bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of Carboxylic Acid from Aryl Halide and Carbon Monoxide Catalyzed by Nickel Carbonyl
Authors: Nakayama Mikitake , Mizoroki Tsutomu 
Published: July 2006

Abstract
In the reacion of aryl bromide with carbon monoxide in the presence of water and a catalytic amount of nickel carbonyl, it has been found that aromatic carboxylic acids (benzoic acid, polymethylbenzoic acid, α-naphthoic acid, etc.) are formed in very high yields when such salts of carboxylic acids as potassium acetate or sodium benzoate are added to the starting materials. The carbonylation reaction of aryl bromide is strongly inhibited by the hydrobromic acid formed, and the addition of the salt of carboxylic acid effectively decreases its concentration in the course of the reaction. When the amount of potassium acetate is larger than that of aryl bromide, the rate of the carbonylation reaction of bromobenzene to form benzoic acid is proportional to the amounts of bromo-benzene, nickel tetracarbonyl, and water and to the reciprocal of the carbon monoxide pressure. From these kinetic data, the effect of the salts of carboxylic acids and the course of the reaction are discussed.
Molecular Orbital Treatment of Nitric Oxide Radicals. II. ESR Spectra of Aliphatic Nitric Oxide Radicals
Authors: Kikuchi Osamu 
Published: July 2006

Abstract
Quantitative discussions of the ESR spectra of aliphatic nitric oxide radicals have been undertaken on the basis of the molecular orbitals of all-valence-electrons, which were evaluated by the approximate SCF method with the CNDO/2 approximation. The spin density on the methyl proton in the dimethyl nitric oxide radical is proportional to cos2θ, where θ is the angle between the nitrogen 2pz orbital and the plane containing the C–N and the G–H bonds; the small hyperfine splitting constants of β-protons appearing in some substituted nitric oxide radicals are understood as resulting from the sterically-restricted conformations of substituted groups. The deviation of the g factor of aliphatic nitric oxide from the free spin comes from the large spin densities localized on the nitrogen and the oxygen atoms, and the small excitation energy, from the nonbonding orbital of the oxygen to the odd π-orbital. The electronic structures and g factors of some other radicals are compared to those of aliphatic nitric oxide radicals.
Determination of the S*–T Transition Probabilities of Some Xanthene and Thiazine Dyes on the Basis of the T-Energy Transfer. I. Experiment in Ethanol Solutions
Authors: Nemoto Masae , Kokubun Hiroshi , Koizumi Masao 
Published: July 2006

Abstract
Intersystem crossing probability, \varphiSTA for fluorescein, eosine, erythrosine, methylene blue and thionine in ethanol (only for fluorescein, 30 vol% alkaline aqueous ethanol solution), has been determined by comparing the quantum yield of the direct (Φ) and sensitized photoreduction (Φs), on the basis of the following relations,
Φ=\varphiSTAβ Φs=\varphiSTDγβ
where β is the fraction of triplet dye molecules that are reduced eventually, \varphiSTA and \varphiSTD are respectively for acceptor (dye) and donor (sensitizer) and γ is the energy transfer efficiency, which was assumed as 1. ATU was used as a reducing agent. 1,2,5,6-dibenzanthracene, triphenylene, anthracene and β-acetonaphthone were used as sensitizers. It has been confirmed that the above relations and assumption hold generally. Different sensitizers usually gave nearly the same \varphiSTA values (with the exception of thionine-anthracene. β-Acetonaphthone gave in general somewhat smaller values). The most probable \varphiSTA values obtained are; fluorescein (0.007), eosine 0.43±0.04, erythrosine 1.1±0.06, methylene blue 0.52±0.03, thionine 0.62±0.03. The values for xanthene dyes agree moderately well with the ones reported by Porter et al. for the aqueous solution of pH=9, fluorescein 0.05, eosine 0.71, erythrosine 1.07. Using the above \varphiSTA values, the ratio of the deactivation and genuine reaction between triplet dye and ATU has been evaluated. The ratio increases in the order, fluorescein&lt;eosine&lt;erythrosine, thionine&lt;methylene blue.
Photooxidation of Anthracene
Authors: Sugiyama Noboru , Iwata Masaaki , Yoshioka Michikazu , Yamada Kazutoshi , Aoyama Hiromu 
Published: July 2006

Abstract
It was found that anthracene (I) was converted to 9,10-anthraquinone (III) and bianthrone (IV) by irradiation via anthracene peroxide (II). The reaction proceeded most effectively in carbon disulfide. Also IV was found to be oxidized to III by oxygen in singlet state.
Oligomerization of Isoprene by Hafnium Catalysts
Authors: Misono Akira , Uchida Yasuzo , Furuhata Ken-ichi , Yoshida Shohei 
Published: July 2006

Abstract
Oligomerization of isoprene by the catalyst system consisting of hafnium(IV) n-butoxide and diethylaluminum chloride was studied. Isoprene was oligomerized to a mixture of dimers, trimers and higher oligomers. The compound, 2,6-dimethyl-1-trans-3,6-octatriene, was the main dimer of isoprene in this reaction. The maximum yield of this dimer in the reaction at 130°C for 2 hr was accomplished when the molar ratio of diethylaluminum chloride to hafnium(IV) n-butoxide was 4.7. The addition of tetrahydrofuran or triphenylphosphine kept the selectivity for the dimer nearly constant. These results were compared with those obtained by the catalyst system consisting of titanium (IV) n-butoxide or zirconium(IV) n-butoxide and diethylaluminum chloride.
Specific Association of Riboflavin and Adenine Derivatives in Chloroform Solution and the Effect of Barbiturates on the Association
Authors: Kyogoku Yoshimasa , Yu Byung Sul 
Published: July 2006

Abstract
Riboflavin-2′,3′,4′,5′-tetraacetate and tetrabutyrate have been found to associate with 9-ethyladenine. They form stronger complexes with each other than with themselves and with other nucleic acid purine and pyrimidine derivatives. The association constants of the formation of the complexes were determined from the infrared spectra to be 130 and 95m−1 respectively. The complex is a 1 : 1 cyclic hydrogen bonded dimer through the imino and the 2-C carbonyl groups of the isoalloxazine ring and the amino group of the adenine residue. 9-Ethyladenine is an effective quencher of the fluorescence of riboflavin tetraacetate. The quenching appears mainly due to the coplanar interaction through hydrogen bonds and partly due to the collision interaction with the purine rings. Some barbiturates were found to prevent the formation of the complex of the adenine and riboflavin derivatives by the formation of more stable complexes with ethyladenine.
Synthetic Studies of the Flavone Derivatives. X. The Synthesis of 3,4′,5-Trihydroxy-3′,6,7-trimethoxyflavone and the Structures of Chrysosplenin and Chrysosplenetin
Authors: Fukui Kenji , Matsumoto Takashi , Tanaka Sachihiko 
Published: July 2006

Abstract
The acid-catalyzed isomerization of 4-benzyloxy-2′-hydroxy-3,4′,5′,6′-tetramethoxychalcone gave 4′-benzyloxy-3′,5,6,7-tetramethoxyflavanone, which was then converted by oxidation to 4′-benzyloxy-3-hydroxy-3′,5,6,7-tetramethoxyflavone. This, after debenzylation to 3,4′-dihydroxy-3′,5,6,7-tetramethoxyflavone, was partially demethylated with aluminum chloride or aniline hydrochloride to give 3,4′,5-trihydroxy-3′,6,7-trimethoxyflavone (I) (mp 213–214°C), the structure proposed previously for the chrysosplenetin (mp 177–178°C) isolated from Chrysosplenium japonicum Makino. However, the synthetic flavone was found to be different from natural chrysosplenetin by a mixed melting point determination and by a comparison of the spectra. Finally, the structures of chrysosplenetin and chrysosplenin were established by the spectroscopic studies to be 4′,5-dihydroxy-3,3′,6,7-tetramethoxyflavone (XIII) and its 4′-glucoside (XIV) respectively. The revised structure for chrysosplenetin has been fully confirmed by direct comparison with an authentic sample.
Polarographic Studies of Dissolved Oxygen in DMSO-Water Mixtures
Authors: Fujinaga Taitiro , Izutsu Kosuke , Adachi Takeo 
Published: July 2006

Abstract
The solubility and polarographic behavior of dissolved oxygen have been investigated in air-saturated DMSO-water mixtures at 25°C and 45°C. The first oxygen wave, which corresponds to one-electron reduction to superoxide ions in water-poor DMSO solutions of 0.1 m Et4NClO4, changes to a two-electron process in the range of water content between 10 and 30% because of the protonation reaction due to water. The rate of protonation is potential-dependent. The rate also depends on the species and the concentrations of the supporting electrolytes. The temperature effect is small. Using the solubility and polarographic data obtained, the polarographic diffusion coefficients of oxygen in the mixed solvent have been calculated.
Spectroscopic Studies of Poly nuclear Complexes. I. Preparations and Circular Dichroisms of Tetrakis(l-propylenediamine)-dicobalt(III) Complexes Containing μ-Amido Group
Authors: Sasaki Yoichi , Fujita Junnosuke , Saito Kazuo 
Published: July 2006

Abstract
New binuclear cobalt(III) complexes, (−)D-[(l-pn)2Co(μ-NH2,O2)Co(l-pn)2](NO3)4·3H2O, (+)D-[(l-pn)2Co(μ-NH2,O2)Co(l-pn)2]I3·6H2O, (+)D-[(l-pn)2Co(μ-NH2,NO2)Co(l-pn)2]Br4·6H2O, (+)D-[(l-pn)2Co(μ-NH2,OH)Co(l.pn)2](NO3)4·2H2O and (−)D-[(l-pn)2Co(μ-NH2,SO4)Co-(l-pn)2](NO3)3 were prepared and their absolute configurations determined to be ΛΛ on the consideration of the stereospecific coordination of l-propylenediamine (l-pn) to the metal ion. On the basis of these identifications, absolute configurations of the corresponding ethylenediamine-(en) complex ions were assigned. The nature of the d–d bands of these polynuclear complexes seems to be very similar to those of uninuclear cobalt(III) complexes. One of the two central cobalt(III) ions is regarded as a member of an asymmetric chelate ligand to the other cobalt ion, and the CD corresponding to the d–d bands appears to depend mainly on the strength of vicinal effect due to such a chelate ring.
Polarographic Studies of the Solubilization of Disperse-dyes
Authors: Hayano Shigeo , Shinozuka Noriko 
Published: July 2006

Abstract
The apparent mean particle size of the solubilized dye in nonionic surfactant solutions is determined from the polarographic diffusion coefficient. The diffusion coefficient and the particle size obtained are in good agreement with those of the nonionic surfactant micelle reported in the literature. For the system of polyoxyethylene nonylphenyl ether (NP-\bar19) and 1,4-diaminoanthraquinone, the particle size increases with the dye concentration; however, the particle size is almost constant for the system of NP-\bar19 and 1,4,5,8-tetraaminoanthraquinone (TAA). When a certain quantity of TAA is solubilized into the 10−3–10−2m NP-\bar19 solution, the particle size is also constant. In the case of the polyoxyethylene lauryl ether (LA-\bar14) and TAA system, the particle size markedly decreases with the increase in the dye concentration. This tendency suggests that the numbers of micelles increase with the concentration of the solubilizate. The fact that the half-wave potential of the dye reduction is independent of the concentration of the surfactants is explained in terms of the similarity between the electrode process of the solubilized dye and that of the dissolved dye.
Nature of Acid Sites on the Surface of Silica-alumina. I. The Relation between the Acid Property of Sites and the Heat of Immersion
Authors: Miura Masaji , Kubota Yukio , Iwaki Toru , Takimoto Kazuto , Muraoka Yoshinori 
Published: July 2006

Abstract
The acidity and the acid strength of the sites of such solid catalysts as silica gel, alumina, and silica-alumina were determined by the n-butylamine titration method using the Hammett indicators. The distribution of the acid sites on the surfaces of these catalysts was found to vary with the outgassing temperature, and also with the alumina content in the case of silica-alumina. The heats of immersion of these catalysts in water and in an aqueous solution of n-butylamine were measured. The heat value corresponding to the difference between these two cases, as well as the number of acid sites, showed a maximum at contents of 10–20%. These phenomena are discussed with reference to the results of the diffuse reflection measurements.
The Crystal Structure of Riboflavin Hydrobromide Monohydrate
Authors: Tanaka Nobuo , Ashida Tamaichi , Sasada Yoshio , Kakudo Masao 
Published: July 2006

Abstract
The crystal structure of riboflavin hydrobromide monohydrate has been determined by a three-dimensional X-ray analysis. The space group is P 212121 with four formula units in the unit cell of dimensions a=18.28, b=6.99 and c=14.77 Å. The structural parameters were refined by means of a block-diagonal least-squares method, the final R factor being 0.07. The ribitol does not form a furanose ring but a chain. The protonation of the isoalloxazine ring occurs at the N(1) atom, and the C(4a)-N(10) bond is found to be a double bond. The bromide ion is situated midway between two isoalloxazine rings separated by a period along the b axis.
Preparation and Circular Dichroism of trans(N)- and cis(N)-Isomers of (Ammoniatriacetato)(amino-acidato)cobalt(III) Complexes
Authors: Koine Norio , Sakota Naokazu , Hidaka Jinsai , Shimura Yoichi 
Published: July 2006

Abstract
Eleven new complexes, trans(N)- or cis(N)-isomers of (ammoniatriacetato)(amino-acidato)cobalt(III) ions, have been synthesized as their potassium salts, where the amino acids are glycine, β-alanine, γ-aminobutyric acid, sarcosine, l-alanine, l-serine, l-valine and l-proline. The geometrical isomers have been separated by ion-exchange column chromatography and their structures determined on the basis of their absorption spectra and proton magnetic resonance spectra. Stereoselectivity about the formation of the trans and cis isomers was found. The circular dichroism of the complexes containing optically active amino acidato ligands has been measured and discussed in relation to so-called vicinal contribution by the optically active ligands.
Studies on Fluorene Derivatives. XXV. Abnormal Products, Tribiphenylenepropanes, of the Michael Addition of 9,9′-Bifluorenylidenes and Fluorenes, and Syntheses of Related Compounds
Authors: Suzuki Kazuo , Minabe Masahiro , Fujimoto Minoru , Nohara Noboru 
Published: July 2006

Abstract
A normal compound, 2′,7′-dibromotribiphenylenepropane (IV), and an abnormal compound, 2′,7′,2″,7″-tetrabromotribiphenylenepropane (VI), were obtained by the Michael addition of 9,9′-bifluorenylidene (I) and 2,7-dibromofluorene (III). In addition, another normal compound, 2,7,2′,7′-tetrabromotribiphenylenepropane (VIII) and three abnormal compound, IV, VI, and tribiphenylenepropane (VII), were isolated by the Michael addition of 2,7,2′,7′-tetrabromo-9,9′-bifluorenylidene (IX) and fluorene (II). In both cases, the normal compounds were obtained in the presence of sodium ethoxide in ethanol. The abnormal compounds might be formed by the further condensation of 2,7-dibromo-9,9′-bifluorenylidene (V) and III or II in the presence of alkali. The related compounds, 2,7-dibromotribiphenylenepropane (X), IV, VI, VIII, and 2,7,2′,7′,2″,7″-hexabromotribiphenylenepropane, were synthesized by the reaction of substituted 9-fluorenyllithium and substituted 9-bromo-9,9′-bifluorenyl in an absolute xylene solution. The thermal decomposition of X and VIII afforded bromosubstituted or nonbromosubstituted-9,9′-bifluorenylidenes, 9,9′-bifluorenyls, fluorenones, and fluorenes. The ethanolysis of 2,7-dibromo-9′-hydroxy-9,9′-bifluorenyl gave fluorenone and III.
Kinetics of Multidentate Ligand Substitution Reactions. IV. Substitution Reactions of BT with Cobalt(II) and Nickel(II) Chelates of 1,2-Diaminocyclohexanetetraacetic Acid and Diethylenetriaminepentaacetic Acid
Authors: Kodama Mutsuo , Sasaki Chifumi , Miyamoto Katsumi 
Published: July 2006

Abstract
The substitution reactions of Eriochrom Black T (BT) with cobalt(II) and nickel(II) chelates of 1,2-diaminocyclohexanetetraacetic acid (CyDTA) and of diethylenetriaminepentaacetic acid (DTPA) were studied spectrophotometrically. The reactions of BT with CyDTA and DTPA chelates of these metal(II) ions were found to have the same reaction mechanism as the reactions with EDTA chelates did, but to be considerably slower than the latter reactions. On the basis of a comparison of the observed rate constants with those calculated on the basis of the proposed reaction mechanism (glycinate intermediate), the steric effect due to the cyclohexane ring in the CyDTA or –CH2–CH2–N(CH2–COO−)–CH2–CH2–N(CH2–COO−)2 group in DTPA on the reaction rate was discussed in a quantitative manner. The effect due to the former group was estimated to be smaller than that due to the latter group.
The Hydrogenation Catalysts Prepared from Transition Metal Chloride and Triethylaluminum
Authors: Takegami Yoshinobu , Ueno Toru , Fujii Takao 
Published: July 2006

Abstract
Catalysts composed of anhydrous iron(III) chloride, cobalt(II) chloride, or nickel(II) chloride plus triethylaluminum have been used for the hydrogenation of olefin. The catalytic activity has changed with the Al(C2H5)3/MCln ratio. The optimum ratios for the hydrogenation of styrene have been found to be 1–7 for the iron catalyst, 0.2–1 for the cobalt catalyst, and 0.3–2 for the nickel catalyst. Cyclohexane has been used satisfactorily as a solvent. Tetrahydrofuran could be used for the nickel catalyst, but its presence was unfavorable for the iron and cobalt catalysts. The gas evolved in the reaction of the transition metal chlorides with triethylaluminum has been found to be essentially ethane, and sluggish gas absorption was observed when the atmosphere was switched to hydrogen. Ethylbenzene was formed in the treatment of the catalyst with styrene under nitrogen; the amount increased considerably if the catalyst was pre-treated with hydrogen. Ethane was formed in the hydrogen-treatment of the reaction mixture of nickel chloride and triethylaluminum. On the basis of these results, it has been assumed that metal hydride has been formed by the hydrogenolysis of metal - ethyl bonds.
Mass Spectrometry of Tautomeric Compounds. I. Absence of Keto-Enol Tautomerism in Fragment Ions
Authors: Nakata Hisao , Tatematsu Akira 
Published: July 2006

Abstract
In order to examine a possibility of keto-enol tautomerism in molecular and fragment ions, diethyl di-n-butylmalonate (Ia), methyl 2-n-butylhexanoate (IIa), and 2,2-di-n-propyl-5,5-dimethyl-1,3-cyclohexanedione (IIIa) were synthesized and their mass spectra were compared with those of respective mono-alkyl derivatives, Ib, IIb, and IIIb. The first step of the fragmentation of each dialkyl compounds is the cleavage of one of the alkyl side chains by McLafferty rearrangement to give an enol fragment ion (E). Comparisons of the behavior of this enol fragment ion with that of the corresponding molecular ion (K) of mono-alkyl derivatives indicate that the keto and enol forms of these compounds exhibited entirely different fragmentation patterns. Thus, the enol fragment ion of m/e 216 from Ia loses C3H7· through the allylic cleavage of an enol double bond to give an abundant m/e 173 peak, while the keto ion of m/e 216 from Ib loses C4H8 to afford a strong m/e 160 peak. In a similar manner, the enol fragment ion of m/e 130 from IIa gives an intense peak at m/e 87, and the keto ion of m/e 130 from IIb yields an ion at m/e 74. In the spectrum of IIIa, a peak at m/e 140 that is observed in the IIIb spectrum did not appear. These results clearly suggest that no keto-enol tautomerism takes place in these ions in a mass spectrometer.
Metal Complexes with Amino Acid Amides. II. Preparations and Circular Dichroism Behavior of the Copper(II) Complexes
Authors: Komorita Takashi , Hidaka Jinsai , Shimura Yoichi 
Published: July 2006

Abstract
Planar bis-type complexes of copper(II) with l-leucine-, l-valine-, l-phenylalanine- and l-proline-amidate ligands have been newly synthesized and characterized mainly spectroscopically together with the known complexes with glycine- and l-alanine-amidates. The geometrical structures of these [Cu(N)4]-type complexes have been tentatively determined. The blue colored complexes, Cu(glycine-amide)2SO4 and its l-alanine amide analogue, have been isolated, too. The circular dichroism spectra of the complexes containing optically active ligands have been measured in various solvents and discussed in comparison with the available data for square planar d8-complexes or for amino acidato complexes. A number of interesting relations were observed among the circular dichroism spectra of the copper(II) and the square planar d8 complexes with optically active bidentate ligands.
Reaction Rates in Binary Mixed Solvents.
Authors: Kondo Yasuhiko , Kusaka Toshiharu , Tokura Niichiro 
Published: July 2006

Abstract
The rate constants of the Menschutkin reaction between methyl iodide and pyridine, N,N-dimethylaniline, 2,6-dimethylpyridine, and N,N-dimethyl-o-toluidine have been measured in a liq. SO2-nitrobenzene mixture. These results have then been analyzed by the procedure described in a previous paper. The findings regarding the reactions of unsubstituted amines with methyl iodide have been explained theoretically by taking into account the specific solvation of amines by liq. SO2 and that of an activated complex by a nitrobenzene solvent, whereas the behavior of the rate constants in the reactions of o-substituted amines in mixed solvents can be explained by assuming the specific solvation of an activated complex by liq. SO2 only. In conformity with the above results and the difference in the effect of an o-methyl group on the reaction rates between liq. SO2 and a nitrobenzene solvent, the mutual relation of the activation free energies of these reactions has been discussed.
Photoreversible Photographic Systems. VI. Reverse Photochromism of 1,3,3-Trimethylspiro[indoline-2,2′-benzopyran]-8′-carboxylic Acid
Authors: Shimizu Isamu , Kokado Hiroshi , Inoue Eiichi 
Published: July 2006

Abstract
Many derivatives of 1,3,3-trimethylspiro[indoline-2,2′-benzopyran] (1) exhibit photoreversible color changes in organic solvents. One of the derivatives 1,3,3-trimethylspiro[indoline-2,2′-benzopyran]-8′-carboxylic acid (2) shows “reverse photochromism” in polar solvents. The compound 2 exhibits a deep color in the polar solvent and the color is bleached by irradiation with either visible or ultraviolet light. The color reappears thermally as the irradiation is ceased. The thermal conversion rate from the colorless form to the colored one depends on the solvents. On the other hand, the isomer 1,3,3-trimethylspiro[indoline-2,2′-benzopyran]-6′-carboxylic acid shows neither normal nor reverse photochromism under usual conditions, but exhibits reverse photochromism when acid such as malonic acid is added into the solution. The compound 2 is assumed to have a merocyanine dye-like structure due to the intramolecular proton transfer.
Solvent Effects of Charge-transfer Complexes
Authors: Aihara Jun-ichi , Tsuda Motoyuki , Inokuchi Hiroo 
Published: July 2006

Abstract
The solvent effects of charge-transfer complexes were examined in various solvents. During the course of investigations pertaining to aromatic-TCNE complexes, Brownstein’s and McRae’s formulae were found to be valid. The gas-phase spectra of these charge-transfer complexes may be regarded as the origin of the solvent effects. The anomalous behaviour of carbonyl solvent molecules was also discussed.