bluuebunny/crossref_metadata_2025 huggingface dataset:
The Dehydrochlorination of gem-Dichloroalkane and the Formation of Dienes from the Reactions of Butenes and Cyclohexene with Chlorine through Molten Salt
Authors: Kikkawa Sh\={o}ichi , Nomura Masakatsu , Shimizu Michimasa
Published: July 2006

The dehydrochlorination of 1,1-dichloropropane and 1,1-dichloro-3-methylbutane was carried out over molten salt catalysts (mainly ZnCl2-containing melts) using a conventional flow system. The cis/trans ratio (1.8) of the resulting olefins from 1,1-dichlorobutane was found to stand between the ratio (1.4) with 1,1-dichloro-3-methylbutane and the ratio (2.2) with 1,1-dichloropropane; this can be explained by considering the stereochemistry of the adsorbed carbonium ions. The detailed results of the reactions of three butene isomers with chlorine through molten salts were presented. The selective formation of butadiene was explained in terms of the thermally assisted attack of chlorine in the allylic positions of butene, followed by the 1,2- or 1,4-elimination of HCl from chlorobutenes, a process which is strongly assisted by the ZnCl2-containing melts. The reaction of 2-methyl-2-butene and cyclohexene with chlorine through molten salts was also undertaken. The addition of Zn powder to ZnCl2 melts in advance was found to improve the selectivity for the formation of isoprene and cyclohexadiene. Because the HCl evolved reacts instantly with Zn powder to afford ZnCl2 and hydrogen, Zn powder substantially prohibits the addition of HCl to dienes yielding chlorobutenes and chlorocyclohexenes.
12,13-Epoxy-C-nor-D-homosteroids. VIH. Transformation of 12α,13α-Epoxyetiojerv-5-ene-3,17-dione 3,3-Ethylene Acetal into Testosterone
Authors: Murai Akio , Iwasa Noriaki , Masamune Tadashi
Published: July 2006

Transformation of the title epoxy ketone (2) into testosterone (1), which implies synthesis of the hormone 1 from jervine, is described. Irradiation of 2 by a low-pressure lamp in dioxane afforded an androstane-12,17-dione derivative, which was reduced regioselectively with lithium tri-t-butoxyaluminium hydride to give 12β-hydroxy ketone (5). The compound 5 was transformed via a. four-step process into androstan-4-ene-3,17-dione, which was converted into 1 by a known procedure. The overall yield amounted to 1.8% from jervine.
Electron Transfer Sensitization. II. Photo-cyclodimerization and -polymerization of N-Vinylcarbazole
Authors: Kitamura Noboru , Tazuke Shigeo
Published: July 2006

Photoinduced ternary electron transfer reactions have been demonstrated in the system of perylene(Pe)-1,4-dicyanobenzene(DCB)-N-vinylcarbazole(VCZ) in acetone. Photoexcited perylene was recycled via two successive electron transfer reactions while VCZ-cyclodimer and/or -polymer were obtained in good yields. Quantum yields for VCZ-cyclodimer and -polymer formation were larger in the electron transfer sensitization system in comparison with the other reaction systems such as in the Pe–VCZ or the VCZ–DCB system. The photocatalytic effect of the electron transfer sensitization was clearly confirmed in the present system, by estimating the overall sensitizer efficiency as over 8000 although chain propagation steps of VCZ cation radical are involved in the present reaction processes.
Conversion of Carbon-Sulfur Linkages into Carbon–Silicon Ones via Reductive Silylation. Preparation of Silyl Enol Ethers of Acyltrimethylsilanes
Authors: Kuwajima Isao , Mori Akio , Kato Masahiro
Published: July 2006

Reductive cleavage of carbon–sulfur linkages of silyl enol ethers of thiocarboxylic S-esters can be induced by treatment with sodium or potassium–sodium alloy in the presence of chlorotrimethylsilane, and the corresponding silyl enol ethers of acyltrimethylsilanes can be prepared in high yields.
Bondings on the TeI4 Tetramer, as Studied by Means of NQR
Authors: Okuda Tsutomu , Yamada Koji , Negita Hisao
Published: July 2006

The 127I NQR and its Zeeman effect on the TeI4 single crystal were investigated. Ten nonequivalent iodine atoms were detected, in agreement with the X-ray analysis by Krebs and Paulat. Six of them were assigned to terminal atoms, two to bridge atoms, and the remaining two to pyramidal iodine atoms, on the basis of their quadrupole coupling constants and asymmetry parameters. One of the bridging iodine atoms takes an efg z-axis parallel to the shorter Te–I bond, but the other bridging iodine atom takes an efg z-axis perpendicular to the bridging plane. This difference can be explained by a simple model based on the Townes-Dailey treatment and is consistent with that difference to be expected from the bridging-bond length. The extremely small coupling constants for the pyramidal iodine atoms could be interpreted by covalency, assuming a hybridization of the s-orbital to the pure p-bond configuration.
The Crystal Structure of the 1,3-Di-p-tolyl-5-phenylverdazyl Radical
Authors: Azuma Nagao
Published: July 2006

The crystals of 1,3-di-p-tolyl-5-phenylverdazyl are monoclinic, with the space group P21⁄c and with a=10.66(1), b=21.76(1), c=8.171(6) Å, β=98.8(1)°, and Z=4. The crystal structure has been determined by means of X-ray diffraction. The molecular structure is similar to those of other verdazyls. The molecules are packed in a column along the c axis.
One-electron Reduction Potentials of Several Electron Acceptor Molecules and Cation Radicals of Donors
Authors: Iida Yôichi
Published: July 2006

Reversible one-electron reduction potential values of several electron acceptor molecules and cation radicals of donors were estimated by means of the equilibrium constant of electron transfer reaction between ion radicals in acetonitrile solution, and the results were compared with the observed electrochemical data.
A Photoacoustic and Fluorescent Spectroscopic Study of Uranyl Compounds
Authors: Sugitani Yoshinori , Nomura Hiroshi , Nagashima Kozo
Published: July 2006

The fluorescent emission spectra and fluorescent lifetimes have been measured for several available uranyl salts and natural mineral zippeite. The absolute quantum efficiency data of UO2SO4·0.5H2O, H2(UO2)2(PO4)2·8H2O, and UO2(CH3COO)2·2H2O have been obtained by the simultaneous measurement of the photoacoustic and excitation spectra.
The Linearity of the Substituent-induced Carbon-13 Chemical Shifts of α-Carbons with Charge Densities in Aromatic Side Chains. II. 4-Substituted Phenylacetylenes
Authors: Niwa Jun
Published: July 2006

The propriety of considering the magnetic contributions to the 13C chemical shift from the neighboring carbon atoms and from the ‘ring-current’ has been examined for the SCS of α-carbons of 4-substituted phenylacetylenes. The SCS values corrected for the above contributions are well correlated with the 2p electron densities.
Nuclear Quadrupole Resonance of AlBr3 Molecular Complexes
Authors: Okuda Tsutomu , Ohta Hiroshi , Ishihara Hideta , Yamada Koji , Negita Hisao
Published: July 2006

We observed the 81Br NQR of several molecular complexes of AlBr3 with amines such as (CH3)3N, C5H5N, C6H5NH2, and (C6H5)2NH. All the 81Br resonance lines were found in the frequency range of 78–86 MHz at room temperature except for AlBr3·2C5H5N. From the Zeeman analysis, it was proved that AlBr3·2C5H5N should be expressed with the molecular formula 2AlBr3·4C5H5N and contains cation species AlBr2(C5H5N)4+ with two 81Br resonance lines near 70 MHz and anion species AlBr4− with four 81Br resonance lines near 80 MHz. The two 81Br resonance lines of AlBr3·(CH3)3N disappeared at about 40 °C due to hindered rotation of the whole molecule. The lower two 81Br resonance lines of AlBr2(C5H5N)4+ have positive temperature coefficients.
Effect of Cl− and Br− Ions and pH on the Flatband Potentials of Silver Halide Sheet Crystal Electrodes
Authors: Sumi Seiichi , Watanabe Tadashi , Fujishima Akira , Honda Kenichi
Published: July 2006

Flatband potential (Efb), which coincides with the Fermi level in energy, was determined for AgCl and AgBr electrodes by electrochemical measurement of the capacitance of the space charge layer of a semiconductor in contact with a solution. The values of Efb for both AgCl and AgBr electrodes in an electrolyte solution were −4.8 V vs. vacuum. The energy levels of the electrodes could be determined from this value. The behavior of the AgCl electrode is somewhat like an n-type semiconductor, and that of the AgBr electrode very much like an intrinsic semiconductor. The Efb values for the AgCl and AgBr electrodes change cathodically in electrolyte solutions with Cl− and Br− ions, respectively, but not with H+ or OH− ions. This seems to be associated with the Ag+ ion effect in spectral sensitization. It is concluded that the Ag+ ion effect arises from a downward shift of the band edge of silver halides.
Thermochemical Estimation of Destabilization Energies of 1,2-, 1,3-, and 1,4-Dicyanobenzenes Due to Interactions between Substituents. Appendix: Dipole Moments in Solution of the Dicyanobenzenes
Authors: Sato-Toshima Tomoko , Sakiyama Minoru , Seki Syûzô
Published: July 2006

Enthalpies of combustion of 1,2-, 1,3-, and 1,4-dicyanobenzenes were determined by precision oxygen-bomb calorimetry. Enthalpies of sublimation of these compounds were obtained by the measurement of temperature dependence of vapor pressure. The standard enthalpies of combustion ΔHc°(298.15 K)/kJ mol−1 and the standard enthalpies of sublimation ΔHS(298.15 K)/kJ mol−1 are as follows: −4000.36±0.67 and 86.9±1.5 for 1,2-dicyanobenzene; −3992.29±0.75 and 90.1±1.5 for 1,3-dicyanobenzene; −3988.04±0.59 and 88.8±1.5 for 1,4-dicyanobenzene, respectively. Thermochemical destabilization energies were estimated by comparing the derived standard enthalpies of formation in gaseous state with those estimated for hypothetical non-destabilized molecules. They were discussed in terms of electrostatic interactions between highly electronegative and dipolar cyano substituents on one and the same benzene ring. Dipole moments of the dicyanobenzenes in benzene and dioxane solutions are reported in Appendix.
N-Alkylation of Cytosine and Its Nucleosides with Trialkyl Phosphates
Authors: Hayashi Masahiro , Yamauchi Kiyoshi , Kinoshita Masayoshi
Published: July 2006

Cytosine has been readily alkylated with trialkyl phosphates to give the corresponding N-alkyl derivatives, trimethyl phosphate being especially useful for the N-methylation of the base moiety of cytosine nucleosides.
Liposomal Membranes. V. Interaction of Zinc(II) Ion with Egg Phosphatidylcholine Liposomes
Authors: Sunamoto Junzo , Shironita Masaharu , Kawauchi Noriaki
Published: July 2006

The efficiency of encapsulation of several divalent metal ions, mainly Zn(II) ion, into egg lecithin liposomes has been investigated with particular attention to the stability of liposomal membranes against the transition metal(II) ions. The stronger interaction of metal ions to lecithins led to the less formation of liposomes. The addition of a suitable amount of nonionic detergent, 2-[ω-hydroxypentadeca(oxyethylene)-α-yl]-1,3-bis(dodecyloxy)propane (2C1215G, see text), enhanced the encapsulation of Zn(II) and Cu(II) ions in liposomes. The stoichiometric measurement for the binding of Zn(II) ion to single compartment liposomes of egg lecithin suggested that a Zn(II) ion is interacting with three or four lecithin molecules on the average in both halves of liposomal bilayers. Even under the circumstances, the bilayer structure of liposomes was certainly kept stable, which was electron micrographically visualized.
Effect of Polyether Linkages on the Carboxylation of Sodium Phenoxide
Authors: Sakakibara Tsutomu , Haraguchi Kazuyo
Published: July 2006

In the carboxylation of sodium phenoxide under mild conditions, the crown compound or polyethers with three to five ether linkages caused carboxylation to give o- and p-hydroxybenzoic acids, but not ethers with one or two linkages. The chelation of sodium phenoxide with polyethers changed the formation ratio of isomers.
Solvent Induced Structural Change of 18-Crown-6 Complexed Ion Pair with 9-Fluorenone Anion Radical as Studied by ESR Spectroscopy
Authors: Nakamura Kazuo
Published: July 2006

ESR spectra of the ion pairs of the 9-fluorenone anion radical with 18-crown-6 complexed sodium and potassium ions were examined. From the dependence of the carbonyl 13C hyperfine splitting of the fluorenone anion on temperature and solvent, it was conclude that an ethereal solvent molecule can solvate the crown complexed cation on the opposite side of the anion with respect to the plane of the crown ether ring, equilibrium taking place between the solvated and unsolvated ion pairs in ethereal solution. The unsolvated species of both the potassium and the sodium ion pairs and the solvated species of the sodium ion pair are classified as contact ion pairs, the solvated species of the potassium ion pair a crown separated one. The equilibrium constant between the solvated and unsolvated ion pairs changes with temperature and solvent. From this change the enthalpy changes of solvation process were estimated for several solvents.
Direct Measurement of Interaction Energy between Solids and Gases. VII. Heats of Adsorption of Carbon Monoxide on Cu(II)-exchanged Zeolites Y
Authors: Miwa Yoji , Tsutsumi Kazuo , Takahashi Hiroshi
Published: July 2006

Differential heats of the adsorption of carbon monoxide on Cu(II)Y zeolites were calorimetrically determined. The heat of adsorption was larger on Cu(II)Y zeolites than on the NaY zeolite, and increased with the degree of Cu(II) ion-exchange. Repeated adsorption-desorption measurements revealed an increase in the heat of adsorption, which is considered to be due mainly to the migration of copper(II) ions from inaccessible sites for carbon monoxide to accessible ones in the process of adsorption-desorption.
Outer-sphere Assocation of Some Achiral Cobalt (III)–Amine Complexes as Measured by Their Induced Circular Dichroism Spectra in Aqueous (R,R)-Tartrate Solutions
Authors: Miyoshi Katsuhiko , Oh Chang Eon , Yoneda Hayami
Published: July 2006

Outer-sphere association constants KA of inherently achiral cobalt(III)–amine complexes, [Co(NH3)6]3+, [Co(NH3)4(en)]3+, and trans-[Co(NH3)2(en)2]3+ with (R,R)-tartrate anion (d-tart2−) were determined by measuring their weak CD spectra induced when they were dissolved in aqueous d-tart2− solutions at 25 °C. It was found that the KA values are not so different among these three complexes, whereas their molar CD intensity ΔεMX gained by the association with d-tart2− increases with increasing number of their chelate rings. This was tentatively interpreted to mean that the distortion of the Co(III)–N bonds brought about by outer-sphere association with chiral d-tart2− is greater when bidentate ligands (en) are coordinated than when unidentate ones (NH3) are, i.e., when the complex has more chelate rings. Also it was found that the KA value thus obtained for [Co(NH3)6]3+ is much smaller than that determined by measuring the magnitude of its charge-transfer band which newly appears upon the addition of d-tart2−. From the above finding and other experimental results, it was suggested that induced CD is well developed in these achiral amine complexes when the two hydroxyl oxygen atoms of d-tart2− simultaneously form hydrogen-bonds with amine protons of the ligands.
Kinetics of the Stereoselective Deuteration of Malonate Hydrogens in Some Bis(malonato)cobalt(III) Compounds and the Reversal of Stereoselectivity Induced by the Solution pH
Authors: Sakaguchi Ushio , Morito Kaiji , Yoneda Hayami
Published: July 2006

The deuteration rates at malonate methylene groups have been measured for several [Co(mal)2(N)2]− ions over the pD range of 2 to 9 at 36.4 °C, where mal=malonate ion, (N)2=ethylenediamine, cis-(NH3)2, 1,3-propanediamine, N,N′-dimethylethylenediamine, cis-(pyridine)2, and 1,10-phenanthroline. The malonate deuteration is acid-catalysed at pD less than about 4 and base-catalysed at higher pD in all the compounds. In the aminocontaining compounds (the first four compounds), the reaction proceeds stereoselectively in both high and low pD regions. Though the degree of the stereoselectivity depends upon the compound, the fast-exchanging hydrogen is, for all the amino-containing compounds, the one which is adjacent to the coordinating nitrogen atom. The mechanisms of acid- and base-catalysed deuteration, as well as the origin of the stereoselectivity, are discussed. For the ethylenediamine and cis-(NH3)2 compounds, reversal of the stereoselectivity takes place at around pD=8 and 9, respectively, and the fast-exchanging hydrogen becomes the one farthest apart from the coordinating nitrogen. Concomitant with this reversal, both malonate and amine exchange rates fall together. Thus, the rate of hydrogen-deuterium exchange at the NH3 groups does not show the usual first-order dependence upon the OD− concentration. These observations are explained by a mechanism in which equally reactive malonate and amine hydrogens compete for OD− catalyst.
Studies on Characteristics of Electron Capture Responses. IV. Carrier Gas Flow-rate Dependence of Electron Capture Coefficients
Authors: Takeuchi Masahiro
Published: July 2006

The electron capture coefficients, K, defined by Wentworth et al. were measured on several samples in various carrier gas flow-rates at the detector temperatures of 200–320 °C. The effect of the flow-rate on the value of K was considered. The results revealed that the flow-rate dependence of K for each sample was closely related to one of the three electron capture reaction processes. In a sample undergoing the non-dissociative electron capture reaction, the values of K were generally not affected by the flow-rate; they decreased slightly with increasing the flow-rate at higher temperatures. In a sample undergoing the dissociative electron capture reaction, the values of K increased significantly with increasing the flow-rate at all temperatures. In a sample undergoing the dissociative electron capture reaction through an anion radical intermediate, the values of K were slightly or not at all affected by the flow-rate at lower temperatures, but increased gradually with increasing the flow-rate at higher temperatures.
Formation of Hydrogen Peroxide by Two-stage Acid Hydrolysis of trans(NO2,O2)-[μ-Peroxo-bis{nitrtobis(ethylenediamine)cobalt(III)}] and Reaction Kinetics
Authors: Shibahara Takashi , Kuroya Hisao , Mori Masayasu
Published: July 2006

The aquation rate of trans(NO2,O2)-[(NO2)(en)2CoO2Co(en)2(NO2)]2+ has been measured in acidic aqueous solution at [H+]=0.003–0.25 M and I=0.50 M (LiClO4), the final products being trans-[Co(NO2)(OH2)(en)2]2+ and H2O2 in marked contrast to the acid decomposition of [(NH3)5CoO2Co(NH3)5]4+ where the final products are Co(II) and O2. The reaction consists of two stages, each of which has preequilibrium of protonation. The observed rate constants for the first and second stages are consistent with the formula, k1obsd=k1K1[H+]⁄(1+K1[H+]) (i=1, 2), indicating the existence of protonated reactive forms in both stages. The rate constants, activation parameters and equilibrium constants are k1=7.46 s−1 (25 °C), ΔH1\eweq=66.9±1.3 k J mol−1, ΔS1\eweq=−2.9±4.2 J K−1mol−1, and K1=3.44 M−1 (25 °C) for the first stage and k2=0.400 s−1 (25 °C), ΔH2\eweq=85.4±2.1 kJ mol−1, ΔS2\eweq=33.5±7.1 J K−1 mol−1, and K2=2.98 M−1 (25 °C) for the second stage. The solution of the reaction intermediate [Co(NO2)(O2H)(en)2]+ has been obtained by ion exchange technique and characterized by the UV and visible spectra. The factors which decide the reaction path are discussed.
Precise Determination of Dissolved Gases in Sea Water by Shipboard Gas Chromatography
Authors: Gamo Toshitaka , Horibe Yoshio
Published: July 2006

A gas chromatographic system is applied to shipboard measurement of dissolved argon, oxygen, nitrogen, and total inorganic carbon dioxide in sea water. Gases are stripped from acidified sea water with helium carrier gas, separated by passing through silica-gel and molecular sieve 5A columns, and subsequently analyzed with a thermal conductivity detector and an ultrasonic detector. Ca. 15 min is required to analyze a 3 cm3 sea water sample. Intercalibration by other analytical techniques for oxygen and total carbon dioxide confirmed the accuracy of this method. Vertical profiles of the gases in the Pacific Ocean demonstrate the merit of the method.
The Preparation of Vanadium Tetrachloride from Vanadium Dichloride Oxide and Vanadium Trichloride and the Hydrogen Reduction Process of Vanadium Tetrachloride
Authors: Yajima Akimasa , Matsuzaki Ryoko , Saeki Yuzo
Published: July 2006

The reactions of VCl2O and VCl3 with chlorine, and the reaction of VCl3O, formed by the chlorination of VCl2O, with chlorine in the presence of carbon were examined. The products formed by the reaction between gaseous VCl4 and hydrogen at various temperatures, and the behavior of VCl3 and VCl2 on heating in a hydrogen stream were examined. The reaction between VCl2O and chlorine occurs above ca. 120 °C and proceeds markedly above ca. 170 °C to form VCl3O. VCl4 can be obtained by passing the gaseous VCl3O together with chlorine through a carbon bed held at ca. 700 °C. The reaction between VCl3 and chlorine occurs above ca. 80 °C and proceeds markedly above ca. 170 °C to form VCl4. The hydrogen reduction process of VCl4 in the vapor phase may be represented as follows: The reaction between VCl4 and hydrogen, 2VCl4(g)+H2(g)→2VCl3(s)+2HCl(g), proceeds above ca. 500 °C to form VCl3. Subsequently, the hydrogen reduction of the VCl3, 2VCl3(s)+H2(g)→2VCl2(s)+2HCl(g), and the disproportionate of the VCl3, 2VCl3(s)→VCl2(s)+VCl4(g), proceed to form VCl2. Above ca. 620 °C, the reaction between the VCl2 and hydrogen, VCl2(s)+H2(g)→V(s)+2HCl(g), proceeds to form vanadium.
The Determination of the Oxidation States of Neptunium in Sodium Hydroxide Solutions by Adsorption on Zirconium(IV) Hydroxide
Authors: Shiokawa Yoshinobu , Sat\={o} Akiko , Suzuki Shin
Published: July 2006

An adsorption method for determining the distribution of the oxidation states of neptunium in sodium hydroxide solutions is proposed. In the range of sodium hydroxide concentrations of 1–2 M (1 M=1 mol dm−3), the Np(V) was almost entirely adsorbed on zirconium(IV) hydroxide, while both Np(VI) and Np(VII) remained in the supernatant. By means of this adsorption method, it was found that Np(V) in tracer quantities, though it was most stable in acidic or neutral solutions, was not the most stable state in sodium hydroxide solutions. Also, the oxidation and reduction of Np in sodium hydroxide solutions were investigated.
Indirect Spectrophotometric Determination of Phosphate Employing the Solubilization of Methylene Blue Molybdophosphate with Zephiramine
Authors: Shida Junichi , Matsuo Tsutomu
Published: July 2006

A highly sensitive indirect spectrophotometric method for phosphate was developed. The ion-association complex of molybdophosphate with Methylene Blue was precipitated in a nitric-acid medium. The complex was adsorbed on (1+4 v/v) cyclohexane–MIBK. The excess of Methylene Blue was removed by washing the organic phase with water. The complex was solubilized with a Zephiramine acidic aqueous solution. By measuring the absorbance of Methylene Blue in the aqueous solution at 660 nm, the phosphate was determined. The calibration curve was linear in the 0.31–3.1 μg range of phosphate, and the molar absorptivity was 2.5×105 l·mol−1·cm−1. The absorbance of the reagent blank was 0.019±0.001, and the recommended procedure was applied to the repetitive determination of 1.55 μg of phosphorus. The ten determinations produced a coefficient of variation of 1.6%. Arsenic, germanium and silicon, which form heteropolyacids like phosphorus, interfered seriously.
Preparation and Stereochemistry of Bis(1,10-phenanthroline)- and Bis(2,2′-bipyridine)chromium(III) Complexes Containing 2,2′-Bipyridine N,N′-Dioxide or Its 3,3′-Dimethyl Derivative
Authors: Kanno Hideaki , Kashiwabara Kazuo , Fujita Junnosuke
Published: July 2006

Bis(1,10-phenanthroline)- and bis(2,2′-bipyridine)chromium(III) complexes containing a seven-membered chelate ligand, 2,2′-bipyridine N,N′-dioxide(bpdo) or 3,3′-dimethyl-2,2′-bipyridine N,N′-dioxide(mbdo) were prepared. Each complex gave only one of two possible pairs of enantiomers resolved by SP-Sephadex column chromatography. On the basis of the circular dichroism spectra, molecular models, and recovery of the optically active free mbdo ligand from the resolved mbdo complexes, it was found that all the enantiomeric pairs consist of Δ(δ) and Λ(λ) isomers involving the skew dioxide chelate ligands in the ob configuration.
Steric Effect in Regioselective Cyclization of 3,4-Epoxy Alcohols to Oxetanes
Authors: Masamune Tadashi , Sato Shingo , Abiko Atsushi , Ono Mitsunori , Murai Akio
Published: July 2006

A number of 3,4-epoxy alcohols, involving critical structural factors for oxetane formation by intramolecular cyclization, were prepared and treated with base under aqueous (KOH in 75% aq DMSO) and anhydrous conditions (NaH in THF). The result of the reactions of cis- and trans-4,5-epoxy-2-rnethyl-2-undecanols, coupled with that of 1-(2,3-epoxybutyl)- and 1-(2,3-epoxy-3-methylbutyl)-1-cyclohexanols (1a and 1b), indicated that the regioselective oxetane formations of 3,4-epoxy alcohols with alkoxide anions are much insensitive to steric hindrance at the attacked oxirane rings, compared with the corresponding reactions with carbanions, while that of 1-(2,3-epoxypropyl)-1-cycloalkanols revealed that the relevant reactions depend on bulkiness of attacking alkoxide anions. Moreover, the result of the reactions of 1-(1,2-epoxycycloalkyl)-2-methyl-2-propanols under the aqueous conditions demonstrated that the oxetane formations are affected seriously by steric hindrance at the attacked oxirane rings, although the result was in striking contrast with the corresponding result with carbanions. On the other hand, the reactions of 3,4-epoxy alcohols under the anhydrous conditions proceeded in different manner, depending on the structures of the epoxides; namely, fragmentation took place as major reactions with some epoxides, while intramolecular cyclization occurred predominantly with other epoxides.
Synthesis, Absolute Configuration, and Chiroptical Property of (+)-cis-4b,5,9b,10-Tetrahydroindeno[2,1-a]indene-5,10-dione
Authors: Ogura Fumio , Nakao Akio , Nakagawa Masazumi
Published: July 2006

The title compound having the (4bS,9bS) configuration was prepared from (2S,3S)-(+)-2,3-diphenylsuccinic acid, and the circular dichroic property was discussed.
Low-temperature Photolysis of ortho-Substituted Azidobiphenyls. Formation of Phenazines from 2,2′-Diazidobiphenyls
Authors: Yabe Akira
Published: July 2006

It was found that the unexpected phenazines were formed as minor products by the low-temperature photolysis of 2,2′-diazidobiphenyls in a rigid matrix. The phenazine formation results from the 1,1′-C–C bond fission of the biphenyl nucleus and suggests the aziridine intermediates. The low-temperature photolysis of 2-azido-2′-methylbiphenyl and 2-azido-2′,4′,6′-trimethylbiphenyl leads to the triplet-derived phenanthridine derivatives as major products.
Photoreactions of Flavanones
Authors: Matsushima Ryoka , Kishimoto Tsuneo , Suzuki Morio , Morioka Motonobu , Mizuno Hideo
Published: July 2006

Parent and substituted flavanones undergo photochemical opening of the pyrone ring to give corresponding 2′-hydroxychalcones in benzene, pyridine, acetonitrile etc., the yields varying from 0 to 70% with substituents. The reaction is depressed by the addition of 1,3-pentadiene, nitrosobenzene, or acrylonitrile. On the other hand, flavanone and 4-chromanone undergo photoreduction in 2-propanol to give reductive coupling products and solvent adducts as isomeric mixtures. 7,8-Benzoflavanone does not undergo photoreduction in 2-propanol but the ring opening reaction instead. Mechanisms have been discussed in terms of the relative contribution and π,π* character in the lowest triplet states.
A Novel Synthesis of 2-(1-Imidazolyl)benzophenones
Authors: Kayama Yasutaka , Hara Takeshi , Sunami Tamiko
Published: July 2006

2-(1-Imidazolyl)benzophenones were prepared from 3-(2,2-dialkoxyethyl)-3,4-dihydro-4-hydroxy-4-phenylquinazolines and a corresponding 4-alkoxy derivative by heating in formic acid or in sulfuric acid-ethanol.
The Chemical Conversion of the Photo-dimer of 2-Acetyl-5-methyl-1,4-benzoquinone. The Determination of the Regiochemistry of the Dimer
Authors: Miyagi Yo , Maruyama Kazuhiro , Yoshimoto Sachiko
Published: July 2006

From the photo-dimer (2a) of 2-acetyl-5-methyl-1,4-benzoquinone, mono- and diacetyl derivatives and 2,6-dimethyl-1,4,5,8,9-pentaacetoxyphenanthrene (3) were prepared. 3 was oxidized to 2,6-dimethyl-1,4,5,8-tetraacetoxy-9,10-phenanthrenequinone (4). The acetoxyl groups of 4 were partly deuterated to assign their 1H NMR signals. A series of chemical conversions of 2a to 4  via  3 unambiguously clarified the regiochemistry of 2a.
Nuclear Magnetic Resonance Studies of Hydrosilanes. III. A Correlation of Hammett σ Constants with 29Si–H Coupling Constants for Substituted Phenoxy- and (Phenylthio)dimethylsilanes
Authors: Watanabe Hamao , Akaba Ryoichi , Iezumi Takao , Nagai Yoichiro
Published: July 2006

The 29Si–H coupling constants and Si–H chemical shifts have been determined for a series of substituted phenoxy- and (phenylthio)dimethylsilanes. The J(29Si–H) values are shown to be correlated well with the Hammett σ constants for the substituent on benzene ring in compounds Ar–Y–SiMe2H, where Y=O and S. In comparison with the data for the analogs of the other types of organodimethylsilanes, such as aryldimethylsilanes, substituted benzyldimethylsilanes, and aryltetramethyldisilanes, the present results are discussed on the basis of the substituent effects through the intervening oxygen and sulfur. The transmission efficiency of Y was in the order, S>CH2≈SiMe2>O. For the series of (phenylthio)dimethylsilanes, the J(29Si–H) values observed were larger than those for the predicted ones. This deviation was interpreted in terms of the sulfur d-orbital participation via the electron-acceptor, “σ-π” conjugation.
Removal and Recovery of Organic Pollutants from Aquatic Environment. V. Crosslinked Poly(hydroxystyrene) as a Polymeric Adsorbent for Removal and Recovery of ε-Caprolactam from Aqueous Solution
Authors: Kawabata Nariyoshi , Taketani Yukihiko
Published: July 2006

Crosslinked poly(hydroxystyrene) (PHS resin) was found to be useful as a polymeric adsorbent for removal and recovery of ε-caprolactam from aqueous solution. The breakthrough capacity of PHS resins with <1-mg/l leakage in the effluent was 50–90 mg/dry g, which was scarcely affected by the presence of hydrochloric acid, sodium hydroxide, and inorganic salts such as sodium chloride, potassium chloride, calcium chloride, and magnesium chloride. Elution of the adsorbed ε-caprolactam from PHS resin was easily accomplished by a simple treatment with methanol, and PHS resin was efficiently regenerated. ε-Caprolactam was concentrated into 10–30 g/l solution.
Assignment of Fundamental Vibrations of N,N′-Dimethylthiourea
Authors: Devi Kolar Ramakrishnaiaa Gayathri , Sathyanarayana Dixit Narayanarao
Published: July 2006

The infrared spectra of symmetric N,N′-dimethylthiourea (s-DMTU) and its N-deuterated (s-DMTU-d2) species have been measured. The fundamental frequencies have been assigned by comparison with the assignments in structurally related molecules and the infrared band shifts on N-deuteration, S-methylation, available Raman data and with the aid of theoretical band assignments from normal coordinate treatments for s-DMTU-d0 and -d2. A force field is derived for s-DMTU by transferring the force constants chiefly from N-methylthiourea and the subsequent refinement of the force constants by a least squares procedure.
Synthesis of Some Disperse Anthraquinone Dyes
Authors: Metwally Saoud A M , Youssef Mohamed S K , Younes Mansour I
Published: July 2006

1-Hydroxy- and/or 1-aminoanthraquinones was allowed to react with formaldehyde in an alkaline medium to give 1-hydroxy- or 1-amino-2-hydroxymethyl-9,10-anthracenediols, which gave by air oxidation, (hydroxymethyl) anthraquinone derivatives. Interaction of 1-amino-2-(hydroxymethyl) anthraquinone or its 4-bromo derivative with carbonyl compounds in the presence of an acid catalyst gave 1,3-oxazine derivatives (2). The methylene group in position-2 of the 1,3-oxazine ring was found to be highly reactive and reacted with carbonyl compounds to form the corresponding 2-arylmethylene derivatives. Selective oxidation of dimethyloxazine derivatives with SeO2 gave the corresponding dialdehyde, which interacted with aromatic amines to give the corresponding Schiff’s bases. The bromine atom in the 6-position of 2 was easily replaced by aromatic amines to give blue disperse dyes.
Interaction between Aromatics and Zinc Chloride. II. The Formation of σ-Complexes and Cation Radicals on Supported Zinc Chloride
Authors: Morita Mikio , Hirosawa Kunio , Sato Toshio , Ouchi Koji
Published: July 2006

Anhydrous zinc chloride supported in the solid state was found to produce colored intermediates by reactions with aromatics (anthracene, naphthacene, pentacene, pyrene, pelyrene, and chrysene) at 60 °C. The measurements of their electronic absorption spectra and ESR spectra confirmed that these were the same aromatics-zinc chloride σ-complexes and aromatics cation radicals as those formed in molten zinc chloride.
Relative Electron-capture Efficiency of Disubstituted Benzene in γ-Irradiated MTHF Glass at 77 K
Authors: Shimokawa Toshinari
Published: July 2006

The relative electron-capture efficiencies of disubstituted benzenes were measured by a competitive method. It was found that the efficiencies of the disubstituted benzenes are correlated with the reactivity towards nucleophilic species as expressed by Hammett’s substituent constant. The logarithmic values of the efficiency are roughly proportional to the polarographic half-wave reduction potentials and to the electron affinities.
The Hydrolytic Rate of Barbituric Acid and the Extrathermodynamic Relationship
Authors: Asada Shozo , Yamamoto Midori , Nishijo Jujiro
Published: July 2006

The enthalpy-entropy relationship of activation was subjected to discussion in connection with the alkaline hydrolysis of 10 barbituric acids. The extrathermodynamic linear equation was derived by using several parameters; the dissociation constant (pK), the 13C shift value [δc(5)] at the 5-position of the ring, and/ or the molecular connectivity index (χ).
Mössbauer Effect in Fluorotrimethyltin(IV)
Authors: Negita Hisao , Boku Ryukei , Sugiya Masahiro , Ichiba Sumio
Published: July 2006

The angular dependent Mossbauer spectra of 119Sn in needle crystals of fluorotrimethyltin(IV) were studied at 110 K. The principal axis of the electric-field gradient was observed at about 20° from the a axis. 19F NMR spectra of the solid were also studied. From the temperature dependence of the linewidth, the activation energy for the motion of the F atom was estimated to be 6.7±1.3 kJ mol−1.
Isomeric Transition-activated 80Br and 82Br Reactions in the Gaseous CH3Br–HBr System
Authors: Kondo Kenjiro , Yagi Masuo
Published: July 2006

The isomeric transition(IT)-activated 80Br and 82Br reactions in the gaseous H80mBr–CH3Br and H82mBr–CH3Br systems have been compared and the roles of the charge and kinetic energy imparted to 80Br and 82Br in recombina tion reactions studied using a Kr moderator. The products CH3Br, CH2Br2, CHBr3, and CH3CH2Br in both reactions are only formed via thermal ionic processes. This differs from the 82mBrBr–CH3Br system, in which the reaction products are only formed through excess kinetic energy processes. The difference between the two reactions has been explained on the basis of the cross sections for charge neutralization and ion molecule reactions of Br+ ions as a function of the kinetic energy initially imparted to the 80Br or 82Br atoms. An isotope effect has been observed between the IT-activated 80Br and 82Br reactions with CH3Br, and attributed to the difference in the decay modes of 80mBr and 82mBr. Furthermore, the analysis of product yields due to the successive internal conversion process in 80mBr suggested that the second Auger process from the excited 80Br occurs in a liquid-like condition such as ion-clusters.
Catalysis by Mixed Oxide Perovskites. I. Hydrogenolysis of Ethylene and Ethane on LaCoO3
Authors: Ichimura Kenji , Inoue Yasunobu , Yasumori Iwao
Published: July 2006

Catalysis by a mixed oxide with a perovskite structure, LaCoO3, was studied for the hydrogenolysis of ethylene and ethane at temperatures 300–600 K using the hydrogen-excess mixtures. The high and stable activity was obtained by evacuating LaCoO3 at 600 K. Ethylene hydrogenolysis above 420 K proceeded consecutively via the intermediate, ethane, to produce methane, whereas only the hydrogenation to form ethane occurred below 420 K. Different temperature dependence of the rate was observed, i.e., the activation energy of −19.3 kJ·mol−1 in the range 420–600 K and 33.6 kJ·mol−1 in the range 300–420 K. The mechanistic analysis and tracer study using D2 showed that the slow step of the hydrogenation shifts, with increasing temperature, from the adsorption of hydrogen to the surface reaction between hydrogen atom and ethyl radical. The hydrogenolysis of ethane produced only methane and no ethylene was observed in gas phase; the reaction orders with respect to hydrogen and ethane pressures were, respectively, −0.5 and 1.0. In the reaction with D2, methane [D4] was the main product and an equilibrium among the formed H2, HD, and D2 was quickly established. The adsorption of ethane to undergo the rupture of the carbon-carbon bond and to form monocarbon species was proposed to be a slow step. The catalytic activities of the component oxides, La2O3 and Co2O3, were also examined for a comparison. The structure and electronic states of LaCoO3 were investigated by means of X-ray diffraction and X-ray photoelectron spectroscopy in connection with the catalytic activity. It was proposed that the hydrogenation proceeded mainly on a pair of La3+ and O2− ions, whereas the hydrogenolysis was accelerated by the Co3+ ion; the (110) plane is suggested to be the most favorable for the catalysis.
The Collection of Uranium from Sea Water with Hydrous Metal Oxide. IV. Physical Properties and Uranium Adsorption of Hydrous Titanium(IV) Oxide
Authors: Yamashita Hisao , Ozawa Yoshihiro , Nakajima Fumito , Murata Toshifumi
Published: July 2006

The adsorption of uranium from sea water with hydrous titanium(IV) oxide(HTO) was studied. HTO was prepared by mixing titanium(IV) chloride and aqueous ammonia at different pHs and temperatures. The fundamental property of HTO was investigated for apparent crystal size, specific surface area, and pore size. The uranium uptake of HTO was found to depend more strongly on the temperature than on the pH in the preparation. HTO prepared at higher temperatures exhibited larger pores and a higher uranium uptake. A kinetic study of the uranium adsorption revealed that the rate of adsorption was controlled by the particle diffusion. The diffusion coefficients were calculated.
The Raman Spectra of Aligned Thin Films of Nematic Liquid Crystals
Authors: Yamada Haruka , Fukumura Keiji , Tamamushi Bun-ichi
Published: July 2006

The Raman spectra of thin films of nematic liquid crystals, MBBA and NP-5A, have been measured for samples sandwiched between two glass (or quartz) plates, which had been pretreated in several ways. The intensities of the fundamental bands of the molecules and the polarization components of each band depend on the molecular orientation structures, such as the homogeneous and homeotropic alignments. The intensity ratio provides a semi-quantitative measure for the molecular orientation, and the Raman results are compared with those from polarizing microscopic observations and infrared spectra. The molecular orientation of the liquid crystals varies with the concentrations of surface-active agents as well as the materials used for the pretreatment of the plates. The molecular interactions, which give rise to the orientation structures, are briefly discussed.
A New Assisted Reaction in the Photodecomposition Reaction of Dibenzoyl Peroxide
Authors: Sakaguchi Yoshio , Hayashi Hisaharu , Nagakura Saburo
Published: July 2006

2,2′-, 2,3′-, and 3,3′-Dimethylbiphenyls were found in the photodecomposition reaction of dibenzoyl peroxide using toluene as solvent. We carried out the experiments to study the external magnetic field, oxygen scavenging, and excitation light intensity effects on their yields. It is concluded that they are produced through the dimerization of (benzoyloxy)methylcyclohexadienyl radicals. This is a new case of the assisted reaction by benzoyloxyl radical. The yields of dimethylbiphenyls were found to be affected remarkably by the small variation of the concentration of benzoyloxyl radical through the three experiments.
Thermal Decomposition of Graphite Fluoride. II. Kinetics of Thermal Decomposition of (CF)n in a Vacuum
Authors: Watanabe Nobuatsu , Koyama Satoshi
Published: July 2006

The rate of thermal decomposition of (CF)n prepared under several reaction conditions was measured in a vacuum. The rate was expressed by Avrami-Erofeyev’s equation of second-order for highly oriented sample and of first-order for disordered one. The apparent activation energies of the decomposition reaction were about 50 kcal/mol (1 cal=4.184 J) for the former, and about 14 kcal/mol in higher temperature region and about 100 kcal/mol in lower temperature region for the latter. Thermal decomposition of (CF)n proceeds two-dimensionally around a nucleus of carbon which is formed at the initial stage of decomposition. The rate of thermal decomposition of various samples is dependent on the number of the nucleus forming sites. The nucleation of carbon takes place on a grain boundary between two small crystallites of (CF)n. The rate of the growth of the nucleus is fast along the grain boundary but slow in other directions. The activation energy was estimated to be about 100 kcal/mol for the former and almost 0 kcal/mol for the latter.
Thermal Decomposition of Graphite Fluoride. III. Thermal Decomposition of (CF)n in Oxygen Atmosphere
Authors: Watanabe Nobuatsu , Kawamura Toshihiko , Koyama Satoshi
Published: July 2006

Thermal decomposition of (CF)n was carried out under an oxygen atmosphere. The decomposition temperature was found to be a decisive factor to control the decomposition mechanism and the structure of residual substances. The decomposition reaction proceeded faster in oxygen than in a vacuum at temperatures higher than 588 °C. However, it was reversed below 588 °C. The decomposition mechanism in high temperature region was similar to that in a vacuum. The ESCA spectra of residual substances prepared above 588 °C indicated the presence of carbon atoms which were not bonded with fluorine, namely the nuclei comprised of carbon still remained even in oxygen. The rate of the weight decrease was larger in oxygen than in a vacuum because of the reaction of carbon nuclei, which was formed by thermal decomposition, with oxygen. On the other hand, it considerably decreased below 588 °C, where no nuclei was found for any sample.
The J-aggregate 5,5′,6,6′-Tetrachloro-1,1′-diethyl-3,3′-bis(4-sulfobutyl)benzimidazolocarbocyanine Sodium Salt in Aqueous Solution
Authors: Makio Shigetoshi , Kanamaru Nobuaki , Tanaka Jiro
Published: July 2006

The aggregation of the title dye in a dilute alkaline aqueous solution is investigated at 283–303 K by measuring the electronic absorption spectra. The association number is estimated to be 8, the heat of formation and the entropy change for the association are found as ΔH=−91.5 kcal mol−1 (1 cal=4.184J) and ΔS=−139.3 cal K−1 mol−1, respectively. The structure of the octamer is discussed from a view of spectral shift, intermolecular force and the crystalline structural data. The lifetimes, quantum yields and polarization of fluorescence are investigated on the monomeric and the J-aggregate state of the dye. The energy transfer between several J-aggregate units is indicated in the excited state.
Possible Role of Denatured Albumin in Formation of “Heat-resistant” Serum Albumin
Authors: Terada Hiroshi , Watanabe Kazuhiko , Kametani Fujio
Published: July 2006

Studies with the probe dye 2-(4-hydroxyphenylazo)benzoic acid, which can detect small conformational differences in serum albumin, showed that the conformation of “heat-resistant” serum albumin (form N′) was not constant, but depended on the heating temperature, becoming similar to that of the denatured monomer as the heating temperature was increased from 55 °C to 70 °C in buffer of pH 7.0. Denatured albumin was suggested to protect native serum albumin from full denaturation. In the presence of denatured albumin, native albumin was found to undergo only a slight conformational change to give the N′ form. This protective effect may explain why a constant amount of serum albumin remains as “heat-resistant” serum albumin even after prolonged heating.
Singlet Energy Transfer in p-Terphenyl Crystal Doped with Tetracene
Authors: Shinohara Hiroyuki , Kotani Masahiro
Published: July 2006

The transfer of singlet energy in p-terphenyl crystal was measured as a function of the dopant (tetracene) concentration and the temperature. The simple hopping model yields a value of 3×10−14 s. This value is believed to be correct within a factor of 5. In the low temperature phase of the crystal, the energy transfer is temperature dependent with an activation energy of 66 cm−1 in undeuterated p-terphenyl and 90 cm−1 in perdeuterated p-terphenyl. It seems probable that in the low temperature phase the freedom of the conformational change of the molecule plays an important role in the energy migration.
Nitrogen Determination by Pyrolysis Using Steam. I.
Authors: Nomura Akira , Morita Yazaemon , Kogure Yukitoshi
Published: July 2006

Pyrolysis of nitrogen compounds with use of steam and FeCl3–Al2O3 catalyst was investigated in detail in order to develop a new method for nitrogen determination. The catalyst was prepared by mixing an aqueous FeCl3 solution and porous active Al2O3 for column chromatography and drying the mixture. A sample solution containing nitrogen was added to the catalyst in a boat and was then covered with an additional catalyst after removal of the solvent, leaving the sample adsorbed on the catalyst. The boat was then inserted into a pyrolysis tube, the sample being pyrolyzed in the presence of steam also used as carrier gas. The nitrogen in the sample converted into ammonia by the pyrolysis reaction was determined by titration after steam distillation under alkaline conditions. The nitrogen compounds except for N–O and N–N bonded compounds were converted quantitatively into ammonia by the pyrolysis under optimum conditions. The reaction was applied to the determination of nitrogen in various compounds.
Synthesis and Characterization of Metal Complexes with Schiff Bases Obtained from N,N′-Bis(3-aminopropyl)piperazine and Salicylaldehyde Derivatives
Authors: Kuma Hiro , Yamada Shoichiro
Published: July 2006

Cobalt(II), nickel(II), cobalt(III), manganese(III), and iron(III) complexes have been synthesized with Schiff bases (abbreviated as X-sal-prpi) derived from N,N′-bis(3-aminopropyl)piperazine and salicylaldehyde derivatives. On the basis of electronic spectra, infrared spectra, and magnetic data, the structures of the metal complexes are discussed. Complexes of the type CoII(X-sal-prpi) are five-coordinated, and MIII(X-sal-prpi)ClO4 consist of six-coordinated [M(X-sal-prpi)]+ and free ClO4− ions, the ligands X-sal-prpi being quinquidentate in the former and sexadentate in the latter.