylimidazolium cation was employed for its synthesis. The hybrid crystal contained δ-type octamolybdate (Mo8) isomer, and possessed alternate stacking of Mo8 monolayers and interdigitated surfactant bilayers. The crystal structure was compared with polyoxomolybdate hybrid crystals comprising 1-dodecyl-3-methylimidazolium surfactant, which preferred ß-type Mo8 isomer. The less bulky hydrophilic moiety of the 1-dodecylimidazolium interacted with the δ-Mo8 anion by N-H···O hydrogen bonds, which presumably induced the formation of the δ-Mo8 anion. Anhydrous conductivity of the hybrid crystal was estimated to be 5.5 × 10(-6) S·cm(-1) at 443 K by alternating current (AC) impedance spectroscopy.

Ionic liquid-phase synthesis of 1,5-disubstituted 1,2,3-triazoles.

A simplified ionic liquid-phase synthesis of 1,5-disubstituted 1,2,3-triazole was developed. Nineteen 1,5-disubstituted 1,2,3-triazoles were successfully obtained by merely washing the ionic liquid phase with ether, thus avoiding the need for intermediate purification.