bluuebunny/crossref_metadata_2025_split huggingface dataset:
Decomposition of Ammonia and Reactivity of Nitrogen Absorbed on Molybdenum
Authors: Tsuchiya Susumu , Ozaki Atsumu 
Published: July 2006

Abstract
Adsorption measurements during the course of ammonia decomposition over molybdenum catalyst have been carried out in a closed circulating system. It was found that most of the nitrogen produced was taken up by molybdenum, and the initial rate of the reaction was independent of the ammonia pressure in a certain region. During the decomposition the nitrogen uptake was several times as much as the amount required to saturate the catalyst surface, which indicates the formation of nitride layers. The catalytic activity of molybdenum trioxide for ammonia decomposition was also observed, and the formation of nitride layers was again suggested. The nitrogen sorbed on molybdenum was removed as ammonia by admitting hydrogen and was displaced by oxygen added afterwards.
Reactions of Tungsten Oxy-dichlorodialkoxides with Cyclopentadiene and Sodium Cyclopentadienide
Authors: Anand S P , Multani R K , Jain B D 
Published: July 2006

Abstract
The formation of π-cyclopentadienyl tungsten oxychlorodialkoxides as a result of the interaction between cyclopentadiene or its sodium derivative with tungsten oxy-dichlorodialkoxides, having the general formula C5H5WOCl(OR)2, where R is CH3, C2H5, (Remark: Graphics omitted.), CH3CH2CH2 and CH3CH2CH2CH2 along with the thermal stabilities and infrared spectra of the above products, has been studied and reported.
The Indirect Determination of Mercury in an Aqueous Solution using the Ligand Exchange Reaction
Authors: Kawai Itsuro , Hara Tadashi 
Published: July 2006

Abstract
A new method for the indirect determination of mercury in an aqueous solution has been established on the basis of the fact that the absorption and evolution of propylene in the reaction between mercuric ion and propylene take place reversibly and quantitatively under proper conditions. In the method proposed, the propylene in the 1 : 1 π-complex is displaced with such complexing agents as chloride, bromide, iodide and EDTA, and the quantity of the propylene evolved is measured manometrically. By the present method, up to 70 mg Hg can be estimated within ±0.08 mg in about 15 min. Common cations and anions do not interfere. Though silver(I) and palladium ions interfere, their interferences are removed by suitable procedures. By improving the apparatus, it should be possible to estimate much smaller amounts of mercury than the above value.
Solvolysis of Organic Phosphates. II. Pyridylmethyl Phosphates as Effected by the Presence of Polyvalent Metal Ions
Authors: Murakami Yukito , Takagi Makoto 
Published: July 2006

Abstract
Influence of polyvalent metal ions on the hydrolysis of 2-, 3- and 4-pyridylmethyl phosphate was investigated at μ=0.01 in a lower pH range. The thorium ion accelerated the hydrolysis rate of all the phosphates to a remarkable extent as investigated at 40, 70 and 90°C. The primary participation of the phosphate moiety of each pyridylmethyl phosphate in the interaction with thorium(IV) was considered to be the main cause of this catalysis. Thus, the thorium catalysis was mechanistically distinguished from the copper catalysis which has been clarified previously. In addition, the vanadyl ion also demonstrated positive catalytic effect. On the other hand, iron(III) and aluminum(III) retarded the hydrolysis rate. This was ascribed to the reduced fraction of the active monoionic species as a result of metal-complex formation with the phosphates in the course of hydrolysis.
Oxytocin Analogues Containing No Disulfide Bond. I. Synthesis of the Lactam of l-Tyrosyl-l-isoleucyl-l-glutaminyl-l-asparaginyl-l-α-aminosuberyl-l-prolyl-l-leucylglycine Amide
Authors: Kobayashi Akiko , Hase Satoe , Kiyoi Reiko , Sakakibara Shumpei 
Published: July 2006

Abstract
The synthesis of an analogue of deamino-oxytocin, which has an ethylene linkage in place of the disulfide bond, was studied in order to establish a general route for the synthesis of such cyclic peptides. l-α-Aminosuberic acid (Asu) was converted to the N-benzyloxycarbonyl-ω-t-butyl ester and was used as the starting substance for the synthesis. A protected octapeptide was prepared by the step-by-step elongation method with the respective benzyloxycarbonylamino acid active esters, and finally the cyclization of the ω-carboxyl group of the Asu-residue to the amino group of the tyrosyl-residue was achieved by the trifluoroacetate method. The final product showed obviously higher oxytocin-like activities than those reported previously. The conditions for the syntheses of p-nitrophenyl and 2,4,5-trichlorophenyl trifluoroacetates were improved during the investigation.
Structural Study of the Catalytic Activity of Alkyl Chloride in the Polymerization of N-Phenylethylenimine
Authors: Kagiya Tsutomu , Kondo Tomizo , Obata Keigo 
Published: July 2006

Abstract
The catalytic activity of various alkyl chlorides in the polymerization of N-phenylethylenimine was studied from the structural point of view. Both the polymerization rate and the molecular weight of the polymer obtained varied with the kind of alkyl chloride. The rate of monomer consumption is expressed by a first-order rate equation with respect to the monomer concentration in the early stage of the polymerization. The efficiency factors of the catalysts differ with the kind of alkyl chloride and increase with an increase in the reaction time. When the chloride of a conjugated alkyl group is used, the polymerization rate decreases with an increase in the ionization potential of the alkyl radical, while it increases when chlorides of a non-conjugated alkyl are used. The structural study of the catalytic activity of the alkyl chloride was made quantitatively from the energetic point of view.
Alkaline Decomposition of Triarylsulfonium Halides with Various Bases
Authors: Oae Shigeru , Khim Yong He 
Published: July 2006

Abstract
Alkaline decomposition of triarylsulfonium bromides with various bases was found to give different products depending on the nature of the bases. The reaction of triarylsulfonium bromide with either piperidide anion or thiophenoxide ion seems to proceed with the initial attack of piperidide anion or thiophenoxide ion of the carbon atom of C-S bond (SN reaction on carbon atom), while the reaction of diarylethoxysulfonium tetrafluoroborate with thiophenoxide ion is presumed to involve the initial attack of thiophenoxide ion on the sulfur atom at low temperature (SN reaction on sulfur atom). When triarylsulfonium bromide was subjected to the reaction with potassium hydroxide in aqueous ethanol, the main path was the alkaline decomposition which proceeds via the nucleophilic attack of the ethoxide ion on the sulfur atom. In the treatment with hydroxide ion in water, the decomposition appears to proceed mainly via two mechanistic routes, i.e., the processes involving the nucleophilic attack of hydroxide ion on both aromatic carbon and the sulfur atoms. A free radical process cannot be excluded, but appears unlikely.
Reaction of Ethyl Diazoacetate with Cupric Chloride
Authors: Saegusa Takeo , Ito Yoshihiko , Shimizu Toyoji , Kobayashi Shiro 
Published: July 2006

Abstract
The reaction of ethyl diazoacetate (1) with CuCl2 was investigated. Ethyl chloroacetate (2), ethyl dichloroacetate (3) and a mixture of ethyl dichloromaleate (4) and ethyl dichlorofumarate (5) were produced. These products were explained by assuming 1-chloro-1-ehtoxycarbonylmethylcopper complexes, (10) and (11). The reactions of 1 with HgCl2 and CoCl2 were examined in detail as reference reactions from the mechanistic view point.
Preparation of Vinyl Ethers by Transetherification in the Presence of Molecular Sieves
Authors: Yuki Heimei , Hatada Koichi , Nagata Kazuhiko , Kajiyama Ken-ichi 
Published: July 2006

Abstract
The interchange reaction: CH3OCH=CH2+ROH \ightleftarrows ROCH=CH2+CH3OH, which is catalyzed by Hg(OAc)2, has been studied. It was found that the equilibrium could be smoothly shifted toward the product by the selective absorption of the produced methanol on molecular sieves of the type 4A (MS-4A) and that the yield of the desired vinyl ether could be increased. According to this method, we prepared various vinyl ethers, including ethyl, isopropyl, isobutyl, t-butyl vinyl ether, and benzyl vinyl ethers. The yields of the alkyl vinyl ethers decrease as their alkyl groups become more electron-donating. The effects of the reaction conditions and the pretreatment of the molecular sieves have been investigated.
Electronic Spectra of O-Alkyl Thiobenzoates and Their Derivatives
Authors: Ohno Atsuyoshi , Koizumi Tamotsu , Ohnishi Yutaka , Tsuchihashi Gen-ichi 
Published: July 2006

Abstract
The absorption spectra of O-methyl and -ethyl thiobenzoates and their p- and m-methoxy, methyl and chloro derivatives have been studied. The substituent effect on the n→π* transition of thiocarbonyl group has been discussed with the use of the Hammett relationship.
Electrical Conduction of TCNQ Ion Radical Salts under High Pressure
Authors: Shirotani Ichimin , Kajiwara Takashi , Inokuchi Hiroo , Akimoto Syun-iti 
Published: July 2006

Abstract
With an increase in the pressure, the electrical resistance of several TCNQ anion radical salts dropped rapidly in the low-pressure region and levelled off at high pressures. The temperature dependence of the resistance of compressed salt was studied over the region from 77°K to 200°K. The values of the activation energy decreased with an increase in the pressure. However, the metallic behaviour was not observed under very high pressures. The conduction mechanism of TCNQ, salts was discussed from the point of view of a band scheme.
Optical and Acoustic Branches and Frequency Distribution of Polyethylene Glycol Chain
Authors: Matsuura Hiroatsu , Miyazawa Tatsuo 
Published: July 2006

Abstract
Optical and acoustic branches of chain vibrations of polyethylene glycol were treated. The nature of these branches was elucidated on the basis of potential-energy distributions and phase relations. From dispersion curves (frequency versus phase difference), the frequency distribution of chain vibrations was calculated, in order to analyze thermal-neutron scattering spectra. Vibrational assignments of scattering peaks in the region 600–200 cm−1 were made with reference to the frequency distribution peaks and potential-energy distributions calculated for the single chain.
Gravimetric Determination of Palladium, Silver, Mercury and Copper with 2-Mercaptomethylbenzimidazole
Authors: Bera Bimal C , Chakrabartty M M 
Published: July 2006

Abstract
New selective methods are described for the gravimetric determination of palladium, silver, copper and mercury with 2-mercaptomethylbenzimidazole. In the presence of EDTA or tartrate, palladium, silver and mercruy are determined at pH of 4–5. Copper is determined as the copper(I) complex in the same pH range using cyanide as a reducing and complexing agent. Thermogravimetric studies reveal adequate thermal stability of the complexes. X-Ray studies confirm the identity of the end products in the thermolysis of the copper(I) and copper(II) complexes.
The Effect of Acetate Ion on the Rate of the Reaction between Cobalt(II) and Manganese(II)-Ethylenediaminetetraacetate Complexes
Authors: Kimura Masaru 
Published: July 2006

Abstract
The kinetics of the substitution reactions of cobalt(II) ions and manganese(II)-ethylene-diaminetetraacetate complexes have been studied in acetate buffer solutions at 25°C and at ionic strength of 0.2. The reaction was treated as to proceed through both hydrated metal ions and monoacetato complexes. The rate constants for six elementary reaction paths, three of which involve hydrated cobalt(II) ions and the others, monoacetatocobalt(II) complexes, were determined. The values obtained indicate that all the reactions proceeding through monoacetatocobalt(II) complexes are about three times faster than the corresponding reactions proceeding through hydrated cobalt(II) ions.
The Effect of Phthalate Ion and Acetate Ion on the Rate of the Reaction between Nickel(II) and Cobalt(II)-Nitrilotriacetate Complexes
Authors: Kimura Masaru 
Published: July 2006

Abstract
A kinetic study of the substitution reactions of nickel(II) ions and cobalt(II)-nitrilotriacetate complexes in phthalate and in acetate buffer has been carried out using a procedure previously reported. The reaction was made to proceed through both hydrated nickel(II) ions and monophthalatonickel(II) complexes or monoacetatonickel(II) complexes. The rate constants for eight elementary reaction paths, four of which involve the hydrated nickel(II) ions, while the others involve the monophthalatonickel(II) complexes (the monoacetatonickel(II) complexes in the case of the measurements in acetate media), were determined at an ionic strength of 0.2 at 25°C. The values obtained indicate that all the reactions proceeding through the monophthalatonickel(II) complexes are slower than the corresponding reactions proceeding through hydrated nickel(II) ions; however, all the reactions proceeding through monoacetatonickel(II) complexes are faster than the corresponding reactions proceeding through hydrated nickel(II) ions. Thus, the kinetic reactivity is in the order of: NiOAc+&gt;Ni2+&gt;NiPh, where Ph2− indicates a bivalent phthalate anion.
Stability Constants of Some Uranyl Complexes. II
Authors: Ramamoorthy S , Santappa M 
Published: July 2006

Abstract
Stability constants of complexes of uranyl ion with various carboxylic acids were determined by the pH titration method at 31°C and μ=0.1 (NaClO4) in the pH range 2.5–3.5. The 1 : 1 and 1 : 2 complexes were formed with crotonic, pyruvic, malonic, and diglycolic acids and only the 1 : 1 complex with formic, propionic, succinic, adipic, maleic, fumaric acids. The effect of ring size and presence of oxygen atom as keto or ether oxygen or that of double bonds in the ligand acids on the stabilities of the corresponding complexes are discussed.
Chemical Effects Associated with β-Decay Process. III. The Chemical Behavior of 144Pr Decayed from 144Ce(III)-EDTA Complexes in the Solid Phase
Authors: Shiokawa Takanobu , Kudo Hiroshi , Omori Takashi 
Published: July 2006

Abstract
The chemical behavior of 144Pr formed by the β−–decay of 144Ce in crystals of 144Ce(III)-EDTA complexes has been investigated by means of ion-exchange techniques. The initial yield of 144Pr3+ ion, which reflects the distribution of the 144Pr atoms in the crystal, is independent of the dissolving condition, but is affected by the amount of hydration in the crystal. Abnormal behavior of 144Pr atom has not been found in the ammonium salt. These results suggest that in the solid phase 144Pr3+ or its precursor may be produced as a result of multiple charging of the daughter following electron shake-off and internal conversion of γ-rays.
Long-term Integration of Polarographic Currents and Its Analytical Application
Authors: Matsuda Kiyoshi , Tamamushi Reita 
Published: July 2006

Abstract
The integral readout technique was applied to the accurate determination of average polarographic currents. The long-term integration of polarographic currents provides a useful method of compensating residual currents and thus of increasing the sensitivity and accuracy of the d. c. polarographic analysis. The analytical utility of the proposed method was tested with cadmium, lead, and zinc ions in chloride solutions; these ions were found to be determined with reasonable accuracy even at concentrations as low as 10−6 m. Depolarizers at concentrations of the order of 10−4 m can be determined accurately in air-saturated solutions. The present method has the considerable merit that its sensitivity is not affected by the degree of reversibility of the electrode reaction. The integral technique was also applied successfully to the compensation of residual currents by the twin-cell system, in which a pair of dropping mercury electrodes is not necessarily synchronized.
The Reaction of Alcohols and Hydrocarbons in a Silent Electric Discharge. I. The Decomposition of 2-Propanol by the Discharge
Authors: Hiraki Teruo 
Published: July 2006

Abstract
The reaction of 2-propanol under a silent electric discharge was studied using two kinds of discharge tubes. One was Siemen’s tube, which was used for investigating a silent discharge decomposition of 2-propanol. The other was a special tube that had one side of the walls made of copper or its salts; it was used for studying the effects of the wall on the decomposition. The main liquid products were acetaldehyde, acetone, dl-2-butanol, 2-methyl-2-propanol, 2-methyl-2-butanol, and hydrocarbons. The gaseous products were methane, C2–C4-hydrocarbons, carbon monoxide, carbon dioxide, and hydrogen. These components were obtained in every run, regardless of the type of tube used. However, the distribution of the products varied with the sort of tube. The formation of 2-methyl-2-butanol can be explained by the addition of a 1-hydroxyisopropyl radical with the ethylene produced; the only product formed by adding this radical to ethylene was the one-to-one adduct. By replacing one side of the glassy walls with a wall of a glass-filter-packed copper or its salts, the yield of 2-methyl-2-propanol was increased relatively, and those of 2-methyl-2-butanol and dl-2-pentanol were decreased.
The Synthesis of Poly-l-arginine Hydrobromide and Copolymers of l-Arginine and Other Amino Acids
Authors: Hayakawa Tadao , Kondo Yoshiyuki , Yamamoto Hiroyuki , Murakami Yukiko 
Published: July 2006

Abstract
Pure crystalline Nω,ω′-dicarbobenzyloxy-l-arginine N-carboxyanhydride hydrochloride was obtained from Nα,ω,ω′-tricarbobenzyloxy-l-arginine and thionyl chloride. It was polymerized to poly-Nω,ω′-dicarbobenzyloxy-l-arginine. This polymer was converted to poly-Nω-carbobenzyloxy-l-arginine by treating it with alcoholic potassium hydroxide; also, both carbobenzyloxy groups of the protected polymer were completely removed into poly-l-arginine by treating them with hydrogen bromide in glacial acetic acid. Several copolymers containing l-arginine residue were also prepared by the copolymerization of the above NCA and the NCAs of other amino acids, such as γ-benzyl-l-glutamate, l-alanine, and Nε-carbobenzyloxy-l-lysine.
Intramolecular Hydrogen Bonds. XIII. The Preferable Conformation of α-Hydroxy-carboxylic and o-Hydroxybenzoic Acids
Authors: Mori Nobuo , Asano Yuzuru , Irie Toshiko , Tsuzuki Yojiro 
Published: July 2006

Abstract
The infrared hydroxyl and carbonyl stretching absorption spectra of salicylic, mandelic, and α-hydroxyisobutyric acids have been measured in dilute carbon tetrachloride solutions. The spectral data indicate that the first two acids exist exclusively in an internally-bonded conformation, one where the phenolic and the alcoholic hydroxyl groups form a hydrogen bond with the carbonyl oxygen atom of the cis-carboxyl structure, while the last acid takes, apart from such a conformation, another internally-bonded conformation, one where the hydroxyl group of the trans-carboxyl structure interacts with the alcoholic oxygen atom.
Ethylidenation of l-Sorbose
Authors: Maeda Takashi , Kiyokawa Masumi , Tokuyama Kanji 
Published: July 2006

Abstract
The ethylidenation of l-sorbose (I) with acetaldehyde dimethylacetal in the presence of an acid was studied. When the reaction was interrupted at the initial stage, an equilibrium mixture of the two possible cyclic acetals, 1,2-O-(III) and 1,3-O-ethylidene-α-l-sorbopyranose (V), was obtained. When the reaction was allowed to proceed for longer periods of time, 1,3:4,6-di-O-ethylidene-β-l-sorbofuranose (IX) was mainly isolated; the transformation of this to two diastereoisomeric 2,3:4,6-di-O-ethylidene-α-l-sorbofuranoses (XV and XVIII) required the use of highly acidic conditions. A pathway of I→(III\ightleftarrowsV)→IX→(XV+XVIII) was tentatively proposed for the ethylidenation of I.
Ultrasonic Relaxation of Water-Dioxane System
Authors: Arakawa Kiyoshi , Takenaka Nobuo 
Published: July 2006

Abstract
Ultrasonic investigations of the water-dioxane system were made by means of an ultrasonic pulse technique. The ultrasonic velocity and absorption of the solutions were measured in the frequency range from 5 to 45 Mc/sec. The temperature was varied from 20 to 60°C. It was observed in the velocity vs. concentration curves obtained at various temperatures that all curves converged at 0.03–0.04 mol fraction of dioxane. The ultrasonic absorption of pure dioxane was found to increase with the rise of temperature, which might be ascribed to the vibrational relaxation. From the ultrasonic absorption data obtained for the solutions of the water-dioxane system in various compositions and temperatures it was observed that at 0.3–0.4 mol fraction of dioxane an absorption peak was present in the absorption vs. concentration curve, and also that there was no shift of the concentration at the peak with the variation of temperature. Some discussion on the structure of the water-dioxane system was given from the ultrasonic data obtained.
Syntheses and Reactions of Functional Polymers. XL. Enhanced Reactivity of Poly(vinyl chloride) by Neighboring-Group Participation of the N,N-Disubstituted Dithiocarbamate Function
Authors: Nakai Takeshi , Kawaoka Hideo , Okawara Makoto 
Published: July 2006

Abstract
In order to demonstrate that neighboring-group participation of the N,N-disubstituted dithiocarbamate function is involved in the substitution reaction of poly (vinyl chloride) (PVC) with the dithiocarbamate anion, the rates of reactions of PVC and the copolymer (vinyl chloride-S-vinyl N,N-diethyldithiocarbamate) with −SCS-NEt2 were compared under the same conditions. These polymer reactions were undertaken in dimethylformamide or tetrahydrofuran at 45°C. The rate enhancements with the copolymer were observed in both solvents. From these observations, it was concluded that the chloromethylene groups in PVC neighboring the dithiocarbamate function were activated .toward the nucleophile via neighboring-group participation. This is the first time that neighboring-group participation involving the polymer main chain might be observed in the polymer reaction. The difference in reaction mechanism between the polymer reaction and the model reaction was discussed.
The Synthesis of Regular Copolymers of Glycine and Alanine
Authors: Takahashi Sho 
Published: July 2006

Abstract
The synthesis of polypeptides with a repeating sequence of glycines and l-alanines, i. e., poly-(l-Ala-Gly-Gly), poly-(l-Ala-l-Ala-Gly), and poly-(l-Ala-l-Ala-l-Ala-Gly), are reported. Polymerization was achieved by a self-condensation of p-nitrophenyl esters of the corresponding tri- or tetrapeptides.
Studies of Aminosugars. XXIII. The Total Synthesis of Kanamycin B
Authors: Umezawa Sumio , Koto Shinkiti , Tatsuta Kuniaki , Hineno Hirokuni , Nishimura Yoshio , Tsumura Takayuki 
Published: July 2006

Abstract
4-O-(3,4-Di-O-benzyl-2,6-dicarbobenzoxyamino-2,6-dideoxy-α-d-glucopyranosyl)-N,N′-dicar-bobenzoxy-2-deoxystreptamine has been prepared from neamine and condensed with 3-acetamido-2,4,6-tri-O-benzyl-3-deoxy-α-d-glucopyranosyl chloride by a modified Koenigs-Knorr reaction to give an α,α-diglycoside. The identity of the product with a substance of the same structure derived from natural kanamycin B was shown. Removal of the masking groups from the product gave the synthetic kanamycin B, which was identical with natural kanamycin B.