bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature Effects on the Electronic Spectra of 2-Methyl-1-aceanthrenone
Authors: Hirayama Satoshi 
Published: July 2006

Abstract
The absorption, fluorescence, and excitation spectra of 2-methyl-1-aceanthrenone (I) were investigated in several solvents in the temperature range of 77–298 K. The results show that the hydrogen-bonded (fluorescent) and non-hydrogen-bonded (very weakly fluorescent) molecules of I coexist in ethanol to a comparable extent. This is the reason why its absorption spectra are very broad in alcoholic solvents. With a decrease in the temperature, the apparent fluorescence quantum yield in ethanol at first rises to a maximum (0.37) at 197 K and then decreases. Below ca. 113 K, a new fluorescence band due to the non-hydrogen-bonded molecule appears. In 2-methyltetrahydrofuran (MTHF), the temperature dependence of the fluorescence quantum yield of I is significant only at low temperatures. The yield varies monotonously from 0.014 at 132 K to 0.30 at 77 K. A behavior intermediate between those in ethanol and in MTHF is observed in EPA. The rise and fall of the fluorescence quantum yield in ethanol or in EPA may be interpreted in terms of the temperature-dependent concentration change in the hydrogen-bonded molecule. From the results in MTHF, the maximum rate constant of the intersystem crossing between the S1ππ* and Tnπ* states is estimated to be of the order of 1013 s−1.
Photosensitized Decomposition of Trioxalatocobaltate (III) Ion by Organic Triplet Sensitizers
Authors: Sakuraba Shukichi , Kakuta Akio , Matsushima Ryoka 
Published: July 2006

Abstract
Sensitized decomposition of the trioxalatocobaltate(III) ion was studied in deoxygenated aqueous solution at room temperature, using biacetyl as an n-π* triplet sensitizer and 9-carboxyanthracene as a π-π* triplet sensitizer. In the presence of one of these sensitizers the photodecomposition rate of the complex was increased, and the plot of the reciprocal of the sensitization quantum yield as a function of the concentration of the complex gave a straight line for each sensitization system. On the other hand, the complex quenched the phosphorescence without affecting the fluorescence of the sensitizers, indicating a triplet energy transfer mechanism. A photokinetic treatment of the data for both the sensitized photolysis and the quenching process gave a result in line with proposed mechanism for bimolecular triplet energy transfer.
A Conformational Study of the NOx(x=1 or 2)-catalyzed Isomerization of cis-2-Butene Using the INDO-UHF Method
Authors: Ohkubo Katsutoshi , Ikebe Hiromichi , Okada Masahide 
Published: July 2006

Abstract
The NOx(x=1 or 2)-catalyzed isomerization of cis-2-butene was investigated by means of the INDO-UHF theory, with a particular view to the energetic and conformational aspects of the reaction. The NO2-addition process to form the intermediate radical (R1) had no appreciable activation barrier, although the NO2-fission process from the intermediate radical (R2) had the C-NO2 dissociation energy of 44.6 kcal/mol. Some characteristic features of the stretched C-C bond in the intermediate radical (R1) were; (1) rcc=1.45 Å, which was roughly equal to the value (1.481 Å) in cis-2-butene at the transition state of its thermal isomerization; (2) a pseudo π-conjugation with a small π-character (about 13% of ECCR) in comparison with that (about 29% of ECCR) in cis-2-butene, and (3) approximately the same magnitude of the hfsc value (34.40–34.47 G) for the sp2-hydrid carbon as that (experimental value of 39.07 G) for the said atom in the ethyl radical. The calculated internal-rotation barrier of the intermediate radical (R1) around the C–C bond (1.75–3.01 kcal/mol in the two rotating directions) was smaller than that (around 4 kcal/mol) obtained from the thermodynamic estimations. The energetically most stable or unstable rotamer was found in the staggered or the eclipsed configuration respectively; a hydrogen-bonding effect on the stabilization was observed in staggered configuration, although a remarkable effect of the homoconjugation or the repulsive interaction of unpaired and lone-paired electrons can be disregarded in the present internal-rotamer.
Refinement of the Crystal Structure of Sodium Hexahydroxoantimonate(V), NaSb(OH)6
Authors: Asai Takeshi 
Published: July 2006

Abstract
The crystal structure of sodium hexahydroxoantimonate (V), NaSb(OH)6, has been refined. The previous structure given by Schrewelius was confirmed, but the positional parameters of oxygen atoms were shifted significantly. Both antimony and sodium atoms are surrounded by six oxygen atoms octahedrally. The interatomic distances are: Sb–O=1.972–1.999 Å (mean 1.98 Å), O–O=2.758–2.834 Å (2.80 Å) for an SbO6 octahedron, Na–O=2.375–2.406 Å (2.39 Å) and O–O=3.229–3.526 Å (3.38Å) for an NaO6 octahedron. Two types of sequences of hydrogen bonds were recognized. They were compared with the sequences of hydrogen bonds in In(OH)3 and MnSn(OH)6.
The Photobleaching: of Trapped Electrons and the Electron Capture of Radicals in γ-Irradiated Hydrocarbon Matrices at 77 K
Authors: Ishikawa Yo-ichi , Oka Ko-ichi , Sato Shin 
Published: July 2006

Abstract
The rate of the photobleaching of the trapped electrons in the 3-methylhexane and methylcyclohexane matrices at 77 K was measured by means of ESR as a function of the concentration of the 3-methylhexyl or methylcyclohexyl radicals present in the matrices. The quantum yield of the photobleaching at the wavelength of 1300 nm increased with the increase in the radical concentration. The stable products such as olefins formed during the γ-irradiation did not affect the quantum efficiency. These results support the suggestion made by Willard et al. that the 3-methylhexyl and methylcyclohexyl radicals capture the electrons released from the trapping sites by the irradiation of the infrared light. A comparison showed that the radicals are comparable with sulfur hexafluoride in electron capture.
Distribution of Trapped Electron-Cation Distance in γ-Irradiated 2-Methyltetrahydrofuran Glassy Matrix
Authors: Ichikawa Tsuneki , Yoshida Hiroshi , Hayashi Koichiro 
Published: July 2006

Abstract
An approach was presented to elucidate the distribution of trapped electron-cation distance from isothermal decay of the trapped electron by numerically solving the Smoluchowski equation and was applied to the observed isothermal decay of trapped electron at 92.2–95.0 K in 2-methyltetrahydrofuran glass irradiated by γ-rays at 77 K. The distribution curve (the probability density of finding initially the electron at the distance r) thus obtained was close to a Gaussian function.
Quantitative Estimates of π-Contact-term Contributions to the Lanthanideinduced Paramagnetic 1H Shifts in Aniline and m-Toluidine
Authors: Hirayama Masatoshi , Sato Michihiko , Takeuchi Makoto , Saito Makoto 
Published: July 2006

Abstract
The paramagnetic proton chemical shifts induced by a series of Ln(FOD)3(Ln=Pr, Eu, Dy, Ho, Er, and Yb) were observed for aniline and m-toluidine in CCl4. In an attempt to separate the pseudo-contact(pcs) and contact shift(cs) contributions, the spin-density distributions of the π-cation radicals or the Ni(AcAc)2-induced shifts were used for the cs pattern in a molecule, as well as the geometric factors for the pcs pattern. The appropriate regions of the two geometric parameters were determined by the computer-search method for the least-squares fits of the observed to the calculated shifts. Thus, the intramolecular average value of the ratio of cs-to-pcs contributions was evaluated. The variation in this ratio with an Ln ion corresponds relatively well to that of the theoretical ratio, |〈SZ〉⁄|δ|, where 〈Sz〉 has been calculated by Golding et al. and where δ is the relative pcs predicted by Bleaney et al.
Interpretation of Shake-up Satellites in the X-Ray Photoelectron Spectra of Small Hydride Molecules by One-Center-Expansion ab initio Calculation with Equivalent-Core Approximation
Authors: Fujikawa Takashi , Aoyama Tomoo , Ohta Toshiaki , Kuroda Haruo 
Published: July 2006

Abstract
One-center-expansion ab initio calculations with STO basis set were carried out on H2O, NH3, CH4 and BH3, to estimate the energies and probabilities of shake-up processes accompanying the photoionization of a core level. A method based on equivalent-core approximation and that based on configuration interaction procedure were applied to obtain wave functions of core-hole ions. It is shown that the calculations by the former method yield very satisfactory results, not only for the core ionization potential, but also for the energies and intensities of shake-up satellites.
Anodic Wave Polarography of N-2-Aminoethyl-N-2-hydroxyethylcarbodithioic Acid
Authors: Sugawara Masao , Kambara Tomihito 
Published: July 2006

Abstract
N-2-Aminoethyl-N-2-hydroxyethylcarbodithioic acid (Hahdtc) in an alkaline medium gives at the dropping mercury electrode an adsorption prewave due to the two-electron oxidation of mercury. The electrode reaction at pH=13.1–10.1 was inferred to proceed according to
Hg+2ahdtc^-\ightleftarrowsHg(ahdtc)_2+2e\labeleq1
The surface excess of the mercury(II) chelate was estimated to be 3.0×10−10mol cm−2.
The Pressure Broadening of the Cadmium-resonance Line at 326.1 nm in Ammonia and Argon
Authors: Umemoto Hironobu , Yamamoto Shunzo , Sato Shin 
Published: July 2006

Abstract
The ratio of the collison-broadening cross-section of ammonia to that of argon for the cadmium-resonance line at 326.1 nm has been estimated to be 2.1 by comparing the experimental data of the transmission measurement with the theoretically calculated numerical table. The table shows the relation between the transmission of a resonance line passing through the system containing absorbing atoms and the ratio of the Lorentz half-breadth to the Doppler half-breadth at different values of two parameters; the optical density, and the ratio of the Doppler half-breadth of the emission line to that of the absorption line. This table may have universal importance for the study of the absorption of atomic spectra.
A Study of Catalysis by Uranium Oxide and Its Mixed Catalysts. IX. A Catalytic Reduction of Nitric Oxide with Carbon Monoxide
Authors: Nozaki Fumio , Matsukawa Fumio , Mano Yoshikazu 
Published: July 2006

Abstract
The reduction of NO with CO over the uranium oxide catalyst and its mixed catalysts with alkali metal oxide or alkaline earth metal oxide has been investigated using conventional flow and pulse reactors at temperatures of 250 to 450 °C under atmospheric pressure. The activity of the uranium oxide catalyst without any additive was higher than that of the Fe2O3 catalyst, although it was inferior to that of the CuO–Cr2O3 catalyst. The addition of alkali metal oxide or alkaline earth metal oxide to uranium oxide, particularly in the case of Cs2O or K2O, was effective in enhancing the catalyst activity. The W/F-conversion curves revealed that the reduction of NO to N2 proceeds consecutively, passing through N2O as a gas-phase intermediate. The reaction rates were formulated as r=kPCO1.0PNO0.4. The kinetic study suggested a redox reaction sequence. The oxidation states of the catalysts were discussed on the basis of X-ray diffractograms.
Ultra-thin Layer of Lipids in Polymer Film and Its Electric Properties. New Sorption Method to Prepare a Model Biomembrane System
Authors: Yoshida Tadayoshi , Ogura Shin-ichiro , Okuyama Masataka 
Published: July 2006

Abstract
The ultra-thin layer of glycerol α-cis-9-octadecenate (glycerol α-monooleate:GMO) could be formed by impregnating nitrocellulose (NC) film with GMO and by then filling microscopically the interstices of the network structure of NC with microdrops of GMO. The dielectric dispersion characteristic of this film was found to be similar to that observed for bimolecular films. In a concentrated KCl solution (100 mM), however, an anomalous dielectric dispersion phenomenon was observed below 10 kHz. The low-frequency dispersion was attributed to surface conductance along the planes of contact between the GMO microdrops and the NC network. The ultra-thin film of di(cis-9-octadecenyl)phosphate (dioleyl phosphate: DOPH) could also be formed by this method. When a constant DC voltage (50 mV) was applied across the film in a 20 mM KCl solution, the electric current through the whole system changed periodically.
Ion-Solvent Interaction of Tetraalkylammonium Ions in Dimethyl Sulphoxide from Electrolytic Conductivity Data
Authors: Jha Jai Shanker , Singh Sudha , Gopal Ram 
Published: July 2006

Abstract
Ion-solvent interaction of some tetraalkylammonium ions in dimethyl sulphoxide has been studied in this communication from the point of view of electrolytic conductivity and the derived Walden product. The R4N+ ions do not appear to interact strongly with this solvent; further, the salts examined appear to be completely dissociated in the concentration range studied here.
The Thermal Decomposition Reactions of Bivalent Metal Succinates in the Solid State
Authors: Yokobayashi Hiroko , Nagase Kenzo , Muraishi Kazuo 
Published: July 2006

Abstract
The thermal decomposition reactions of MC4H4O4 (M : Mg(II), Co(II), Ni(II), Cu(II), Zn(II), and Pb(II)) in nitrogen or helium were investigated by means of TG-DTA, X-ray diffraction measurements, gas chromatography, and combustion analysis for carbon. The decomposition residues of the Mg and Zn salts were composed of the corresponding metal oxides and some carbon, while those of the Co, Ni, Cu, and Pb salts were composed of the corresponding metals and some carbon. H2, O2, CO, CO2, H2O, CH4, C2H2, C2H4, HCOOCH3, HCOOC2H5, CH3COOC2H5, C2H5COOC2H5, and (CH2CO)2O were identified as the gaseous decomposition products; the compositions of the gaseous mixtures varied a great deal with the metals. Possible reaction mechanisms were discussed mainly on the basis of the decomposition products.
The Gas-chromatographic Determination of Selenium in Copper Metal and Copper Salts with 4-Nitro-o-phenylenediamine
Authors: Shimoishi Yasuaki 
Published: July 2006

Abstract
The gas-chromatographic method using an electron-capture detector has a high sensitivity for the determination of selenium. Moreover, as the reaction of selenium(IV) with 4-nitro-o-phenylenediamine is scarcely disturbed by other elements, the chemical separation from the matrix element is not necessary. The direct determination of very small amounts of selenium in copper and copper salts has been investigated. A mixture of equal volumes of nitric acid, hydrochloric acid, and perchloric acid dissolves the copper sample and also oxidizes the selenium to the quadrivalent state quantitatively. No loss of selenium was observed upon this treatment. The proposed method can determine the selenium in copper samples in amounts as low as 0.005 μg/g.
Isomerism of the Metal Complexes Containing Multidentate Ligands. VI. Geometric and Optical Isomers of the Tris(meso-2,3-butanediamine)-cobalt(III) Complex
Authors: Kojima Masaaki , Funaki Hiromi , Yoshikawa Yuzo , Yamasaki Kazuo 
Published: July 2006

Abstract
The tris(meso-2,3-butanediamine)cobalt(III) complex was prepared, and four possible isomers, mer-Λ, mer-Δ, facial-Λ, facial-Δ, were isolated by column chromatography on SP-Sephadex in the formation ratio of 1.4 : 1.4 : 1.0 : 1.0. The configurations and conformations of these isomers were proposed on the basis of the electronic, the circular dichorism, and the PMR spectra.
The Kinetics and Mechanisms of Reaction of Iodine with Bis(N,N-diethyldithiocarbamato)dimethyltin(IV) and Related Compounds
Authors: Kita Hidetoshi , Tanaka Koji , Tanaka Toshio 
Published: July 2006

Abstract
The reactions of Me2SnL(S2CNEt2) (L=S2CNEt2 (1) and I (2)) with iodine in cyclohexane were investigated employing a stopped-flow technique. The kinetic data indicate that the reaction in the presence of a large excess of 1 or 2 proceeds via a charge-transfer complex of Me2SnL(S2CNEt2)·I2, which decomposes in the ratedetermining step to yield Me2SnI(L) and unstable I(S2CNEt2). This unstable intermediate reacts with the excess 1 or 2 to afford Me2SnI(L) and tetraethylthiuramdisulfide (3). The reaction of 1 with a large excess of I2was also kinetically studied to reveal the formation of the 1 : 2 complex, Me2Sn(S2CNEt2)2·2I2, as an intermediate; this intermediate then undergoes a simultaneous degradation to afford Me2SnI2 and 3. The transition state in the reaction is discussed.
Effects of Solvents and Added Amines on the Selective Hydrogenation of 2-Naphthol over Urushibara Nickel and Cobalt Catalysts
Authors: Kajitani Masatsugu , Watanabe Yoshio , Iimura Yutaka , Sugimori Akira 
Published: July 2006

Abstract
The selective hydrogenation of 2-naphthol (NL) was investigated with Ni (U-Ni-B, U-Ni-A, and R-Ni) and Co (U-Co-B, U-Co-A, and R-Co) catalysts in various solvents at elevated temperatures and pressure (50 kg/cm2). U-Ni-B and U-Ni-A exhibited a high selectivity for the formation of 1,2,3,4-tetrahydro-2-naphthol (ac-TL), expecially in alcoholic solvents, while the hydrogenation with R-Ni in Et2O, i-PrOH, and benzene solvents gave preferentially 5,6,7,8-tetrahydro-2-naphthol (ar-TL). The ar-TL formation over Ni catalysts decreased in the following order, irrespective of the catalysts. i-PrOH&gt;EtOH&gt;MeOH and Et2O&gt; benzene. However, the selectivity over Co catalyst was influenced to a lesser extent by the solvents. The addition of amines promoted the hydrogenation of NL to ar-TL in the following order: prim-&gt;sec-&gt;tert-amine in EtOH over Ni and Co catalysts. In general, Ni catalysts are more susceptible to the effects of solvents and added amines than Co catalysts.
The Finkelstein Reaction in Acetonitrile–Alcohol Mixtures. An Approach to an Anion Solvation by Means of a Multi-step Solvation Model
Authors: Kondo Yasuhiko , Kato Toshio , Tokura Niichiro 
Published: July 2006

Abstract
The rate constants were determined for both processes of the Finkelstein reaction in acetonitrile–alcohol mixtures at 30 °C:
CH_3Br+I^-\oversetk_f\undersetk_r\ightleftarrowsCH_3I+Br^-
Theoretical equations were derived describing the dependence of the rate constant on the composition changes in the solvent mixtures. These equations describe the change in the rate constant in terms of changes in the activity coefficient. The results were analyzed by means of the equations; they lead to the conclusion that anions have multiple solvation equilibria with alcohols. The relative magnitudes of the step-by-step association constants and of the solvation numbers thus determined agreed with the results determined spectrophotometrically.
Selective Homogeneous Hydrogenation of 3-Oxo-1,4-diene Steroids. III. On the Formation of Saturated 5α-Ketone in the Hydrogenation Catalyzed by Dichlorotris(triphenylphosphine)ruthenium
Authors: Nishimura Shigeo , Ichino Tomio , Akimoto Akira , Tsuneda Kiyoshi , Mori Hiromu 
Published: July 2006

Abstract
Hydrogenation of 1,4-androstadiene-2,17-dione (1) with RuCl2(Ph3P)3 gives some saturated 5α-ketone together with 4-androstene-3,17-dione (2). The ratio of 2 to the saturated ketone formed increases almost in proportion to hydrogen pressure. The rate dependence upon hydrogen pressure has been shown to be first-order for formation of 2 and zero-order for formation of the saturated ketone. A mechanism which involves a 1,5-hydride shift at an intermediate species is proposed for the stereoselective formation of the 5α-ketone.
An Attempt to Predict Thermal Pericyclic Reactions by a Sequential Nucleophilic Scheme
Authors: Ito Suketaka , Kakehi Akikazu , Tanaka Yumo 
Published: July 2006

Abstract
A simple, mnemonic method for predicting pericyclic reactions in ground states has been worked out by treating a multi-center reaction as a sequence of one-center reactions analogous to nucleophilic substitution type reaction. The analysis of reaction is carried out by illustrating localized MO’s and their stepwise transformation. This method can lead to predictions for thermal pericyclic reactions in agreement with the Woodward-Hoffmann rules and the HOMO-LUMO interaction method. A simple modification of this method is applicable to reactions in excited states.
Chemical Structure and Some Properties of Roseoflavin
Authors: Kasai Sabu , Miura Retsu , Matsui Kunio 
Published: July 2006

Abstract
Roseoflavin (I) is identified as 7-methyl-8-dimethylamino-10-(1′-d-ribityl)-isoalloxazine (IX) by comparing I with four diastereoisomers of 7-methyl-8-dimethylamino-10-d-n-pentitylisoalloxazine, which were synthesized from 2-dimethylamino-4-amino-toluene, d-pentoses, and violuric acid. The coincidence of chemical and physical properties—elemental analysis, UV-visible absorption spectrum, melting point, optical rotation, Rf value in thin layer chromatography, and NMR spectrum—of free and acetylated I with those of the free and acetylated IX, respectively, verified the identity. Some of the properties of I and acetylated I (pKa, oxidation-reduction, absorption spectra, and extinction coefficients of various ionic species, and photosensitivity) are also described.
The Role of Nucleophilic Solvents in the Acid-Catalyzed Cyclization of a Cross-Conjugated Cycloalkadienone
Authors: Noyori Ryoji , Ohnishi Yasushi , Katô Masao 
Published: July 2006

Abstract
In acetic acid or methanol containing a trace amount of H2SO4, 2,8-cyclononadienone cyclizes readily to give bicyclic ketones; the mechanism including the role of the nucleophilic media is discussed.
New Syntheses of Fervenulin (1,3-Dimethyl-7-azalumazine) and Analogs
Authors: Yoneda Fumio , Nagamatsu Tomohisa 
Published: July 2006

Abstract
A new, convenient method for the synthesis of fervenulin and its derivatives on the basis of the condensation of 6-amino-5-nitrosouracils and aldehyde hydrazones is described. A transformation of toxoflavins into fervenulins via 1-demethyltoxoflavins is also described. The alkylation of 1-demethyltoxoflavin with several alcohols in the presence of diethyl azodicarboxylate and triphenylphosphine gave the corresponding fervenulin homologs.
The Hydroxyphenylation of Methylstyrenes with Phenylpalladium Chloride
Authors: Horino Hiroshi , Inoue Naoto 
Published: July 2006

Abstract
The reaction of α- or β-methylstyrene with phenylpalladium chloride in aqueous acetone were studied. From cis- or trans-β-methylstyrene, a mixture of erythro and threo isomers of hydroxyphenylation products PhMeCHCHOHPh (VIa, VIb) and chlorophenylation products PhMeCHCHClPh (IVa, IVb) were obtained accompanying the phenylated olefins (I, II, and III). The main reaction product was the tertiary alcohol PhCH2C(OH)MePh (V). The reaction of α-methylstyrene with phenylpalladium chloride gave V exclusively. Phenylpalladium acetate and phenylpalladium bromide were used as phenylating agents. The yields of hydroxyphenylation products are in decreasing order: chloride&gt;bromide&gt;acetate.
Structure of a Main Metabolite of Piroheptine Excreted in Urine of Rabbits; X-Ray Analysis of Its Hydrobromide
Authors: Tokuma Yoji , Koda Shigetaka , Tsubouchi Shinji , Morimoto Yukiyoshi 
Published: July 2006

Abstract
The structure of a main metabolite of piroheptine excreted in urine after administered to rabbits has been determined by X-ray analysis of its hydrobromide, C22H26NOBr. The crystals are monoclinic with space group P21/n, the unit-cell dimensions are: a=14.28, b=12.50, c=10.97 Å, β=96.06°. The intensities were estimated visually from multiple-film equi-inclination Weissenberg photographs. The structure was solved by the heavy atom method. The atomic parameters were refined by the block-diagonal least-squares method, and the final R index was 0.11. The established structure is shown by the following formula (hereafter, named as piroheptine metabolite HBr)
(Remark: Graphics omitted.)
It has been cleared that the hydroxylation in the metabolic process takes place at the 2-position in the benzene ring located far from the N-ethyl group on pyrrolidine ring, and piroheptine metabolite HBr and piroheptine HBr differ considerably in their conformations in the crystalline state.