In order to make clear the amino-imino tautomerization mechanism in the lowest excited singlet state and spectroscopic behavior of fluorescence spectrum of the 2-aminopyridine-acetic acid system, the ab initio molecular orbital calculation at the 6-31G level with a geometry-optimization was carried out for the 2-aminopyridine-formic acid system used as a model system for the 2-aminopyridine-acetic acid system. From calculated results the following conclusions were drawn: (1) The lowest excited singlet state (S₁) of the optimized models of 2-aminopyridine, 2-aminopyridine-formic acid complex (amino complex), 2-aminopyridinium formate complex (cation complex), and 2 (1H) -pyridinimine-formic acid complex (imino complex) are of π, π* character. (2) In the S₁ state the imino complex is the most stable. It is more stable than the cation complex by 5.36 kJ mol^-1. The cation complex is more stable than the amino complex by 13.65 kJ mol^-1 in the same state. The order of stability for these three complexes in the S₁ state is reverse to that of the corresponding one in the ground state. (3) The calculated potential energy surface suggests that the amino-imino tautomerization may proceed through the cation complex as a reaction intermediate in the Si state. (4) The calculated potential barrier height from the amino complex to the cation complex is 3.78 kJ mol^-1 in the Si state. The potential barrier height is very low in comparing with the corresponding one (13.10 kJ mol^-1) in the ground state. (5) The potential barrier height from the cation complex to the imino complex is 9.23 kJ mol^-1, which corresponds to the value of 39.00 kJ mol^-1 in the ground state. (6) The potential barrier heights from the amino complex to the imino complex in the S₁ state are much lower than the corresponding ones in the ground state. (7) The order of stability among the three complexes in the Si state is consistent with that concluded from the spectroscopic behavior of the fluorescence spectrum of 2-aminopyridine in the low concentration of acetic acid. As the concentration of acetic acid increases, the cation complex may be more stabilized in energy than the imino complex due to the dipole-dipole interaction between the solute and solvent, because the cation complex has the largest dipole moment among the three complexes. Therefore, the order of stability may be as the cation complex>the imino complex>the amino complex. This order of stability is consistent with that concluded from the behavior of the fluorescence spectrum of 2aminopyridine in the higher concentration of acetic acid.

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Density (p) dependences of the bending strength (σ) and the Vickers hardness (Hv) of the ₂O₃-ZrO₂ [Y₂O₃ partially stabilized ZrO₂ (Y-PSZ)] composite ceramics were expressed by power laws of σ∝pⁿ and Hv ∝p^m, respectively. The value n decreased largely when the composite contained 20-50wt% Al₂O₃. The change of value m was small in this range. The values of n and m depend upon the fractal dimension d, which is related to the structure of composite ceramics. The change of both values in the Al₂O₃ content of 20-50 wt% shows that the structure changes from ZrO₂ type to Al₂O₃ one.
The tetragonal phase of ZrO₂ component was highly stabilized in the composite ceram ics. The relationship between the value of bending strength and quantity of tetragonal phase was notclear.

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Calcium molybdate (CaMoO₄) crystals were grown from Na₂MoO₄ and KCl fluxes by a slow cooling method. At 1100 °C, CaMoO₄ was dissolved in Na₂MoO₄ at a concentration of about 37.5 mol%. The eutectic temperature was 675±5 °C. The Na₂MoO₄ flux growth was conducted by heating mixtures at 1100 °C for 5 h, followed by cooling to 450 °C at a rate of 5°C h^-1. Colorless and transparent CaMoO₄ bulky crystals of sizes up to 9.0 mm were obtained. The crystal sizes were dependent on the solute content. The most suitable solute content was 30 mol%. The basic form of the crystals was an octahedron bounded by {112} faces. The CaMo04 crystals doped with neodymium (CaMoO₄: Nd), up to 6.3 mm in size, were also grown from the Na₂MoO₄ flux. The neodymium was incorporated preferentially in the center parts of crystals. On the other hand, CaMoO₄ had a solubility of about 7.2 mol% in KCl at 900°C. The eutectic temperature was 725±5°C. The KCl flux growth was conducted by heating mixtures at 900 °C for 10 h, followed by cooling to 500 °C at a rate of 5 °Ch^-1. Colorless and transparent CaMoO₄ needle crystals of lengths up to 2.5 mm and diameters of 25 pm were obtained. The most suitable solute content was 3 mol%. The needle crystals elongated in the [001] direction. The KCl flux did not produce CaMoO₄: Nd needle crystals.

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The reaction of thiosemicarbazide with benzyl chloride by the use of benzyltriethylammonium chloride (BTEAC) as the phase-transfer catalyst (PTC) and aqueous sodium hydroxide solution resulted in the formation of 1, 1, 2-tribenzy1-2-cyanohydrazine (1a). The similar reactions of various alkyl halide, such as 1-bromo-2-phenylethane, allyl bromide and butyl bromide, also gave cyanohydrazine derivatives. Further, thiosemicarbazones were allowed to react with alkyl halides under the phase transfer conditions to give alkylcyanohydrazone derivatives in good yields.

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A convenient method for the preparation of 1, 2-diamines was developed by Michael addition of an amino group equivalent to nitro olefins, followed by the reduction of the obtained adducts to th e corresponding 1, 2-diamines. After screening various amino group equivalents, it was found that Oalkylhydroxylamines were quite effective to produce 1, 2-diamines in high yields, while ammonia and benzylamine gave unsatisfactory results. These two reactions, addition and reduction, could be carr ied out simply in o ne-pot reaction; that is, M ichael addition of O -alkylhydroxylamine to n itro olefins r apidly proceeded just by treating nitro olefins w ith O-alkylhydroxylamine hydrochloride and sodium hyd rogencarbonate in tetrahydrofuran. After the addition reaction was completed, a palladium catalyst and ethanol were directly added to the reaction mixture. The resulting mixture was then stirred under an atmospheric pressure of hydrogen at room temperature to yield the desired 1, 2-diamines. The abo ve convenient one-pot procedure for the preparation of 1, 2-diamines was successfully applied to va rious nitro olefins. Palladium on a ctivated carbon was a suitable catalyst for t he hydrogenation of the a dducts to afford the corresponding 1, 2-diamines in 77-88% yields. The adducts formed from aliphat ic nitro olefins and O-alkylhydroxylamine were converted to the desired 1, 2-diamines in 8 7-92% yields b y using palladium hydroxide on activated carbon.

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A bipolar membrane is a composite membrane consisting of an anion exchange membrane and a cation exchagne membrane in series, and H⁺ and OH^- ions are separately produced by water-splitting at an intra-membrane interface under a reverse potential. This characteristic of bipolar membranes may enable one to make a polymer actuator of soft bending. A bipolar membrane was prepared by adhering a weakly acidic cation exchange membrane onto a commercial anion exchange membrane, and repeated bending was observed under a periodically alternating electric field when it was immersed in an NaC1aqueous solution. The extent of bending of the bipolar membrane was dependent on the strength and pulse width of the supplied electric potential. The response of bending to the applied potential can be interpreted as not due to the water-splitting, but due to the penetration of Na⁺ and Cl^- ions into the bipolar membrane.

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Thin films of aluminum co-doped SiO₂: Sm²⁺ were prepared by rf magnetron sputtering method. Effects of Al dopant on fluorescence spectra and local structure of Sm²⁺ ions were studied. The peak intensity due to the ⁵D₀-⁷F₀ transition of Sm²⁺ ions increases by more than one order of magnitude with an addition of Al dopant. For specimens with low concentration of Sm2+, the peak intensity increases with an increase in the Sm²⁺ concentration. The rate of the increase in peak intensity with Sm²⁺ concentration depends on the kind of co-sputtered Al compounds. The width of the peak becomes narrow, and the position of the peak shifts to a shorter wavelength with an addition of Al dopant. It is thought that the addition of Al dopant prevents the clustering of Sm²⁺ ions and leads to the homogeneous dispersion of Sm²⁺ ions in the SiO₂ glass matrix.

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In order to embody retrosyntheses that experimental chemists intuitively recognize on a computer, we have developed the proposal function of retrosynthetic processes utiliiing transforms, TransformOriented module for Synthesis Planning (called TOSP). Although the concept of TOSP is identical to that of conventional empirical computer-assisted synthesis planning systems such as LHASA and SECS, the retrosynthetic proposal algorithm of TOSP is different from those of conventional empirical computer-assisted synthesis planning systems. TOSP has six remarkable characteristics as follows: (1)construction of bit sets of topological information for the target molecule, (2) acquisition of general functional groups based on the topological information, (3) perception of substructural functional groups in the target molecule, (4) simplification for description of transforms in the form of transform file, (5) treatment of equivalent bonds with improvement of Set Reduction algorithm, and (6) original treatment of aromatic bonds when these bonds are strategic bonds.
In addition, we applied practical compounds to TOSP for confirming the utility of it. As the result, it was proved that TOSP had the effective ability to propose retrosynthetic processes using combined known organic synthetic reactions.

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Extrinsic photocarrier generation site in a layered organic photoreceptor has been characterized from a structural viewpoint and its formation process. A series of experiments has been carried out on a layered photoreceptor which has a carrier generation layer (CGL) containing a triphenylamine trisazo pigment as the main component. The excitons produced in the bulk of the CGL were proven to dissociate into free carriers extrinsically at the interface between the CGL and the carrier transport layer (CTL). The cross-sectional TEM micrograph of the photoreceptor revealed that the carrier transport molecule (CTM) and polycarbonate which comprise the CTL penetrate into the CGL during the wetovercoating formation of the CTL. This phenomenon is interpreted based on diffusion. According to the result, it is deduced that the photocarrier generation site is not a planar CGL/CTL interface but threedimensional interface between the carrier generation material (CGM) particle and the penetrated CTMs in the bulk of the CGL. The number of photocarrier generation sites are almost saturated in the case where the CTM content in the CTL is more than 50 wt%. The diffusion length of the exciton to produce photocarriers is considered to be within the primary particle size of the CGM. Consequently, a high sensitivity for photocarrier generation is recognized to be due to the CTM penetration, which causes a great number of photocarrier generation sites and a short exciton diffusion length.

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A hydrophobic effect on electrocatalysis of an electropolymerized poly (2, 3, 5, 6-tetrafluoroaniline)(PFA) film-coated basal plane graphite (BPG) electrode in the redox of some p-quinones/hydroquinones was voltammetrically examined in a perchloric acid solution, comparing with other polyaniline film-coated electrodes. The hydrophobic PFA film-coated electrode indicated a relatively high catalytic activity in the redox of hydrophobic p-quinones/hydroquinones in comparison to hydrophilic ones. This substrate-selectivity was rationalized as due to a hydrophilic-hydrophobic interaction between the electrodes and substrates.

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The delocalization of protons in HZSM-5 type zeolite films was investigated by the complex impedance method. The conductivities under various water vapor pressures were calculated from both the Cole-Cole plot analysis and the impedance at 1 kHz. The conductivity of HZSM-5 (Al) zeolite film with 170 of SiO₂/Al₂O₃ ratio was strongly dependent on the water vapor pressure and increased with an increase inthe vapor pressure. On the other hand, the conductivities of the silicalite film (SiO₂/Al₂O₃ ratio > 5000) and the pellet prepared by compressing the powdery HZSM-5 zeolite with 173 of SiO₂/Al₂O₃ ratio hardly increased with the water vapor pressure. The conductivities of HZSM-5 type metallosilicates (HZSM-5 (Ga) and HZSM-5 (Fe)) films were also measured. From the results obtained, it was concluded that (1) the acidic sites associated with the framework aluminums are the active centers for the proton conductivity, (2) adsorbed water molecules are responsible for the conduction and (3) the polycrystalline zeolite film is very effective for estimation of proton mobility.

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Oligomeric bis (tributylstannyloxy)siloxanes were readily prepared by the reaction of sodium metasilicate and bis (tributyltin) oxide. The ratios of Sn/Si contained in the obtained siloxanes ranged from 2 to 3, which were estimated by gravimetric analyses. Tributylstannyl group was shown to be an effective protection group against the self-condensation to give silica gel.

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