The molecular assemblies of photosynthetic reaction centers (RCs) driving the light-to-redox energy conversion have been studied by chemical analytical and various spectroscopic means. As a result, one molecule of chlorophyll (Chl) a′, the C13²-epimer of the dominant pigment Chl a, was detected for the first time as an essential component of photosystem I RC of higher plants, algae, and cyanobacteria. Further, two molecules each of bacteriochlorophyll (BChl) g′ and 8¹–OH–Chl a in heliobacterial RCs, two molecules of BChl a′ in the RC of a green sulfur bacterium Chlorobium tepidum, and one or two molecules of Chl d′ in the RC of a cyanobacterium Acaryochloris marina were detected. In addition, the chemical structure of BChl 663, the primary acceptor in the RC of green sulfur bacteria, and that of Zn–BChl a found in Acidiphilium rubrum, were determined. Detection/identification of these novel minor but key pigments would contribute to the discussion on the molecular machinery of photosynthetic reaction centers.

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After cathodic polarization, nickel(II) hydroxide-deposited carbon powder [Ni(OH)₂/C] was investigated by XRD, magnetism measurement, and TEM observation. More than 1.4% of the nickel(II) hydroxide deposited on the surface of the carbon powder was electrochemically reduced and fine nickel particles were formed. Since the fine nickel particles act as active sites for charge/discharge reactions, the initial activation of hydrogen storage alloy negative electrodes was promoted by adding Ni(OH)₂/C.

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A stable precursor solution for SiO₂ film formation was prepared from the reaction of tetraethoxysilane with glucose in ethanol, by the regulation of the hydrolysis of the alkoxide through the complex formation of the sugar toward Si. The resulting solution involving diethylamine could be spin-coated on a quartz glass with excellent coatability. By firing the precursor film at above 600 °C, transparent and crack-free film with ca. 500 nm thickness was obtained. The precursor solution has a long-term stability. By the XPS spectra of the films formed at 600 and 1000 °C, it was elucidated that the nitrogen atoms were completely removed from the precursor films. Thermal properties of the precursor powders obtained from the solution were also examined by TG-DTA. Au-dispersed SiO₂ films with several Au content ratios of Au/Si in the range from 0.01 to 0.1 were also prepared by the application of the precursor solution. Graft-polymer stabilized Au clusters in ethanol were well dispersed into the SiO₂ precursor solution. The SiO₂ precursor solution added with Au clusters, could be spin-coated on a quartz glass with excellent coatability. Blue shifts of the maximal positions of the absorption band due to the surface plasmon resonance of Au clusters were observed, in the absorption spectra of the Au-dispersed SiO₂ films. By the XRD spectra of the SiO₂ film with dispersed Au clusters, it was elucidated that the crystallite size of the Au clusters does not depend on the contents.

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The reaction of acetoacetates or benzoylacetone with hexamethylenetetramine in aqueous ammonium carbonate solution at room temperature gave 2,6-dimethyl-1,4-dihydropyridines (DHP) directly. These DHPs were oxidized to the corresponding pyridine derivatives quantitatively by air oxidation. Reaction machanism is also discussed.

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Pseudomonas cepacia lipase (PCL), which catalyzes transesterification between 1,2,3-tripropanetriyl tributyrate (1) and aliphatic secondary alcohol 2 to give the corresponding (R)-butyrate 3, has been studied using twelve organic solvents and fifteen alcohols at 30 °C. Among systems studied, 4-nonanol in carbon tetrachloride was only the case where no reaction was observed. The plots of the enantioselectivity (E value) against carbon number (CN) of 2 showed the minima at CN = 8, 9 and 10 for 2-, 3- and 4-alkanols, respectively. The log E values showed a rough negative correlation with the solvent hydrophobicity (log P) except bulky solvents, in which the log E values were smaller than those expected from log P. Their correlations were different depending on the structure of 2. The initial rate constants (k) of enantiomers in racemic 2 were estimated. The k value of (S) isomer showed the maxima at CN = 8, 9 and 10 for 2-, 3- and 4-alkanols, respectively. The k values showed a rough positive correlation with log P except bulky solvents, in which these values were larger than those expected from log P. The slope of the log k vs. log P plot for (R) isomer was smaller than that for the counterpart, and their correlation was also varied with the structure of 2.
Based on the above results, we concluded that the enantioselectivity was affected by a combination of the structures of substrate and solvent and the solvent hydrophobicity. A plausible active site model involving a participation of the solvent for PCL catalyzed transesterification was proposed and discussed.

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Sulfated poly[2-(glucosyloxy)ethyl methacrylate] (degree of sulfation = 1.07, 2.13, 3.86), which was bioinspired glycopolymer, was synthesized by polymerization of 2-(glucosyloxy)ethyl methacrylate followed by sulfation of the obtained polymer. Effects of the sulfated poly[2-(glucosyloxy)ethyl methacrylate]s with various degree of sulfations on the cell proliferation activity of fibroblast growth factors (FGFs). Sulfated poly[2-(glucosyloxy)ethyl methacrylate]s with higher and lower degree of sulfations activated FGF-1 and FGF-2, respectively.

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Periodic changes in the thickness of crosslinked poly(allyltrimethylammonium chloride) (PATMAC) gel membranes, induced by a periodic voltage change, were confirmed to continue for several hours stably on a microelectrode. The amplitude of the periodic change was proportional to the applied voltage, and was dependent on the concentration of NaCl solutions, in which all the membranes were preliminarily equilibrated before use. The amplitude was largest when it was equilibrated in 0.03–0.05 mol dm⁻³ NaCl solutions. Moreover, a propagating wave could be generated on the surface of a gel membrane fixed on a 5-electrode or 10-electrode, by switching the polarity of each microelectrode in order.

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Effect of affinity with 2-methylheptane of melamine resin on cracking on melamine-cured coating film was clarified by mineral spirits tolerance (MST). It was found that cracking occurred easily on the coating film having higher MST in exposure test. The coating film having higher MST led to remarkable changes in glass transition temperature, cross-linking density, tensile strength and ultimate elongation. It was also found that the coating film having higher MST had lower initial cross-linking density.
Based on the IR spectra of the coating film after exposure test, it was found that the amounts of alkyl-group and melamine decreased and they were more in the coating film having higher MST.
The cracking of melamine-cured coating film was affected by MST of melamine resin, and the coating film having higher MST occurred the cracking at short time compared to lower ones. It was thought that higher penetration of water to coating film caused by the initial lower cross-linking density led to the hydrolysis of the film and the cracking occurred by falling of physical properties of the film.

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Trimellitic anhydride (TMA) microcapsule toners, used as foaming control agent in the field of printing, have been synthesized by liquid phase separation which is a kind of the coacervation method. Liquid phase separation is most promising for the microencapsulation of TMA, since it can create TMA microcapsules without using an aqueous solution. In the previous paper²⁾, we explained that the instability of TMA toner charge results in the reaction between TMA and charge control agent (CCA). In this study, in order to restrain the reaction, neutral calcium petronate was used as CCA. Additionally, the microcapsule wall was multilayered by liquid phase separation. The liquid toner prepared by this study was able to be used for a commercial printing machine. Furthermore, the foaming restraint effects satisfied the industrial requirements in the field of printing.

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The calcium carbonate coprecipitation method was studied for simplified determination of magnesium ions in water by flame atomic absorption spectrometry (F-AAS).
A 15 mL of 8 gCa L⁻¹ calcium chloride and 15 mL of 20 w/v% potassium carbonate as a coprecipitant were added to sample water containing magnesium ions, followed by stirring for 30 min at room temperature. The resulting magnesium ions were quantitatively coprecipitated with calcium carbonate. The precipitate was collected onto a membrane filter (0.45 μm) and then dissolved with dipping for 15 min in 10 mL of (1 + 11)HCl. The solution was made up to 100 mL with distilled water to prepare the sample solution for F-AAS.
The detection limit for magnesium was 0.9 μg L⁻¹(3σ), and the lower limit of determination was 3.2 μg L⁻¹(10σ) in case of 200 mL of sample water.
This calcium carbonate coprecipitation method has no significant interferences in the analysis of water samples of 50 to 400 mL, and could be used as a preconcentration method for simplified determination by F-AAS of magnesium ions in water.

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A disk-format solid phase extraction method for the determination of the pesticides, by gas chromatography/mass spectrometry (GC/MS) with electron ionization (EI) is described. This method provides good linearity of the calibration curve and repeatability. The correlation coefficients of calibration curve were estimated to be from 0.981 to 0.999 for these pesticides in the concentration range from 0.2 mg/L to 2 mg/L. These compounds were adsorbed on a disk-format solid phase from river water and rain water. A capital acetone and hexane was investigated as solvents for elution of these compounds adsorbed on the solid phase. As a result, a capital acetone and hexane turned out to be very effective and a high recovery (about 100%) was obtained for these pesticides in distilled water. This method was successfully applied to analyze the pesticides in river water and rain water.

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Lithium ion batteries using LiMn₂O₄ for a positive electrode and graphite for a negative electrode are expected as power sources for electric vehicles (EV) or hybrid electric vehicles (HEV) due to superior high specific energy and power. However, cycle degradation is a serious problem, in particular, at high temperature region because batteries in EV and HEV are used in a wide range of temperature from −30 to 55 °C.
In this work, the cycle degradation of battery at 45 °C and the degradation mechanism have been investigated. The cycle degradation with lowering the capacity and the rise in the internal resistance of the battery was observed. In order to examine the mechanism of this degradation, the structural and compositional change of each electrode were investigated by various analytical methods.
The large dispersion of Mn(II) at electrode surface was observed by means of ESR for the degraded electrode (Figs. 3 and 4). A broad ⁷Li-NMR peak was observed at 400–600 ppm in the initial sample, while it disappeared and another broad peak was observed at 0 ppm in the degraded sample (Fig. 5). This fact suggests that the Jahn-Teller-distortion induced a phase transition from cubic LiMn₂O₄ to tetragonal Li₂Mn₂O₄ phase and the disorder of the structure. The phase transition is considered to be one of the origins of cycle degradation, since the lithium ion mobility is smaller in tetragonal than in cubic phase.
The thick film was observed on the surface of degraded negative electrode. The phosphoric acid component which is considered to be a decomposition product of LiPF₆ was observed in the film (Fig. 7). It is suggested that the formation of film on the negative electrode will be one of the reasons why the increase of internal resistance of Li-ion batteries is observed in cycle degradation.

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Partial reduction of highly reactive NiAl₂O₄ spinel was investigated concerning with the raw spinel powder prepared by thermal decomposition of Al₂(SO₄)₃–NiSO₄ solid solutions. Solid solution of Al₂(SO₄)₃ with NiSO₄ was prepared from mixed aqueous solutions by a rapid dry using micro wave heating. The Ni²⁺ ion is soluble in the anhydrous aluminum sulfate crystal lattice over a wide range up to 65 mol% of (NiSO₄)/(NiSO₄ + Al₂(SO₄)₃). The anhydrous sulfate thermally decomposed to form the crystalline phases of spinel, η-Al₂O₃ and NiO at 900 °C. The lattice parameter of the spinel changed linearly with the Ni content ranging from about 20 mol% to 50 mol% of (NiO)/(NiO + Al₂O₃) without any other crystalline phases coexisted. The compacted NiAl₂O₄ spinel powder buried in a carbon powder was heated to partially reduce. On heating up to 700 °C the NiO segregated from the spinel leading to its enrichment in Al₂O₃. Metal Ni appeared above 800 °C, coexisting with the NiO and the spinel. The lattice parameter of the spinel decreased with decreasing the content of Ni in the spinel. The α-Al₂O₃/Ni composite was formed after heating at 1300 °C, while three phases of the NiO, the metal Ni and the spinel were coexisted until heating at 1200 °C.

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Cyclometalated complexes of 2-substituted 8-quinolinols possessing two or three carbon side chains have been prepared in the presence of a second ligand. The 5,5- or 5,6-chelate ring system containing a Pd(II)- or Pt(II)-C(sp³) bond is very stable. There are notable steric interactions among three adjacent substituents. The X-ray structure analysis of the complex containing a bulky second ligand, such as PPh₃, reveals a remarkable distortion within the Pd-coordination plane. The steric repulsion was observed also in solution by ¹H-NMR spectroscopy. A novel cyclometalated palladium complex of 3′-azido-3′-deoxythymidine (AZT) was prepared and the steric interaction was investigated by H-H COSY analysis.

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α-Methoxycarboxylic acids 1 undergo decarbonylative α,α-diarylation reaction with arenes 2 in the presence of phosphorus pentoxide-methanesulfonic acid mixture (P₂O₅–MsOH). However, 2-methoxyacetic acid (1d) shows different reaction behavior from those of other α-carboxylic acids (1). Trifluoromethanesulfonic acid (TfOH)-mediated reaction of 2-methoxyacetic acid (1d) with arenes 2 yields anthracene derivatives 10 in addition to Friedel-Crafts acylation type products and diarylmethanes 4. The reaction behavior was elucidated by estimating the influence of the kind of acidic medium and the substrate structure. Furthermore, based on the results of the reaction of the model compounds for the corresponding suspected reaction pathways, the adequacy of the pathways was evaluated. TfOH-mediated reactions of 2-methoxyacetic acid (1d) with arenes except for that with benzene (2f) proved to proceed via α-hydroxyacetophenone homologues 7 and 11, 1,1-diarylethanediol derivatives 14, and 1,2,2-triarylethanol derivative 17.

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An effective synthesis of a series of fluorine-containing polyfunctional aromatic compounds, 4-halo-3-trifluoromethylbenzonitriles 1a–c was performed by the use of some tetrahedral copper-cyano complexes as Sandmeyer cyanating reagents and sublimation in the isolation and purification process. In the conversion of the corresponding diazonium salts to the target benzonitrile derivatives (1a–c), three tetrahedral tetracyanocopper complexes, K₃[Cu(CN)₄], Na₃[Cu(CN)₄], and K₂[Cu(CN)₄ · NH₃], proved to be effective as Sandmeyer cyanating reagents though copper(I) cyanide gave the target compounds in moderate yields. Furthermore, the yields of nitriles 1a–c in the reaction with the copper(I) complexes were rather higher than that with the copper(II) complex, K₂[Cu(CN)₄ · NH₃]. The conversion reactions to nitriles 1a–c are suggested to proceed through an S_NAr mechanism.

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Silver(I) carboxylate-BINAP complex, water tolerant and air-stable, is a highly efficient catalyst for Mukaiyama aldol reaction using silyl enol ethers or ketene silyl acetals as nucleophiles. The Mukaiyama aldol reaction of aldehydes or keto esters in DMF afforded aldol products quantitatively in a short reaction time by this silver(I) carboxylate-BINAP catalyst. Using ketene silyl acetals, aliphatic ketones also gave the aldol products in high yields, however, with aromatic ketones both aldol reaction and silyl transfer reaction were observed. The silver(I) carboxylate-BINAP catalyst acts as a good catalyst for Mukaiyama Michael addition of α,β-unsaturated ketones. The catalyst strongly activates nucleophiles to cause the aldol reaction easily.

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Callus cultures of Taxus cuspidata were induced from young stems in a modified Gamborg B5 medium with various known auxines. Taxol^® (Paclitaxel) (1) (0.010% based on dry callus weight) and its relating compounds containing oxetane ring 7–10 were isolated from the fast-growing callus cultures (CR-5 cell strain) with NAA 0.5 mg/L in the medium, together with taxuyunnanine C (2) and its 14-acyloxy derivatives 3–6 in high yields (total 0.49%). The dry callus culture was extracted with hexane, ethyl acetate, and methyl alcohol successively. These extracts were separated by the combination of silica gel flash chromatography and HPLC. Taxol (1), 7-epitaxol (7), and taxol C (8) were isolated from the extracts of EtOAc and MeOH in 0.010%, 0.002%, and 0.001% yields, respectively. Taxuyunnanine C (2) and its 14-acyloxy derivatives 3, 4, 5 and 6 were obtained from these extracts in 0.135%, 0.014%, 0.009%, 0.275% and 0.053% yields respectively.

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Under nitrogen atmosphere diethyl maleate was hydrogenated to give diethyl succinate in a high yield with metallic nickel/Zn/H₂O/EtOH catalyst system in the presence of a large amount of zinc powder and water. Metallic nickel was an active species for the hydrogenation and zinc powder and water were reagents to produce hydrogen. Benzylideneaniline was hydrogenated to give N-phenylbenzylamine in a moderate yield under the reaction conditions and it was appreciably hydrolyzed to afford aniline and benzaldehyde at the same time.

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Four kinds of single crystals of hexagonal apatite type Nd_x(SiO₄)₆O_1.5x−12 (x = 8–9.33), which is an oxide ionic conductor, were prepared by the FZ method and samples for electrical measurements (the conductivity components parallel and perpendicular to the c-axis of single crystal) were prepared. The conductivities of the component parallel to the c-axis were higher about one order of magnitude, compared with those of the component perpendicular. The values of (Nd/Si) × 6 of four kinds of samples were 8.63, 8.67, 8.91 and 9.33 determined by electron probe micro-analysis. The conductivity was slightly increased with decreasing the value of (Nd/Si) × 6.

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6-Acetyl-2,2-dimethyl-4-chromanone(6), isolated from Tussilago farfara LINN., was prepared by oxidation of 6-ethyl-2,2-dimethyl-4-chromanone(4) using chromium(VI) oxide in acetic anhydride and acetic acid.
The compound 4 was obtained, via the intermediate of ester 3, by condensation of p-ethylphenol and 3-methylcrotonic acid using diphosphorus pentaoxide in polyphsphoric acid.
The conversion of 3 to 4 also proceeds efficiently by stirring of the reaction mixture with glass globes in the absence of diphosphorus pentaoxide.

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We found a novel ring-expansion reaction of 1,3-dioxacycloheptane with ethylene oxide to form 1,4,7,10-tetraoxacyclotetradecane. The reaction is thought to be composed of the following three steps: first, formation of an active intermediate from 3 mol of ethylene oxide and 1 mol of 1,3-dioxacycloheptane; second, elimination of formaldehyde from the intermediate; and finally, cyclization to form 1,4,7,10-tetraoxacyclotetradecane. The relation between the ring size and the ring strain energy is thought to be deeply involved in a significant factor in this novel reaction.

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The hydrophilic surface of poly(ethylene terephthalate) (PET) film, obtained by partial hydrolysis, was converted to hydrophobic one under dry air, saturated water vapor atmosphere, nitrogen, and vacuum at temperatures ranging from 0 to 80 °C. The hydrophilicity of the surface increased significantly faster under the saturated water vapor although it was the most hydrophilic in the examined conditions. From the dependence of the absolute temperature on the rate of hydrophilicity change for each storage condition, a discontinuous point at ca. 50 °C was observable only under the water vapor condition. This relation indicates that the appreciable acceleration of the hydrophilicity change on the surface under the hydrophilic condition might be resulted from the increase of the surface mobility due to the water adsorption on the PET surface.

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The properties of an optical sensor based on the oxygen-induced and temperature-induced luminescence quenching of tetrakis(pentafluorophenyl)porphyrinatoplatinum (PtTFPP) and 3,9-perylenedicarboxylic acid diisobutyl ester immobilized in a polystyrene film were investigated. The luminescence from PtTFPP in a polystyrene film was quenched by oxygen. On the other hand, the luminescence from 3,9-perylenedicarboxylic acid diisobutyl ester was not quenched by oxygen. Thus, the coincidence measurement for oxygen and temperature changes were attained using PtTFPP and 3,9-perylenedicarboxylic acid diisobutyl ester immobilized in polystyrene film.

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In this study, we investigated the change in the removal rate of boric acid relative to the saturation rate (=dissolved amount/saturated amount) for gypsum in solution and its pH dependence, as well as the composition of the compounds found in the precipitate after the reaction. The results showed that almost 100% of boric acid in solution is removed by the addition of gypsum at a saturation rate of >0.75 in the pH range of 10.5–13, which is probably due to the increase of the amount of ettringite formed in the precipitate. This makes it possible to thoroughly process boric acid-containing wastewater using the same amount of coagulants as in the conventional method.

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