Porous oxygen electrodes were prepared by using either activated carbon or silver powder as electrocatalysts and their limiting current density (i_L) was measured as a function of the thickness of the catalyst layer. The i, value increased proportionally with increasing layer thickness when the thickness was smaller than about 0.2 mm for the carbon electrodes and about 0.1 mm for silver electrodes. When the thickness exceeded these values, i, was almost constant. This suggested that the electrochemical oxygen reduction took place not only at the electrode/electrolyte interface, but also in a zonal area extending toward the gas side. Polarization data of double-layered electrodes consisting of carbon and silver layers revealed that the reactive zone was located in the vicinity of the electrolyte side. Electrodes thicker than the reactive zone brought about an additional polarization loss due to the gas-diffusional resistance.

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The NO adsorption on jarosite, β-FeO(OH) and their mixture has been examined by two dynamic methods (pulse and flow methods) and a static method (a gravitational method). The adsorbents were prepared by hydrolysis of aqueous mixed solutions of FeCl₃and Fe₂(SO₄)3 at 100°C and at pH 2.0. Composition, surface area, and crystal shape of the precipitates depended on the mol percent ƒ of Cl^- in anions of hydrolyzing solution (Table 1). Dependence of NO adsorption on ƒ(100× FeCl₃/(FeCl₃+Fe₂(SO₄)₃) (mol%))was approximately similar in the three methods examined (Fig.2∼4). The plot of the amount of NO adsorbed against the composition of hydrolyzing solution gave two maxima at ƒ=75% and 95% (Fig.2∼4). The high adsorbability of the precipitate from the mixed solution of ƒ=75% was attributed to thin jarosite crystals in the mixture. β-FeO(OH)crystals (needle shape) precipitated from ƒ=95% adsorbed large amount of NO (mg⋅g^-1), because the β-FeO(OH) has high specific surface area (170 m²⋅g^-1) in comparison with usual (spindle shape) β-FeO(OH) (20 m²⋅g^-1). The NO adsorbability has been discussed on the basis of adsorption amounts in the three methods.

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Synthesis of 1, 3-dimethyladamantane(DMA) was studied using raw materials obtained from petrochemical sources. A novel synthesis of DMA was found, using as starting materials cyclopentadiene(CPD) and norbornene(NB) derived from ethylene and CPD. Namely, the Diels-Alder reaction of CPD with NB to yield tetracyclo[6.2.1.^{3, 6}. 0^{2, 7}]dodec4-ene(TCDD-ene) at 230°C(TCDD-ene yield 78%) was followed by quantitative hydrogenation of TCDD-ene to obtain tetracyclo[6.2.1.^{3, 6}. 0^{2, 7}]dodecane(TCDD; C₁₂H₁₈), and finaly hydrorearrangement of TCDD giving the adamantanes, DMA +1-ethyladamantane(Et-Ad), was conducted over metals(Pt-Re-Ni) supported on Y zeolite exchanged with rare earth under hydrogen containing hydrogen chloride (5%). The adamantanes were obtained at 250°C(yield of adamantanes, 66%).
In spite of the strain energy of TCDD which is higher than that of tricyclo[5.2.1.0^{2, 6}]decane(TCD; C₁₀H₁₆) to give adamantane(AdH), the selectivity for adamantanes (C₁₂H₂₀) was higher than that of AdH over the bifunctional catalyst. The reason for the high adamantane selectivity was estimated that the strain energy of intermediates(tricyclic compounds; C₁₂H₂₀)obtained by hydrocracking of TCDD, is fairly lower than that of TCD, which is in a suitable range of the strain energy for rearrangement of the tricyclic compound to an adamantane skeleton.

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A series of 3 R₂O₃Ta₂O₃(R₃TaO₇, R =rare earth) samples were synthesized by the solid state reaction at 1350°C for 96 h( 1 ) or at 1700°C for 4 h( 2 ), melting and cooling( 3 ), rapid quenching of the melt( 4 ) and annealing of samples obtained by rapid quenching at 1350°C for 96 h( 5 ) or at 1700°C for 4 h( 6 ). The crystal structures of these samples were examined by powder X-ray diffraction method. X-ray diffraction pattern of sample( 2)(R₃TaO₇ after heating at 1700°C for 4 h) was identical with that of sample(6) (annealin g at 1700°C for 4 h). So that, the phase equilibrium was confirmed for the samples heated at 1700°C for 4 h. Similarly, equilibrium states were attained by heating and annealing at 1350°C for 96 h (sampe( 1 ) and sample( 5 )). With the decrease of ionic radii of R³⁺ions from R=La(1.032 Å) to Ta⁵⁺(0.64 Å), the crystal structure of R₃TaO₇ obtained by solid state reaction became in higher symmetry with the disordered states; weberite type orthorhombic (space group: Cmcm or C 222₁)>pseudo-cubic>pyrochlore type cubic>fluorite type cubic, as shown in Table 1. The rapid quenching of the melt brought about disordered phases with a little higher symmetry and larger unit cell volume (Fig.7). Partially disordered phases were obtained by rapid quenching for R₃TaO₇ with larger R₃₊ ions. A phase transition seems to occur between 1350°C and 1700°C in Flo₃TaO₇, and above 1700°C close to the melting point in other R₃TaO₇ with larger R₃₊ ions than Ho₃₊ (Fig.9). This phase transition seems to be an order-disorder type transition mainly in cation sublattice.

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The effect of H₄P₂O₇ addition on the formation of CaHPO₄ in the neutralization reaction of H₃PO₄ with lime milk was studied. Calcium monohydrogenorthophosphate anhydrate powder with various particular characteristics were obtained under the different preparation conditions -change of H₃PO₄ concentration (37.5∼75%), reaction temperature (60∼80°C), H₄P₂O₇ concentration (0∼10% relative to CaHPO₄), time of H₄P₂O₇ addition (30∼110 min after the initiation of neutralization) and their physical properties such as the average particle size, average crystallite size, tapping density, pressed density and particle morphology were examined. Aggregates of CaHPO₄ were formed and the crystallite size of CaHPO₄at (111) was decreased considerably by H₄P₂O₇ addition. An increase in H₄P₂O₇ concentration and the delay of the addition time of H₄P₂O₇ decreased the primary particle size but increased the secondary particle size. The SEM observation of initialy obtained crystals showed that CaHPO₄ was precipitated immediately as the aggregate when 11413207 was added. It is discussed that the size of primary particles of CaHPO₄ decreased with the increase of H₄P₂O₇ concentration as examined by pH variation during the neutralization reaction. The aggregates composed of primary particles having various sizes were prepared by adjusting H₃PO₄ concentration and reaction' temperature. In this occasion, there is an obvious relationship between the primary particle size and tapping density of CaHPO₄. The method for preparation of aggregated CaHPO₄ powder has been established.

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The granular or needle crystalline particles of ZnO prepared by gas-phase oxidation of zinc metal vapor were heated in the range of 350∼700°C, and the change of adsorption state of water on the surface of these particles was examined. The results obtained are the following: By heating at 500°C or above
(1) The amount of h ydroxyl groups on the surface of these particles decreased, while the amount of released water which had been adsorbed increased at around 80°C.
(2) The peak at around 500°C due to the dewatering from the isolated hydro xyl groups on the granular particles possessing large surface area of crystal face (001) shifted gradually to a lower temperature around 400°C. However, for the needle particles having large surface area of crystal surface (100), the adsorbed water which was also expected to be released at around 400°C was not observed by the heat treatment at 500°C or above.
From these results, it can be concluded that the adsorbed water at around 400°C is not on the hydroxyl groups having closed hydrogen bonds, but on the isolated hydroxyl groups bonded with zinc ions whose lattice sites of the crystal surface are changed by the heat treatment.

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It was found that mercury(II) was coprecipitated with bismuth(III) iodide at pHs of 8 to 9 and that the coprecipitated mercury(II) was recovered in an acidic medium by sublimating the bismuth(II) iodide at 80°C. On the basis of this finding, a method for determining mercury(II) in the presence of iodide ion was proposed. To 2 l of a sampl e solution containing mercury(II) (5×10^-8mol) and iodide ion (10^-3mol⋅dm^-3) are added 10 ml of 1 moldm-3 bismuth(III) nitrate solution. After the adjustment of the pH to 3 with sodium hydroxide, the suspension is allowed to stand for 10 min with stirring. Then ammonia is added to adjust the pH between 8 and 9 and the suspension is again allowed to stand for 10 min with stirring. The precipitate, filtered off on a 0.45μm membrane filter, is transferred to an Erlenmeyer flask with 50 ml of 6 mol⋅dm^-3 sulfuric acid and 1 ml of 6 mol⋅dm^-3 nitric acid. The blackish suspension thus obtained is heated at 80°C for 30 min with stirring. Bismuth(III) iodide is sublimated and a white suspension is obtained. The suspension is treated with 2 ml of 6 mol⋅dm^-3 hydrochloric acid to dissolve the precipitate. The resulting clear solution is made up to 100 ml with distilled water and mercury(II)is determined by atomic absorption spectrometry. The recovery of mercury(II) was 95.7%. As much as 1×10^-3mol⋅dm^-3 of Cl^-, Br^-, PO₄^3-, SO₄^2- and 1×10^-6mol⋅dm^-3of CNinterfered.

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Various substituted 2-pyridones [1] and the 1-methylated compounds [2] were included as guest molecules in a host molecule, 1, 1, 6, 6-tetrapheny1-2, 4-hexadiyne-1, 6-diol (TPH). The tautomeric 2-pyridones 1 [1] bearing polar substituents at C-6, which favor the 2-pyridinol form in solution, existed exclusively as the 2-pyridone form in the inclusion complexes. For the formation of the inclusion complex, the ability of [1] was generally greater than that of [2] and the observed substituent effect was distinctly different between [1] and[2]. The photodimerizations of [1] and [2] in solid state of the in clusion complex were also investigated. Only unsubstituted [1a] gave efficiently the trans-anti dimer among [1], while most of [2] gave efficiently and stereoselectively the corresponding dimers. Based on these experimental results, the hydrogen-bonded structures for the inclusion complexes of 2-pyridones [1] and the 1-methyl-2-pyridones [2] with TPH were proposed.

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Synthesis and reactivities of triisocyanatoantimony, Sb(NCO)₃ were investigated. The compound was prepared by the reaction of antimony trichloride with sodium cyanate in the presence of several additives in benzene and THF. It was found that the reaction was accelerated remarkably by using THF as an additive in benzene to give Sb(NCO)₃ in high yield.
Sb(NCO)₃ reacted with amines such as NHEt₂, BuNH₂, C₆H₅NH₂, and NH₃ to afford only the corresponding triureidoantimony compounds, but reacted with alcohols such as i-PrOH, n-, s- and t-BuOH of phenol to yield the corresponding carbamate and trialkoxo- or triphenoxoantimony compounds.
Sb(NCO)₃ reacted also with 2-diethylaminoethanol to give tris(2-diethylaminoethoxo)antimony and 2-diethylaminoethyl carbamate, together with isocyanuric acid.
From these results, it was revealed that Sb(NCO)₃ reacted with a lcohols and phenol to yield the corresponding substituted products, but the reaction with amines provided only the corresponding addition products.

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Heating phenyl isocyanate [PI] with glycidyl phenyl ether [GPE] in dimethyl sulfoxide [DMSO] in the presence of 1-(2-cyanoethyl)-2-phenylimidazole [B] and water as a catalyst gives mainly triphenyl isocyanurate [TPI]. At first, 1, 3-diphenylurea [DPU] is formed by the reaction of PI with a very small amount of water and then the trimerization reaction of PI proceeds.
This reaction was kinetically investigated at 50°C. This trimerization reaction exhibits a definite induction period before the reaction starts, and is first-order in PI (Fig.5, Table 1). The apparent rate constant k was calculated from first-order plots (Fig.5) and it was found k= 0.023×[DPU] +0.019 (Fig.6).

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The synthetic method of 5-fluoro-2'-deoxy-β-uridine: β-FUDR [5] was investigated. It was found that in the presence of Brønsted acid, 5-fluoro-2, 4-bis(trimethylsilyloxy)pyrimidine [1] reacted stereoselectively with 3, 5-bis[O-(p-chlorobenzoyl)]-2-deoxy-α-D-ribofuranosyl chloride [2] to give 3', 5'-bis[O-(p-chlorobenzoy1)]-5-fluoro-2'-deoxy-β-uridine [3] in nearly quantitative yield. β-Stereoselectivity of the substitution of [1] with [2] varied with the kind of Brønsted acids (Table 1). It was proportional to the m ole ratio of [1]/[2] (Table 3) and inversely proportional to the concentration of iron(III)chloride (Table 4). This substitution reaction seems to proceed by the SN 1 and SN 2mechanisms competitively. [5] was synthesized by the reaction of C 3 with ammoniamethanol solution in 99% yield.

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In order to estimate the effect of electron-releasing property of ortho-substituted group on the hydrodeoxygenation of aromatic and heteroaromaticcyclic compounds, benzoxazole, o-aminophenol, o-, m-methoxyphenols and o-, m-, p-methoxybenzenethiols were hydrogenolyzed under the constant hydrogen pressure of 40 atm at 200⋅320°C for 90 min with molybdenum(VI) sulfide as a catalyst. A direct comparison was made between the re sult of hydrodeoxygenation of these oxygen compounds and that of hydrodesulfurization of the sulfur analogues.
Hydrogenol ysis of benzoxazole (Table 1) yielded an appreciable amount of o-aminophenol accompanying with small amounts of phenol, ring-methylated phenols, aniline, ring-methylated anilines and hydrocarbons at a relatively high reaction temperature range. In the case of hydrogenolysis of o-aminophenol (Table 2), the cleavage of both C-O and C-N bond took place evenly, and small amounts of phenol, aniline and C₆-hydrocarbons were produced. These results indicate that the electron-releasing property of the N atom contained in ortho-substituted groups of both benzoxazole and o-aminophenol scarcely affect the C-O bond cleavage in the hydrodeoxygenation. The methoxyl group in o-methoxyphenol (Table 4) also scarcely affected the C-(OH) bond cleavage.
In the case of the hydrodesulfurization of the sulfur analo gues, o-, m- and p-methoxybenzenethiols (Table 3), the easiness of the C-S bond cleavage was in the following order: o-≈p->> m-isomer. The effect of electron-releasing property of para-methoxyl group on the C-S bond cleavage was observed significantly, whereas the similar effect of ortho-methoxyl group was not able to be observed since the internal rearrangement reaction took place prior to the hydrodesulfurization. It was suggested that the ortho- or para-methoxyl group with electron-releasing property might play an important role apparently in the C-S bond cleavage on the hydrodesulfurization.

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The solvent effect on the ratio of 2and 4-azo dye in the coupling products of 1-naphthol with p-nitrobenzenediazonium tetrafluoroborate has been studied in various nonaqueous solvents at 20°C In polar protic solvents(I) such as methanol, ethanol, 1-propanol and acetic acid, the selectivities of 2-azo dye formation were 5, 4, 3 and 3%, respectively, which were less than the value (7%) in water. In the nonpolar aprotic solvents(II) such as benzene, toluene, cyclohexane, dichloromethane and carbon tetrachloride, the selectivities of 2-azo dye increased to some extent and were 15, 20, 21, 30 and 22%, respectively. The solvent effect was discussed and the reaction was interpreted in SEAr mechanism, along with the base catalysis in deprotonation from the a-complex.

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New isopropenyl-1, 3, 5-triazines, e. g., 2-acetylamino-[1], proPanoylamino-[2], butanoylamino[3] hexanoylamino-[4] and octanoylamino-[5] 4-anilino-6-isopropenyl-1, 3, 5triazines were prepared by acylation of 2-amino-4-anilino-6-isopropenyl-1, 3, 5-triazine (AAIT) with the corresponding acid anhydrides. The homopolymerization of these monomers and their copolymerizations with styrene and methyl methacrylate (M₁) were carried out in dimethyl sulfoxide at 60°C using azobisisobutyronitrile as an initiator. Monomer reactivity ratios (r and r₂), the Q and e values for these monomers (M₂) were 0.13∼0.17, 1.2∼1.4, 2.2∼2.6 and 0.40∼0.56 for styrene (M₁) and 0.24∼0.32, 1.4∼1.7, 2.2 and -0.420∼-0.55 for methyl methacrylate (M₁), respectively.

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The chelating resin containing iminodiacetic acid was prepared by the reaction of diphenyl phosphonate-formaldehyde resin with iminodiacetic acid for 2 h at 80°C. The adsorption capacity was about 1.9 meq/g-R (dry base). The rate of adsorption is rapid and the solution passes effectively through the resin column. The chelating resin showed the selective adsorption ability for Cu²⁺ ion in the low pH region, and the separation of Cu²⁺ ion from divalent metal ions is possible by elution with 0.15 moldm^-3 HCl. The Co²⁺ and Ni²⁺ ions loaded on a column can be also separated from each other by eluti on with 1.0 moldm^-3 CH₃COOH. The resin has a resistance against oxidant, and showed good adsorption ability for Cr₂O₇^2- ion in an aqueous H₂SO₄ solution. The Cr₂O₇2- ion adsorbed on the resin was effectively eluted with 0.3 v/v% 11202-0.1 moldm^-3 NaOH solution.

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A hollow fiber type porous chelating resin containing amide oxime as a functional group was synthesized and used as an adsorbent for the recovery of uranium. Hollow fiber type porous polyethylene was used as a base polymer. Acrylonitrile was grafted onto it by the radiation-induced graft polymerization. By changing the reaction time, four kinds of graft polymer were obtained. The degree of grafting ranged from 79% to 127%. Each resin was soaked in hydroxylamine solution, and the cyano group was converted to amide oxime group. By elemental analysis, the amount of nitrogen introduced on the graft polymer resin in amidoximation was determined to range fro m 4.3 mmol to 8.5 mmol per 1 g of base polymer. Most of the nitrogen is considered to belong to the amide oxime group. The pore radius, which was initially distributed broadly from about 500A to 10000A for the base polymer, was changed to about 1000A with narrow distribution by the grafting. The pore volume was 1.2-1.4 cm' per 1 gram of the amide oxime resin, which was about half of that of the initial base polymer. But the pore volume per 1 g base polymer of the amide oxime resin increased with an increase in the grafting degree, e. g.4.5 cm3/g base polymer at 127% of grafting degree. Specific surface area, which was 30m2/g in base polymer, decreased with an increase in the grafting degree, e. g.15 m ²/g at 127% of grafting degree. Both the amoun ts of the adsorbed hydrochloric acid and the adsorbed copper were about 1.5 times of the amount of nitrogen introduced in the amidoximation. The reaso n is considered to be caused by the formation of hydroxamic acid and amide from the measurements of the IR spectra. The amount of uranium adsorbed on the resin was 64% of the amount of nitrogen introduced in the amidoximation.

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The Diels-Alder adduct of 2-hexadecylfuran and maleic anhydride was treated with conc. H2SO4 at low temperature to afford 3-hexadecylphthalic anhydride. The anhydride rea cted with ammonia to give hexadecylphthalamic acid ammonium salt. The salt was successfully applied to solvent extraction of heavy metal ions. Several heavy metal ions were extracted fr om aqueous phases (pH 2 to 6) to a heptane phase by the extractant in the order of easiness Hg2+> Cu²⁺> pb²⁺ > Cd^2+> Co²⁺> Ni²⁺, The solvent extractant was found to be most effective to extract mercury(II) ion among all cases tried. When a 5-time excess of the extractant relating to a metal ion was employed, all metal ions were approximately 100% extracted. The metal ions were easily back-extracted by dilute mineral acid. Moreover, the organic phase recovered after the back extraction was subjected to further extraction of metal ions Other related compounds like 3-hexadecylphtha lic anhydride, 3-hexadecylphthalimide, and ethyl hydrogen hexadecylphthalate could not be used for the extraction of metal ions to heptane.

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Mercury(II) ion is reduced by activated carbon (A. C. ) and the reduced mercury volatilizes from solution by aeration. In this paper, effects of ligand on the reduction of mercury(II)ion have been studied using three kinds of A. C. by measuring the amount of volatilized mercury and discussed in connection with the chemical species of Hg(10 in aqueous solution. In the absence of ligands, free Hg(II) (He²⁺Hg(OH)₂) was easily reduced below pH 8, but the amount of the volatilized mercury decreased with increasing pH value (Fig.2). Hg(II)-acetate complexes were reduced in the same manner as free Hgan by Takeda and Mitsui A. C., but not by Mitsubishi A. C. (Fig.6). When He+ existed as Hg(II)-(gly)₂ complex, the amount of volatilized mercury was less than that of fre e Hg( II) at neutral pH, but increased above pH 9 (Fig.6). In the presence of EDTA, a significant volatilization was observed at about pH 10 with Mitsubishi A. C., whereas a little volatilization was observed at lower pHs with Takeda A. C.. However, there was no volatilization with Mitsui A. C. (Fig.7). In the presence of halide ions, picolinic acid or cysteine, the volatilization did not occur when mercury(I0 existed as Hg(II)X_n, (n=2, 3, 4) complexes, but HgC12 was slightly reduced by Takeda A. C. in acidic solutions (Figs.3, 4, 5, Tables 2, 3). From these results, it is concluded that various mercury(ff )complexes are reduced by activated carbon and this reaction is affected not only by the chemical species of Hg(II), but also by the kind of activated carbon and pH of the solution. It will be necessary to take into account such reduction reaction for the study of removal or adsorption mechanism of mercury(II) by activated carbon. t Removal of Heavy Metal Ions by Activated Carbon. V.

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A study was made of the synthesis of 1-ethyladamantane (Et-Ad) from adamantane (AdH)and ethylene over solid acid. Et-Ad is rearranged by the acid catalysts into 1, 3-dimethyladamantane (DMA). The typical solid acid such as silica-alumina (80: 20), was found to catalyze ethylation of AdH at 230-270°C. In the presence of hydrogen chloride, catalytic activity was found to increase (Et-A d Yield 14%). On the other hand, zeolite, exchanged with rare earth metals showed catalytic activity higher than silica-alumina in the AdH ethylation, and indicated the consecutive rearrangement of Et-Ad to DMA. t Rearrangement of Saturated Tricyclic Hydrocarbon on Bifunctional Cataly st. VI.

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Alumina supported copper (II) bromide and chloride were found to be very effective for the halogenation of phenylacetylene. Reaction of phenylacetylene with alumina-supported copper(II) halide in carbon tetrachloride gave a mixture of monohalide, dihalide and trihalide. The ratio of the products depends heavily on the reaction conditions. As for chlorination using CuCl₂/Al₂O₃, the reaction at 50°C for 0.5 h produced mainly 1-chloro-2 phenyl-acetylene, but α, β, γ-trichlorostyrene was produced predominantly from the reaction at 80°C for 3 h.

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Polymer complexes composed of inorganic and organic and/or inorganic materials were prepare by mixing iron(III) hydroxide sulfate [Fe₂(OH)_n(SO₄)_3-ⁿ/₂]_m(PFS) with the potassium sulfate of poly(vinyl alcohol) (PVSK) and with the sodium tetraphosphate (TPP). The iron contents, reflectnig the PFS content, in each polymer complexes (PECs) prepared in PFS-TPP system are higher than that of the PECs prepared in PFS-PVSK system. Solubilities of the PEC in many organic solvents and the miscibil ity in the three-component system suggests a characteristic property of the PEC consisting of inorganic materials.

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