Terrestrial organisms were supposed to be abiogenetically born in primordial sea about 4 billion years ago, using organic compounds in seawater. We performed experiments simulating the environments of primitive planets or interstellar dusts to examine possible formation of bioorganic compounds essential for the first organisms. When a gas mixture of Titan-type, which contained methane and nitrogen, was exposed to a spark discharge, such organic compounds as hydrocarbons, “amino acid precursors, ” and some nucleic acid bases like cytosine were formed: The amino acid precursors are compounds which give amino acids after acid hydrolysis. If a gas mixture of carbon monoxide, nitrogen and water (“mildlyreduced gas mixture”) was used, spark discharges gave only trace amount of the amino acid precursors. The same type of gas mixture was irradiated with high energy particles, the amino acid precursors were formed in high yield, together with uracil and imidazole. Some of the amino acid precursors had molecular weight of several hundreds, thus they might be condensates of amino acids. Amino acid. precursors were also formed when a simulated ice mantle (10 K) of interstellar dust particles was irradiated with high energy particles. These results suggest that (i) cosmic ray-induced formation of bioorganic compounds was important if the primitive terrestrial atmosphere was mildly reduced, (ii) exogenous organic compounds delivered by bodies like comets could not be negligible, particularly if the primitive terrestrial atmophere was non-reduced, and (iii)f urther simulation studies on abiotic syntheses of bioorganic compounds will be required to evaluate “the RNA-world hypothesis” and “the Oligomerworld hypothesis”.

View full abstract

This article covers the history and present progress of the industrial asymmetric synthesis by use of BINAP (2, 2'-bis(diphenylphosphino)-1, 1'-binaphthyl)-metal catalysts. Especially, the historic discovery of the BINAP-rhodium( I ) -catalyzed 1, 3-hydrogen migration of N, N-diethylgeranylamine (GDEA) and the achievement of practical preparation of optically active BINAP, led to the establishment of the first industrial process for efficient production of 1-menthol employing asymmetric catalysts.
Continuing efforts have been devoted to the exploration of new catalytic reactions using new BINAPmetal complexes and their applications to industrial asymmetric synthesis. Among them, asymmetric hydrogenation of functionalyzed olefins and ketones by use of BINAP-ruthenium (II) complexes provides fruitful results. Today, a wide range of chiral compounds including the pharmaceutical intermediates 4-acetoxy-2-azetidinone (4-AA) and 1, 2-propanediol (2-PPD) are produced in industrial scale in Takasago.

View full abstract

A composite film was prepared from chemically synthesized poly (o-aminophenol) (PoAP) and poly (vinyl alcohol) (PVA) and the application of the composite film to a humidity sensor investigated. The PoAP showed a ladder structure with an aggregation morphology. The electric conductivity of the composite film was linearly related with the atmospheric humidity, extending from 1.5×1010^-5to 1.4 S cm10^-1in response to the change in humidity from 13% to 99%. The measurements performed in both moistening and desiccating processes accompanied with no any hysteresis. These properties are favorable for the application to a humidity sensor. The change in conductivity of the composite film was suggested to relate to the shift of the equilibrium between the conducting salt and the insulating base forms of PoAP depending on the atmospheric humidity.

View full abstract

In partially hydrolyzing of Pb-Ti double alkoxide, the hydrolysis and polymerization reaction was affected by the kind of catalyst and then the several fiber morphology and different crystallization were observed. The complex process during the firing of the PbTiO₃ bulk gel and fiber was discussed. Large amount of organic materials and water were involved in bulk gel and fibers before the crystallization. The gel and fiber prepared under acidic conditions had larger amount of water than that prepared under basic condition. Microstructure of fibers was depended on the structure of polymer derived from the hydrolysis of Pb-Ti double alkoxide. The as-prepared amorphous fibers was crystallized from pyrochlore to tetragonal perovskite phase by the firing at 600°Cand then the crystallinity of tetragonal phase is influenced by the kind of catalyst.

View full abstract

Coercive force of barium ferrite is much influenced by a grinding process with a planetary ball mill or an automatic glass mortar. Influential factors on this occasion have been analyzed by measuring the normal magnetic hysteresis loop curve, remainder magnetizaition curve, and X-ray diffraction pattern of various samples prepared by calcining, milling, and annealing barium ferrite.
The coercive force of barium ferrite that was ground with a planetary ball mill increased or decreased, b ut the pretreatment with the automatic glass mortar led only to the increase of the coercive force. It was disclosed that the enhancement of the coercive force is mainly caused by the orientation of crystal plate and the reduction of the coercive force by the random distortion of the crystal lattice.

View full abstract

In order to synthesize pillared micas having larger basal spacing with controlled microporous properties, expandable Li-exchanged fluorine micas having different layer charges (x) [Li_xMg3_3-xLi_xSi₄O₁₀F₂(x=O.5, 0.8)] were allowed to react with various polynuclear hydroxochromium (III) ion solutions having different OH/Cr ratios at different temperatures, and the effects of reaction temperature on formation and properties of chromia pillared fluorine micas were studied. When intercalation was carried out above 80°Cusing solution of OH/Cr = 2.0, more highly polymerized Cr (III) -species were intercalated, compared with the case of intercalation at room temperature. The cation selectivity caused by layer charge of host mica crystals changed with reaction temperature; this resulted in larger amount [2.01mol (Si₄O₁₀)^-1] of intercalation of highly polymerized Cr (III)-species above 80°C even when layer charge of host crystals was large (x= 0.8). Consequently, pillared micas intercalated above 80°C showed more expanded basal spacings than those intercalated at room temperature. Pillared micas having larger layer charge (0.8) also kept larger basal spacings than those having smaller layer charge (0.5) when heated at 400-700°C, showing basal spacings of 1.1-1.4 nm. Moreover, pillared micas obtained by the reaction above 80°C showed larger specific surface area than those obtained at room temperature in the heating temperature range of 200-300°C.

View full abstract

A variety of Lewis bases such as amines, phosphines, arsines, and stibines were effectively catalyzed trifluoromethylation of benzaldehyde using trimethyl (trifluoromethyl)silane (1). Among them amines exhibited highest activities (59-82% yield), and activities of phosphines, arsines, stibines and pyridine were rather low. When aldehydes such as aromatic aldehydes, aliphatic aldehydes and α, β-unsaturated aldehyde were used as substrates, the trifluoromethylated products (2) were obtained in good yields (mostly > 60% yield). Ketones were less reactive for the present reaction, however, ones bearing trifluoromethyl group attached directly to their carbonyl groups, exhibited higher reactivities to give the desired products in good yields. The Lewis base catalyzed reaction can be also applied to perfluoroalkylation of carbonyl compounds by using (perfluoroalkyl) silanes (3). Asymmetric trifluoromethylation of benzaldehyde was investigated by using chiral Lewis bases as catalysts. Many chiral Lewis bases such as alkaloids, amino acid derivatives, or chiral phosphines were effective for proceeding the trifluoromethylation, but enantiomer excesses of the products were low (<10%ee) The higher enantiomer excesses were observed by using trialkyl (trifluoromethyl) silanes bearing bulky alkyl groups on the silicon atom. When triethyl (trifluoromethyl) silane (5c) was used, the best result (21%ee) was obtained.

View full abstract

A mixture of acridine and sodium amide in the equimolar ratio was heated without solvent at 130°C or more; 9-aminoacridine was then obtained in 31.0% yield during the melting of the mixture. The reaction mixture was coagulated a few minutes after the reaction started, and 9-aminoacridine finally produced.9, 9', 10, 10'-Tetrahydro-9, 9'-biacridine as another product was yielded slowly during both the melting and solid condition of the reaction mixture. The important characteristic of this reaction was that acridine readily underwent amination as the Chichibabin reaction; at the same time, the acridine was reduced by the hydrogen produced during the reaction. Therefore, 9-aminoacridine and 9, 9', 10, 10'-tetrahydro-9, 9'-biacridine were obtained in this reaction when simply heated without solvent; this Chichibabin reaction was a novel reaction of acridine.

View full abstract

Several polyamines were reacted with carbon disulfide in water in the presence of palm-shell active charcoal. The reaction proceeded readily after the adsorption of the reactants on the charcoal to form polythiourea. The resultant polythiourea was firmly immobilized on the surface of the charcoal.
The polythiourea-immobilized charcoals showed superior adsorption ability for mer cury (II) ion. The highest adsorption was obtained for the polythiourea formed from polyethylenimine with molecular weight of 1800 and for which the immobilization ratio relative to charcoal was 11.8 wt%. The increased immobilization higher than this value caused decreases in surface area and adsorption ability. It was supposed that a thin layer of the polythiourea was formed on the charcoal in the former case. The polythiouraimmobilized charcoal was packed in a glass-tube, and for which an aqueous solution of 10 ppm of mercury (II) ion was eluted at a velocity of L V= 5. The mercury (II) ion concentration in the eluted solution rose above the upper limit value permitted by law (5 ppb) after 10 h. The total adsorption of mercury (II) ion was 0.6 mol per 1 liter of the polythiourea-immobilized charcoal.
The polythiourea-immobilized charcoal prepared by this method should p ractically be used as adsorbent of mercury (II) ion.

View full abstract

The titled p-oxo-metal(III) phthalocyanine dimers were prepared and investigated their polymorphs through X-ray diffraction analysis. It was found that μ-oxo-aluminum phthalocyanine dimer and, μ-oxo-gallium phthalocyanine dimer have several polymorphs, but one of the target compounds, that is μ-oxo-indium phthalocyanine dimer, could not be synthesized because chloroindium phthalocyanine was easily hydrolyzed through acid-pasting treatment procedure to give metal-free phthalocyanine. The characterization of these compounds by the several chemical analytical methods was satisfied for the target molecules and the FD-Mass analysis distinguished clearly between the hydroxymetal phthalocyanine and the corresponding phthalocyanine dimer. We also studied their photoconductive properties on the bilayer photoreceptor consisted of the above phthalocyanine dimer as the charge generating material. It was found that the specific polymorphs of μ-oxo-metal(III) phthalocyanine dimers have good photoconductive properties: the APL- II (the II type of μ-oxo-Al(III) phthalocyanine dimer discussed in this article) has a good spectral response of the photosensitivity in the shorter wavelength, and the GPL-G (the G type of μ-oxo-Ga (III) phthalocyanine dimer discussed in this article) has a fairly high photosensitivity in the wavelength region of laser diode light wavelength, compared with the common phthalocyanine photoreceptors.

View full abstract

A time-resolved chemiluminescence detection system has been prepared for the measurement of photoinitiated chemiluminescence (PICL) in the initial period ( <1 s after illumination of excitation light). A nitrogen pulse laser was used as the source of excitation light. Photoinitiated chemiluminescence induced by the pulse laser is measured by a photomultiplier tube, and recorded by a digital osiloscope. The couplings of the photocatalytic reactions of TiO₂ with luminol-CL and bis (2, 4, 6-trichlorophenyl)oxalate (TCP0)-CL have been used for two PICL systems. Time-resolved PICL results show that the CL intensity-time profiles are different in the two PICL systems. The detecting system can be used for the measurement of PICL in the initial period. Its time resolution is ca.1 ms.

View full abstract

Effects of substituents, solvents, concentration, and temperature on tautomerization of ethyl 3-oxobutyrate and its 2-alkyl derivatives were studied. The tautomeric equilibria of ethyl 3-oxobutyrate depend mainly on the polarity and hydrogen-bond donor acidity of solvents. On the other hand, the tautomerization of the 2-methyl derivative is independent of the solvent. Keto-enol interconversion of the keto esters shifts from the keto form to the enol form with an increase in temperature. In addition, rate constants for interconversion from the keto to the enol of ethyl 2-butyl-3-oxobutyrate were determined using H-D exchange reaction.

View full abstract