bluuebunny/crossref_metadata_2025_split huggingface dataset:
Formation of Cubic Molybdenum Carbide by the Carbonization of MoO3 with Plasma Arc and Properties of the Products
Authors: Matsumoto Osamu , Saito Michio , Yoshino Takashi 
Published: July 2006

Abstract
The formation of cubic molybdenum carbide (α-MoC1−x) by the carbonization of MoO3 with graphite by heating with argon plasma arc was studied. α-MoC1−x including a small amount of hexagoanl η-MoC1−x. was formed. By the carbonization of mixture of MoO3 and TiO2 with graphite, a cubic solid solution of Mo–Ti–C system was formed. Chemical and X-ray analyses showed that the cubic form is defective in carbon content. The density of the cubic form was in agreement with that determined by means of X-ray diffraction. The products were found to be superconductors, the transition temperature varying with composition. The highest transition temperature 11.7 K was obtained for Mo0.95TiO0.05C0.75.
Nitration of Decamethylbiphenyl and 2,3,5,6-Pentamethyl-2′,3′,4′,5′,6′-pentachlorobiphenyl with Fuming Nitric Acid. Exclusive Ortho Orientation for the Side-chain Attack
Authors: Suzuki Hitomi , Yagiu Osamu , Hanafusa Terukiyo 
Published: July 2006

Abstract
Products obtained by the reaction of the title compounds with fuming nitric acid in dichloromethane were investigated. Decamethylbiphenyl gave 6,6′-bis(nitrooxymethyl)-2,2′,3,3′,4,4′,5,5′-octamethylbiphenyl or 2,6,6′-tris(nitrooxymethyl)-2′,3,3′,4,4′,5,5′-heptamethylbiphenyl as the major product, depending on the amount of nitrating agent. 2,3,4,5,6-Pentamethyl-2′,3′,4′,5′,6′-pentachlorobiphenyl similarly gave 6-nitrooxymethyl-2,3,4,5-tetramethyl-2′,3′,4′,5′,6′-pentachlorobiphenyl or 2,6-bis(nitrooxymethyl)-3,4.5-trimethyl-2′,3′,4′,5′,6′-pentachlorobiphenyl. Some plausible reaction sequences for the exclusive ortho attack on the alkyl side-chains of biphenyl systems have been suggested.
Studies on Cyclic Dipeptides. II. Isomerization among cyclo(-4-Hydroxyprolyl-4-hydroxyprolyl-)s and a Novel Conversion of d-allo-Hydroxyproline to l-Hydroxyproline
Authors: Eguchi Chikahiko , Kakuta Akio 
Published: July 2006

Abstract
The isomerization among c-l-Hyp-l-Hyp (1), c-l-Hyp-d-aHyp (2) and c-d-aHyp-d-aHyp (3) has been examined in ethanolic sodium ethoxide at 25–78 °C as well as in aqueous solutions at 75–250 °C. At equilibrium state, 1 was predominant and 2 was not found at all in the reaction mixture. By the use of this isomerization reaction and the difference of solubility between 1 and 3, 3 could be converted almost quantitatively to 1. The mixture of 1 and 3 was obtained in good yield directly from d-aHyp or l-Hyp by heating in water or ethylene glycol. 1 was hydrolyzed quantitatively to l-Hyp by acid. Thus, l-Hyp was obtained with the yield of 59% from d-aHyp by combination of preparation, isomerization and acid hydrolysis of cyclic dipeptide.
Chemical Studies on Tuberactinomycin. VII. Synthesis of γ-Hydroxy-β-lysine
Authors: Wakamiya Tateaki , Teshima Tadashi , Kubota Ichiro , Shiba Tetsuo , Kaneko Takeo 
Published: July 2006

Abstract
γ-Hydroxy-β-lysine is a new basic amino acid isolated from the hydrolyzates of antitubercular peptides, tuberactinomycin A and N. In order to confirm the structure and establish the stereochemistry of the amino acid, two diastereoisomers of γ-hydroxy-Dl-β-lysine were synthesized by Arndt-Eistert synthesis via β-hiydroxyornithine. Synthetic erythro and threo isomers were found to be identical spectroscopically and chromatographically with the corresponding forms obtained from the antibiotics respectively.
Conformational Analysis About N–N Bond by NMR Spectroscopy: N-Sulphonyl Derivatives of N-Aminoimides of Anthracene-Citraconic Anhydride and Naphthalene-Maleic Anhydride Adducts
Authors: Verma S M , Rao O Subba , Sinha K O P 
Published: July 2006

Abstract
A series of N′,N′-disulphonyl and N′-sulphonyl-N′-acetyl derivatives of N-amino-9,10-dihydroanthracene-9,10-endo-α-methyl-α,β-succinimide and N-amino-1,2,3,4-tetrahydro-1,4-etheno/ethano-naphthalene-2,3-exo/endo-dicarboximides with a benzo ring in the cage-moiety were prepared and their NMR spectra were studied. Shielding constants of the substituents provide evidence for the non-eclipsed conformations of the N′-substituents with the ring carbonyls. The preferred conformations of N′-sulphonyl-N′-acetyl derivatives are explained on steric grounds. In N′-tosyl-N′-acetyl derivatives the tosyl group takes up a fixed conformation about N′-SO2 bond in which the aryl part of the tosyl group projects away from the cage-moiety.
The Crystal and Molecular Structure of Dimeric [3-(Salicylideneamino)-1-propanolato(2–)]copper(II)
Authors: Nassiff Peter J , Boyko E R , Thompson Loren D 
Published: July 2006

Abstract
The crystal structure of dimeric [3-(salicylideneamino)-1-propanolato(2–)]copper(II) has been determined by X-ray diffraction. The two copper atoms are square planar with a separation of 3.021 (4) Å and are bridged with aliphatic oxygens. The unusually low antiferromagnetism, explained by superexchange, has been correlated with the Cu–O–Cu angles of similar complexes.
Stereochemistry of Ionic Thiol Addition to Acetylenic Ketones
Authors: Omar Mohamed Tawfik , Basyouni Mohamed Nabih 
Published: July 2006

Abstract
Piperidine-catalysed addition of thiols to benzoyl- and p-chlorobenzoyl-phenylacetylenes in benzene gave a mixture of (E)- and (Z)-1-aryl-3-arylthio-3-phenyl-2-propen-1-ones. However, in methanol or aqueous 1,4-dioxane only the (Z)-isomers were obtained. Configurational assignments to the isomers were based on NMR, UV, and IR spectroscopy.
The Isomerization of Purine Nucleosides in a Dilute Alkaline Solution
Authors: Suzuki Yoshihisa , Yatabe Setsuko 
Published: July 2006

Abstract
A further study of the isomerization of inosine (1a) in a dilute alkaline solution has revealed the formation of α-pyranbsyl isomer (4a) and its β-isomer (3a). Adenosine (1b) was isomerized at 130 °C for 12 hr at pH 10, giving α-furanosyl (2b) (2% yield), β-pyranosyl (3b) (11%), and the α-pyranosyl isomer (4b) (0.8%), respectively; 65% of the 1b also remained. 9-β-d-Ribopyranosyl-6-mercaptopurine (3c) was prepared through this reaction from the corresponding β-furanoside (1c). Arabinosyl or xylosyl purine nucleosides were also isomerized, whereas neither 2′-deoxy nor 2′-substituted nucleoside showed any clear evidence of isomerization. In conclusion, the purine base and the 2′-hydroxyl anion are essential to the alkaline isomerization of nucleosides. By means of NMR, both 4a and 4b were found to have a 1C conformation, while 3a and 3b have a Cl conformation.
Alkylation of Phenols. II. The Selective Formation of Thymol from m-Cresol and Propylene with a γ-Alumina Catalyst
Authors: Nitta Masahiro , Aomura Kazuo , Yamaguchi Katsumi 
Published: July 2006

Abstract
The alkylation of m-cresol with propylene was carried out over a γ-alumina catalyst in a flow system under atmospheric pressure. It was found that the composition of the thymol mixture thus obtained was greatly ortho-rich. It was also observed that the catalytic activity varied with the temperature and the atmosphere for the calcination of the catalyst, whereas the selectivity for thymol formation was almost constant at about 90% at the reaction temperature of 250 °C. It has been established that thymol can be obtained selectively by vaporphase alkylation over a commercial γ-alumina catalyst under appropriate reaction conditions. Furthermore, the active sites of γ-alumina for this reaction were investigated by the poisoning technique with acids and bases. It was suggested that, for the alkylation, the Lewis-acid sites (surface aluminum) and the adjacent acid sites (surface hydroxyl) are necessary. The mechanism of the alkylation on those sites is also discussed.
Reactions in the Adsorbed Layer: Hydrogenation of Acetone on Nickel Catalysts
Authors: Miyata Hisashi , Minobe Mitsuhiko , Kubokawa Yutaka 
Published: July 2006

Abstract
The hydrogenation of acetone adsorbed and the dehydrogenation of isopropanol adsorbed on silica-supported nickel catalyst have been studied by following the changes of hydrogen pressure and the reaction products as well as the IR spectra of adsorbed species. It was found that the formation of isopropanol proceeds via a precursor composed of acetone and hydrogen. The activation energies of hydrogenation of acetone adsorbed and of dehydrogenation of isopropanol adsorbed were 11–13 and 4–8 kcal/mol, respectively. The activation energy of the desorption was 13 kcal/mol for isopropanol and 19 kcal/mol for acetone. From the results the potential energy change during the hydrogenation of acetone was determined.
The Magnetic Properties of Verdazyl Free Radicals. VI. ESR Studies of Pairs and Triadst of the Symmetrical Triphenylverdazyl Radical in the 1,3,5-Triphenylbenzene Matrix
Authors: Azuma Nagao , Ohya-Nishiguchi Hiroaki , Yamauchi Jun , Mukai Kazuo , Deguchi Yasuo 
Published: July 2006

Abstract
Single-crystal ESR studies have been carried out on symmetrical triphenylverdazyl (TPV) doped in a diamagnetic 1,3,5-triphenylbenzene (TPB) crystal at room temperature. There have appeared seven pairs of fine-structure absorptions in addition to the hyperfine splittings. Three out of the seven pairs have been assigned as zero-field splittings due to radical pairs, while the other three pairs have been identified as from radical triads. The six fine structure tensors have been determined through the angular variation of the resonance-field separations. The structures of the pairs and triads of TPV were discussed on the basis of the fine structure tensors, the crystal structures of TPB and TPV, and the spin distribution in the radical molecule, assuming that the unit cell of the mixed crystal with the radical concentration of less than 11.1% is identical with that of the host crystal, TPB. Within the limits of the X-ray examination, this assumption was found to be reliable. It was found that the molecular planes in each species are almost parallel to the bc-plane and that all the C-phenyl rings lie in the c-direction.
Electronic Spectra of Perylene Crystals
Authors: Tanaka Jiro , Kishi Tohru , Tanaka Masashi 
Published: July 2006

Abstract
The electronic absorption and emission spectra of α and β forms of perylene have been investigated. The lowtemperature spectra have been studied with the (001) plane, and adetailed vibrational analysis is presented. The reflection measurements with the (001) plane and the (110)or (1\bar10) plane are carried out, and the Kramers-Kronig transformation is carried out in order to obtain the absorption coefficient. The results present reasonable evidence for the existence of the intermolccular CT transition in the 27000 cm−1 region. The emission spectra at 4.2 K present several novel features of the mechanism of a monomer-like emission of the α-crystal.
Photochemical Reaction of Halo-1,3,5-triazines: Photo-triazinylation
Authors: Yamada Hideo , Shizuka Haruo , Sekiguchi Shizen , Matsui Kohji 
Published: July 2006

Abstract
Chloro-s-triazines or broma-s-triazines containing halogen and/or methoxy subsituents in the s-triazine nucleus gave the corresponding phenyl-s-triazines upon irradiation at 2537Å in the benzene.
Reaction of Chlorohydrocarbons. VI. Co-pyrolysis of Chloroethanes and Methanol on Activated Alumina
Authors: Shinoda Kiyonori 
Published: July 2006

Abstract
Co-pyrolysis of chloroethanes and methanol on activated alumina was carried out in order to elucidate the reaction mechanism. The reaction rate was of first order in chloroethanes in the presence of excess methanol. A linear free energy relationship was found to exist between the reactivities of chloroethanes (at 230°C) and Taft’s σ* constants, ρ* values for reactions of RCH3, RCH2Cl and RCHCl2 series were 0.24, 0.45 and 0.70, respectively. It could be assumed that a β-hydrogen of chloroethanes was abstracted by the nucleophilic attack of methanol, chlorine being removed at the same time. E2 reaction seems to dominate in co-pyrolysis of chloroethanes and methanol on activated alumina.
Reactions of Aryliminotriphenylphosphoranes with Sulfenes
Authors: Kawashima Takayuki , Inamoto Naoki 
Published: July 2006

Abstract
Aryliminotriphenylphosphoranes reacted with methanesulfonyl, ethanesulfonyl and α-toluenesulfonyl chlorides in the presence of triethylamine to give 1 : 2 adducts [α-(N-alkanesulfonyl-N-arylsulfamoyl)alkylidenephosphoranes] and the decomposition products, instead of 1 : 1 adducts [α-(N-arylsulfamoyl)alkylidenephosphoranes). They were obtained under ice-cooling, the structure being of betaine type. In the case of methanesulfonyl chloride, isomeric 1 : 2 adduct [α-(N-arylsulfamoyl)methanesulfonylmethylenephosphorane] was also obtained. 2-Propanesulfonyl chloride gave N-triphenylphosphonio-N-arylsulfamate instead of expected adduct. In the absence of triethylamine, α-(N-arylsulfamoyl) alkyltriphenylphosphonium chlorides were obtained in good yields. Possible mechanisms of these reactions have been discussed.
Metal Phosphinylides and Phosphinothioylides. I. Formation of Metal Diphenylphosphinylides and Diphenylphosphinothioylides and the Reactions with Some Organic Halides and Aldehydes
Authors: Emoto Tateki , Gomi Hideyuki , Yoshifuji Masaaki , Okazaki Renji , Inamoto Naoki 
Published: July 2006

Abstract
Lithium diphenylphosphinylide or diphenylphosphinothioylide ([Ph2PX]Li; X=O, S), prepared from diphenylphosphine oxide or sulfide and n-butyllithium, reacted with methyl iodide, acetaldehyde and benzaldehyde to give the corresponding phosphine oxides or sulfides in good yields, indicating the formation of C–P bond. Formation of [Ph2PS]MgCl from diphenylphosphinothioyl chloride (1) and magnesium was confirmed by the similar reactions. When 1 was allowed to react with magnesium or sodium for a long time, diphenylphosphides ([Ph2P]M) were produced by desulfurization, together with [Ph2PS]M (M=MgCl, Na). Reaction of 1 with [Ph2PS]M gave tetraphenyldiphosphine disulfide through formation of P-P bond, while diphenylphosphinyl chloride and [Ph2PO]M reacted through formation of P–O bond. The difference has been explained by soft-hard-acid-base concept.
Metal Phosphinylides and Phosphinothioylides. II. Effects of Metals on the Reactions of [Ph2PX]M with Benzaldehyde and p-Benzoquinone
Authors: Goda Koshiro , Gomi Hideyuki , Yoshifuji Masaaki , Inamoto Naoki 
Published: July 2006

Abstract
Reactions of [Ph2PO]M with benzaldehyde gave benzyl benzoate and benzyldiphenylphosphine oxide (3) in the case of M=Na, 3, α-hydroxybenzyldiphenylphosphine oxide, benzyl alcohol, benzoin and benzil in the case of M=MgCl, and 3 in the case of M=ZnCl. Reactions of [Ph2PX]M with p-benzoquinone gave 2,5-dihydroxyphenyldiphenylphosphine oxide or sulfide and p-hydroxyphenyl diphenylphosphinate in the cases X=O, S and M=Li, MgCl, Al, and 1,4-phenylene bis(diphenylphosphinate) or bis(diphenylphosphinothioate) in the cases X=O, S and M=FeCl. The reaction mechanisms have been discussed.
Anomeric Effect in Sulfur Heterocycles Carrying Sulfur Substituents
Authors: Oki Michinori , Sugawara Tadashi , Iwamura Hiizu 
Published: July 2006

Abstract
Conformational analysis of 1,3,5-trithiane derivatives with sulfur-substituents was carried out with the aid of PMR spectra at various temperatures. 2-Phenylthio-1,3,5-trithiane exhibited the strong anomeric effect whereas 2-phenylthiothiane the moderate. This enhanced anomeric effect in trithiane derivatives was attributed to both the stabilization of the axial form and the destabilization of the equatorial form. cis-2,4-Bis(phenylthio)-1,3,5-trithiane was found to possess a diaxial conformation to a fair extent in support of the presence of the strong anomeric effect. Equilibration between cis and trans forms of 2,4-bis(phenylthio)-1,3,5-trithiane was carried out to show that the trans form was more stable than the cis. The barrier to inversion of trans-2,4-bis(phenylthio)-1,3,5-trithiane was obtained as ca. 11 kcal/mol.
Die Rolle des Oxydationseffekts bei der Lithentwicklung
Authors: Suga Tsuneo 
Published: July 2006

Abstract
Als Fortsetzung früherer Mitteilungen, in welchen der Autor auf die oxydative Wirkung der Oxydationsprodukte des Hydrochinons bei der Lithentwicklung hinwies, wurde hier der Oxydationseffekt eingehender untersucht und der Mechanismus der Lithentwicklung diskutiert, obwohl einige Arbeiten keinen Oxydationseffekt vertreten. Die Lithentwicklung hat eine beträchtliche Induktionsperiode, in der man keine Schwärzung bemerken kann. Durch physikalische Entwicklung, die der chemischen Entwicklung und dem Fixieren nachfolgte, bemerkte man eine sichtbare Schwärzung. Diese Versuchsmethode führte zu folgenden Ergebnissen. Während der Induktionsperiode konnte man das Wachstum von Entwicklungskeimen experimentell finden. Der Oxydationseffekt angesammelter Oxydationsprodukte auf die Entwicklungskeime wurde im Entwicklungsverlauf nach der Induktionsperiode als wirksam betrachtet. Während der Induktionsperiode wurde aber eine Oxydation der Entwicklungskeime durch die diffundierenden Oxydationsprodukte als Saumeffekt beobachtet. Durch die Feststellung des Oxydationseffekts ist die Folgerung über den Mechanismus der Lithentwicklung die gleiche wie in früheren Arbeiten, kann aber ausführlicher beschrieben werden.
The Methylation of Phenol and the Decomposition of Methanol on ZnO–Fe2O3 Catalyst
Authors: Kotanigawa Takeshi 
Published: July 2006

Abstract
As a result of a series of studies, ZnO–Fe2O3 catalysts have been shown to promote the selective methylation (k1) of phenol at the ortho position and also to promote the decomposition of methanol (k2). The activation energies were determined to be 22±2 kcal/mol for the methylation and 27 ±3 kcal/mol for the decomposition. The selectivity factor (S=k1⁄k2) of the simultaneous reaction was determined for five types of catalysts in order to estimate the most favorable catalyst for the methylation. The selectivity factor of these catalysts decrease with the rise in the calcination temperature. For example, the S on the catalysts calcined at 500 °C is approximately at unity but the S on the catalysts calcined at 800 °C is at about 0.4. These results suggest that the calcination using the present catalysts should be controlled at a low temperature.
The Formation and Collapse of Mixed Monolayer of Triolein and Tricaprylin
Authors: Nakagaki Masayuki , Funasaki Noriaki 
Published: July 2006

Abstract
The surface pressure-area curves of mixed monolayers of triolein and tricaprylin and the equilibrium spreading pressures of these liquid mixtures were measured at 25 °C. The surface pressures of the monolayers of the pure components, triolein and tricaprylin, did not vary when the monolayer was compressed below its collapse area, but the surface pressure of their mixed monolayers increased with the compression; the surface pressure at a zero area agreed well with the value of the equilibrium spreading pressure. From the two curves, the one representing the relation between the collapse pressure and the composition of the mixed monolayer, and the other representing the relation between the equilibrium spreading pressure and the composition of the liquid mixture, the compositions of the mixed monolayer and the liquid mixture coexisting in the equilibrium were obtained. Consequently, it was found that the component whose collapse pressure was lower was richer in the liquid mixture than in the mixed monolayer, while the other component, whose collapse pressure was higher, was poorer in the liquid mixture than in the mixed monolayer. It was concluded, on the basis of the phase rule and thermodynamics for a plane interface, that triolein and tricaprylin form a regular mixture in the monolayer as well as in a liquid.
Solvent Extraction Studies of the Hydrolysis of Antimony(III) in Tracer Concentrations
Authors: Shoji Hitoshi , Mabughi Hisao , Saito Nobufusa 
Published: July 2006

Abstract
The hydrolysis of antimony(III) ions was investigated through solvent extraction with dithizone–carbon tetrachloride solutions. In a 3 M (H, Na)ClO4 solution, a tracer concentration of antimony(III) (&lt;10−8M) was found in the form of a monovalent cation, Sb(OH)2+ or SbO+, and a neutral species, Sb(OH)3 or SbO(OH). The former is predominant in strongly acidic media, while the latter becomes abundant in the weakly acidicto-neutral region. One of the constants of successive hydrolysis, K1=[Sb(OH)2+][Sb(OH)3]−1[H+]]−1, was calculated from the distribution ratios, giving the result: logK1=1.236±0.06. The chemical composition of the extracted species was estimated to be Sb(HDz)3.
Intramolecular Hydrogen Bonding and Conformations of α,α-Dialkyl-and α-Alkyl-o-methoxybenzyl Alcohols
Authors: Yamashita Akihiko , Hara Katsuo , Aizawa Shigeko , Hirota Minoru 
Published: July 2006

Abstract
The stable conformations of α-alkyl- and α,α-dialkyl-o-methoxybenzyl alcohols were deduced by measurement of their infrared and PMR spectra. Population of these conformations was estimated from the intensities of the O–H stretching bands of the free and the hydrogen-bonded species. The O–H chemical shifts at infinite dilution (δOH∞) of the free and the hydrogen-bonded species were determined by plotting the δOH∞ values against population obtained from the infrared spectra. An anomalous behavior was observed with the α-alkyl-α-t-butyl alcohols, which might be due to a buttressing effect.
Preparation of 1,7-Disubstituted Indan Derivatives and Their Application to the Synthesis of Tricyclic Heterocyclic Compounds
Authors: Sakane Kazuo , Oda Shinichi , Haruki Eiichi , Otsuji Yoshio , Imoto Eiji 
Published: July 2006

Abstract
The Birch reduction of acenaphthene (1) followed by treatment of the reduction product with sodium ethoxide gave 2a,3-dihydroacenaphthene (3). The oxidation of 3 with hydrogen peroxide gave 2a,3,4,5-tetrahydroacenaphthene-4,5-diol (5). Further oxidation of 5 afforded various 1,7-disubstituted indan derivatives including 7-carboxyindan-1 -acetic acid (7). Two tricyclic N-heterocyclic compounds, 3,3a-dihydrocyclopent[de]quinolin-2(1H)-one (13) and 3,3a-dihydrocydopent[de]isoquinolin-1(2H)-one (17), were synthesized from 7.
A New Synthesis of α,β-Unsaturated Carboxylic Esters. The Condensation of Ethyl Lithiotrimethylsilylacetate with Carbonyl Compounds
Authors: Taguchi Hiroaki , Shimoji Katsuichi , Yamamoto Hisashi , Nozaki Hitosi 
Published: July 2006

Abstract
The key step of the title synthesis involves the conversion of ethyl trimethylsilylacetate to the corresponding enolate, 1, by treatment with lithium dicyclohexylamide in tetrahydrofuran at −78 °C. The condensation of 1 with aldehydes and ketones proceeds smoothly to afford the desired two carbon homologated unsaturated esters in excellent yields. The new process is extended with success to readily-enolizable carbonyl compounds and also to chalcone, which gives no trace of the Michael adduct in the present reaction.
Infrared Absorption Intensities of trans- and cis-Dichloroethylene
Authors: Tanabe Kazutoshi , Saëki Shinnosuke 
Published: July 2006

Abstract
Infrared absorption intensities of trans- and cis-dichloroethylene were measured in the vapor phase, and interpreted in terms of intensity parameters common to the isomers. In order to obtain L matrices, force constants common to the isomers were determined so as to attain the best fit between the observed and calculated frequencies of CHCl=CHCl, CDCl=CDCl and CHCl=CDCl. Using the L matrices thus obtained, intensity parameters were determined so as to attain the best fit between the observed and calculated intensities of CHCl=CHCl. As a result, the observed frequencies and intensities were satisfactorily represented in terms of the force constants and the intensity parameters common to the isomers.