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Thiophene–thiophene copolymers composed of 3-alkylthiophene and a small amount of thiophene bearing cyclic siloxane are synthesized by random copolymerizatin of 2-chloro-3-dodecylthiophene and 2-chlorothiophene bearing cyclic tetrasiloxane as a substituent. Deprotonative metalation of chlorothiophenes with a bulky magnesium amide followed by the addition of nickel catalyst undergoes polymerization to afford statistical copolymer based on the feed ratio. The copolymer bearing a small amount of (1–10%) cyclic siloxane is subjected to the formation of thin film. The treatment of the obtained thin film with an acid vapor results in the formation of film insoluble in any solvent through the formal networking of poly(3-dodecylthiophene) by the effect of a small amount of cyclic siloxane moiety. The measurement of electric properties reveals improved conductivities to 10(6) fold higher than before the acid treatment.

The synthesis of 1,1-difluoro-1-alkenes was achieved by the treatment of dithioesters and thioketones with trimethylsilyl 2-fluorosulfonyl-2,2-difluoroacetate in the presence of a proton sponge cat...

The low dielectric constants of organic semiconductors, relative to those of inorganic materials, are an intrinsic limitation. Improving the dielectric constant is important for the development of ...

This article reports production protocols for nanographenes and the effect of the reaction conditions on their structures and optical properties. These fundamental studies are of value for explorin...

This account highlights the development of efficient methods for generation of alkyl radicals from organosilicon peroxides and their applications in selective alkylation reactions. Compared with co...

The selective reduction of α,β-unsaturated carbonyl compounds was achieved to produce saturated carbonyl compounds with aqueous HI solution. The introduction of an aryl group at an α or β position ...

Graphene nanoribbons (GNRs), which are narrow and elongated strips of graphene, enable the formation of a more interconnected pore structure than two-dimensional graphenes. In this work, hydrated G...

The new and versatile method for the synthesis of integrastatin core has been developed by the use of o-toluic acid and 2′-hydroxyacetophenone with NaH/sec-BuLi, followed by the reaction of dihydro...

An isolated cluster of 32 ammonia (NH3) molecules was simulated at 50 and 100 K by the ab initio fragment molecular orbital based molecular dynamics (FMO-MD) method to analyze the effect of electro...

The versatility of the synthesis of sulfonated aromatic polymers using NiBr2 was investigated. The copolymerization of sulfo-dichlorobenzene protected with a neopentyl group was carried out with ch...

Hydrogen adsorption/desorption properties of magnesium oxalate and calcium oxalate (M(ox); M = Mg2+ and Ca2+) were measured at selected temperatures between 77 K and 200 K. The hydrogen uptake amou...

In this study, the hydrolytic condensation of 3-(2-aminoethylamino)propyltrimethoxysilane and 3-aminopropyltrimethoxysilane was performed using aqueous trifluoromethanesulfonic acid (HOTf) as a cat...

Absorption properties of 13 bisazomethine dyes in a crystalline state were studied by optical waveguide spectroscopy. Their solid-state absorption spectra were found to shift bathocromically relative to those in solution with no remarkable change in a spectral shape. The observed spectral shifts were characterized in terms of two intermolecular interactions, conformational change and exciton interaction, on the basis of the crystal structure. Solid-state fluorescence properties of the diethylamino derivatives were also examined for their electronic characterization. The characteristic two-dimensional staircase structure, one of the proposed structures of J-aggregates, was found to play a significant role in the bathochromic spectral shift of all the bisazomethine derivatives.

Dehydration and rehydration behavior of a layered double hydroxide (LDH), Mg2Al(OH)6.2Cl0.8·nH2O, was investigated. The dehydration proceeds in two steps; at first interlayer water is released from 50 °C, then dehydration condensation of hydroxyl groups starts from 300 °C. Interlayer anion Cl− is also desorbed as HCl during the second dehydration. The mole fraction of water removed by dehydration before the HCl desorption was estimated by thermogravimetric analysis; 1.85 mol-H2O/mol-LDH. The dehydrated material, without HCl loss, was quantitatively hydrated by refluxing in water for 480 min.

This article describes the full details of our reductive approach to nitrones from amides. Reduction of N-siloxyamides with the Schwartz reagent [Cp2ZrHCl], followed by addition of an acid provided functionalized nitrones. The developed conditions were then extended to a catalytic version with the Vaska complex [IrCl(CO)(PPh3)2] and (Me2HSi)2O starting from N-hydroxyamides. 1H NMR studies of the Ir-catalyzed reaction revealed that the developed conditions promoted two different types of catalytic reactions including dehydrosilylation of an N-hydroxyl group and subsequent hydrosilylation of an amide carbonyl. A salient feature of our methods is their high chemoselectivity in the presence of a variety of functional groups. In addition, our reductive methods enabled concise synthesis of cyclic and macrocyclic nitrones, which are known to be challenging compounds to access by conventional methods.

The structure and electronic features of neutral and positively charged pyrene and perylene derivatives were explored. The radical cation of 1,3,6,8-tetraarylpyrene 1 was examined by ESR, UV-vis-NIR spectroscopy and theoretical calculations. The addition of 2 equiv of oxidant to 1 resulted in the formation of dication 12+. The single-crystal X-ray structure of 12+ proved that the aromatic part relocates from biphenyl unit to naphthyl unit upon 2e- oxidation of 1. We have also investigated the oxidation processes of 3,9-diarylperylene 2 and 3,10-diarylperylene 3. The radical cations of 2・+ and 3・+ showed ESR signals and the spin densities were proven to delocalize at 3,4,9,10-positions. In the case of doubly charged 3,9-diarylperylene, we could find the anthracene structure in the core, while the phenanthrene skeleton appeared in two-electron oxidized 3,10-diarylperylene. Finally we validated this phenomenon to apply for the higher analogue terrylene, discovering its large aromaticity relocation upon the 2e- oxidation.

We investigated stable radical distribution and particle tracks in sucrose irradiated by C ion irradiation with continuous wave (CW) electron paramagnetic resonance (EPR) and 9 GHz EPR imaging. Both EPR results were compared with X–ray irradiation at a similar dose. Radical distribution in sucrose crystals induced by C ion and X–ray irradiation were completely different. The 2D EPR imaging results suggested that radical species were mostly located inside the sucrose crystal. Fewer radicals were found on the surface region of the sucrose crystal. The high radical intensities in relation to the C ion energy deposition are clearly observed at Bragg peak region. No trace of the stable radicals was found after the peak region. The stable radicals of sucrose were distributed as results of recombination of radicals induced by particle interaction. For the first time, the present EPR images showed the stable radical distribution and particle tracks in the crystal in association with particle-sucrose interaction.

Much interest has been paid to the origin of homochirality, such as that of l-amino acids. The proposed origins of chirality have usually induced only low enantiomeric excess. Thus, asymmetric amplification by asymmetric autocatalysis has been invoked. Asymmetric autocatalysis of 5-pyrimidyl alkanol in the enantioselective addition of diisopropylzinc to pyrimidine-5-carbaldehyde is a unique example of amplification of chirality. Crystallization of possible intermediates, specifically zinc alkoxides of this 5-pyrimidyl alkanol, was investigated to obtain mechanistic insights into this reaction. Single-crystal X-ray crystallography of the formed zinc alkoxide crystals shows the existence of tetramer or higher oligomer structures in this asymmetric autocatalytic system.

Pigments in the printing inks employed for Japanese hand-engraved stamps, the first issues of Japanese postage stamps, were analyzed and characterized by means of FTIR, Raman, and XRF spectroscopy....

We examined intermolecular hydrogen-bonding interactions of pyrene derivatives bearing a urea unit, referred to as 1PUP (one pyrenyl group) and 1DPU (two pyrenyl groups). 1DPU showed a new emission...

Optical properties of three crystal modifications of 5-t-butyl-2,3-dicyano-6-[4-(dimethylamino)styryl]pyrazine having different color appearances were measured and interpreted on the basis of crystal structure analysis. Two of the three modifications exhibited a bathochromic spectral shift both in absorption and fluorescence compared with those in a toluene solution of the dye. The crystal structure analysis revealed that a two-dimensional brick-wall structure is formed in both modifications. In contrast, the third modification showed a hypsochromic absorption shift with a large bathochromic fluorescence shift. The crystal structure of this modification was characterized by a one-dimensional stacked molecular column. The optical characteristics of the three modifications were qualitatively interpreted in terms of excitonic intermolecular interaction on the basis of their crystal structures.

The reactions of [MoII2(OAc)4] (OAc−: acetato) with catecholato derivatives (R-Cat2−), possessing electron-donating t-Bu groups (3,6-DTBCat2−) or electron-withdrawing Br groups (Br4Cat2−), results ...

[60]Fullerene assembly films consisting of C60 and 1,2-diaminoethane (ethylenediamine) were easily fabricated on an amino-group-modified substrate by an alternate immersion process. The C60-assembl...

Organic electron-accepting materials with light absorbance and wide absorption bands are sorely needed as alternatives to fullerene derivatives for organic electronics, in particular for organic ph...