EXAFS was applied to analyse the structure of hopeite crystals, specified as Zn_3-xMn_x, (PO₄)₂.4 H₂O and Zn₃(PO₄)₂.4H₂O. XANES spectrum for Zn-K absorption edge of the hopeite crystals containing a manganese component was compared with that of the manganese free sample (Fig.1). Both spectra showed almost same values of the absorption edge (9.6629.663 keV), but the amplitude of XANES spectrum for the former was smaller than that for the latter. These facts are explained that the manganese component generated a crystalline strain and the local structure of the crystal was disordered. Further, XANES spectrum for manganese components in modified hopeite crystals were investigated (Fig.2), and compared with those of MnO and MnO2 as standard samples (Fig.3). Though Mn-K absorption edges were 6.545--6.546 keV for both the modified hopeite crystals and MnO, that of MnO2 showed a higher value by 5--6 eV than the former samples. These facts suggest that manganese exists as Mn(II) in the modified hopeite crystals.
The oxygen corresponding to first neighboring atom of the zinc appeared at 0.146 nm and 0.144 nm (Figs.4 and 5) by means of Fourier transforms of EXAFS. Since φ (K) contained a deviation of phase ishift, these data imply apparent bond distances. Therefore, reverse operation of Fourier transform and curve fitting were carried out to determine the real bond distances. The results obtained were 0.194 nm for the former and 0.196 nm for the latter (Figs.6 and 7, Table 1). It was found that the bond distances expressed Zn-O bond due to a tetrahedron structure of [ZnO4] in hopeite crystals. The coordination number of zinc atom was about four, revealing the [ZnO₄] structure. On the other hand, oxygen atom was found to exist at 0.162 nm from manganese atom in the modified hopeite crystals (Fig.11). However, reverse operation of Fourier transform and curve fitting provided the value of 0.215 nm as the real bond distance (Fig.13). The coordination number for manganese atoms obtained from the 1 st peak was 6.8. It was found that the bond distance of 0.215 nm corresponds to the Mn-O bond due to the octahedral structure of [MnO₂(H₂O)₄] in the modified hopeite crystals (Fig.14).

View full abstract

A -planar-type oxygen sensor using a NAFION thick film 'was -developed- for monitoring oxygen partial pressures at ambient temperature (Fig.1). The NAFION thick film was coated on an alumina substrate, and on top of it the counter Au electrode, and the sensing Pt electrode were deposited, leaving a space 0.5 mm in between, by means of RF sputtering (Fig.2). The electromotive force (EMF) of the sensor was found to vary logar ithmically with oxygen partial pressure at 25°C, in accordance with the Nernst 's equation (Figs.3 and 4). The short-circuit current of the sensor was also found to respond almost linearly to the oxygen partial pressure at 25°C (Fig.5). The humidity dependence of the EMF and the 'shortcircuit current of the sensor was scarcely observed under highly humid atmosphere (Fig.6). The 90% response time in amperometric sensing was about 1, min during increasing oxygen partial pressure (Fig.7). This planar type sensor would be compatible with miniaturization as well as simplification at the point that the reference gas flow is not necessary.

View full abstract

The effects of nickel sources on the physical properties and catalytic activities of nickelalumina catalysts were investigated. The catalysts were prepared by impregnation method using five kinds of nickel compounds (nickel nitrate, nickel formate, nickel acetate, nickel carbonate and nickel chloride) as nickel sources.
The nickel particle size observed by puls e reaction technique and TEM showed that catalysts prepared from nickel carbonate and nickel formate gave large nickel crystallites, while those prepared from nickel nitrate and nickel acetate exhibited high dispersion. TPR measurement revealed a strong nickel-alumina interaction in the catalysts prepared from nickel formate and nickel carbonate. On the other hand, the catalysts prepared from nickel nitrate and nickel acetate showed a weak nickel-alumina interaction. The nickel particle size was correlated with the nickel-support interaction in these catalysts and they can be controlled by nickel starting materials.
The activities of the catalysts for the hydrogenation of benzene and the dealkylation of toluene were investigated. The catalysts prepared by using nickel nitrate and nickel acetate showed high activities for both reactions while the catalysts prepared from nickel formate and nickel carbonate exhibited low activities. The nature of the active sites produced on the supports from the various nickel sources was discussed from the standpoint of the carrier effects.

View full abstract

In order to investigate the effect of alkoxyl groups in the regioselective cleavage of cyclopropane rings, n-methoxybicyclo[n-3.1.0]alkanes (n=6, 7, 8 and 9) and n-cyclohexyloxybicyclo[n-3.1.0]alkanes (n=6 and 7) were hydrogenated with palladium-charcoal (Pd-C)or Raney nickel catalyst in methanol solution at room temperature under the atmospheric pressure. When the methoxy derivatives were hydrogenated, endo and exo isomers of cornpounds with n=8 and 9 were cleaved at the adjacent bond of the methoxyl group exclusively. In the case of the compounds with n=7, the exo isomer was exclusively cleaved at the adjacent bond, whereas the endo isomer was cleaved at the opposite bond of the methoxyl group (condensed bond) accompanied by the cleavage of the adjacent bond. In the hydrogenolysis of the compound with n=6, the opposite bond was cleaved more easily. The endo isomer was exclusively cleaved at the opposite bond to give cyclohexane as a main product. The exo isomer was cleaved at the both bonds and gave significant amount of methoxycyclohexanes. The behavior of n-cyclohexyloxybicyclo[n-3.1.0]alkanes were similar to those of methoxy derivatives. These results suggest that releasing the intermolecular strain is the dominant factor on the regioselective cleavage of these cyclopropane derivatives. The alkoxyl group does not always play as the electron-donating group but behaves as the electron-attracting group by the adsorption on the catalyst surface and assists the cleavage of the adjacent bond of alkoxy substituent.

View full abstract

Hidasuki is a characteristic red-colored pattern on the surface of Bizen-Yaki and it is only where straw ropes are wound that Hidasuki appeares. In this study heating process of a mixture of halloysite, one of the clay minerals in Bizen-clay, and potassium chloride was studied to clarify the formation mechanism of Hidasuki. At its dehydroxylation temperature, halloysite reacted with potassium chloride to form two volatile substaces, hydrogen chloride and water. With the increase of the amount of potassium chloride, the hydrogen chloride and water formation temperature was lowered. The whole quantity of potassium chloride completely reacted with halloysite when the amount added was less than 20 wt% of halloysite at the dehydroxylation temperature (molar ratio of halloysite to potassium chloride is 1 to O.6 ), though 30 wt% was too much to finish the complete reaction. Residual potassium chloride melted at 768°C and it vanished at about 900°C through vaporization. During its vaporizing stage, a small amount of hydrogen chloride was also detected. And at 1042°C, kaliophilite and a small amount of corundum were formed. Kaliophilite reacted with quartz and formed leucite successively at 1240°C. For the exothermic peak at 980°C, caused by the formation of r-alumina or spinel, observed through the differential thermal analysis, it became weaker with the amount of potassium chloride added and further disappeared when more than 20 wt% potassium chloride was added, On the other hand, the amount of mullite formed at 1300°C was found to become greater in proportion to the exothermic peak intensity at 980°C.

View full abstract

Liquid-junction potentials are examined between strong acid solutions or pH-standards and various salt bridge electrolytes. Salt bridge electrolytes with cation transference numbers smaller than that of KCI are recommended for measurements of the hydrogen ion concentrations in acid solutions because they reduce changes in liquid-junction potentials resulting from the hydrogen ions. Apparent response slopes of a glass-reference electrode pair determined with two pH-standards (phthalate and neutral phosphate) were approximately proportional to the transference numbers of cation in salt bridge electrolytes. The well-known requisite that the transference numbers of symmetrical electrolytes should be nearly 0.5 in order to minimize liquid-junction potentials in the pH region near to neutral was confirmed on the basis of both the liquid-junction potentials in acid solutions and the apparent slopes of pH-response. A mixture of KC1 (3.03 mol. dm^-3) and CH₃CO₂Na (0.97 mol?dm^-3) is suitable for general measurements in the pH region between 4 and 9 because the ideal Nernstian slope is obtained with three standards (phthalate, neutral phosphate, and borate) at 25°C. A 3 mol.drn^-3 solution of KNO₃ is also useful as the salt bridge of single electrolyte because a straight calibration line is obtained with three standards within an experimental error although its response slope is lower than the Nernstian one. The salt bridges with KC1-CH₃CO₂Na or KNO₃ are useful for the pH of carbonate or oxalate standard, respectively, as well as the above-mentioned three standards, if an error of about 0.01 pH unit is allowed. The KNO₃, salt bridge is superior for practical use to the KC1 salt bridge which has been widely utilized because it gives good linearities in the calibration with standards.

View full abstract

The extraction of potassium picrate (Pic^-) with 18?crown-6 (L) into 9 kinds of solvents has been studied at 25.0°C. The overall extraction equilibrium in all solvents used is shown by following equation; K⁺+Lo+Pic^-=KLPic_o, where subscript "o" and Pic- show organic phase and picrate ion, respectively. Extraction constants of ion-pairs KLPic (K_ox=[KLPic]₀/([KL⁺] [Pic^-]), were calculated from stability constant between K+ and L in the aqueous phase, distribution coefficient of L (K_dL, ) and overall extraction equilibrium constants. The values of log Kex are 4.95 (CH₂Cl₂), 4.85 (CHC1₃), 4.43 (CH₂C1CH₂C1), 3.39 (C₆H₅C1), 2.31(C₆H₅CH₃), 1.91 (rn-(CH₃)₂C₅H₄), 1.51 (C₆H₅CH(CH₃)₂), 1.48 (CS₂), and 1.04 (C₂H₅OC₂H ₅). It was found that there was a good linear relationship between log Kex and lo g K_d. _L. Distribution coefficients of KLPic (log K_d) between water and benzene analogues were successfuly explained in terms of the regular solution theory. Solubility parameter and molar volume of KLPic were found to be 12.3 (cal. cm^-3)1/2 and 280 cm3. mo1^-1. Absorption spectra of KLPic in the extraction solvents show ed that KLPic would be considered to be solvated in solvents, CHC1₃, CH₂C1₂, CH₂CICH₂C1, and C₂H₅OC₂H₅. Then, higher K_d value of these solvents than predicted one would be due to the solvation to KLPic in the organic phase. Linear relation ship between log K_ex and log K_{d, L}, was theoretically explained by the regular solution theory, in which solvation of extraction solvent to KLPic and L was taken into account. The slope of the curve agreed well with the ratio of the molar volume of L calculated from X-ray data to that of KLPic determined here.

View full abstract

The compounds 9-(2-dimethylaminomethylphenyl)fluorene 4 and 9-(2-dimethylaminomethylphenyl)9-fluorenol 5 were prepared from 9-(2-methylpheny1)-9-fluorenol 1 via several steps. It turned out that their predominant conformer was sp-form at room temperature. By the addition of trifluoroacetic acid into the CDC1₃ solution of 4, trifluoroacetate of 4 was formed and the predominant sp-form of 4 was changed to ap-form of the salt. In this case, the stability of the op salt could be ascribed to a presence of the N-H-. π interaction between ⁺NH(CH₃)₂, group and the fluorene ring. The fact that the interaction in 4-ap s alt was stronger than that in 9-(2-dimethylaminophenyl)fluorene 6 could be accounted for by the stronger basicity of dimethylaminomethyl moiety of 4 than that of dimethylamino moiety of 6. Furthermore, the effect of the acidity of added acid on the conformational equilibrium of 4 salt was investigated by use of acetic acid to compare with trifluoroacetic acid. Rotational Isomerism in Fluorene Derivatives. XIX.

View full abstract

The reactions of 1-aryl-2-hydroxy-1-alkanone dimethyl acetal 1 with dibromotriphenylphosphorane 2 or dichlorotriphenylphosphorane 3 in the presence of pyridine at reflux ternperature gave methyl 2-arylalkanecarboxylate 4. The acetals 1 having an electron-donating group on the aromatic ring gave 4 in 94-95% yield. On the other hand, the reaction of 1with diiodotriphenylphosphorane 5 gave 1-aryl-1-methoxy-2-alkanone 6 in a high yield (8488%). It is assumed that the reacti\ons of 1 with 2 or 3 proceed through an intermediate formed by the 1, 2-migration of aryl group and the elimination of triphenylphosphine oxide from alkoxyphosphonium salt 7, and that the reaction of 1 with 5 proceeds through an oxirane formed by the elimination of methyl iodide and the phosphine oxide from 7.

View full abstract

Amphiphilic phosphate monomers "Sodium alkyl 2-hydroxy-3-methacryloyloxypropyl phosphate(C_n-AHMP-Na)" were synthesized by the reaction of sodium alkyl hydrogenphosphates (C_n-MAP-Na) and 2, 3-epoxypropyl methacrylate (EPM). The analyses of HPLC and ³¹PNMR spectra of C₁₂-AHMP-Na showed that the opening of the epoxy ring of EPM was the β-fission. Some physicochemical properties of Cn-AHMP-Na (solubility in several types of solvents, critical micelle concentration (cmc), surface tension, free energy of micellization, area per molecule) were measured. (Tables 1, 2, Fig.4). As shown in the phase diagram (in the ra nge of 25-100°C) of a C₁₂-AHMP-Na/water system, micellar solution (under 36% C₁₂-AHMP-Na concentration), midd le phase (39-62%), lamellar phase (67-72%), and crystal (over 85%) were observed (Fig.5), In order to fix the middle phase structure, the C₁₂-AHMP-Na/Water (1: 1) mixture was tried to photo-polymerize, but the middle phase structure was not stabilized and an isotropic polymer was obtained, C_n-AHMP-Na monomers were easily polymerized in aqueous solution by a radical initiator. C₁₂-AHMP-Na homopolymer increased the viscosity of the aqueous and methanolic solutions., Cross-linked polymers, prepared from C_n-AHMP-Na and polyethyleneglycol diacrylate, absorbed water (20-70 gig-polymer) and methanol (40-64 gig-polymer), but did not absorb ethanol so much (0.04-4.2 gig-polymer) (Table 3). The Reaction of Epoxy-compound with Phosphate. I

View full abstract

Photovoltaic properties of multilayer-type organic thin film solar cells were investigated. Phthalocyanines (Pc) and perylene derivatives (PTC) shown in Fig.1 were employed for ptype and n-type layers, respectively. The cell structure was Indium tin oxide (ITO)/PTC/Pc/Au, and the cells were irradiated with white light through the ITO electrode. The thicknesses of organic layers were typically 500Å. Positive voltages appeared on Au electrodes with photo-irradiation. Short-circuit currents of the cell were proportional to the light intensity of incident light, and open-circuit voltages were proportional to the log (light intensity). The wavelength dependence of short-circuit currents reflected the absorption spectra of both Pc and PTC layers, indicating the occurrence of effective carrier generation in both organic layers. Power conversion efficiencies of the cells ranged between 0.02 and 2.0 6% at the incident white light of 11.2 mW/cm² (Tables 2 and 3). The highest po wer conversion efficiency was obtained in the ITO/H₂, Pc/PV/Au cell, and the fill factor of the cell was 0.61. The major factors that determined short-circuit currents, open-circuit voltages, and fill factorsiwere discussed.

View full abstract

The Second Harmonic Generation (SHG) of 50 various alkylthio substituted chalcones which are quite different from nitroaniline derivatibes were investigated. A series of compounds having halogen substituent in the 4'-position showed high SHG activity and a high blueregion transparency. As a result of crystal structure analysis of 4-methylthio-4'-chlorochalcone, the crystal was noncentrosymmetric structure which belonged to space group Pc, and molecules were piled up in the same direction in parallel and its dipole-moment remained strong in the crystal.

View full abstract

The economical recovery methods of indium in the sulfuric acid leaching soln. of zinc leach residue (103 mg In.dm^-3-2.1 g Fe³⁺. dm^-8-4.1 g Fe²⁺. dm^-3-8.1 mg Ni. dm^-3-pH 0.7) with chelate resin containing aminomethylphosphonic acid moiety (MC-95), were examined. By the reductione of Fe³⁺ to Fe²⁺ in the leaching soln the adsorptivity for iron on MC-95 was almost lost and that for indium on MC-95 was increased to 1.5 to 2 times. Indium adsorption rate at 60°C was 1.5 times as fast as that at 25°C. It was found that indium adsorbed on MC-95 was able to be eluted with a mixed aq. soln. of sodium sulfide and sodium hydroxide, and that indium in the eluate was able to be deposited and recovered neatiy 100% yields by the oxidation of sodium sulfide in the eluate. Indium hydroxide of more than 99% purity was recoverd effectively by the enforcement of the following process in order: (1), the reduction of Fe³⁺ in the leaching soln., (2) the contact treatment of MC-95 with reduced leaching aq. soln., (3) the elution of metal ions other than indium by the contact of MC-95 with 2mol H₂SO₄. dm^-3 aq. soln., (4) the elution of indium by the contact treatment of MC-95 with O.0 4 mol Na₂S. dm^-3-2 mol NaOH. dm^-3. aq. soln., (5) the oxidation treatment of the ind ium eluate, and (6) the filtration. StudiesmSeparation, Recovery of PurificationofIndium. II,

View full abstract

Environmental behavior study was cariefl out for LAS, TBP and HCB in Tokyo Bay and some rivers of its drainage basin (Fig.1) The concentrations of these chemicals in water, sediment and fish were analyzed by high-performance liquid chromatography or gas chromatography after solvent extraction or solid phase enrichment. In two surveys in fall (Fig.2 and 6), the concentrations of LAS or TBP in water were high in the river areas, and low in the coast areas of the bay. Much lower concentrations were found at the sites away from the coast. Mixing of fresh water and sea water plays an important role in determining the concentrations of chemicals in the bay water. HCB was found in the bay water only in the survey soon after the rivers had risen by storm in summer (Fig.4). LAS was also found to be low concentrations in the survey. These results showed that there happened much release of HCB absorbed on river sediment and soil to the bay from its drainage basin only in the heavy rainfall, while hydrophilic LAS was always transported into the bay. Input of chemicals to the bay is affected by their physicochemical properties and weather conditions. Biochemical and physicochemical properties of chemicals control their behaviors after they are discharged into the bay. The concentration of more biodegradable LAS was decreased more rapidly than less biodegradable TBP in the bay water. Hydrophobic HCB was highly concentrated in the sediment or the fish.

View full abstract

The occurrence conditions for cold nuclear fusion were researched using palladium and titanium rods. In researching the conditions of fusion, it is important to examine fusi on rates absolutely. In order to detect a very small amount of neutrons quantitatively from the other radiant rays (γ-ray), the well-type neutron detector coniposed of an NE-213 liquidscintillator and a pulse shape discriminator was made (Figs.1, 2). This detector was found to detect the fusion rate more'. than 1 x 10^-22d-d/s.
The phenomena of fusion were investigated for the ele ctrolysis method and the gas absorptiondesorption method by this detector. In this electrolysis method, D2O containing 0.1mol. dm^-8 LiOD was electrolyzed under several conditions (Table 1) by using the electrochemical cells consisted of the palladium cathode and the platinum anode. There was no difference between the energy spectra during electrolysis and the background energy spectra (Fig.6). On the other side, in a gas absorption-desorption cycle method (Figs.3, 4), generation of neutron was tested for casted titanium rods. In this case, it was found that 2.452 MeV specified neutron signal could not be caught but about 30-600 times larger radiation signal than the background was detected during the desorption process of D₂ from titanium (Figs.8, 9). We presume from the results of detector with an NE-213 scintillator that the radiation would be γ-ray and that γ-ray generation would come from p-D reaction in titanium rods.

View full abstract

Synthesis of 2, 4'-dinitrodiphenyl ether (2, 4'-DNDPE), an intermediate of high-functional polymers, was carried out by the condensation of p- or o-chloronitrobenzene and sodium - or p-nitrophenolate in 1, 3 -dimethy1-2-imidazolidinone (dipolar aprotic solvent) at 1o40 and 180°C (Table 1 and Table 2). It shows that it is difficult to obtain 2, 4'-DNDPE selectively in high yield by this method due to by-production of 4, 4'- and 2, 2'-isomers. The results imply that the nucleophilic substitution occurs between dinitrodiphenyl ether and sodium nitrophenolate (Scheme 1).

View full abstract