bluuebunny/crossref_metadata_2025 huggingface dataset:
Semburins and Swertiols, Novel 2,8-Dioxabicyclo[3.3.1]nonanes and Their Precursory Alcohols, from Swertia japonica Makino
Authors: Sakai Tsutomu , Nakagawa Yoshiko , Iwashita Takashi , Naoki Hideo , Sakan Takeo
Published: July 2006

The steam-volatile constituents of Swertia japonica Makino have been studied, and 71 components of the oil (comprising nearly 90% of the sample) have been identified. Structures of three novel 2,8-dioxabicyclo[3.3.1]nonanes (semburin, isosemburin, and neosemburin) and their precursory alcohols (swertiol, isoswertiol, and isoneoswertiol) have been established by spectroscopic analysis and chemical transformation data. The presence of 2-epi-isoneoswertiol, which was named neoswertiol, was detected by GC/MS. This is the first time that the 2,8-dioxabicyclo[3.3.1]nonane skeleton has been encountered in natural products.
X-Ray Structure Determination of (−)-Obtusane, a New Sesquiterpene from the Red Alga, Laurencia nipponica Yamada
Authors: Furusaki Akio , Matsumoto Takeshi , Kurata Kazuya , Suzuki Teruaki , Suzuki Minoru , Kurosawa Etsuro
Published: July 2006

A new sesquiterpene (C15H23Br2Cl, mp 172–173 °C) isolated from Laurencia nipponica Yamada has been found to be (−)-obtusane by X-ray crystal structure analysis.
The Precipitation-Spectrophotometric Determination of Dithionate Ions with Bis(diethylenetriamine)nickel(II) Chloride Solution
Authors: Sato Tsugio , Okabe Taijiro
Published: July 2006

A solution containing dithionate ions is treated with bis(diethylenetriamine)nickel(II) chloride solution to precipitate dithionate as [Ni(dien)2]S2O6 complex. After centrifugation, the concentration of nickel(II) ions in the supernatant is spectrophotometrically determined by dimethylglyoxime method. There is no interference from SO42− SO32−, S2O32−, S4O62−, HN(SO3)22−, S2−, or Fe3+.
Mosomorphic Phenyl Benzoate and 1,3-Dioxane Derivatives Bearing Terminal Vinyl Group
Authors: Kamogawa Hiroyoshi , Hirose Tomoki , Nanasawa Masato
Published: July 2006

4-Alkylphenyl 2-chloro-4-(4-vinylbenzoyloxy) benzoates and 2-phenyl-1,3-dioxane derivatives with terminal vinyl groups were synthesized. Most of the novel compounds obtained possess characteristic mesomorphic ranges.
A Stereoselective Synthesis of (3E,5Z)-3,5-Tetradecadienoic Acid (Megatomoic Acid), the Sex Attractant of the Black Carpet Beetle
Authors: Tsuboi Sadao , Masuda Toshihide , Takeda Akira
Published: July 2006

The total synthesis of (3E,5Z)-3,5-tetradecadienoic acid (megatomoic acid) is accomplished with 74% stereoselectivity through the use of stereoselective rearrangement of ethyl 3,4-tridecadienoate to ethyl (2E,4Z)-2,4-tridecadienoate with alumina and the extension of the carbon chain with methyl methylthiomethyl sulfone.
Catalytic Epoxidation of Cyclohexene with t-Butyl Hydroperoxide in the Presence of Various Molybdenum Complexes
Authors: Yamazaki Masashi , Endo Hidetoshi , Tomoyama Masato , Kurusu Yasuhiko
Published: July 2006

A ligand can play an important role in the activity of the molybdenum-catalyzed epoxidation. Molybdenum complex was changed to the reactive intermediate through the reaction of catalyst with t-BuOOH. Oxalate, edta, and phenoxyl groups were selected as ligands. The phenoxyl group was most effective for the epoxidation. This effect was interpreted by the HSAB concept.
The Reaction of Olefins with Malonic Acid in the Presence of Manganese(III) Acetate
Authors: Ito Nobuyuki , Nishino Hiroshi , Kurosawa Kazu
Published: July 2006

The reaction of 1,1-diphenylethene with malonic acid in the presence of manganese(III) acetate gave 3,3,8,8-tetraphenyl-2,7-dioxaspiro[4.4]nonane-1,6-dione and 4,4-diphenyl-2-(2,2-diphenylethenyl)-4-butanolide. Similar reactions with 1,1-bis(4-methoxyphenyl)ethene, methylenecyclohexane, 2-phenylpropene, 1-octene, and cyclohexene yielded the corresponding 2,7-dioxaspiro[4.4]nonane-1,6-diones.
Hydrogenation of Diphenylethyne Catalyzed by PdCl2 in CH2Cl2 and Polyethylene Glycol
Authors: Suzuki Nobutaka , Ayaguchi Yasuo , Tsukanaka Tsuneaki , Izawa Yasuji
Published: July 2006

A practically homogeneous system of PdCl2 in CH2Cl2 in the presence of polyethylene glycol catalyzed hydrogenation reactions of diphenylethyne (1) and cis-1,2-diphenylethene (2) to 2 and/or 1,2-diphenylethane (4). Under the conditions, the selectivity of the hydrogenation of 1 to 2 against that of 1 to 4 was excellent, compared to that using the Pd/C system.
Steroids. III. New Synthesis of Ring-D Seco Steroids
Authors: Takahashi Tomoyoshi , Satoh Yasuo
Published: July 2006

16β-Azido-5α-androstan-17-one derivatives were cleaved with bromine in acetic acid at room temperature, to furnish 16-cyano and 16-carbamoyl-16,17-seco-5α-androstan-17-oic acids. 17-Aza-D-homo-5α-androstan-16,17a-dione derivatives were also synthesized.
Anharmonic Potential Functions and Intrinsic Reaction Coordinates of Polyatomic Molecules
Authors: Machida Katsunosuke
Published: July 2006

A general method has been developed to describe the atomic motion along a given intrinsic reaction coordinate (IRC) in the vicinity of the potential minimum of a polyatomic molecule whose anharmonic force constants are known experimentally or theoretically. The components of the position vector of a configuration point on an IRC in the normal coordinate space are expanded as power series of the path length from the origin measured along the IRC. Explicit expressions of the expansion coefficients up to the third order have been given in terms of the normal frequencies and the anharmonic force constants with respect to the normal coordinates. The atomic loci along the IRC are given by transformation from the normal coordinates to the Cartesian displacements. Through application to formaldehyde and water, the method has proved to be useful to check if a given normal coordinate can be connected to any dissociation path on large distortion of the molecule.
Thermal and Dielectric Properties of Liquid Crystals with a Coumarin Skeleton
Authors: Nakai Hidetsugu , Takenaka Shunsuke , Kusabayashi Shigekazu
Published: July 2006

In order to examine the liquid crystalline properties of coumain, 3-X- and 7-Y-substituted coumarins where X=cyano and n-alkoxycarbonyl, and Y=4-n-alkyl- and 4-n-alkoxybenzoyl, 4-alkoxycinnamoyloxy, 4′-alkyl- and 4′-alkoxy-4-biphenylylcarbonyloxy, and 4-(4-alkoxybenzoyloxy)benzoyloxy (4) groups have been prepared. The compounds with X=alkoxycarbonyl group tend to exhibit strong smectic properties, and compounds with X=cyano exhibit stable nematic phases, whereas the coumarin core seems to facilitate a lateral separation of molecules in the mesophase due to its large molecular breadth. The heptyloxy homolog of 4 exhibits a reentrant behavior of the C–Nre–SA–N–I type. The thermal properties are discussed in terms of the polarity and polarizability of coumarin, and the molecular structure. The dielectric properties of the compounds have also been examined and discussed in terms of the polarity of the coumarin core.
The Study of Metal Colloids Produced by Means of Gas Evaporation Technique. I. Preparation Method and Optical Properties in Ethanol
Authors: Kimura Keisaku , Bandow Shunji
Published: July 2006

Three new methods for the preparation of metal colloid in organic solvent are presented. These methods were the matrix isolation method, the gas flow-cold trap method and the gas flow–solution trap method; the latter was found to give a good colloid solution for the optical measurements. The metals reported are high purity Ag, Au, Cu, In, Al, Ca, Sn, and Pb. The stability of the colloid is dependent on the kind of metals: Al, In, Au, and Ag are stable, and Pb, Sn, Ca, and Cu are unstable. The optical absorption spectra of these sols were measured in ethanol solution in Ar atmosphere. They are discussed in relation to those reported on the solid matrix or on the solid substrate.
The Preparation of Tri-t-butoxysiloxy-substituted 1,3,5-Triazines
Authors: Abe Yoshimoto , Nagao Yukinori , Sato Kenji , Misono Takahisa
Published: July 2006

The title derivatives were prepared to obtain 1,3,5-triazines with a better solubility than chloro- and amino-1,3,5-triazine, which are not very soluble in common organic solvents.
Thermodynamic Study for Dibenzo-24-crown-8 Complexes with Alkali Metal Ions in Nonaqueous Solvents
Authors: Takeda Yasuyuki
Published: July 2006

Complex-formation constants (KML+) of dibenzo-24-crown-8 (DB24C8) with alkali metal ions in acetonitrile and the solubility of DB24C8 in methanol, acetonitrile, and propylene carbonate were determined conductometrically and spectrophotometrically at 25 °C, respectively. The KML+ value sequences of the alkali metal ions with DB24C8 are Na+>Cs+>K+=Rb+. Dibenzo-24-crown-8 shows no remarkable selectivity for the alkali metal ions in acetonitrile. Transfer activity coefficients of the DB24C8 complexes with alkali metal ions were calculated from these data and literature values of transfer activity coefficients of alkali metal ions. For the same alkali metal ion, the bulky DB24C8-alkali metal ion complex is more soluble in the aprotic solvents acetonitrile and propylene carbonate than in the protic solvent methanol as compared with the case of the alkali metal ion itself. The transfer activity coefficient of the DB24C8-alkali metal ion complex from methanol to acetonitrile is somewhat sensitive to the variation of the alkali metal ion in the DB24C8 cavity, whereas the mobility of the DB24C8-alkali metal ion complex at the same concentration in the solvents is not sensitive.
Hydrophobic Vitamin B12. I. Preparation and Axial Ligation Behavior of Hydrophobic Vitamin B12r
Authors: Murakami Yukito , Hisaeda Yoshio , Kajihara Akiro
Published: July 2006

Heptamethyl cobyrinate perchlorate, [Cob(II)ester]ClO4, was prepared in a good yield from cyanocobalamin. This hydrophobic complex is structurally comparable to the base-off form of vitamin B12r. Thermodynamic parameters (ΔG, ΔH, and ΔS) for axial ligation of [Cob(II)ester]ClO4 with various amines in dichloromethane and toluene were determined by electronic spectroscopy. The isoequilibrium temperatures obtained from plots of ΔH  vs. ΔS were 194±20 and 317±20 K in dichloromethane and toluene, respectively. The equilibrium is primarily controlled by entropy at ordinary temperatures and the logK1 value varies sensitively along with the change in pKa of amine in dichloromethane, while the equilibrium values were almost invariant to the choice of amine in toluene because the measurements were carried out near the isoequilibrium temperature. The logK1 value for [Cob(II)ester]ClO4, different from the case of cobalt(II)-porphyrin complexes, depends on the nature of solvent used and undergoes wide variations. The possible functions of equatorial ligands involved in these two different complexes in the axial ligation behavior were discussed.
13C NMR Signal Assignments of Herqueinone and Its Phenalenone Derivatives
Authors: Suga Takayuki , Yoshioka Takamitsu , Hirata Toshifumi , Aoki Tadashi
Published: July 2006

The full assignments of the 13C NMR signals of the herqueinone-type phenalenone, herqueinone, were established by a combination of the single-frequency off-resonance decoupling technique and the 13C-enrichment technique using the 13C-labeled tracer. Furthermore, the full assignments of the 13C NMR signals of deoxyherqueinone-type, dihydroherqueinone-type, and xanthoherqueinone-type phenalenone were completed on the basis of the application of the chemical shift rule and the mutual comparison of their chemical shifts.
Studies on Heterocyclic Analogs of Azulenes. XI. Syntheses and Cycloadditions of Cyclohepta[4,5]pyrrolo[1,2-a]imidazoles and Cyclohept[d]imidazo[1,2-a]imidazoles
Authors: Abe Noritaka , Nishiwaki Tarozaemon , Yamamoto Hideko , Kunishige Noboru
Published: July 2006

Cyclohepta[4,5]pyrrolo[1,2-a]imidazoles (1,3a-diazacyclopent[a]azulenes) (2) and cyclohept[d]imidazo[1,2-a]imidazoles (1,3a,9-triazacyclopent[a]azulenes) (6) were synthesized from 2-aminocyclohepta[b]pyrroles and 2-aminocycloheptimidazole, respectively, in moderate to good yields. Reactions of 2 and 6 with reactive acetylenes gave 2-azacyclohepta[ef]cycl[3.2.2]azines together with bis(1,3a-diazacyclopent[a]azuleno)[1,7]diaza[12]annulenes (4) and 2,3-diazacyclohepta[ef]cycl[3.2.2]azines together with bis(1,3a,9-triazacyclopent[a]azuleno)[1,7]diaza[12]annulenes (8), respectively. Reactions of 2 and 6 with electron deficient olefins gave 4 and 8, respectively. These reactions proceeded regioselectively via 1,10-dipolar intermediates.
X-Ray Diffraction Study on the Coordination Structure of Chlorocopper(II) Complexes in Highly Concentrated Methanolic CuCl2 Solution
Authors: Ichihashi Mitsuyoshi , Wakita Hisanobu , Masuda Isao
Published: July 2006

The structures of the solute complexes existing in methanolic CuCl2 solutions with concentrations of 1.055–3.250 mol dm−3 were investigated by X-ray diffraction analysis. The solute complexes which were predominantly present could be formulated as [CuCln(CH3OH)6–n] (n=1–3); they have an axially elongated octahedral structure including Cl− at the equatorial site. The Cu-O bond distance was 2.230–2.238 Å. Methanol molecules were coordinated at the equatorial site with the Cu-O bond distance of 1.926–1.950 Å and at the axial site with that of 2.423–2.473 Å. When the initial concentration of CuCl2 was kept within the range examined here, almost all of the Cu2+ ions formed chloro complexes.
Reduction of Sulfonic Acids and Related Organosulfur Compounds with Triphenylphosphine–Iodine System
Authors: Oae Shigeru , Togo Hideo
Published: July 2006

Arenesulfonic acids, their sodium salts, and alkyl arenesulfonates can be reduced readily to the corresponding arenethiols quantitatively by treatment with a mixture of triphenylphosphine and a catalytic amount of iodine, while alkanesulfonic acids, sulfinic acids, disulfides, thiosulfonic testers, and sulfonates are also readily reduced to the corresponding thiols similarly. Upon treatment with a mixture of triphenylphosphine and excess iodine, however, these aliphatic sulfur compounds are converted eventually to the corresponding alkyl iodides. The relative reactivities of these sulfonyl derivatives in the reaction with the triphenylphosphine–iodine system are the following. Aromatic series: ArSO2Cl, ArSO2SAr′>ArSO2H>ArSO3R>ArSO3−HNBu3+ (or PyH+)>ArSO3H>ArSO2SO2Ar>>ArSO2CH2C(CH3)3, ArSO3Ar′. Aliphatic series: RSO2Cl, RSO2SR′, RSO2−HNBu3+>RSO3−HNBu3+>RSSR, RSO2H>RSO3H>RSH>RSO3R′. In these reactions, the arenesulfonic acids bearing electron-donating substituents can be reduced more readily than those having electron-withdrawing substituents.
Biomimetic Reduction of Sulfuric Acid
Authors: Oae Shigeru , Togo Hideo
Published: July 2006

Sulfuric acid and sodium sulfate were readily reduced to elemental sulfur and hydrogen sulfide upon treatment with a mixture of either one of polyphosphoric acid derivatives, PPE, PPA, and P4O10, which can form a mixed anhydride having –P–O–S– linkage, and iodide or thiol. Sulfur dioxide, which is undoubtedly one of important intermediates, was trapped by p-tolyllithium to afford p-toluenesulfinic acid which was converted to p-tolyl methyl sulfone upon treatment with methyl iodide, though the yield was low. Sulfur trioxide which has been postulated as the key intermediate in the biological reduction of inorganic sulfate, was also trapped by mesitylene to give mesitylenesulfonic acid in a high yield. The reduction of sulfate to elemental sulfur and hydrogen sulfide is considered to proceed through the course which resembles the biological reaction path involved in the assimilatory metabolism of inorganic sulfate in microorganisms and plants.
57Fe Spin-lattice Relaxation Time of Fe(CO)5 and Ferrocene
Authors: Nozawa Tsunenori , Hatano Masahiro , Sato Mitsuo , Toida Yoshiharu , Batholdi Enrico
Published: July 2006

Spin-lattice relaxation times (T1’s) of 57Fe were determined by the inversion recovery method to be 80 (±10) s at 293 K and 4 (±1) s at 303 K for Fe(CO)5 and ferrocene, respectively. Predominant relaxation mechanisms were considered to be chemical shift anisotropy and spin-rotation for the former and the latter complexes, respectively.
Study of the Behavior of “Uptake and Release” of Oxygen into Perfluorocarbon–Water Emulsions
Authors: Meguro Kenjiro , Watanabe Hiroshi , Kato Hiromu , Ogihara Kimihiko , Esumi Kunio
Published: July 2006

Stable O/W type emulsions of perfluorocarbon such as perfluorodecalin (FDC) and perfluorotributylamine (FTBA) were prepared by using poly(oxyethylene)-poly(oxypropylene) block copolymer (Pluronic F-68) and sorbitan monolaurate (SL-10) as emulsifiers. The relationships between the behavior of “uptake and release” of oxygen into the emulsions and the factors responsible for a stable emulsion were studied. The initial rates of “uptake and release” of oxygen into the emulsions decreased with increasing the mean particle size, the concentration of emulsifiers, and the viscosities of the emulsions. On the other hand, the saturated amount of oxygen in the emulsions was independent on the mean particle size, but depended on the total amount of the perfluorocarbons in the emulsion.
The Preparation of Poly(dicarbon monofluoride) via the Graphite Intercalation Compound
Authors: Watanabe Nobuatsu , Nakajima Tsuyoshi , Kawaguchi Masayuki , Izumi Akira
Published: July 2006

Poly(dicarbon monofluoride), (C2F)n is prepared with a higher reaction rate via the graphite interca lation compound formed through a reaction with F2 and AlF3 than from exfoliated graphite itself. The former process also has the advantage of including the formation of exfoliated graphite by the decomposition of an intercalation compound and its fluorination. The graphite fluoride thus prepared contained (C2F)n by 60–78%. The reaction time required for completing the reaction did not give a linear relationship, but a minimum point around 267×102 Pa against the fluorine pressure and there was almost no increase above 667×102 Pa of fluorine. However, the F/C ratios of graphite fluoride had, inversely, a maximum point against the fluorine pressure, indicating that the (C2F)n content in graphite fluoride was approximately proportional to the reaction time.
Enthalpies of Combustion of Organic Compounds. IV. Acetanilide and Nicotinic Acid
Authors: Sato-Toshima Tomoko , Kamaguchi Akeji , Nishiyama Keiichi , Sakiyama Minoru , Seki Syûzô
Published: July 2006

Standard energies of combustion at 298.15 K have been determined for crystalline acetanilide and nicotinic acid by static oxygen bomb calorimetry. Derived standard enthalpies of combustion and of formation are −(4224.8±1.0) and −(209.5±1.5) kJ mol−1 for acetanilide, and −(2730.83±0.48) and −(344.81±0.92) kJ mol−1 for nicotinic acid, respectively. Nicotinic acid pellets of 1.2 g in mass showed remarkable tendency to spatter when partially burnt. Factors governing the completeness of combustion of the material have been explored through 28 test combustion experiments.
Electrophilic Additions of Rigid Methylenecyclohexane. A Correlation of the Stereochemical Course of the Methoxymercuration-demercuration and the 1,3-Dipolar Cycloaddition
Authors: Nitta Makoto , Omata Akihiko , Hirayama Setsuko , Yajima Yuji
Published: July 2006

The stereochemical course of the methoxymercuration-demercurations and the 1,3-dipolar cycloadditions of mesitonitrile oxide on the exocyclic double bonds of 2,4-dimethyl-7-methylenetetracyclo[3.3.0.0.2,804,6]octan-3-one (4a), its corresponding exo-3-ol (4b), endo-3-ol (4c), and 2,3,4-trimethyl-7-methylenetetracyclo[3.3.0.0.2,804,6]octan-3-exo-ol (4d) were investigated. In the methoxymercurations of 4a and 4b, the methoxyl group was incorporated in the exo and endo positions, with endo preferred over exo. On the other hand, 4c and 4d underwent the stereospecific incorporation of the methoxyl group in the endo position. In the 1,3-dipolar cycloadditions, 4a or 4b afforded exo- and endo-adducts, with the exo-adduct preferred. These results seem to imply similar stereochemical course of the formation of the mercurinium-ion intermediates and the 1,3-dipolar cycloadditions. The results are discussed on the basis of the steric hindrance of the molecular framework and the substituents which are located at the C-3 position.
Simple Synthesis and Chemicophysical Properties of Polyoxa[n]ferrocenophanes and Its Alkali Metal Complexes
Authors: Akabori Sadatoshi , Habata Yoichi , Sakamoto Yhoko , Sato Masaru , Ebine Seiji
Published: July 2006

Polyoxaferrocenophanes were synthesized by a one-pot reaction of 1,1′-diacetoxyferrocene with dichloride. Crystalline 1 : 1 complexes of 3a with LiSCN, NaSCN, and KSCN were isolated. The 1H-NMR and Mössbauer spectra of these complexes suggest the possibility of a certain interaction between the iron atom of the ferrocene nuclei and complexed cation. The new type of ferrocenophane 3a extracts a thallium ion most effectively, the extractability of several metal ions being in this order; Tl+>Rb+>K+>Cs+>Na+.
Chemical Studies on the Mistletoe. V. The Structure of Taxillusin, a New Flavonoid Glycoside Isolated from Taxillus kaempferi
Authors: Sakurai Atsushi , Okumura Yasuaki
Published: July 2006

A new flavonoid glycoside, taxillusin was isolated from Taxillus kaempferi (DC.) Danser and (2R,3R)-taxifolin 3-β-d-glucopyranoside 6″-gallate was assigned to this substance from studies on the hydrolysis products and from analyses of the 1H-NMR and carbon-13 NMR spectra.
NAD(P)+-NAD(P)H Model. 39. Asymmetric Reduction by 1,4-Dihydronicotinamide Derivative Bound to Protein
Authors: Ohno Atsuyoshi , Ushida Satoshi , Oka Shinzaburo
Published: July 2006

1,4-Dihydronicotinamide derivatives covalently bound to NH2 or SH group of proteins such as reduced keratin (RK), egg white albumin (EWA), and bovine serum albumin (BSA) have been synthesized and subjected to the reductions of α,α,α-trifluoroacetophenone derivatives. Chiral alcohol is obtained in the reaction with 1,4-dihydronicotinamide modified by the SH group of BSA.
Electronic Structures and Spectra of a Novel Diquinone; 1,4 : 5,8-Anthracenediquinone
Authors: Fukuda Masahiko , Tajiri Akio , Oda Masaji , Hatano Masahiro
Published: July 2006

Assignment of the electronic absorption spectrum of 1,4 : 5,8-anthracenediquinone (1,4 : 5,8-ADQ) has been carried out with the aid of magnetic circular dichroism and LCAO MO SCF CI calculations including all valence electrons. The lowest energy absorption region of 1,4 : 5,8-ADQ has been revealed to be composed of the n-π* transition or transitions. The higher energy absorption region has been concluded to consist of four π-π* transitions, which are regarded as Lb, La, Ba, and Bb in the Platt’s notation for anthracene. The above assignment of 1,4 : 5,8-ADQ has been experimentally confirmed with its linear dichroism spectra in stretched polyethylene sheets and its circular dichroism spectra in the β-cyclodextrin solution. The relationship between the absorption spectra of 1,4 : 5,8-ADQ and 1,4-naphthoquinone has been discussed from the experimental and theoretical points of view.
Excited-state Reactions of Coumarins in Aqueous Solutions. I. The Phototautomerization of 7-Hydroxycoumarin and Its Derivative
Authors: Moriya Tetsuo
Published: July 2006

The kinetics and mechanism of the reaction in the photo-excited state of 7-hydroxycoumarin and its derivative have been studied in aqueous solutions by means of measuring the fluorescence spectra and the fluorescence lifetime. The four fluorescence bands have been identified as emissions from the neutral, anionic, tautomeric, and cationic forms of 7-hydroxycoumarins. The quantitative analysis was performed by using the rate equation which included the term for the direct conversion of the excited neutral molecule to its tautomer in addition to the usual reaction term of dissociation. The rate constants of the tautomerization and dissociation were discussed in detail, and it was revealed that the tautomerization in aqueous solutions was mainly caused by the transfer of a proton between two active sites in the molecule. Such an intramolecular proton-transfer of the coumarins, found first in this paper, is considered to be promoted by water molecules with a hydrogen bond surrounding the excited molecule.
Study of the Mixed Solutions of an Anionic and a Nonionic Surfactant by Using the Azo-hydrazone Tautomerism of an Acidic Dye
Authors: Meguro Kenjiro , Tabata Yujin , Fujimoto Naoki , Esumi Kunio
Published: July 2006

The absorbances of the azo-hydrazone tautomer of sodium 4-(p-sulfonatophenylazo)-1-naphthol-2-sulfonate dissolved in an aqueous solution of polyethylene glycol octyl dodecyl ether (8ED) were measured in the presence of various concentrations of sodium dodecyl sulfate (SDS). The existence of a mixed micellar region of SDS and 8ED in the bulk solution was confirmed by this azo-hydrazone tautomer method.
The Spectrophotometric Determination of Phosphate and Arsenate by Selective Extraction with Mixed Solvents
Authors: Shida Junichi , Kakizaki Satoru , Hozumi Yasuomi , Itoh Akiko , Matsuo Tsutomu
Published: July 2006

A spectrophotometric method for the simultaneous determination of phosphate and arsenate by selective solvent extraction was examined. First, molybdophosphate was extracted with 1-butanol–chloroform in the presence of molybdoarsenate, and then the molybdoarsenate in the aqueous phase was extracted with MIBK, followed by reduction directly in the organic phase to Molybdenum Blue.
Optical Determination of Carboxylate Ions Utilizing Flocculation of Colloidal Al(OH)3
Authors: Muto Masayuki , Yamahachi Yuko
Published: July 2006

Flocculation of colloidal Al(OH)3 occurs by adding a suitable amount of Congo Red, and the supernatant liquid become scolorless. When some carboxylate ions are present in this colloidal mixture, the quantity of Al(OH)3 decreases because of the formation of complexes, and then excess Congo Red gives a red color to the supernatant liquid. The indirect determination of some kinds of carboxylate ions was carried out by applying the measurement of optical absorption to the supernatant fraction.
Optical Resolution of Aspartic Acid by Using Copper Complexes of Optically Active Amino Acids
Authors: Harada Kaoru , Fujii Noriko
Published: July 2006

Dl-Aspartic acid was resolved with high optical purity in the presence of an optically active amino acid copper complex. The mechanism of the optical resolution was explained by the competitive inhibition of crystallization.
Phase Equilibria in the La2O3–V2O3–V2O5 System at 1200 °C
Authors: Kitayama Kenzo , Zoshima Daizo , Katsura Takashi
Published: July 2006

The phase equilibria in the La2O3–V2O3–V2O5 system were established at 1200 °C by changing oxygen partial pressures from −0.68 (air) to −13.00 in terms of logPO2. In this system, 0.81La2O3·0.19V2O5(La1.62V0.38O3.38), 3La2O3·V2O5(La3VO7), 0.71La2O3·0.29V2O5(La1.42V0.58O3.58), LaVO4, LaVO3, VnO2n−1 (n=2–7), and VO2 were stable. LaVO3, LaVO4, La1.62V0.38O3.38, La3VO7, and La1.42V0.58O3.58 have nonstoichiometric compositions. On the basis of the phase equilibria, the Gibbs energies of the reactions:

31⁄50La2O3+19⁄50LaVO3+19⁄100O2=La1.62V0.38O3.38

50⁄31La1.62V0.38O3.38+12⁄31LaVO3+6⁄31O2=La3VO7

21⁄50La3VO7+4⁄25 LaVO3+2⁄25O2=La1.42V0.58O3.58

LaVO3+1⁄2O2=LaVO4

were determined to be −64.0, −55.8, −21.6, and −131.5 kJ respectively.
Epilaurallene, a New Nonterpenoid C15-Bromoallene from the Red Alga Laurencia nipponica Yamada
Authors: Suzuki Minoru , Koizumi Kuniko , Kikuchi Hajime , Suzuki Teruaki , Kurosawa Etsuro
Published: July 2006

A new halogenated nonterpenoid C15-compound, epilaurallene, has been isolated as a major constituent from the title alga along with several known compounds, and its structure was determined by the spectral and chemical methods. Epilaurallene is an epimer at C-4 of laurallene and was shown to possess S-configuration at C-4.
Oxidative Dehydrogenation of Bis(salicylideneaminato)copper(II) Complex in Pyridine and Formation of 2-Cyanophenolato Complex
Authors: Matsushita Takayuki , Shono Toshiyuki
Published: July 2006

The copper(II) complex of salicylideneamine (salamH) reacts with molecular oxygen in pyridine to give the 2-cyanophenolato complex, [Cu(2-CNphO)2(py)2], in good yield, where 2-CNphOH and py denote 2-cyanophenol and pyridine, respectively. This complex was characterized by the infrared and electronic spectra and by its magnetic susceptibilities, and was compared with the authentic complex, [Cu(2-CNphO)2(py)2]. The mechanism for the oxidation of the coordinated imino groups is discussed.
Analysis for the Oligomerization Mechanism of Styrene by Field Desorption Mass Spectrometry
Authors: Saito Jun , Hara Junji , Toda Shozo , Tanaka Shigeyuki
Published: July 2006

Measurements were made of field desorption mass spectra of normal and deuterated styrene oligomers synthesized in various alkylbenzenes. Several series of molecular ion peaks are observed in both the spectra. From a comparison between them we have identified oligomers’ end groups and derived formation mechanisms for individual molecular species. It has been clarified that molecular species independent of solvents are produced through chain transfer of propagating radicals to styrene dimers. Analysis for the polymerization mechanism of styrene as well as characterization of polymer molecules has been successfully performed by field desorption mass spectrometry.
Aromatic Nucleophilic Substitution. XVI. Stopped-flow Kinetics of Formation and Decomposition of 1,3- and 1,1-Disubstituted Anionic σ Complexes in Reactions of 1-Dimethylamino-2,4-dinitronaphthalene with Potassium Alkoxides in Dimethyl Sulfoxide–Alcohol
Authors: Sekiguchi Shizen , Tone Noboru , Takei Toshio , Tomoto Noboru
Published: July 2006

Reactions of 1-dimethylamino-2,4-dinitronaphthalene with potassium methoxide or ethoxide were carried out in DMSO–CH3OH or DMSO–C2H5OH (90:10 v/v), respectively, where the 1,3-disubstituted anionic σ complexes were first rapidly formed, undergoing isomerizations to the 1,1-disubstituted anionic σ complexes. Rates and activation parameters were determined by kinetic studies using stopped-flow and conventional spectrophotometers. The rate constant (25 °C) for the formation of 1,3-disubstituted one in DMSO–CH3OH is about half that in DMSO–C2H5OH, whereas the rate constant (25 °C) for its decomposition is more than twice that in DMSO–C2H5OH. The apparent pseudo-first-order rate constant for the formation of 1,1-disubstituted anionic σ complex in DMSO–CH3OH depends upon the methoxide ion concentration, whereas that in DMSO–C2H5OH is almost independent of the ethoxide ion concentration. The mechanism is discussed on the basis of activation parameters.
Aryliminodimagnesium Reagents. V. The Reaction with Bifunctional Nitroarenes
Authors: Okubo Masao , Aratani Hiroyuki , Gond\={o} Takayuki , Koga K\={o}ji
Published: July 2006

The reactions of p-methylphenyliminodimagnesium reagent (p-MeC6H4N(MgBr)2) with p- and m-dinitrobenzenes, bis(p-nitrophenyl) methane, bis(p-nitrophenyl) sulfide and ether, p- and m-nitrobenzaldehydes as well as 4-nitro-4′-methylbenzophenone were investigated. p-Dinitrobenzene, which is the strongest electron-acceptor among the substrates used, gave ca. 30% combined yield of bis(azoxy) and azoxy azo products. The oxidative coupling product, 4,4′-dimethylazobenzene, was isolated in 20–30% yields. About 60% combined yield of the bis(azoxy) and azoxy azo products was obtained in the same reaction with m-dinitrobenzene, which is less electron-accepting than the p-isomer. In the reaction of bis(p-nitrophenyl)methane, bis(p-nitrophenyl) sulfide and ether with five molar amounts of the reagent, ca. 70% combined yields of bis(azoxy), azoxy azo, and bis(azo) products were obtained. On the treatment of the nitrobenzaldehydes and the nitrobenzophenone, in contrast, the reaction took place exclusively on the nitro group. The results are discussed in terms of the electron-accepting ability of substrates.
The Effect of Temperature on the Formation of Benzyl Radical-Halide Ion Complexes in γ-Irradiated Organic Glassy Matrices
Authors: Izumida Tatsuo , Fujii Kuniaki , Ogasawara Masaaki , Yoshida Hiroshi
Published: July 2006

Broad structureless charge-transfer (CT) bands of benzyl radical-halide ion (\dotBz- - -X−) complexes have been observed in 3-methylhexane (3MHx) and 2-methyltetrahydrofuran (MTHF) matrices containing BzCl and BzBr irradiated with γ-rays at 4.2 K. 3MHx and ethanol matrices containing BzI also showed the CT band when warmed from the irradiation temperature to 77 K. These observations are in marked contrast with previous ones in which the CT band was found to be present only in alkane matrices when irradiated at 77 K. The CT band has been found to shift to the blue with increasing matrix polarity, as expected from a large contribution of the solvation of the ion to the CT transition energy of the radical-anion complex. The observed nature and behavior of the CT bands indicates that the dissociative electron attachment reaction in the matrices is a stepwise process: The formation of a \dotBz- - -X− complex and its dissociation. These steps proceed readily in more polar environments and for lighter ions. For the electron attachment to BzI at 4.2 K, an even earlier step, an ionic entity prior to the C–I bond dissociation, was indicated.
Conductimetric Study of the Ion Pair Formation in Mixtures of Bivalent Metal Nitrates and Sodium Sulfate in Aqueous Solutions
Authors: Katayama Shunzo , Tanaka Kazuko , Tamamushi Reita
Published: July 2006

The conductance behavior of electrolyte mixtures was investigated for the systems of bivalent metal nitrates and sodium sulfate in aqueous solutions of high ionic strengths (I≥0.3 mol dm−3) at 25 °C. Significant deviations of the measured conductivities from the additivity were observed in all the systems, which can be attributed to the ion pair formation of the bivalent metal ion with sulfate ion. The conditional formation constants, Kc, were determined by means of computer analysis of the deviation; Kc-values at each ionic strength were found to decrease in the sequence Cd>Mn\simeqNi\simeqCo\simeqZn>Mg.
Hydrates of Organic Compounds. VII. The Effect of Anions on the Formation of Clathrate Hydrates of Tetrabutylammonium Salts
Authors: Nakayama Haruo
Published: July 2006

Phase diagrams of the binary mixtures of tetrabutylammonium salt [(n-C4H9)4N]nX (X=NO2, NO3, BrO3, ClO3, IO3, ClO4, MnO4, and NCS for n=1; X=CO3, SO4, WO4, and CrO4 for n=2; and X=PO4 for n=3) with water were determined over the temperature range between −10 and +50 °C. From these diagrams the following results were obtained: (1) the formation of a clathrate-like hydrate for salts having such anions as NO2−, NO3−, BrO3−, ClO3−, IO3−, SO42−, and PO43− was newly confirmed; (2) the melting point of the clathrate hydrate of the salt with monovalent anion was appreciably influenced by the kind of anion; (3) in the hydrates of the salt having either di- or trivalent anions, the melting points were relatively high and were only slightly affected by the kind of anion; (4) the crystal structure of these hydrates was essentially the same as that of the tetrabutylammonium fluoride hydrate, judging from the hydration numbers; (5) the solubilities in water of both permanganate and perchlorate were markedly lower than that of the iodide; and (6) in the thiocyanate system a phase separation into two liquid phases was observed at temperatures higher than +3.5 °C. The effect of a monovalent anion on the stability of the clathrate hydrate was discussed in connection with the conventional partial molal volume of the anion.
Hydrogen Evolution from Alkaline Formaldehyde Solution
Authors: Okamoto Hiroshi , Katsumoto Masayuki , Kudo Tetsuichi
Published: July 2006

Hydrogen is evolved from an alkaline solution of formaldehyde in the presence of a tungsten carbide catalyst at room temperature under atmospheric pressure. Neither platinum nor palladium shows any catalytic activity to this reaction. The hydrogen evolution competes with the Gannizzaro reaction.
Intensity Enhancement Caused by Complex Formation between Pyrene and Alcohols
Authors: Nakajima Akira
Published: July 2006

The enhancement of the weak 0-0 band in the absorption spectrum of pyrene has been observed using various mixtures of cyclohexane and alcohols. The relations of the absorption coefficients with the alcohol concentrations have been studied on the assumption of 1:1 complex formation between pyrene and alcohols. The association constants for the hydrogen-bonded complexes have been estimated to be of a reasonable order of magnitude(0.1–0.4 mol−1 dm3).
Wetting of Coal by Aqueous Surfactant Solutions
Authors: Esumi Kunio , Meguro Kenjiro , Honda Hidemasa
Published: July 2006

The rates of wetting of coals of various carbon content by aqueous anionic surfactant solutions were measured. It was found that the rates of wetting increased with increasing concentration of the anionic surfactant in solution and further, the addition of electrolyte significantly promoted the rates of wetting. The presence of the electrolyte on the surface of coal after wetting was confirmed by the zeta potential measurement.
The Preparation and Some Properties of Cobalt(II) Schiff Base Complexes and Their Molecular Oxygen Adducts
Authors: Kasuga Kuninobu , Nagahara Takeo , Tsuge Akira , Sogabe Kunihisa , Yamamoto Yasuo
Published: July 2006

Seven new cobalt(II) complexes with a tetradentate Schiff base and their three oxygen adducts were synthesized. The adducts were stable at room temperature for several weeks. The isolated oxygen adducts showed intense new bands in the 1130–1150 cm−1 range characteristic of superoxide-like 1:1 oxygenated metal complexes. The ESR spectra of the adducts showed eight-lined, hyperfine structures with a very small splitting (10–20 G) at 77 K. The adducts obtained were identified as monomeric 1:1 oxygen species, two complexes of which showed a reversible oxygenation in a 1,2-dichloroethane solution at 6 °C.
Syntheses and Properties of Dinuclear Copper(II) Complexes with 2,6-Bis[bis(2-pyridylmethyl)aminomethyl]-4-methylphenol
Authors: Suzuki Masatatsu , Kanatomi Hajime , Demura Youichi , Murase Ichiro
Published: July 2006

The dinucleating ligand, 2,6-bis[bis(2-pyridylmethyl)aminomethyl]-4-methylphenol](Hbpmp), formed two types of dinuclear copper(II) complexes, [Cu2(bpmp)X2]n+(X=Cl−, N3− py(pyridine), or Him(imidazole), and n=1 or 3), and [Cu2(bpmp)X]2+(X=CH3COO− or im−). On the basis of the dinucleating nature of the ligand (bpmp), the elemental analyses and the conductivity measurements in acetonitrile, it is concluded that the complexes have dimeric unit of [Cu2(bpmp)X2]n+ or [Cu2(bpmp)X]2+. In [Cu2(bpmp)X2]n+ type complexes, two copper(II) ions are linked only by a single phenolate bridge. Magnetic susceptibilities of those complexes obey Curie-Weiss law in the temperature range 80–300 K with the Weiss constants ≈−4 K, indicating that weak antiferromagnetic interactions are present in these complexes. In [Cu2[bpmp)X]2+ type complexes, however, two copper(II) ions are bridged by phenolate and acetate, or phenolate and imidazolate. Cryomagnetic measurements of the acetato and the imidazolato complexes showed antiferromagnetic interactions with the −2J values of 82 and 66 cm−1, respectively. All the complexes exhibited absorption bands at 20000–22000 cm−1 except for the azido complex. The origin of those bands are discussed.
Kinetics of the Racemization of Tris(1,10-phenanthroline)nickel(II). Hydrophobic Interaction of the Complex Ion with 1-Alkanesulfonate Ions
Authors: Tachiyashiki Satoshi , Yamatera Hideo
Published: July 2006

The kinetics of the racemization of [Ni(phen)3]2+ were investigated in the presence of 1-alkanesulfonate ions (n-CnH2n+1SO3−; n=8, 10, 12, and 14). The racemization rate decreased with the increase in the alkanesulfonate concentrations in the region of low sulfonate concentrations; then, in the region of higher concentrations, it began to increase, but it never exceeded the rate in water. The rate changes at low and high alkanesulfonate concentrations were related to the formation of the 1:1 and 1:m aggregates of the complex ion with alkanesulfonate ions respectively. A comparison of the aggregate formation constants of [Ni(phen)3]2+ with those of [Fe(phen)3]2+ confirmed that hydrophobic interaction is responsible for the aggregate formation. The energy of hydrophobic interaction between [Ni(phen)3]2+ and an alkanesulfonate ion was estimated to be 1.0±0.1 kJ mol−1 per methylene group of the latter. The kinetic behavior of the racemization of [Ni(phen)3]2+ in the aggregates was also compared with those of the racemization and dissociation of [Fe(phen)3]2+, and it was discussed in relation to the racemization mechanism of [Ni(phen)3]2+. The reaction rates of the complexes in D2O solutions were also reported.
Kinetics of the Racemization and Dissociation of Tris(1,10-phenanthroline)iron(II) and Tris(2,2′-bipyridine)iron(II) in Sodium Dodecyl Sulfate Solutions
Authors: Tachiyashiki Satoshi , Yamatera Hideo
Published: July 2006

The kinetics of the racemization and dissociation of [Fe(phen)3]2+ (phen=1,10-phenanthroline) and [Fe(bpy)3]2+ (bpy=2,2′-bipyridine) was investigated in aqueous sodium dodecyl sulfate (SDS) solutions. The racemization and dissociation rates of the complexes increased with the increase in the SDS concentration to reach limiting values at concentrations above the critical micelle concentration (cmc). The rate changes occurring below the cmc were explained in terms of the formation of at least three kinds of premicellar aggregates of the complex ion with dodecyl sulfate ions. In the region slightly above the cmc, where the concentration of the complex ion is larger than that of the micelle, the rates continued to increase with the increase in the micellar concentration, suggesting that the complex ions interacted with the micelles. A comparison of the kinetic behavior in aqueous micellar solutions with that in organic solvents revealed that the complexes were located inside the micelle–water interface. The mechanisms of the acceleration in the micelle were discussed.
Mössbauer Study of Tin(II) Chloride Hydroxide and Tin(II) Hydroxide Oxide
Authors: Ichiba Sumio , Takeshita Mitsuru
Published: July 2006

The precipitates obtained by addition of a solution of NaHCO3 to a solution of SnCl2 at various pH were studied by thermal analysis, Mössbauer spectroscopy, and X-ray powder diffraction. The formula of the tin(II) chloride hydroxide precipitate obtained in the range of pH 1.9–2.5 was determined as 2SnO·SnCl2·H2O, or Sn3O(OH)2Cl2, and the formula of the hydroxide oxide obtained in the range of pH 7.0–7.7 was 3SnO·2H2O, or Sn3(OH)4O. In the intermediate pH range, the chloride ions were gradually replaced by hydroxide ions. The dehydration of hydroxide oxide to produce SnO occurred in two stages and the disproportionation reaction of SnO to SnO2 and β-tin proceeded via Sn2O3.
Oxidation of S,S-Diaryl-N-(p-tolylsulfonyl)sulfilimines and N-Unsubstituted S,S-Diaryl-sulfilimines with Potassium Hyperoxide Anion Radical (O2\ewdot) in the Presence of 1-Bromopropane, Benzoyl Chloride, p-Tolylsulfonyl Chloride, Carbon Tetrachloride, Chloroform, or Dichloromethane in Aprotic Media
Authors: Akutagawa Kunihiko , Furukawa Naomichi , Oae Shigeru
Published: July 2006

The reaction of S,S-diaryl-N-(p-tolylsulfonyl)sulfilimines and N-unsubstituted diaryl-sulfilimines with hyperoxide anion radical (O2\ewdot) in the presence of 18-crown-6 as a catalyst together with 1-bromopropane/benzene, benzoyl chloride/benzene, p-tolylsulfonyl chloride/benzene, carbon tetrachloride, chloroform, or dichloromethane, gave the corresponding sulfoximines, through nucleophilic oxidation with an intermediary dioxy species formed upon treatment of organic halides with potassium hyperoxide (KO2).
ESR Studies of Spin-Spin Dipolar Interaction in Pure and Diluted Phenoxyl Radical Solids
Authors: Mukai Kazuo , Ueda Kyozo , Ishizu Kazuhiko , Yamauchi Seigo
Published: July 2006

ESR studies have been carried out on powder samples of pure phenoxyl (2,6-di-t-butyl-4-phenylphenoxyl) and 3% phenoxyl diluted in its diamagnetic corresponding phenol matrix. The dipolar splittings due to the spin pairs in closest approach have been observed for both the pure and 3% phenoxyl.
Silver Ion-induced Allylation of Furan with Cyclopropyl Halides
Authors: Shimizu Nobujiro , Watanabe Kenji , Tsuno Yuho
Published: July 2006

Allyl species generated from 1-bromo-2-phenylcyclopropane and seven different 1,1-dihalocyclopropanes with the aid of silver perchlorate reacted with furan in a regio- and stereoselective manner to give a series of 2-allylfuran derivatives in fair to good yields.
Aqueous Dispersion of Iron Oxide by Acrylic Oligomer Surfactants
Authors: Esumi Kunio , Ogihara Kimihiko , Meguro Kenjiro
Published: July 2006

The aqueous dispersion of iron oxide by acrylic oligomer surfactants was examined by particle size and zeta potential measurements. Iron oxide particles were suspended in an aqueous iron(III) chloride solution to render the surface positively charged. The iron oxide particles so prepared were then flocculated by the addition of a small amount of acrylic oligomer surfactant. The floes of iron oxide could be redispersed by further addition of acrylic oligomer surfactant. The flocculation and the redispersion processes can be explained in terms of a “two-fold adsorption layer” mechanism of the acrylic oligomer surfactant. The concentrations of acrylic oligomer surfactants needed to achieve flocculation and redispersion decreased with an increase in acrylic content of the oligomer surfactants.
Catalytic Activity of MoO3 and V2O5 Highly Dispersed on TiO2 for Oxidation Reactions
Authors: Ono Takehiko , Nakagawa Yoshiro , Miyata Hisashi , Kubokawa Yutaka
Published: July 2006

The structure of Mo–Ti oxide catalysts has been investigated by using IR and XRD techniques. At a low Mo content, MoO3 is highly dispersed on TiO2, an amorphous phase being formed. Simultaneously, a shift of the Mo=O band from 995 cm−1 to 950 and 905 cm−1 takes place. The maximum rate of the oxidation of C2H5OH and C3H6 over Mo–Ti-6(atom% of Mo) is attributable to the weakening of the Mo=O bond. The 18O tracer and kinetic studies of the oxidation of C3H6 over Mo–Ti and V–Ti oxides suggest that a redox mechanism is applicable, the rate constants of reduction and reoxidation step being determined. The promoter action of TiO2 support is attributed mainly to the increase in the rate of reduction step.
Synthesis and Isomerism of Mixed (Amine)(carboxylato) Complexes with the [Pd(N)n(O)4−n]-type (n=1–4) and Their Circular Dichroism Spectra
Authors: Nakayama Kazuhiko , Komorita Takashi , Shimura Yoichi
Published: July 2006

A large number of mixed-ligand [Pd(N)n(O)4−n]-type complexes (n=1–4) which contain at least one optically active ligand were synthesized and isolated in a systematic manner. (S)-Propylenediamine, (2S)-N1,N1-diethyl-1,2-propanediamine, and (S)-amino carboxylates were employed as one ligand, which is optically active; ammonia, diamines, amino carboxylates, acetates, and dicarboxylates as the other ligand occupying the remaining coordination sites. Isomerism could be detected in the mixed complexes of an unsymmetrical diamine and an amino carboxylate and has been discussed on the basis of 13C NMR and CD spectra. Moreover, the influence of optically inactive ligands on the vicinal CD spectra has been examined, and also the additivity of vicinal CD contributions of two different optically active ligands has been demonstrated.