The microwave spectra of ethyl nitrite (CH₃CH₂O¹⁵NO or CD₃CD₂ONO) have been assigned between 8.5 and 32 GHz, and the rotational constants for three rotational isomers-cis-trans, cis-gauche, and trans-gauche have been obtained. The rotational constants of these isomers for normal species have already been measured by Turner (1979). A least squares fit of the rotational constants obtained by this study and those obtained by Turner gave the values of r0, structural parameters of ethyl nitrite, which are shown in Table 5. The dihedral angles were found to be 96.5° and 86.0° for cis-gauche and trans-gauche isomers, respectively. The CON and ONO bond angles of cis-gauche form more broadened than those of trans-gauche one by 2.8° and =10°, respectively; these changes were considered to show the existence of considerable steric effect between alkyl group and terminal oxygen atom.

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The effects of L-α-alanine on peptization, dispersion and coagulation of iron(III) hydroxide particles were investigated. Firstly, iron(III) hydroxide was peptized by adding the precipitate into an aqueous solution of alanine and boiling for 8h. The effects of alanine concentration and pH value on peptization were examined. Secondly, coagulation of a iron(III) hydroxide sol, which was prepared hydrolyzing an aqueous iron(III) chloride solution, was examined by a turbidity measurement. The effects of alanine concentration and pH value on coagulation were also examined in this system. Comparing the results of both experiments, precise peptization conditions of iron(III) hydroxide were determined.
It was found that the adsorption of alanine onto the iron(III) hydroxide particles varied the interfacial electrochemical properties of the particles, so that it affected peptization, dispersion and coagulation of iron(III) hydroxide. The complex formed between alanine molecules and iron(III)ions also influenced these phenomena. It was thus concluded that the best peptization was achieved under the following conditions: pH value is lower than the isoelectric point of L-α-alanine(pH6)and the molar ratio of [Alanine] to [Fe]is 0.1 to 0.25.

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The reduction of NO to N₂ using NH₃ as a reducing agent has been investigated over various CuO-Fe2O3-activated carbon catalysts. The mixed CuO-Fe₂O₃-activated carbon catalysts, which were prepared in such an appropriate composition that a CuO/Fe₂O, molar ratio was close to unity and a content of the CuO-Fe₂O₃ component was about 5% based on the total weight of the catalyst, showed a high activity and a high selectivity for N2 formation even at temperatures below iocec. In addition, there was a significant difference in temperature-dependence of the catalytic activity between CuO-Fe₂O₃-activated carbon and CuO-activated carbon: the former ternary catalyst retained its high activity even at temperatures higher than 200°C, while in the latter binary catalyst a drastic decrease in the activity was observed at temperatures above 150°C.
The reaction-rate data obtained at the temperatures ranging from 65 to 85°C enabled the formation of an approximate rate equation. The oxidation state of the catalysts and the role of coexistence of Fe₂O, in the catalytic action were also discussed qualitatively.

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Catalytic oxidation of propane, methane, and carbon monoxide has been investigated on various perovskite-type catalysts, which were prepared by heating the coprecitates of metal acetates or nitrates at relatively low calcination temperatures (850°). The surface areas of the catalystswere comparatively large (2-7²·g^-1). The reaction orders and the apparent activation energies were determined for some of the catalysts.
The general tendency of the catalytic actvity depending on the B-site metal cation was determined to be Co>Mn>Ni>Fe>Cr. Among the cobaltite perovskites, La_0.8Sr_0.2-CoO₃ was the most active and its activity was comparative to or higher than those of the Pt, Pd and Ni catalysts (Fig.2). By substituting Sr" upto 20% in the A-site of LaCoO₃, the catalytic activity increased, but it decreased slightly with further substitution (Fig.3). The catalytic activity of La_0.8SrO₂CoO₃ was changed by the calcination temperature, having a muximum at 850° (Fig.4). As for LaCoO₃, the effect of the calcination temperature on the activity was small. Possible interpretations of the effects of the calcination temperature and of the Sr" substitution were given.

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The reactivity of powder mixtures calcined at 600°C for 1h in He atmosphere was examined on the basis of their behavior at 300°C in a flowing C0+1/2 SO, gas. The tested powders were prepared by mixing mechanically α-Fe₂O₃ and metal oxide, which can be any one of α-Al₂O₃, γ-Al₂O₃, MgO or CaO. All the oxides were well ground to pass a 200 mesh sieve. A reaction gas-chromatographic technique and X-ray analysis were used for the study of the reduction of SO, to sulfur and the analysis of mixed powders after the reactions, respectively. A maximum catalytic activity for the reduction of SO₂, SO₂ + 2 CO→ 1/2 S2 + 2 CO₂ ( 1)and 1/2 S₂ + CO→ COS ( 2 ), was attained at a specific mixing ratio of each mixture. In a single pulse of CO, Fe₂O₈ was easily reduced to Fe₃O₄ but in a mixed pulse of CO + 1/2 SO₂, no change of Fe₂08 resulted. This behavior was discussed in connection with the redox reaction between Fe₂O₃ and nascent Fe₃O₄. The unique catalytic behavior of powder mixtures appeared to be related to the surface reaction of Fe₂O₃ with oxide, which occurred by heating the mixture at 600°C, and property of nascent Fe₃O₄ is probably affected by the surface reaction.

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The nitriding of Nb-Ti (Nb: 20, 40, 60, 80 wt%), Ti-V (Ti: 40, 60, 80 wt%), 50 V-50 Nb (wt%) alloy plates with N₂., (1 atm) were carried out at 1100-1350°C and the kinetics was investigated by a gravimetric method. In all alloys the initial rate of nitriding followed the parabolic law and the parabolic rate constants were obtained. In Nb-Ti alloy plate specimens, the rate constants of 20 Nb, 40 Nb and 60 Nb were nearly equal to one another and that of 80Nb was smaller than those of the others. In Ti-V plate specimens, the rate constant decreased as 40 Ti>60 Ti>80 Ti as shown in Fig.4.
The deposit rate of nitrided phase was investigated by measuring the depth of nitrided phase. The dependence of the deposit rate of nitrided phase on the composition of alloy was different from that of the nitriding rate. From this point of view the deposit rate of nitrided phase in high niobium alloys was discussed by appling internal nitridation equation. The deposit rate of Ti rich nitride depends on the diffusion rate of nitrogen in alloy phase.

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The reaction between ZrP₂O₇ and BaCO₂ in the solid state has been studied for the samples mixed in the range of 10-80 mol% BaCO₃. The mixtures were heated at 1400°C for 24 h or at elevated temperatures up to 1400°C (heating rate: 10°C·min^-1) in air. After the reactions had finished, the quenched samples were subjected to X-ray powder diffractometry. The products in the ZrP₂07-BaCO₂ system were Bar, (PO₄) 6, Bar (PO₄)2, 10 BaO.3 132O₅, ZrO₂ (monoclinic and tetragonal), Ba, (PO₄)2, BaZrO₂, and an amorphous phase of ZrO₂-P₂O₅. The double phosphate BaZr₄ (PO₄)₅ was formed in the range from 0 to 55 mol% BaCO₂ and BaZr(PO₄)2 in the range from 20 to 70 mol% BaCO₂. The composition of 10 BaO.3 P₂0, was determined by chemical analysis. The reaction of the mixtures with 20, 50, and 70 mol%BaCO₂ may be carried out stepwise as hereunder:
Unknown product → (Ba₃(PO₄)₂, BaZrO₂) →(10 BaO.3 P₂O₅, ZrO₂) →BaZr(PO₄)₂ →(BaZre (PO₄)6, P₂O₅).

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Sinterability of β″-alumina powders prepared by spray-pyrolysis technique was investigated. Atomizing liquid was ethanolic solution of sodium, magnesium and aluminum nitrates corresponding to Na₂O·0.6MgO·5Al₂O₃. Maximum flame temperatures were varied from 800 to 1400%°C by controlling the furnace temperature. Powders obtained consisted of spherical hollow particles (1-15 μm) of γ-alumina. Volume shrinkage-temperature curve of the powder compact could be divided into four regions: a small shrinkage at 700-1000°C, a substantial shrinkage associated with the phase change of γ- to β, β″-alumina at 1000-1100°C, no shrinkage at 1100-1250°C, and a shrinkage associated with both sintering and grain growth of β, β″-alumina above 1250°C. The sinterability of as-produced powders was increased by the calcination of the powders at 1100-1200°C before the compaction. When as-produced powders were calcined at 1100°C, the sinterability reached a maximum on the powders prepared at the pyrolysis temperature of about 1100°C. From the SEM observation on the structures of sintered bodies, the effect of pyrolysis temperature can be interpreted mainly in terms of the strength of the shell of hollow particles. For the powders prepared at a higher pyrolysis temperature, the formation of β-alumina resulting from the evaporation of Na₂O may partly be responsible f or their lower sinterability. The powders prepared at 1090°C gave a sintered body with the theoretical density by sintering at 1560°C for 4 h. Compacted pellets shrunk generally more in thickness than in diameter. This anisotropic shrinkage was correlated with the degree of preferred orientation of β, β″-alumina particles in the sintered body.

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4- (2-Thiazolylazo) resorcinol (TAR) forms a water-soluble brown complex, which has the selective absorption at 730 nm. By utilizing this peculiar absorption, a highly selective and rapid spectrophotometric method for the determination of trace amounts of iron has been developed. A recommended procedure is as follows; Take 3 ml of O.1% ascorbic acid and 2 ml of 0.05% TAR solutions in a 50 ml volumetric flask. Add a sample solution containing iron up to 120 itg and adjust the pH to 9.2 with 5 ml of 1 mol/l ammonia buffer solution. After making up to the volume with water, measure the absorbance at 730 nm against the reagent blank. The absorbance of the complex is constant in the pH range from 8.9 to 10.3 and the color is stable for 24 h. The combining ratio of iron ( II) to TAR in the complex was found to be 1: 2 by the continuous variation method. The calibration curve obeys the Beer's law over the range from 0 to 120 pg/50 m/ of iron; the molar absorption coefficient of the complex and the Sandell's sensitivity are 2.90×10⁴l·mol^-1·cm^-1 and 1.92ngFe·cm-^-2, respectively. The relative standard deviation of the absorbance was 3.42×10^-3 for 1 μm/ml of iron (II). As the proposed method utilize the specific absorption of iron (II ) -TAR complex, the presence of many ions can be tolerated. The method was applied to the determination of traces of iron in river water, metals and alloys with a satisfactory result.

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Absorption and emission spectra of indium salts in argonir-hydrogen flame were measured with an atomic absorption spectrophotometer. A hollow cathode type D2 lamp and a laboratory made continuum lamp were used as light sources. The absorption spectra consisted of bands originated from InOH at 200-240 nm, InCl at 261-275 nm and 350 nm, In0 at 253 nm, and several indium atomic lines. In the emission spectra there were bands originated from InH at 448-459 nm and In2 at 277-301 nm, 347-365 nm and 367-388 nm along with several indium atomic lines. The absorbances and emission intensities of these spectra were measured at the heights of 10, 15, 20, 25 and 30 mm above the burner head as a function of hydrogen flow rate. With increasing flow rate the absorbance of InO and InCl and emission intensity of In2decreased, while the absorbance of InOH and In and emission intensity of InH and In increased. The dissociation energies of InH and In2 were very small in comparison with those of the other indium compounds. Thus, the concentrations of In, InO, InOH and InCl in this flame are controlled by the following set of balanced reactions,
InOH+H ⇔In + H₂O
InO + 2H ⇔ In + H₂O
InCl+ H⇔ In + HCl

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Eighteen diethyldithiocarbamato-metal( I-IV) chelates (M(ddtc)_n) were synthesized, and their ¹H- and ¹³C-FT-NMR spectra were measured in CDCl3. The values of the chemical shifts obtained are listed in Table 2. The effects of the central metal atoms on the chemical shifts of CH, protons and the ¹³CC chemical shifts of CS and CH, carbons were investigated. The ¹³C chemical shifts of CS and CH, carbons were linearly correlated with the electronegativity (defined by Gordy) of the metal, as is shown in Figs.2 and 3- (a). The ¹³C chemical shifts of CS and CH, carbons shifted to higher field with increasing electronegativity of the metal. The chemical shifts of CH, and CH₃ protons of M(ddtc), , in CDCl₃ were little changed in the concentration range of 2.4 × 10^-4 to 2.9 × 10^4- mol/l. The aspects of the proton spectra of binary mixtures of Ni (ddtc)₂-Cd (ddtc)₂, Ni (ddtc)₂-Hg (ddtc)₂, Ni (ddtc)₂ -Zn (ddtc)₂ and Ni (ddtc)₂Pb (ddtc)₂ in CDCl₃ were examined over the range of -20 to 80°C. The identification of M(ddtc)₂ in a single chelate solution and that of each chelate component in the binary mixture can be respectively carried out by measuring the chemical shifts of CH, protons at room temperature and at -20°C.
The effect of the number of pulse on signal-to-noise ratio (S/N) of the CH₂ proton signal of Zn(ddtc)₂ in CDCl₃ was examined. By using the number of pulse of 1000 times (total time: 2 h), the S/N ratio of 4 was obtained for 2.9 × 10^4- mol/l Zn (ddtc)₂ solution under suitable FTNMR conditions, as is shown in Fig.6.

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Upon pyrolysis of thiobenzoic acid in a sealed glass tube, under a nitrogen atmosphere at 160 -220°C for 90 min, the formation of appreciable amounts of benzoic acid and polymerized products, viz., S-benzyl thiobenzoate, dibenzoyl disulfide, tetraphenylthiophene, and transstilbene, together with the liberation of hydrogen sulfide and sulfur were observed. To elucidate the course of the reaction, thiobenzoic acid and its related compounds were pyrolyzed under various conditions. The reaction. products were analyzed by the combined use of gas chromatography and high speed liquid chromatography.
It was considered that dibenzoyl disulfide and dibenzoyl sulfide formed through the association of benzoylthio and benzoyl radicals, which produced upon radical cleavage of thiobenzoic acid, and that the later product was the main source of S-benzyl thiobenzoate. It was presumed that benzoylthio radical and benzoyl radical further changed into- thiobenzoyl radical and benzoyloxy radical, and these resulting radicals played an important role for the formation of tetraphenylthiophene, trans-stilbene, and benzoic acid.
The main reaction paths for the pyrolysis of thiobenzoic acid were suggested.

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The continuous process for syntheses of alkylpyridine, mainly 2-methylpyridine and 5-ethy2-methylpyridine, from ethylene and ammonia catalyzed by Pd(II) +Cu (II) has been studied. The catalyst, being reduced by the reaction to the respective metal or lower valence ions, was reactivated by their oxidation with air (Table 1). The kinetic study on the separate oxidations of respective catalyst components showed that the reactivation of catalyst proceeded effectively even under mild conditions. Based on these results, continuous process was carried out in two different ways. The first, the semi batch process, i. e., mixture of ethylene and air was introduced into the solution containing catalyst, and the second, the continuous process, i. e., ethylene and the solution containing catalyst were fed to the reactor simultaneously. The selective rate of alkylpyridine more increased in these two processes than that in non continuous process. In addition, the formation ratio of 2-methylpyridine to 5-ethyl-2-methylpyridine was readily controlled by an oxygen concentration of inlet gas (Fig.6) or average residence time of catalyst solution (Fig.7).

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Thermal degradation of polypropylene over glass beads at 476-551°C or catalytic degradation over silica-alumina and CaX zeolite at 428-499°C was carried out under an atmospheric pressure and in terms of a fixed bed flow reactor system. The presence of these catalysts remarkably accelerated the degradation of polypropylene. At the initial stage of the reaction, at 499°C, and under the following feed rate of polypropylene: 0.098 g/min, the yields of gaseous products were 76 and 68 wt% over silica-alumina and CaX, respectively, while it was 10 wt% in thermal degradation case. These catalytic degradations gave a completely different product distribution from that of thermal one and produced less amount of olefins than that of the latter. The amount of olefins in C₂-C₅ gaseous products in silica-alumina case was more than 60 mol%, which was about twice as large as that in CaX case. For liquid products formed over both catalysts at an initial stage of the reaction, difference in average molecular weight, iodine number, or infrared spectrum was not detected.
The distribution of gaseous products in CaX case was more influenced by a contact time or temperature of the reaction than that in silica-alumina case, but the rate of formation of gaseous products was less dependent on the above factors in the former. These results were considered to be due to the difficulty of diffusion of reactant or product into CaX with smaller pores than those of the latter.

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Reaction products obtained by heating o- (p-toluoyl) benzoic acid [1] in polyphosphoric acid at 70-75°C for 20-60 min were crystals [3] and low molecular weight, orange yellow polymer [4], but in treatment for 2-20 h, it was only[4]. The structures of [3] and[4] were determined in terms of IR, NMR, UV spectra, and chemical behavior. The mechanism of the formation of [4] was rationally explained by the occurrence of the addition of cyclic carbonium ion [16] to quinonoid form [17].

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Continued from the previous report, a general spectrophotometric method to determine an equilibrium concentration of a dye monomer, S₁ and that of a complex formed between the dye and a dispersing agent, S_cin a disperse dye bath has been proposed by solving the following ternary simultaneous equations:
_??__??__??_
where K is an equilibrium constant for the complex formation (mole ratio: a/b), C_s is the concentration of the dispersing agent at equilibrium, and Ao is an extrapolated absorbance of a linear plot of over-all absorbance against the dye concenration at its higher concentration region. ε₁, ε_c and ε_a are molar extinction coefficients for the dye monomer, the complex and the dispersing agent, respectively. ε₁ is a mean molar extinction coefficient, (apparent) for the fine-crystalline dye. The subscript, γ₁ andγ₂, indicate the ones for the light of wave length Al and A2, respectively. The equilibrium concentration, C_s of the dispersing agent can be determined simultaneously by means of the present method. Consequently, the equilibrium constants of association of the dye and the complex and the concentrations of their aggregates can also be evaluated.
The dye used in the experiments was azo disperse dye, C. I. Disperse Red 1 (DR 1) and the dispersing agent used was sodium 2-naphthalenesulfonate-formaldehyde condensate (NaNSF). The experimental results reveal that with increasing the concentration of NaNSF both the concentration of the dye monomer, S₁, and that of the dye dimer, S₂, decrease and no aggregates above the trimer may be formed. DR 1 interacts to form an 1: 1 complex with naphthalene nucleus of NaNSF and S_c increases with increasing the concentration of NaNSF. It is inferred that the interaction of the dye molecule with one attached to NaNSF facilitates the binding between the dye molecule and the adjacent nucleus of NaNSF (co-operativity).

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Polymerization of methyl methacrylate was carried out in the presence of calcium sulfite in water medium containing sulfur dioxide. Calcium sulfite powder encapsulated with poly (methyl methacrylate) was obtained. Simultaneously, a small amount of sulfonic acid derivatives of methyl methacrylate were formed as a by-product and the chemical structure of these were identified. The polymer formed on the calcium sulfite surface was extracted with hot benzene, but a significant amount of the polymer remained on the surface. The thermal analysis of the encapsulated powder and the polymer were examined. The polymerization rate was sesitive to the polymerization conditions. The over-all activation energy of polymerization was 16 kcal/mol between 30°C and 60°C. The unextractable polymer had a broader distribution of molecular weight than that of extracted polymer and these polymers had end groups of nearly 1-2 -SO₃H and/or -OSO₃H per each polymer chain. The mechanisms of the polymerization and the encapsulation are discussed.

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The macroreticular chelating resins containing amidoxime groups (RNH) showed selective adsorption ability for uranium in sea water. The satisfactory chelating resins (RNH) were prepared by the reaction of the macroreticular acrylonitrile-divinylbenzene copolymer beads with hydroxylamine (1-1.5 moles per nitrile groups) dissolved in methanol at 60°C for 3-5 h or at 80°C for 1-2 h. The copolymer beads were prepared by the suspension copolymerization of acrylonitrile and divinylbenzene (10-46 mol%) in the presence of toluene (80-100 vol% per monomer), and had the average pore radius, specific surface area and pore volume of 160-200Å, 100-130 m²/g and 0.4-0.7 mug, respectively.

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Recovery of uranium from sea water has been investigated by using the chelating resins (RNH) containing amidoxime groups. The elution of uranium adsorbed on the RNH column was effected, when 10 bed volumes of a 1 N sulfuric acid solution were passed th: ough the column at the space velocity (SV) of 6 When 104 bed volumes of sea water were passed through the RNH column at the SV of 60 h^-1, 80% of uranium in sea water was recovered. When sea water was continuously passed through the column for 130 days at SV of 60uranium adsorbed on RNH was 185 mg/l-R(450 μg/g-R) and 33% of uranium in sea water was recovered. A recycle of adsorption and elution was carried out after 5X 103 bed volumes of sea water were passed through the column. The average recovery of uranium on ten recycles was 82.9%.

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A bisphenol type epoxide resin was cured with azelaic acid in the prese nce of N, N-dimethyl-b enzylamine as an accelerator. The curing process of this system was investigated by th e cihna ntgheems owleecigulhatr s and their distribution, and by the conversion of their reactive groups. The structures of intermediates in this curing process were also studied. By the ad-diti on of the accelerator, the formation of the ester linkages was activ ated and the formation of the ether linkages was inhibited. The products of this reaction had a narrow distribution of molecular weight and a high conversion of the epoxy groups. The structures of the intermediates having molecualr weights 330 to 1400 were estimated from the results of GPC, VPO, NMR and titration analyses. From these observations, it was suggested that the molecular chains of the reaction products were made up by the alternate arrangement of epoxide resin and dicarboxylic acid.

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Crosslinked polymeric membranes were synthesized by the reaction of copolymers of 2-hydrox3-(diethylamino)propyl methacrylate?styrene with cyanuric chloride at 40°C in dioxane. The pervaporation experiments were carried out on benzene-cyclohexane mixture (1: 1 by volume) through these polymeric membranes in order to study the effect of the chemical structure of the membrane, especially of the structure of crosslinking juncture with trapped hydrogen chloride, on the separation characteristics. By correlating the separation characteristics to the dependence of weight swelling ratio on the solvent composition, it was found that a completely selective permeation of benzene could be accomplished under the following conditions: ( 1 ) the membranes don't swell at all in nonselective solvents, ( 2 ) the membranes swell to some extent in selective solvent, ( 3 ) swelling ratio increases monotonously with an increase in the amount of selective solvents.
Benzene was found to be preferentially permeated through the membranes. Moreover, the permeation rate of benzene increased with an increase in the amount of the styrene units which had selective affinity for benzene. The crosslinking juncture with trapped hydrogen chloride was found to be effective for enhancing the selectivity because of the. restraining plasticizing action of benzene to the membranes. It was clarified that the solvent mixture of benzene and cyclohexane can be perfectly separated with high permeation rate by controlling both the composition of copolymer and the degree of crosslinking.

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The removal of quinquevalent or trivalent arsenic in water has been investigated by precipitate flotation using a Denver type or a pressure type flotator. Iron(la) sulfate was used as a coprecipitant and dodecylamine acetate, sodium oleate or sodium doclecyl sulfate as a collector.
In the precipitate flotation of quinquevalent arsenic, sodium dodecyl sulfate was most effective among the above collectors and the optimum pH was 4 to 5. On the other hand, for the removal of trivalent arsenic, sodium oleate was the most suitable collector and the optimum pH was about 8. These results were explained by the fact that the optimum pH for the flotation of iron(III) hydroxide with sodium dodecyl sulfate or sodium oleate coincides with that for the coprecipitation of quinquevalent or trivalent arsenic by iron(III) hydroxide, respectively. The precipitate flotation was more effective than the conventional settling method; less operation time and less iron(III) ion were needed in order to reduce the residual concentration of arsenic to less than 0.5 me (the Japanese effluent standard). When a Denver type flotator was used in the precipitate flotation of quinquevalent arsenic with sodium dodecyl sulfate, large parts of the solution were skimmed off because of voluminous foaming, particularly in the case of low iron (III) ion concentration. On the other hand, when a pressure type flotator was used, the volume of froth layer was very small. Furthemore, the precipitate flotation by using a pressure type flotator could reduce the residual concentration of arsenic to less than 0.5 me by the addition of smaller amount of collector than that by using a Denver type flotator.

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Total and sexivalent chromium concentrations of ten water samples from the Muromi River were determined by isotope dilution mass spectrometry in order to obtain an information on the redox behavior of chromium in river water. The localities of the samples are shown in Fig.1 and the results of analysis for total Cr, Cr(VI), and Cl- are listed in Table 1. Total Cr and Cr(VI) exist more abundantly in the spring water and the stream water above the reservoir than those in the down stream water. The oxidation of Cr(III), to Cr(VI) seemed to occur in ground water. It was also noticed that a marked decrease in total Cr and Cr(VI)concentrations is taking place and the Cr(VI) concentration decreases during the stay of th e river water in the reservoir as the water flows downstream. In reservoir and stream waters e oxidation of Cr(III) would proceed significantly slower way than the reduction of Cr(VI), th with humic substances etc.

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The reduction rates of Cr(V) by some organic compounds were investigated in order to obtain an information on the reactivity of Cr(VI) and organic matter in natural water. Glycine, serine, tyrosine and aspartic acid reduced hardly any Cr(VI) in the solution of pH 2, while cysteine, tannic acid and lignin rapidly reduced it even at pH 4. The reduction rates of Cr(VI) by cysteine and tannic acid were precisely determined as a function of concentration of reactants, pH and temperature. The emprical rate equations are -d[Cr(VI)]/dt=k_cySH·10^3.3×1011[H ⁺]²[CySH][Cr(VI)] for cysteine and =k_Tan[H ⁺] [Tannic acid (mg/l)]^1/2[Cr(VI)] for tannic acid. The apparent rate constants, k_cySH, and k_Tan were found to be 4.8 and 1.4 x10³min^-1 at 20°C, respectively. Cr(VI) in fresh water may be reduced at a considerable rate b rganic matter such as tannic acid and some of the humic substances.

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The reaction of cyanuric chloride-DMF adduct with aryl methyl ketones gave (2 E, 4 Z)-chloro-1, 5-diaryl-2, 4-pentadien-1-ones [10a-k]in fairly good yield. Under similar reaction conditions, propiophenone gave 5-chloro-1, 5-diphenyl-2, 4-dimethy1-2, 4-pentadien-1-one (10 1)and 3-chloro-3-pheny1-2-methylpropenal (9 l), and benzyl phenyl ketone gave 3-chloro-2, diphenylpropenal (9 m). The 2 E, 4 Z configurations of the products were determined by the IR and NMR spectral data.

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The rapid determination method of pyromellitic acid (PMA), pyromellitic monoanhydride (PMMA), or pyromellitic dianhydride (PMDA) was tried by means of NMR spectroscopy. In the spectra of PMA, PMMA, and PMDA mixtures in THF, single sharp signals of these aromatic protons appeared at 8.05, 8.34, and 8.70 ppm, respectively. It was found that PMDA graduately reacted with PMA and formed two equivalent moles of PMMA in THF at a room temperature (Fig.3 and Table 1). PMA, PMMA, and PMDA could be determined by measuring the peak hights of these aromatic proton signals within 20min after dissolving the samples in THF; the formation of PMA did not affect the above determination. The standard deviations of the analytical date of PMA and PMDA, calculated by Youden's method, were 0.59and 0.70, respectively.

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