Adsorption of halogen ions onto the anion ion-exchange resin, Dowex 2-X 8, and ratedetermining steps of the ion exchange reaction were studied by means of the batch method in the presence of magnetic field. Halogen ions used were F^-, Cl^-, Br^- and I^- ions. The magnetic flux density was O.25 T. Ion-exchange rates of all ions were increased by about 10-20% by the presence of the magnetic field. Magnetic field does not affect on the degre e of swelling, the structure of the resin, viscosities and electric conductivities of sample solutions, and total ion exchange capacities. It was found that the rate-determining step of all ionexchanges is the film diffusion and particle diffusion. Its diffusion coefficients and rate constants are increased by the pressence of the magnetic field.

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Preparation of highly active palladium catalyst supported on silica by ion exchange method was investigated. The catalytic activities and physical properties of catalysts were investigated on hydrogen reaction of benzene, CO pulse method, X-ray analysis and the temperature programmed reduction. The Pd/SiO₂ catalysts were prepared by an ion exchange method using various aqueous ammonia solution (28-0.5%) of PdCl₂.
The catalytic activity of Pd/SiO₂ catalyst prepare d using 28% ammonia solution decreased rapidly with a process time in the hydrogenation of benzene. However, the catalysts prepared using aqueous ammonia solution below 1.0% exhibited the high initial activity and little decreased during the reaction for 2 h. In a DTA measurement, the catalyst prepared using high concentration (28%) of ammonia solution showed a peak at 300 °C based on ammonia combustion, while the catalyst prepared using a low ammonia concentration (below 1.0%)did not show a peak around at 300 °C. In the case of the catalyst prepared using a low concentration ammonia solution, palladium oxide on SiO₂ was easily reduced at low temperature and metallic palladium produced contains a number of lattice defects. In conclusion, very high catalytic activity and stability can be achieved when the catalyst is prepared by ion exchange method using a low ammonia concentration of the ion exchange solution.

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The crystal growth process to the X-shaped type crystal of lead sulfate precipitate was examined by using an optical microscope, a scanning electron microscope and X-ray powder diffraction method.

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The determination of platinum by inductively coupled plasma atomic emission spectrometry (ICP-AES) after solvent extraction with potassium O-alkyl dithiocarbonate(KRX) was investigated. The optimum conditions of ICP-AES were as follow: incident power, observation height of measurement, coolant gas flow rate, plasma gas flow rate, carrier gas flow rate and wavelength were 1.0 kW, 13 mm above the coil, 16.0, 1.6, 0.6 l/min and 214.42 nm respectively. Among KRX examined, potassium O-butyl dithiocarbonate (KBuX) was the most suitable complexing reagent. The platinum-O-alkyl dithiocarbonate complex was quantitatively extracted into xylene. The optimum pH was between 5.2 and 6.2. KBuX concentration more than 0.001 mol·dm^-3 was required. The coexistence of 5 mg of Ni(II) decreased the emission signal intensity of platinum, but 1000 mg of Na(I), 100 mg of Al(III), 20 mg of Mg(II), 5 mg of Ce(IV), O.5 mg of K(I), Cu(II), Ni(II), Pd(II), Rh(II), Ir(III), Au(III) and Si(IV) showed no significant interference on the determination of platinum. The relative standard deviation for ten measurements in this method ranged from 1.4 to 1.5% in the determination of 10.0, 30.0 and 50.0 μg of platinum.
This method was applied to the determinatio n of platinum in catalysts and the analytical results were in excellent agreement with the reference'Avalues.

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The crystal structure and thermal phase transition behaviors of 4, 4'-bis(3-alkylureido) diphenylmethane (AUDM) having normal alkyl chain lengths between 4 and 18 even-numbered carbon atoms were investigated by DSC, FT-IR and XRD.

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A novel method for the synthesis of 3-phenyl 1, 3, 4-thiadiazo-2(3H)-one 1 was investigated, and the structure was discussed in terms of resonance stabilization. The thiadiazole 1 was synthesized successfully by the reaction of H-phenyl-H'-thioformylhydrazine with 2-ethoxy1-ethoxycarbonyl-1, 2-dihydroquinoline (EEDQ) in the presence of triethylamine in acetonitrile.
The structural investigation of 1 was carried out by use of spectral data such as ¹H-NMR, ¹³C-NMR, IR and UV spectroscopies, and X-ray analysis. The structure of 1 is b est interpreted by joining of two adjacent, resonance structures of 3pπ-2pπ-2pπ-2pπ (-S-C=N-N-)and 2pπ-2pπ (>C=0) in which each π-electrons on the ring are drifted to oxygen atom of carbonyl group via the aromatic structure based on the resonance stabilized structure.

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Solvent and catalyst effects on addition reaction of phenyl glycidyl ether (PGE) with S-phenyl thioacetate (PTA) were investigated. The addition of PGE with PTA proceeded regioselectively to give the corresponding adduct 2-acetoxy-3- (phenylthio) propyl phenyl ether 1 in 23 and 45% yields without any catalyst in DMF at 90°C for 120 and 360 h, respectively, although the reaction did not proceed under the same conditions in toluene. Furthermore, it was found that some alkali metal salts and metal chlorides, especially PhOK, AcOK, KOCN, KF, and CoCl₂ have high catalytic activity for the reaction of PGE with PTA in aprotic polar solvents such as DMF, NMP, and DMSO.

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Addition reaction of 3-or 4-membered cyclic ethers with various esters was investigated using quaternary onium salts or crown ether complexes as catalysts. The reaction of phenyl glycidyl ether (PGE) with p-substituted phenyl acetates proceeded smoothly, and the p-substituted phenyl acetate with electron-withdrawing groups have higher reactivity than electron donating ones. The reaction of PGE with S-alkyl thioesters such as S-benzyl thioacetate and S-dodecyl thioacetate also proceeded very smoothly to give the corresponding adducts in 95.0 and 93.6% yields, respectively. However, poly[oxy[1-(phenoxymethyl) ethylene]] wa s obtained mainly on the reaction of PGE with benzyl acetate, and the yield of 2-benzyloxy-1(phenoxymethyl)ethyl acetate was only 27%. These results suggest that the reaction of esters having high reactivity with PGE give the corresponding adduct in high yield, but the reaction of esters having low reactivity with PGE took place the ring -opening polymerization product of PGE.
Furthermore, it was also found that the reaction of 4-membered cyclic ether, 3-benzyloxymethyl3-methyloxetane (BMO), with S-phenyl thioacetate produced the corresonding adduct in high yield in the presence of 18-C-6/potassium phenoxide complex as a catalyst.

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Hydroxylation of 3-chloro-1-propene was carried out by use of _L-ascorbic acid and copperor iron-ion in pH 4.0 aqueous acetone with mechanical shaking under argon atmosphere at 30 °C for 12 h. The hydroxylation proceeded easily to give 2-propen-1-ol with catalytic amount of _L-ascorbic acid and copper(I) ion (1/100 mol based on substrate) in better yield than with other systems such as _L-ascorbic acid-copper(II), -iron(II) and -iron (III) and absence of the _L-ascorbic acid.

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A convenient method for the lactonization of 3-(2, 2-dichlorocyclopropyl) alkanoic acids 1a-k), 3-cyclopropylalkanoic acids (3a-d, 5a-e), and bicyclic 2-cyclopropylalkanoic acids (7a-d)using acidic materials is presented.

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Malonaldehyde (MA) analogs (R-MA) including α-alkyl (methyl, Me; ethyl, Et; propyl, Pr and butyl, Bu) and α-phenyl (Ph) MA react with guinine (Gua) under acidic condition to give fluorescent pyrimidopurinones (R-PP). In order to elucidate different mutagenic activities among these chemicals, the rates of the Gua∼R-MA reaction in 1M hydrochloric acid were determined. Kinetic orders in respect to both Gua and R-MA were determine as first order. Rate constants were also determined by the Psuedo-first-order Techniqu([Gua]>>[R-MA]). Rates of the Gua∼R-MA reaction varied considerably with the sub stituted group of MA as follows,
H>Ph>Me>Et>Bu·Pr (40 °C)

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Ten oxadiazole derivatives which were newly synthesized were examined as an emitter in organic electroluminescence (EL) cells. The new oxadiazole derivatives exhibited the photoluminescence (PL) peaks at the wavelength region between 374 and 527 nm. Vacuum-deposited thin films of these compounds had excellent thermal stability, because they have high melting temperature ranging from 240 to 365 °C.

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Aromatic hydrocarbons from the atmosphere were studied to elucidate their sorption into soil. The sorption amount of these hydrocarbons including benzene, toluene and o-xylene could be calculated using Henry's Law equation. Henry's Law constant was highest in o-xylene, less in toluene, and lowest in benzene, it also decreased with increasing water content of soil. The aromatic hydrocarbons were concentrated into dry soil by sorption, and emission of these hydrocarbons from the soil by addition of water was observed. Sorption and emission of the aromatic hydrocarbons would often occur between actual soil and atmosphere in the range of water content of 2-10%, because change of Henry's Law constant was large in this range of water content.

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The amounts of surface hydroxyl groups (OH groups) on alumina reference catalysts (JRC-ALO-1∼5) have been determined by the hydrogen isotope exchange method. The amounts of hydrogen isotope exchanged were measured by a gravimetric technique using precision electrobalance equipped in vacuum system and the amounts obtained were taken as the amounts of OH groups.
By this method, th e densities (OH/cm²) of OH groups of ALO-1∼5 evacuated in the range of 300-450°C were determined.
From this results, it has been found that the densities (OH/cm²) of OH groups of ALO-1∼5 do not depend upon these preparations but do the evacuation temperature.

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Al-doped Sm³⁺: Si0₂ phosphor reduced by hydrogen was characterized by fluorescence spectroscopy. Sharp emission peaks appeared at 684 and 728 nm and were assigned to be the fluorescence of Sm²⁺. The emission was observed only in the presence of Al ions and was reproduced by the reduction-oxidation treatments. The emissions of Sm³⁺ ions were also detected for the reduced phosphor, and their intensities were hardly changed by the reduction. Samarium ions in Al-doped Sm³⁺: Si0₂ phosphor were revealed to be not only atomically dispersed Sm³⁺ ions with Sm-O-Al bonding (Chem. Lett., 829 (1989)) but also, in present study, the reducible Sm³⁺ ions forming small-size Sm₂O₃ cluster in Al-O-Si framework.

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A quantitative research on Yb, which is a rare earth element, has been conducted with a metal furnace AAS.
At first, the o ptical instrumental operating conditions were set for the determination of Yb. The acid, such as HNO₃, H₂SO₄, HClO₄ and HC104 interfered remarkably with the determination of Yb, but HC1 did not interfer up to 2 M. The most of the coexistence metal elements were less effective up to 100 times quantity. Proporsed method has been applied to the determination of Yb in monazite, bastanaesite and xenotime. This method is very simple, and suitable for the determination of trace amounts Yb in the sample containing rare earth element.

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Catalytic vapor phase decomposition of trichloroethylene (TCE) over nonstoichiometric hydroxyapatite (DAp) was investigated at 100-500 °C.
TCE vapor (30-200 ppm) decomposed mainly to CO₂ and CO by passing through a DAp catalyst bed in a tubelar reactor at 400, -500 °C. The conversion exceeded 90%. The formation of gaseous HC1 was very little. By-products were not detected except for 1, 1-dichloroethylene b y GC-FID.
It was assumed that TCE reacted with water vapor and O₂ over DAp catalyst to form CO₂, CO and HC1, and then HC1 was absorbed as Cl^- ions by DAp.

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Decomposition processes of TBP waste under alkaline hydrothermal conditions at 150-350°C, in NaOH solution of 0-1 M with 0₂ pressure of 0-4 MPa were investigated. Almost all TBP decomposed at above 200°C under any O₂ gas pressure. Orthophosphoric acid was rapidly formed above 250°C with the increase of O₂ gas pressure. COD removed ratio exhibited a minimum at 250°C with the formation of water soluble organic materials. Adequate conditions of TBP decomposition for solvent disposal were as follows; TBP/dodecane (30: 70) O.1 cm₃, O₂ gas pressure 4 MPa, NaOH concentration 0.5 M (5cm³), reaction temperature 300°C.

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