Various types of main group element-containing π-electron systems have been synthesized using silole, dibenzoborole, or bis-silicon-bridged stilbene as the key building units. In these π-electron systems, the orbital interaction between the main group element moiety and the π-conjugated framework, such as p_π–π* and σ*–π* conjugation, plays a crucial role in determining their characteristic electronic structures and makes them promising materials for applications in organic electronics and optoelectronics.

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The quality of human life depends to a large degree on the availability of energy sources. The present annual worldwide energy consumption has already attained a level of over 400 exajoules and is expected to further augment steeply from the increase in world population and the rising demand of energy in the developing countries. This implies enhanced depletion of fossil fuel reserves leading to further aggravation of the environmental pollution. Quality of life on earth is threatened unless renewable energy resources can be developed in the near future. Chemistry is expected to make important contributions to identify environmentally friendly solutions of the energy problem. One attractive strategy discussed in this article is the development of systems that mimic natural photosynthesis in the conversion solar energy. The task to be accomplished by these systems is to harvest sunlight and convert it to electricity or drive an uphill chemical reaction. Learning from the concepts used by green plants, we have developed a molecular photovoltaic device whose overall efficiency for solar energy conversion to electricity has already attained 11%. The system is based on the sensitization of nanocrystalline oxide films by charge-transfer sensitizers. The underlying fundamental processes of light trapping by the sensitizer, heterogeneous electron transfer from the electronically excited chromophore into the conduction band of the semiconductor oxide and the percolative migration of the injected electrons through the mesoporous film to the collector electrode, will be described below in detail. The low cost and ease of production of the new cell should benefit large scale applications. These systems will undoubtedly promote the acceptance of renewable energy technologies, not least by setting new standards of convenience and economy. The nanocrystalline semiconductor junctions developed first for dye sensitized solar cells have meanwhile found a realm of other applications ranging from electrochromic and electroluminescent displays to high power lithium insertion batteries. They are also used in tandem cells for the cleavage of water into hydrogen and oxygen by sunlight.

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Prism-shaped CuSeO₃·2H₂O single crystals, with sizes of 0.64–0.77 × 0.45–0.67 × 0.26–0.33 mm, were synthesized via a new hydrothermal reaction of CuCl₂·2H₂O and Se powder in aqueous ammonia at 180 °C. The double crystal X-ray diffraction rocking curve shows that the single crystals have high quality. And optimum conditions for the growth of CuSeO₃·2H₂O single crystals are discussed.

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A convenient —and quick to realize— approach for the synthesis of an ultrathin overlayer of CaCO₃ on TiO₂ thin films is suggested. Since dye-sensitized photoelectrochemical investigations on CaCO₃-thin-layer-coated TiO₂ nanoporous films are hitherto unreported, we performed such investigations by sensitizing our TiO₂–CaCO₃ films with tetrabutylammonium cis-di(thiocyanato)-N,N′-bis(4-carboxylato-4′-carboxylic acid-2,2′-bipyridine)ruthenate(II) and achieved power conversion efficiencies over 9.3% under illumination of AM 1.5 simulated sunlight (95 mW/cm²).

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A novel distorted square-pyramidal N₂S₃-type Co(III) complex with a vacant site was synthesized as an active center model of nitrile hydratases (NHases) and characterized by UV–vis and ¹H NMR spectroscopic and X-ray analyses. The electronic absorption spectra were characteristic of a five-coordinate structure in organic solvents such as acetonitrile, while the complex in an aqueous solution gave different spectrum characteristic of a six-coordinate octahedron. These results suggest that the coordination of a water molecule is a key for the hydration of nitrile compound in the NHases.

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Large-area, high-filling rate, uniform, and single-crystal Ni₅Zn₂₁ nanowire arrays have successfully been synthesized by dc electrodeposition into the nanochannels of anodic alumina membranes (AAM).

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In the presence of acetonitrile and NaOH, when H₂O₂ was added to the solution containing chlorophyll, it was found that a strong chemiluminescence (CL) was emitted. The blue light was emitted with the decomposition of chlorophyll. It is considered that the emitter contains the decomposition products of chlorophyll based on the following measurement results, such as the reduction of absorbance for chlorophyll and the difference of the spectral form between fluorescence and CL. The CL of the chlorines, such as chlorophyll, and the porphyrin analogue compounds were compared under the same conditions. Consequently, the obtained CL was strong in the chlorin complex which contains Mg or Zn. On the other hand, the CL was not strongly observed with porphyrin compounds. In the chlorophyll CL, when the chlorin ring is oxidized by the generated •O₂⁻, the excited molecule would be produced in the process of ring cleavage, and then CL is emitted to the outside.

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A novel highly viscous hydrogel electrolyte with high proton conductivity was prepared via hydration of zinc metaphosphate glass powders. The hydrogel showed a high electrical conductivity of ≈5 mS cm⁻¹ at room temperature due to proton hopping between P–OH groups and water molecules. The hydrogel exhibited a low self-discharge rate. Chronoamperometric measurements indicated that the hydrogel has fast charge-discharge capability.

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By introducing specific RNA–protein interaction into ribosome display method, further stabilization of RNA–ribosome–protein complex was achieved. The amount of mRNA of interest recovered after one round of selection correlates with the strength of RNA–protein interaction. This noncovalent but strong interaction should provide a simple and effective strategy for selections of functional proteins from large libraries.

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A facile one-pot synthesis of terminal alkynes was achieved by microwave irradiation of a mixture of anti-3-aryl-2,3-dibromopropanoic acids, Et₃N and DMF and subsequent irradiation in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). This method requires short reaction time (1–2 min) and gives terminal alkynes in high yields.

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Silver nanowires in large quantities can be obtained through a simple method in the absence of a surfactant or polymer and without addition of external seeding nanocrystallites. A plausible mechanism was proposed to elucidate the formation mechanism of silver nanowires based on TEM studies.

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The synthesis of DHOT-TTP, in which one sulfur atom of BDH-TTP [2,5-bis(1,3-dithiolan-2-ylidene)-1,3,4,6-tetrathiapentalene] is substituted by oxygen, has been accomplished. The DHOT-TTP donor possesses a less planar molecular structure than BDH-TTP, and gives a metallic AuI₂ salt stable down to 1.4 K, the crystal structure of which is elucidated.

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The adsorption behavior of a crosslinked lignophenol gel for various metal ions from chloride medium was investigated. The gel was found to be only effective for the adsorption of Au(III) from weak to strong acidic medium. The analysis of XRD-spectrum and SEM-images of the adsorbent after adsorption revealed the formation of elemental gold by the reduction of the Au(III) ion. Such a result is promising for the development of a recovery system for gold from various industrial wastes.

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The intramolecular electron transfer (ET) between the type 1 Cu and the type 2 Cu in the Cys114Ala mutant of Hyphomicrobium denitrificans nitrite reductase has been observed by pulse radiolysis. At pH 5.4–7.0, the ET rates of C114A having one type 1 Cu and one type 2 Cu per monomer are 10⁴–10⁵ times as large as those of the native enzyme containing two type 1 Cu sites and one type 2 Cu site.

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Drastic conformational change of J-aggregate of 5,10,15, 20-tetrakis(4-sulfonatophenyl)porphyrin (H₂TPPS) was observed by addition of nonionic surfactant (Triton X-100) in acidic medium. The CD spectra of the aggregate (H₄TPPS)_n changed to opposite signed CD spectra in the presence of Triton X-100. The interaction of (H₂TPPS)_n with Triton X-100 was studied by the measurements of UV–vis and fluorescence spectra as well as CD spectra at different concentrations of Triton X-100.

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Schizophyllan binds 1,4-bis(p-amidophenyl)butadiyne and acts as a one-dimensional host to produce fibrous polydiacetylene assemblies through UV-irradiation.

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Polyaniline hollow microspheres with conductivity of 9.7 × 10⁻³ S/cm were synthesized with alkali-guided method. The alkali (NaOH)-guided oxidation of aniline with ammonium peroxydisulfate as well as doping sulfate anion onto polyaniline.

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Q₂[Mo^IVO{1,2-S₂-3,6-(Ph₃CCONH)₂C₆H₂}₂] (Q = NEt₄ (1), PPh₄ (2)) was synthesized and characterized as a model for Mo-enzymes. The crystal structure of 2 shows the slightly distorted square pyramidal core, Mo^IVOS₄. The O-atom transfer reaction from Me₃NO to Me₃N in the presence of 1 proceeds at 30 to 48 times higher rates than in the presence of [Mo^IVO{1,2-S₂-(C₆H₄)}₂]²⁻ (3).

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It is found that helical structures can be formed by a simple achiral fatty acid, oleic acid, in the pH range of 8.0–8.1 at room temperature. Moreover, we succeeded in the first observation of spontaneous dynamics of these helical aggregates in water by optical microscopy.

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Carbon nanotubes (CNTs) have been synthesized over Ni–MgO and Ni–Sm–Mg catalysts by decomposition of CH₄ at 923 K. The addition of Sm into Ni–MgO catalyst promotes its catalytic activity and lifetime. The yield of CNTs obtained over the optimized Ni–Sm–Mg catalyst reaches 1260 wt % relative to the weight of the catalyst, which is more than 4 times that of the Ni–MgO catalyst. The possible interaction between Sm and Ni species is discussed.

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Nanocrystalline CrN was synthesized via thermal reduction–nitridation route by the reaction of CrCl₃ with NH₄Cl and Na in an autoclave at 400 °C. X-ray powder diffraction pattern indicated that the product was cubic CrN. An atomic ratio of Cr to N of 1.08:1 was determined from X-ray photoelectron spectra. Transmission electron microscopy image showed that the sample consisted of particles with the diameters of 20–40 nm.

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Tellurium fibers are first synthesized through the reduction of Na₂TeO₄ by hydrazine hydrate. The as-prepared tellurium fibers are used as templates for further reaction with aqueous AgNO₃ solution to get Ag₂Te fibers at room temperature.

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Photophysical and photocatalytic properties of Cs₂Nb₄O₁₁ consisting of NbO₆ octahedra and NbO₄ tetrahedra were investigated. The band gap of Cs₂Nb₄O₁₁ was 3.7 eV. Broad blue photoluminescence was observed at 77 K. Pretreated NiO-loaded Cs₂Nb₄O₁₁ showed a high activity for water splitting under UV-light irradiation.

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1,3,5-Tris[4-trifluoromethanesulfonyloxy-3-(trimethylsilyl)phenyl]benzene (1), a trisaryne equivalent, was synthesized. The Diels–Alder reaction or the palladium-catalyzed hexasilylation by use of 1 gave modest to excellent yields of diverse polyaromatic hydrocarbons straightforwardly.

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Spherical particles with α-quartz single crystal were obtained from amorphous silica by heating in the atmospheric pressure. The silica particles containing a small amount of titanium oxide and calcium oxide were prepared from metal alkoxides and then were heated at 1000 °C in the atmospheric pressure. The resulting particle was determined to be a single crystal by means of a transmission electron microscopy and electron diffractometry.

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The hybrid reaction system composed of supercritical carbon dioxide and room temperature ionic liquid based on symmetric tetraalkyl ammonium salts can effectively promote the carbon dioxide fixation from aziridine to 2-oxazolidinone in the presence of iodine in high yield of 98% within 5 min. The TOF value under this condition is 254 times larger than that using conventional organic solvent.

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A new thiocyanate selective PVC membrane electrode was prepared by using a tricoordinate dimethylaminobenzaldehyde Schiff base copper(II) complex as neutral carrier, which demonstrates highly selectivity response to thiocyanate with substantially improved performance such as long lifetime, wide potentiometric response range, and low detection limit.

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Photochromic 2-aryl-3-(1-propenyl)maleic anhydride derivatives were synthesized by one pot synthesis and their photochromic performance was examined in solution.

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The intramolecular photocycloaddition of a 1-cyanonaphthalene derivative in microreactors made of poly(dimethylsiloxane) (PDMS) was examined. By using the microreactors and flow system, both the efficiency and regioselectivity increased compared with those under batch conditions.

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The titled tetraselenanaphthalene derivative (BEDO-TSeN) has been synthesized using the reaction of 1,4-dioxene-2,3-diselenolate with tetraiodo- or tetrabromoethylene. The structure of this tetraselenanaphthalene derivative was confirmed by X-ray analysis. The π-donor property of this molecule was determined by CV analysis.

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The dechlorination of polyvinylchloride (PVC) powder initially progressed on an apparent zero order reaction, and proceeded in higher dechlorination range by an apparent first order reaction. The apparent activation energies indicate that the rate of the dehydrochlorination is controlled by the chemical reaction at low temperature, but that from 300 to 400 °C is controlled by heat transfer rate.

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Successive reactions of ω-hydroxycarboxylic acids with an equimolar amount of di-2-thienyl carbonate (2-DTC) in the presence of a catalytic amount of 4-(dimethylamino)pyridine (DMAP) followed by an addition of 2–4 equimolar amounts of iodine afforded the corresponding lactones in good to high yields.

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{100} and {111} facets are typical for metal clusters having FCC structure. We have ever succeeded to obtain square Pt particles having {100} facet on their surface. However, there has not been an effective method to obtain Pt nanoparticles with the other facets, i.e., {111}. In this paper we report a novel preparation method of tetrahedral Pt nanoparticles, whose surface is controlled {111}, by using a thermosensitive capping polymer [poly(N-ethylacrylamide)].

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Enantioselective reaction of α-thio carbanion derived from 1-phenyl-1-(phenylthio)-1-(tributylstannyl)methane with cis-bicyclo[3.3.0]octane-3,7-dione monoethylene ketals in the presence of bis(oxazoline)s gave products with high diastereoselectivity and with high enantioselectivity. The reaction of α-seleno carbanions derived from bis(phenylseleno)arylmethanes also showed high diastereoselectivity and enantioselectivity. Deprotection and subsequent stereospecific elimination afforded axially chiral cis-arylmethylenebicyclo[3.3.0]octanes with high enantioselectivity (up to 99% ee).

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The reactions of formamidine ureas with amines take different paths under protic vs. nonprotic conditions; loss of the urea fragment has been observed for the first time when protons are made available intra- or intermolecularly.

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New pyridine-functionalized proton-switchable calix[4]arenes were synthesized to investigate extraction properties, and performed good extractability toward silver ion in acidic solution.

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Photocatalytic layers of amorphous TiO₂ and polyvinyl alcohol were used for the patterning of low-resistivity metals such as copper and silver without using high cost materials and equipment.

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Potassium or ammonium carboxylates catalyzed Mannich-type reaction between trimethylsilyl enolates and aldimines proceeded smoothly to afford the corresponding β-amino carbonyl compounds in good to high yields with high anti selectivity.

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Cobalt ferrite nanotubes with diameter of 50 nm were prepared using a simple sol–gel process within the pores of anodic aluminum oxide (AAO) template. SEM, TEM, XRD, VSM were used to characterize the morphology, crystalloid structure, and magnetic properties of the samples. The results indicate that the cobalt ferrites thus prepared were polycrystalline phase with the smooth and uniform tube-like structure. The method is also expected to be applicable to the preparation of other multicomponent oxide nanotubes.

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Trifluoromethylation of various aldehydes and ketones with (trifluoromethyl)trimethylsilane in the presence of a catalytic amount of a Lewis base such as lithium acetate proceeded smoothly to afford the corresponding trifluoromethylated adducts in good to high yields.

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A mild and efficient protocol for the coupling of various substituted epoxides 1 with allylgallium reagent generated in situ in a Bu₄NBr–DMF–H₂O system have been developed. The coupling is also found to be equally effective when samarium is used in lieu of gallium and the corresponding homoallylic alcohols 2 were obtained in almost comparable yields.

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Photoluminescence (PL) efficiency of CdTe nanocrystals was investigated as a function of the ratio of surfactant (thioglycolic acid, TGA) to Cd²⁺ used in aqueous preparation. When the ratio was 1.3, a maximum PL efficiency of 65% was obtained. Within our knowledge, this value is the highest ever reported for as-prepared aqueous solution. Surfactants added more than the optimal amount tend to gather densely on the nanocrystals, and distort the surface. This might be one explanation of the decrease of efficiency.

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A new approach has been proposed and was shown to be a feasible method to produce nanosized polymer crystals of poly(acrylic acid). The new approach involves in situ polymerization of acrylic acid in the interlayers of a layered double hydroxides (LDHs) followed by exchange of the polymer anion for carbonate. The key is the use of LDHs as a template.

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Colloidal dispersions of hybrid nanocomposite composed of gold nanoparticles (Au-NPs) and polypyrrole (PPy) were prepared by a sonochemical method, in which gold ion and pyrrole monomer in an aqueous solution were reduced and oxidized, respectively, by ultrasonic irradiation in the presence of poly(N-vinyl-2-pyrrolidone) (PVP).

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A novel fluorescent chemosensor in which two aza-18-crown-6 moieties are linked to a coumarin fluorophore has been synthesized for sensing Fe³⁺. The selective fluorescence enhancement was observed upon binding Fe³⁺ at physiological conditions (pH = 7.4, [NaCl] = 0.135 M, [KCl] = 0.01 M), whereas other metal ions, such as Li⁺, Na⁺, K⁺, Mg²⁺, Ca²⁺, Cu²⁺, Zn²⁺, Co²⁺, Ni²⁺, Mn²⁺, Hg²⁺ and Pb²⁺ produced no effect.

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Positively charged silver nanoparticles capped by cetyltrimethyl ammonium bromide (CTAB) are prepared in aqueous solution. The structure of capping agents on Ag particles is systematically characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermal gravimetric analysis (TGA). It suggests that CTAB molecules form a bilayer shell on Ag surface with a 1:5 rough ratio of inner/outer molecules.

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1,3-Dicarbonyl compounds undergo smooth conjugate addition to α,β-unsaturated ketones in the presence of 10 mol % copper(II) triflate immobilized in air and moisture stable [bmim]BF₄ ionic liquid under extremely mild conditions to afford the corresponding Michael adducts in high to quantitative yield.

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3-[4-(tert-Boc-amino)cinnamoylamino]-α-cyclodextrin (3-4-^tBocCiNH-α-CD) has been found to form a supramolecular polymer in an aqueous solution. The supramolecular polymer was found to take a helical structure. This is the first example of the formation of a helical supramolecular polymer formed by host–guest interactions.

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A convenient and efficient synthesis of substituted quinolines in a simple one-pot reaction of an arylamine 1, an aromatic aldehyde or aliphatic aldehyde 2 and an aliphatic aldehyde 3 in the presence of transition metal complexes or Lewis acids was developed. Among them, the iridium catalyst [Ir(cod)Cl]₂ catalyzed the reaction most efficiently.

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The Ni–Ce–O mixed oxide catalysts prepared by oxalate gel-coprecipitation were found to be highly efficient for the catalytic combustion of methane. Particularly, the relationship between the microstrain of NiO lattice due to the formation of Ce_xNi_1−xO_y solid solutions and the catalytic performance of Ni–Ce–O mixed oxides has been investigated as a function of the Ni/Ce ratio, showing that the lattice strain of the NiO crystals plays a significant role in the methane combustion reaction.

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