The microwave spectra of propyl nitrite, CH₃CH₂CH₂ONO, and its ¹⁵N isotopic species were observed in a frequency range from 18 to 32 GHz. The ground state a-type R-branch and b-type Q-branch transitions were assigned. They were found to correspond to a cis, trans, trans form (sp, ap, ap form) { τ₁(CO-NO) =0°, τ₂ (CC-ON) =180°, τ₃(CC-CO) =180°}. The following rotational constants for the ground state were determined:
The τ₀ structure of cis, trans, trans-propyl nitrite was derived from a least-squares fit of these six rotational constants with reasonably assumed parameters for propyl group as shown in Table 4.

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Iron(III) forms a more stable complex with edta than with 1, 10-phenanthroline (phen), while iron(II) shows the opposite behavior toward the two ligands. The coordination number of iron(II) is six. Since edta is a sexadentate ligand and phen is a bidentate one, ligand replacement of Fe(II)-edta by three molecules of phen is expected.
In order to elucidate the mechanism of the ligand replacement, Fe(III)- edta was cathodically reduced to Fe(II)-edta in a solution containing phen. The reaction rates of the replacement were obtained by measurement of the disappearance rate of Fe(II)-edta with the rotating ring-disc electrode method and by the formation rate of Fe(II)-phen with the spectroelectrochemical method. The rate constants obtained by the two methods agreed closely with each other. The reaction was first order with respect to the concentration of phen.
The activation energy obtained from the Arrhenius plot was small (7 kcal×mol^-1), ne vertheless the rate constant of this reaction, 2.6 x 102 mol^-1·dm³·s^-1 at 25°C, is very small compared with those reported for other ligand replacements. This suggests that on account of steric hindrance the replacement of the third phen molecule is the rate-limiting step.

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The cyclic voltammograms (CV's) in 98% H₂SO₄ were measured on the vapor-grown-based and PAN-based carbon fibers heat-treated at various temperatures. The CV's were strongly dependent on the heat-treatment temperature. The CV of the vapor-grown-based carbon fibers showed the distinct anodic current peaks suggesting the stage transition of the intercalation compound of graphite-sulfuric acid. It also distinguished between the cathodic peaks corresponding to the reduction of the intercalation compound and the graphite oxide. In the CV of the PAN-based carbon fibers, the anodic peaks due to the stage transition of the intercalation compound were not observed. The onset potential of the carbon fibers was measured to be threshold potential which showed the beginning of a marked increase in the anodic current with the degree of 5 μA/mV. The linear relationship was obtained in the plots of the onset potential (first scan) vs. the interlayer spacing d₀₀₂. The vapor-grown-based carbon fibers showed less positive potential of the anodic peak and more positive of the cathodic one compared with the mesophase-pitch-based carbon

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A novel technique to inhibit the deposition of silica scale, which is one of the most serious problems in the utilization of the geothermal energy, is presented. In this techni que pH change only near the deposition surface is attained.
As indicated in Fig.2, the maximum depos i tion rate of the silica scale was found at pH around 9. In regions lower and higher than this pH the deposition rate decreased. The most suitable pH region to inhibit the deposition of the silica scale was found to be the higher region than the maximum pH because of the extremely higher solubility of silica in this alkaline region as well as the low deposition rate. Since it was not necessary to change the pH in bulk solution, the pH change only near the surfa ce on which the silica was deposited was performed by cathodic electrolysis of the so lution on this surface. In this electrolysis OH- is generated by the reaction
H₂O+e^- 1/2H₂+OH^-
to make the pH near the surface hi gher than that of the bulk solution, which is pH 7-8 in most geothermal brines.
Inhibition experiments o f the silica scale deposition to the surface of a heat exchanger from a silica solution (total silica 0.04 mol/dm³, NaCl 0.2 mol/dm³, pH 8.5-9.5) were carried out. The stainless steel surface was kept at 50°C and acted as a cathode aga inst a Pt counter electrode in the solution. At a current density of 0.1 m A/cm² the silica deposition rate decreased to 1.8 mg/cm², nearly a half of the rate at no current as sh own in Fig.3. At 1.0 mA/cm², the silica scale deposition was almost completely inhib ited. The lowest current density necessary to inhibit the deposition of silica scale was O.7 5 m A/cm² as shown in Fig.4.
The silica scale which had been already formed on the surface with no current for two days disappeared after passing a current of 1.0 mA/cm2 for 1 h, as indicated by (+)in Fig.3. In this case the pH near the surface could be high enough by the electrolysi s to dissolve the silica scale.

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The lattice constant of LiCoVO₄, measured by X-ray diffractometry, increases with the elevation of the sintering temperature from 8.291Å at 500°C to 8.297Å at 1000°C (Fig.2). The increase is probably caused by the increase in the concentration of Co²⁺ ion at the tetrahedral sites in the spinel-structure of (CO_x V_1-x)^IV(LiCo_1-xV_x)^VIO₄.
Electrical conductivity measurement at temperat ures between 450 and 1000°C in air by the d. c. four-terminal method has. revealed that the Arrhenius plots of the electrical conductivities of LiCoVO₄ and LiNiVO₄ lie on almost the same straight line with the value of log (σ/S·m_-1)≠2 at 1000°C, and the activation energy is about 2.7 x 10⁵J·mol^-1 in the higher temperature range than 800°C. In the lower temperature range than 800°C, the activation energies of conduction are about 4.1 x 10⁵J·mol^-1 for LiCoVO₄ and about 9.6 x 10⁵J·mol^-1 for LiNiVO4 (Fig.3).
The thermogravimetric study of the stability of LiMVO₄ (M = Co, Ni) under low oxygen partial pressures at 950°C has revealed that LiCoVO₄ and LiNiVO₄ are stable down to the oxygen partial pressures of 6.3 x 10^-15 and 6.3 x 10^-14 atm, respectively (Fig.4).

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A method for the determination of total sulfur in rocks by means of -a simple sulfide ion-selective electrode was developed. A powdered rock sample was heated to solve with tin(II)-strong phosphoric acid at 280°C for 25 min in a flow of nitrogen gas. Hydrog en sulfide formed from sulfide and sulfate-sulfur in rocks by reducing with tin (II)-strong phosphoric acid was absorbed in the mixture solution of sodium hydroxide, glycerol, EDTA and L-ascorbic acid. The pH-value of this solution was kept above 12.3. After being diluted in the volumetric flask with the fresh absorber mentioned above, the solution was poured into a beaker in which the sulfide ion-selective electrode and a reference electrode were dipped, and the electrode potential was measured stirring the solution with a magnetic stirrer. The sulfur content was determined by referring the electrode potential readings to the calibration curve prepared with a standard sodium sulfide solution. Since the electrode potential was very sensitive to the temperature of the solution, the calibration curve was carefully corrected each time to perform the experiment. Each rock sample of 100 mg was enough to determine the total sulfur in the range from O.1 to 1000 ppm (mg/kg). A typical coefficient of variation was 1.88% for the sulfur, content of 198 ppm. For the check of validity of this method the total sulfur contents of several standard rock samples were determined. All results showed good agreement with those determined by other methods.

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The preconcentration of the trace amount of molybdenum in water using dibenzyldithiocarbamate(DBDTC) as a chelating agent and the subsequent determination by X-ray fluorescence analysis has been studied.
The proposed analytical procedure established from the results obtained under various experimental conditions was as follows. An adequate amount of sample solution containing molybdenum was taken and a given volume of DBDTC solution was added at 30°C after adjusting to pH 3.0. The precipitate of Mo-DBDTC chelate was allowed to stand for 15 min, collected on a membrane filter, dried at room temperature and delivered to X-ray fluorescence analysis.
The results in the basic experiments are; 1) The chelate-formation ability of DBDTC was found excellent in view of the fact that the recovery of molybdenum was 99.5%, 2) The caliblation curve showed linear relationship between X-ray intensity and molybdenum amount in the range of 3-30 μg/l, and 3) The standard deviation and the coefficient of variation in ten determinations were 0.21 and 2.11%, respectively, when eleven aqueous sample solutions containing 10.0 μg/l of the element were measured.
The results in seawater samples are; 1) The value by the method mentioned ab ove agreed with the value by the standard addition method, 2) The slope of the straight l ine of the standard addition method was approximately equal to that of the above calibration curve, and 3) The standard deviation and the coefficient of variation in five determinati ons were 0.22 and 2.24%, respectively. These results suggest that coexisting electr olytes in seawater do not interfere with the determination of molybdenum. The recommended procedure was applied to the determination of molybdenum in a seawater sample, and obtained data (10.0 μg/l) agreed to the value of the published data.
The above results indicate that this method is useful for det ermination of the trace amount of molybdenum in water and seawater.

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The titanium(IV) oxide powders were prepared by calcining titanium(IV) hydroxide slurry, which was provided by hydrolysis of titanium(IV) chloride, in the temperature range of 100 to 1000 °C. The thermal decomposition process of the slurry was examined by DTA, TGA and XRD. TiO₂ powders was mainly analysed by means of XPS, PAS an d ESR. No difference in XPS spectra could be detected in the TiO₂ prepared by differe nt methods except that the O_2P, band spectrum was changed with crystal structures ( Fig.3). The PAS spectrum was changed with the crystal structures, depending on the preparation methods. It was revealed by PAS that the anatase had a stronger absorption than that of the rutile at the longer wavelengths of 420 nm or above (Fig.5). A sharp signal in ESR spectrum at around 330 mT appeared in the anatase and TiO_2-xunder irradiation of light, which was supposed to be due to C^2- ion produced by photo-oxygen reduction (Fig.7).
The signal intensity was changed with the preparation methods and proportional to the x-value of TiO_2-x (Fig.8).
Platinum (4.8 wt%) loaded anatase exhibited an excellent photocatalytic activity for photo. dehydration reaction of 2-propanol in water. This activity increased with an increase in crystallinity of the anatase (Table 1).

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Naphtho[2, 3-d]thiazole-4, 9-diones having a substituent in the benzene ring, which were expected to have interesting physiological activities or dyeing properties, were synthesized. Chloronaphtho[2, 3-d]thiazole-4, 9-diones were obtained by amination of 2, 3, 5- and 2, 3, 6-trichloro-1, 4-naphthoquinones followed by ring-closure reaction. Nitration of nap. htho[2, 3-d]thiazole-4, 9-dione in fumic nitric acid-sulfuric acid at 50°C afforded four mononitro compounds: 8-nitro(a major product), 5-nitro, 6-nitro, and 7-nitro derivatives. The structures of 5-nitro and 8-nitro derivatives were determined by deriving the m to the corresponding chloro derivatives. The effects of substituent and thiazole ring in naphtho[2, 3-d]ithiazole-4, 9-diones on the reaction and properties were discussed.

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The Claisen rearrangement of allyl phenyl ethers bearing sodium or potassium oxido group in ortho position was carried out. Their reactivities were about 1800 or 1000 times larger than that of allyl phenyl ether and high ratios of p- to o-rearranged product were observed.
From the results of the experiments, metal oxido groups seem to be mostly dissociated into ions, and metal oxido groups operate accelation effect on the reaction due to the following factors.
(1) Intra molecular repulsion between the oxygen of ether and 0- of the metal oxido group.
(2) Strong electron-releasing effect of 0- in metal oxido group.
Consequently, the specificity of the compounds having metal oxido group in ortho position was attributed to the above two effects operating together.

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Oxidation reaction of phenylhydrazine in various ethers (Et₂O, n-Pr₂O, i-Pr₂O, n-Bu₂O, i-Bu₂O, n-Bu-O-Et, Furan, Anisole, Phenetole) were investigated. Reactions were carried out at 20-25°C for 1 h. in the presence of aqueous solution of sodium periodate.
Benzene, phenyl azide, aniline, biphenyl, azobenzene, and diphenyla mine (trace) were obtained in all reactions.
In addition, phenylhydrazones, 1-(phenylazo)alkyl ethers were obtained in the case of aliphatic ethers and phenyl-substituted ethers in the case of aromatic ethers (see Table 1 and 2).
Pheny l azide and aniline did not react with sodium periodate in the above reaction conditions.
The reaction routes leading to each product are discussed.

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Noncatalytic liquefaction of Morwell coal with tetralin was studied at temperatures of 400 to 450°C, pressures of 20 to 60 MPa, and residence time of 4 to 20 min by continuous flow method. Liquefied products were fractionated into unreacted coal, preasphaltene, asphaltene, and oil. The yield-time profiles were shown in Figs.1 and 2. Chemical reaction. engineering analysis was performed for those profiles using the model involving all possible pathways for the formations of preasphaltene, asphaltene, and oil from coal. Pseudo-firstorder rate constants for each of these mechanistic steps were estimated by nonlinear regression and were compared with those of Wandoan coal described previously. The analytical results by mathematical modeling showed that the liquefaction mechanism of Morwell coal was more complex than that of Wandoan coal due to the direct formation of asphaltene from coal, and that pressure acceleration for initial stage of dissolution of Morwell coal was fairly larger than that of Wandoan coal as shown in Fig.3. The reason for this is also discussed.

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Selective hydrogenation of pyrene and fluoranthene to the corresponding partially hydrogenated derivatives was studied using noble metals on carbon under 30--70 atm of hydrogen. Pd/C catalyst was most selective to produce dihydro- [2]and tetrahydropyrene [5] with the best yields of 48% and 84% at 200°C and 150°C for 1 h and 16 h, respectively. The decreasing yield of [2] with the prolonged reaction time was due to its successive hydrogenation. Higher reaction temperature of 300°C and use of Rh/C catalyst were favorable for the production of hexahydropyrene [3]. Because of the favorable production of [2] and [5] at lower temperatures, rapid heating to the reaction temperature was suggested to be effective to obtain an increased yield of [3]. Hydrogenation of fluoranthene was more rapid and selective: the reaction using Pd/C catalyst at 100°C for O.5 h at 20 atm provided tetrahydrofluoranthene in 77% selectivity at 100% conversion. Based on the product analyses in the course of the reactions, competitive and successive nature of pyrene hydrogenation were suggested. Hydrogenative isomerization of [5] to [3] was ascertained to occur in the reaction with [5].

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Friedel-Crafts reactions of o-xylene, indan and tetralin with benzenesulfonyl chloride in the presence of aluminum chloride in nitrobenzene were studied about temperature effect on isomer distribution under kinetic conditions.
It was found that in indan, the isomer ratio (3-/4 -) increased with temperature, while the ratio (3-/4-) were decreased in o-xylene and in tetralin.
Differences of activation energies and activation entropies in the 3- and 4-position for o-xylene, indan and tetralin were -0.39 kcal/mol, -2.0 e. u. /mol, 0.16, 0.2, and 0.31, 1.5, respectively.
Isokin etic temperatures were 81 and 62°C for o-xylene and tetralin, respectively.
These results suggest that 3-position of o-xylene or tetralin is more reactive than 4position, whereas 4-position is more reactive in indan.
It was conclued that the reaction proceeded with a concerted mechanism in which strong acid-catalytic effect by aluminum chloride and base-catalyzed deprotonation by solvent and/or AlCl₄^- on 3-position were observed in o-xylene and tetralin.

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From the leaves of Leucothoe grayana Max., (3S, 6R, 14R)-3, 6, 14, 16-tetrahydroxy-5, 10seco-ent-kaur-1 (10)-en-5-one [1] was isolated as a new diterpenoid. Its structure was determined by a combination of 400 MHz 'H-NMR decoupling experiment and the conversion of[1] into grayanotoxin II [4].

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Cobalt(II) complexes with mixed ligands of cyanide and 1, 10-phenanthr6line(phen)were found to initiate polymerization of methyl methacrylate(MMA) in an aqueous 'solution containing a surfactant under hydrogen atmosphere. The polymerization of MMA by the complex with the Co/CN/phen ratio of 1: 1: 1 was exclusively investigated. Since the polymerization proceeds only under a hydrogen atmosphere, the hydride of the above complex is the initiator. The polymerization was inhibited by 2 2'-diphenyl-1-picrylhydrazyl. The copolymer composition curve for the copolymerization of MMA with styrene by this initiator was similar to that for the ordinary radical copolymerization. Thus, it is considered that the polymerization of MMA by this initiator proceeded with a radical mechanism. The effective surfactants were the nonionic Tween and Brij types.

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A thermal desorption method by fluidized bed was developed and applied to activated carbon particles containing benzene. The effect of gas temperature, gas flow rate, the amount of activated carbon, desorption time and initial amount of benzene on desorption rate and desorption efficiency were investigated. The desorption rate curve could be approximated by a simple equation consisting of two exponential functions with desorption rate constants. The constants were most affected by the desorption temperature. Desorption efficiency increased with the increasing gas temperature and desorption time, and slightly decreased with the increasing amount of activated carbon, but was not affected signifi cantly by the gas flow rate. When the initial benzene content in the activated carbon increased, the desorption efficiency increased, however, the residual amount of benzene after thermal desorption was almost constant.

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Complex resins obtained by the reaction of polyethylenimine wiih maleic anhydrideisobutene copolymr revealed selective ion adsorption depending on the equivalent ratio of nitrogen to carboxyl group (N/COOH). In detail polyanion-excess complex resins (N/COOH <1) have high adsorption capacity, especially for metal cations such as Cu²⁺ and Zn²⁺, and the resins containing excess polycation (N/COOH>1) are effective for me tal complex anions such as Cr₂O₇^2- and [Cu (edta)]^2-
From the results of adsorption measur e ments of various anions by the polycation-excess complex resin (N/COOH =1..79), it was found that Cr₂O₇^2- had especially high adsorption characteristics.
At pH<6, Cr₂O₇^2- in solution was removed to be less than 0.03 mg·dm^-3 as Cr(VI), though some parts of Cr(VI) changed to Cr(III) through the reduction by the presence of the resin at pH<5.
The results of column test using real wastewater, which contains 10 mg·dm^-3 Cr(VI)and 5000 mg·dm^-3 inorganic salts such as LiBr, indicated that this resin could be effectively used for the treatment of wastewater containing Cr₂O₇^2-.
Moreover, it was found that adsorption amo u nt of Cr₂O₇^2- for this resin increased with an increase of temperature (20-80°C), in contrast with the results for other anion exchange resins.
This res u lt is considered to be caused by the fact that this resin is more durable in the hot water compared to other anion exchange resins.

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The intercalation of histamine (Hist) by α-zirconium hydrogenphosphate proceeds in three steps, resulting in the formation of a complex, Zr(HPO₄)₂(Hist)2·3H₂O, in which the guest molecules are intercalated as a bilayer (12.6Å in thickness). γ-Zirconium hydrogenphosphate intercalates histamine in one step to form a complex, Zr(HPO₄)₂(Hist)0.6·1.5H₂O, containing a monomolecular layer Of 4.9Å thickness in the interlayer space. The striking contrast between the intercalation behavior of histamine towards α- and γ-zirconium hydrogenphosphate is attributable to the difference in the bonding fo rce between the host matrices and the guest molecule, du, e to their structural characteristics.

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New titanium electrodes coated with electroconductive Pb-Ti double oxides were prepared by the electrodepositiort of the oxides from alkaline solutions containing Pb²⁺ and Tl⁺ ions and found to be useful as practical anodes, at least for laboratory works. The electrodes showed characteristic product-selectivities which were different from those of conventional anode materials in the electrooxidation of organic compounds such as acetate ion and 2, 3-butanediol.

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