bluuebunny/crossref_metadata_2025 huggingface dataset:
Jasmonoid Synthesis from sci-4-Heptenoic Acid
Authors: Sato Toshio , Kawara Tatsuo , Sakata Kazumi , Fujisawa Tamotsu
Published: July 2006

Jasmonoids with cis-2-pentenyl side chain such as cis-jasmone, methyl jasmonate, and jasmolone were easily synthesized from cis-4-heptenoic acid obtained by the ring opening reaction of β-propiolactone with di-cis-butenylcuprate.
Synergistic Solvent Extraction of Alkali Metal Picrates by Crown Ethers
Authors: Takeda Yasuyuki
Published: July 2006

The solvent extraction of rubidium and caesium picrates has been studied between benzene and water at 25 °C in the presence of tributyl phosphate (B), 12-crown-4 (12C4), 15-crown-5 (15C5), or both B and 15C5, and the complex-formation constants for the synergistic reactions in the benzene solution have been calculated. For both rubidium and caesium, the sequences of the complex-formation constants for these ligands are B<12C4<15C5, indicating that the complex-formation constant increases with an increase in the number of the donor oxygen atoms of the ligand. The complex-formation constant of rubidium is greater than that of caesium in every system.
The Solubility Curves of Water in Normal Alkane Derivatives with a Polar Group
Authors: Nishino Nobuo , Nakamura Masao
Published: July 2006

Measurements were made of the solubility vs. temperature curves of water in normal alkane derivatives: alkanols, alkylamines, and alkanoic acids. The solubility of water increases monotonically with an increase in the temperature in alkanols and alkanoic acids, while it decreases in alkylamines. The solubility is so great that it often exceeds 1/2 in the mole fraction scale. Phase diagrams were constructed by combining such solubility curves with the solubility curves of these substances in water. The heat of solution at an infinite dilution vs. the temperature for 1-butanol in water is obtained by taking account of the activity coefficient of 1-butanol in its own phase.
Steady-state and Picosecond Studies of Energy Transfer between Dyes with Closely Located S1-Levels. Rhodamine-6G and 3,3′-Diethyl-thiacarbocyanine Iodide in Acetone Solution
Authors: Kusumoto Yoshihumi , Sato Hiroyasu , Maeno Kazuto , Yahiro Shuichi , Nakashima Nobuaki
Published: July 2006

Lasing wavelengths and fluorescence spectra were measured for a mixed dye system containing various concentrations of Rhodamine 6G (Rh-6G) and 3,3′-dietriylthiacarbocyanine iodide (DTC), which have very closely located S1 levels, in acetone at room temperature. A new way of confirming the occurrence of energy transfer is presented on the basis of the reabsorption effect. It was found that most of the pump power absorbed by Rh-6G is transferred to DTC. A study of the fluorescence decay by a picosecond laser revealed that the energy transfer is essentially governed by the Förster mechanism. The observed fluorescence decay data agree fairly well with the R0 value of 73.2 Å calculated from the spectral overlap.
Liquid-Liquid Extraction and Separation of Lanthanum (III)
Authors: Langade A D , Shinde V M
Published: July 2006

Separation of lanthanum(III) from iron(III), molybdenum(VI), vanadium(V), chromium(VI), titanium(IV), bismuth(III), zirconium(IV), scandium(III), uranium(VI), and beryllium is achieved by solvent extraction with mesityl oxide from sodium salicylate solution (0.1 M adjusted to pH 7). Lanthanum from the organic phase is stripped with water and determined photometrically as its arsenazo complex at 570 nm. The extracted species is trisolvated i.e. La(HOC6H4COO)3·3MeO. The results of separation are reported.
The Selective Preparation of N-Acylindigo
Authors: Omote Yoshimori , Fujiki Kiyoko , Awano Hiroshi , Kubota Ikuo , Nishio Takehiko , Aoyama Hiromu
Published: July 2006

The hitherto unknown N-acylindigo has been selectively prepared by heating the corresponding known N,N′-diacylindigo in aqueous pyridine. The data of N-acetyl, N-benzoyl, N-(p-toluoyl), N-(p-chlorobenzoyl), N-(p-nitrobenzoyl), and N-(3,5-dinitrobenzoyl)indigo are summarized.
Reaction of Allyl Diphenyl Phosphates with Soft Bases
Authors: Araki Shuki , Minami Kazuhiro , Butsugan Yasuo
Published: July 2006

The title phosphates were found to react with a variety of soft bases to give nucleophilic substitution products in high yields. The reaction proceeded regiospecifically under mild reaction conditions with preservation of the double bond geometry.
A Method for Independent Determination of Equilibrium Constant and Molar Absorptivity of Molecular Complexes from Spectrophotometric Data
Authors: Seal Bejoy Kumar , Sil Harideb , Banerjee Manas , Mukherjee Dulal Chandra
Published: July 2006

Two separate equations, one cubic in K and the other quadratic in ε, have been developed for calculating K and ε of molecular complexes independently of each other. The equations on testing with various spectrophotometric data yielded values of K and ε which agree with those obtained by others using well known procedures.
Negative Ions Formed by Vacuum Spark Discharge. II. Relative Sensitivity Coefficients for Negative Ions of the Elements Contained in Compressed Aluminium Powder Electrodes for Spark Source Mass Spectroscopy
Authors: Kishi Hiroshi
Published: July 2006

The relative sensitivity coefficients for negative ions of 15 elements contained in compressed aluminium powder electrodes were measured by spark source mass spectroscopy. The relative sensitivity coefficients for the halogens and group VIB elements were found to be the largest, the difference of relative sensitivity coefficients between the elements being larger than in the case of positive ion relative sensitivity coefficients. The logarithm of the relative sensitivity coefficients of negative ions are linearly correlated to the electron affinities of the elements.
The Polarized Spectra and Thermal Diffusivity of Brown Tourmaline as Studied by Photoacoustic Spectroscopy
Authors: Sugitani Yoshinori , Fujinami Masahisa
Published: July 2006

The strong pleochroic band of brown tourmaline at around 24000 cm−1 in the E⊥ c photoacoustic spectra was assigned to d-d(6A1→4A1, 4E) transition of Fe and to charge transfer of Ti, that in the E//c spectra being entirely assigned to charge transfer of Ti. The analysis of the photoacoustic signal intensity vs. chopping frequency gave the thermal diffusivity constant of tourmaline as α=0.15 cm2/s.
The Mechanism of the Hydrolysis of Polyphosphates. V. The Effect of Cations on the Hydrolysis of Pyro- and Triphosphates
Authors: Watanabe Makoto , Matsuura Makoto , Yamada Tamotsu
Published: July 2006

The effect of cations on the rate of hydrolysis of pyro- and triphosphates was studied by adding metal chloride to aqueous solutions of the phosphates. The concentrations of the phosphates and metal chlorides were 0.025 and 0.1 mol dm−3 respectively. Alkali metal, alkaline earth metal, aluminium, and some transition-metal (Mn(II), Co(II), Ni(II), Cu(II), and Zn(II)) cations retarded the hydrolysis of the phosphates in acidic media. The following sequence of efficiency resulted:

trivalent>bivalent>univalent.

The efficiency of elements within one group of the periodic table decreased from top to bottom. On the other hand, in alkaline solutions, alkali metal cations accelerated the hydrolysis of the phosphates and the catalytic effectiveness decreased with an increase in the ionic radius.
Mechanism of the Reaction of Nitriles with Alkaline Hydrogen Peroxide. Reactivity of Peroxycarboximidic Acid and Application to Superoxide Ion Reaction
Authors: Sawaki Yasuhiko , Ogata Yoshiro
Published: July 2006

Formation of peroxycarboximidic acid (1) is not rate-determining in the reaction of nitrile with alkaline hydrogen peroxide to form amide and oxygen; the yield of amide based on H2O2 varies from 20 to 60%. When dimethyl sulfoxide (DMSO), a reactive substrate, is added, the rate is independent of [DMSO] and governed in turn by a rate-determining addition of HOO− to nitrile. This reaction gives a reliable α-value of kHOO−/kHO−, which is 10000 for benzonitrile. A facile conversion of nitrile to amide may be achieved by the reaction in the presence of DMSO, unaccompanied by side reactions such as the epoxyamide formation from α,β-unsaturated nitrile. Kinetics and product analysis suggest that a predominant reaction is not a non-radical oxidation of H2O2 with 1 but a radical decomposition of H2O2 which is induced by the homolysis of anion of 1 (1A). No singlet oxygen could be trapped chemically. The reaction of superoxide ion, O2\ewdot, with acetonitrile is shown to be analogous to that of HOO−; the decomposition of O2\ewdot is fast in the presence of MeCN and DMSO in benzene, affording acetamide and dimethyl sulfone.
New Synthetic Route for the Preparation of 4-Phenylthio-4-butanolide Derivatives by the Use of the Pummerer Rearrangement
Authors: Watanabe Mikio , Nakamori Seijin , Hasegawa Hatsue , Shirai Kozo , Kumamoto Takanobu
Published: July 2006

The Pummerer rearrangement reaction of 2- or 3-substituted 4-(phenylsulfinyl) butyric acids in the presence of an excess amount of acetic anhydride and a catalytic amount of p-toluenesulfonic acid in refluxing toluene for 1 h afforded 2- or 3-substituted 4-phenylthio-4-butanolide (17a–f). Thermolysis in pyridine of 4-phenylsulfinyl 4-butanolides, which were prepared by oxidation of 17a–f, afforded 2- or 3-substituted 2- or 3-buten-4-olides.
Acylchlorination and Related Reactions of Fluoroethenes Using AlCl3 and FeCl3
Authors: Ishikawa Nobuo , Iwakiri Hiroshi , Edamura Kazuya , Kubota Satoshi
Published: July 2006

Acylchlorination of mono-, 1,1-di-, and trifluoroethenes with carboxylic acid chlorides using AlCl3 and FeCl3 as a Lewis acid was investigated. In AlCl3-catalyzed reactions, fluorine-chlorine exchange reaction always occurred in part, while in FeCl3-catalyzed reactions Claisen-type condensation giving β-diketones was observed. Preparations of 2-chloro-2-fluoroethyl, 2-chloro-2,2-difluoroethyl, and 2-chloro-1,2,2-trifluoroethyl ketones are given.
Crystal Structures of Mixed Ligand Copper(II) Complexes Containing l-Amino Acids. II. (l-Alaninato)aqua(l-histidinato)copper(II) Trihydrate
Authors: Ono Taizo , Sasada Yoshio
Published: July 2006

Copper(II) complex containing l-alanine and l-histidine crystallizes from aqueous solution at pH 7.0. Crystals of (l-alaninato)aqua(l-histidinato)copper(II) trihydrate are monoclinic, space group P21  a=10.980(4), b=7.362(3), c=9.700(2) Å, β=101.45(3)°, and Z=2. There is some disorder for the location of three water molecules of crystallization. Four coordinating atoms in an approximately planar arrangement around copper are the α-amino nitrogen and imidazole δ-nitrogen of l-histidine, and α-amino nitrogen and α-carboxyl oxygen of l-alanine. They take a cis conformation with respect to the amino groups. The axial site is occupied with oxygen atom of water, so that the coordination geometry is square-pyramidal. Similarity and difference are discussed in comparison with the coordination mode in copper complexes containing l-histidine and l-asparagine.
Near-infrared Magnetic Circular Dichroism Studies on Iron(III) Horse Heart Cytochrome c
Authors: Kobayashi Nagao , Nozawa Tsunenori , Hatano Masahiro
Published: July 2006

Magnetic circular dichroism (MCD) spectra in the near-infrared region reported first for oxidized cytochrome c in its neutral (pH 5.58), alkaline (pH 11.62), and acidic (pH 1.88) forms exhibit temperature dependence, indicating that they are composed of Faraday C terms, except for the acidic form. The relation between the near-infrared MCD and the heme vicinity is discussed in terms of the structures for the heme chromophore of cytochromec.
The 1H NMR Spectra of [(CH3)2 SbCl2(oxine)] in Several Solvents
Authors: Kawasaki Yoshikane , Kinoshita Masahiro
Published: July 2006

The 1H NMR spectra of dichlorodimethyl(8-quinolinolato)antimony(V), [(CH3)2SbCl2(oxine)], were measured in several solvents. Two methyl signals were observed in some aromatic and aliphatic solvents, although only one signal was detected in dichloromethane. The results were explained by the presence of two isomers in solution.
Photoelectrochemical Behavior of Chlorophyll a-Lipid Films on a Platinum Electrode in an Aqueous Electrolyte
Authors: Miyasaka Tsutomu , Fujishima Akira , Honda Kenichi
Published: July 2006

The photoelectrochemical behavior of chlorophyll a-lipid mixed monolayers coated on a platinum electrode by the Langmuir-Blodgett technique was investigated under potentiostatic conditions in an aqueous electrolyte in the absence of redox agents. Under illumination, cathodic photocurrents were observed at electrodes coated with a sufficient number of monolayers. The quantum efficiency of the photocurrent was estimated to be about 10−4, much lower than that obtainable for dye-sensitized photocurrent on semiconductor electrode. The cathodic photocurrent increased with lowering in the pH of electrolyte. The possibility of the photoreduction of water by excited triplet chlorophyll a is discussed on the basis of observed pH dependence and correlation of the redox potentials involved.
The Effect of Propyl Cellosolve on Water Structure Estimated from Ultrasonic Data
Authors: Nishikawa Sadakatsu , Yamashita Yoshihisa , Mashima Mitsuo
Published: July 2006

Ultrasonic absorption and velocity have been measured in aqueous solution of Propyl Cellosolve (ethylene glycol monopropyl ether) in the frequency range of 7.5 to 220 MHz at 25 °C. A single relaxational process has been found and the mechanism has been attributed to the solute-solvent interaction, AB↔A+B. The rate constants obtained are k12=9.6×107 s−1 for the forward and k21=1.3×108 M−1 s−1 for the backward reaction. The effect of the solute on the water structure has been found to act slightly as the water structure promoter and the results have been discussed comparing with those of Butyl Cellosolve solution.
Separation of Selenide Constituents from Selenide Samples Containing Elemental Selenium
Authors: Tamari Yuzo , Hiraki Keizo , Nishikawa Yasuharu
Published: July 2006

The valence state analysis to determine selenide in mixtures of selenide, elemental selenium, selenite, and selenate compounds was devised by the selective volatilization of selenium as its hydride. As the optimum conditions of the reaction, 6 M (this unit is defined to 1 M=1 mol dm−3 as below.) hydrochloric acid solution was dropped into the mixture and the hydrogen selenide gas generated was absorbed in a solution of sodium hydroxide and hydrogen peroxide. The optimal reaction temperature was found to be 170 °C for 40 min using nitrogen as the carrier gas. Utilizing this method, the fluctuation of the oxidation state of selenium was observed during the storage of zinc selenide samples.
Thermal Reactions of Octahedral Nickel(II) Complexes Containing N,N- and N,N′-Dialkylethylenediamines in a Solid Phase
Authors: Ihara Yoshinori , Izumi Eiichi , Uehara Akira , Tsuchiya Ryokichi , Nakagawa Shigeo , Kyuno Eishin
Published: July 2006

Thermal reactions of the [Ni(H2O)2(AA)2]X2·nH2O complexes in a solid phase were investigated, where AA is N,N′-diethylethylenediamine (NN′-deen), N,N-dimethylethylenediamine (NN-dmen), or N,N′-dimethylethylenediamine (NN′-dmen), and where X− is Cl−, Br−, I−, NO3− or ClO4−. By means of thermal analyses and spectral and magnetic measurements in a series of these complexes before and after heating, the following results were obtained. In the case of the NN′-deen complexes, only the perchlorate deaquates to change from octahedral to square-planar, but the other salts, such as the chloride, bromide, iodide, and nitrate, undergo deaquation-anation keeping their octahedral configuration. The deaquation-anation was also observed in the chloride, bromide, and nitrate of the NN-dmen complexes, but the iodide deaquated, and so was transformed from octahedral to square-planar. In the NN′-dmen complexes, only deaquation-anation was detected, irrespective of the anions (Cl−, Br−, I−, and NO3−). The effects of N-substituents in the diamines and the anions on the above transformation were discussed.
Studies on Characteristics of Electron Capture Responses. VI. A Consideration on the Response Mechanism of the Electron Capture Detector
Authors: Takeuchi Masahiro
Published: July 2006

In order to improve the understanding of the electron capture detector (ECD), a study on the response mechanism has been carried out by using the pulse sampling technique. The ECD currents in the presence and the absence of electron capturing molecules were measured under various pulse conditions. The responses of the ECD probably arise from the current drop based on the slower electron drift velocity in the presence of electron capturing molecules than that in the absence of them.
The Transition Metal-catalyzed N-Alkylation and N-Heterocyclization. A Reductive Transformation of Nitroarenes into (Dialkylamino)arenes and 2,3-Dialkyl-substituted Quinolines Using Aliphatic Aldehydes under Carbon Monoxide
Authors: Watanabe Yoshihisa , Suzuki Naoki , Tsuji Yasushi , Shim Sang Chul , Mitsudo Take-aki
Published: July 2006

The catalytic N-alkylation and N-heterocyclization of nitroarenes occur at 180 °C under a carbon monoxide pressure of 70 atm and in the presence of aldehyde and such transitionmetal complexes as rhodium and palladium complexes, thus giving 2,3-dialkyl-substituted quinolines and (dialkylamino)arenes in good yields. The product selectivity depends greatly on the catalysts: a binary catalyst, RhCl(PPh3)3 and PdCl2, is effective for the N-heterocyclization, while [Rh2Cl2(cod)2] is effective for the N-alkylation.
The Replacement of Electronegative Substituents by an Electron-transfer Mechanism. The Factors Governing the Reaction of Carbonyl and Imino Compounds with Organomagnesium Reagents
Authors: Okubo Masao , Uematsu Yumiko
Published: July 2006

For the purpose of studying the electron-transfer initiated replacement of ortho-methoxy and ortho-halogeno substituents of diaryl ketone anils by the aryl group of ArMgBr, eight anils were prepared. The expected o-methoxy replacement by the phenyl group of PhMgBr, however, was extremely slow, and no o-chloro replacement took place. In contrast, anils of 1-substituted (MeO, Br, Cl) fluorenones gave the replacement products: The distribution of by-products formed via radical pathway in the cases of halogeno-anils was clearly different from that in the case of the methoxy-anil. In the reaction with ArN(MgBr)2, 1-halogenofluorenones afforded the normal condensation products, while 1-methoxyfluorenone gave the “condensation-replacement” product. On the basis of the characteristic product-distributions obtained in the two organomagnesium reactions, the mechanism of methoxy replacement was distinguished from that of halogen replacement. Factors governing the two reactions were proposed and discussed: The structures of the substrates favorable to spin-delocalization, the electron-accepting ability of the substrates, the electron-donating ability of the reagents, the leaving ability of substituents, and their leaving manner.
Photochemical Electrocyclic Reaction Mechanism of Methyleneamine N-Oxide to Form Oxaziridine. MINDO/3 CI Study
Authors: Kikuchi Osamu , Morihashi Kenji , Suzuki Keizo
Published: July 2006

The photochemical electrocyclic reaction mechanism of methyleneamine N-oxide to form oxaziridine was explored on the basis of the potential energy surfaces obtained by the MINDO/3 CI calculation. The strong interaction between the ground state and the doubly-excited state, which appears in the disrotatory cyclization process of the corresponding hydrocarbon system, was not observed. Instead, a deep potential well, which can be a leakage channel from the excited state to the ground state, was found in the S1 surface. The predicted reaction path is characteristic of hetero-atom conjugated systems, and an important participation of the oxygen σ lone-pair electrons is expected in this reaction path.
New Building Blocks for Heterocyclic Syntheses. Silylated Methyl Isothiocyanates
Authors: Hirao Toshikazu , Yamada Atsushi , Hayashi Ken-ichiro , Ohshiro Yoshiki , Agawa Toshio
Published: July 2006

Trimethylsilylmethyl isothiocyanate, bis(trimethylsilyl)methyl isothiocyanate, and tris(trimethylsilyl)methyl isothiocyanate were prepared. The fluoride-catalyzed reaction of trimethylsilylmethyl isothiocyanate with aldehydes or ketones afforded oxazolidine-2-thione derivatives, which involves the isothiocyanato carbanion as an intermediate. Imidazolidine-2-thiones were similarly prepared from imines. The reaction of bis(trimethylsilyl)methyl isothiocyanate with benzaldehyde in the presence of a catalytic amount of n-Bu4NF gave styryl isothiocyanate and 5-phenyl-4-trimethylsilyloxazolidine-2-thione. On the similar treatment of tris(trimethylsilyl)methyl isothiocyanate, 4-benzyl-5-phenyl-4-oxazoline-2-thione, and α-(trimethylsilyl)styryl isothiocyanate were obtained.
Gas-chromatographic Measurements of Dinitrogen Oxide in Air
Authors: Muramatsu Hisafumi , Hirota Michio , Makino Yukio
Published: July 2006

To obtain an average tropospheric mixing ratio of dinitrogen oxide over Japan, 90 air samples were collected by aircraft at altitudes up to 7 km from Autumn, 1978, to Spring, 1979, and were analysed by the GC-ECD method. The mean volume-mixing ratio of N2O was 0.310 ppm, and the standard deviation was 0.014 ppm. These results show that the tropospheric N2O is well mixed and that its mixing ratio is higher than 0.30 ppm.
The Thermal Decomposition of N,O-Diacyl-N-t-butylhydroxylamines. III. Novel Routes to 2-Substituted 1,2-Benzisothiazol-3-(2H)-ones
Authors: Uchida Yuzuru , Kozuka Seizi
Published: July 2006

The reactions of N-alkyl- and N-aryl-2-(methylsulfinyl)benzamides and N-[2-(methylthio)benzoyl]-N-alkylhydroxylamines with thionyl chloride have been found to give 2-substituted 1,2-benzisothiazol-3(2H)-ones in nearly quantitative yields. The reactions of N-[2-(methylthio)benzoyl]-N-arylhydroxylamines with thionyl chloride gave chlorinated anilides as the major products.
Synthesis of Phytuberin
Authors: Murai Akio , Ono Mitsunori , Masamune Tadashi
Published: July 2006

The first synthesis of phytuberin, which mimics the proposed biogeneses in critical stages, is described. The synthesis also establishes the absolute configuration.
Upon DNP-aromatic Rule. Effect of Introducing a Methyl Group to the β-Position upon the CD Spectra of DNP Derivatives of Aromatic α-Amino Acids
Authors: Kawai Masao , Nagai Ukon , Tanaka Atsuko
Published: July 2006

CD spectra of N-DNP-O-benzoyl derivatives of l-serine, l-threonine, and l-allothreonine and DNP derivatives of l-phenylalanine and (βR)- and (βS)-β-methyl-l-phenylalanines were studied. The effect of methyl substitution at the β-position upon their CD spectra was explained by the change in the population of the rotamer g− (χ1=−60°) which was shown to be responsible for the characteristic negative Cotton effect at ≈400 nm. The negative sign of the [θ]≈400max values of the DNP derivatives of aromatic l-α-amino acids described by DNP-aromatic rule was proved to be due to the contribution of the rotamer g−.
A Convenient Method for Preparation of 2-(Methylthio)alkanoic Acids and Their Related Compounds Using the Carbanions of Substituted Malonic Esters
Authors: Ogura Katsuyuki , Itoh Hiroshi , Morita Toshio , Sanada Kunio , Iida Hirotada
Published: July 2006

Starting from alkyl- or aryl-substituted malonic esters prepared by various methods, 2-(methylthio)alkanoic acids are synthesized by successive treatment with sodium ethoxide and with S-methyl methanethiosulfonate, followed by alkaline hydrolysis which causes concurrent decarboxylation. Production of 2-(phenylthio)alkanoic acids is also achieved in a similar manner.
Mass Spectra of Furanoeremophilane Derivatives
Authors: Nagano Hajime , Kuroda Chiaki , Moriyama Yoshihiko , Tsuyuki Takahiko , Takahashi Takeyoshi
Published: July 2006

Mass spectral fragmentations of furanoeremophilane derivatives bearing oxygen-function on B ring were investigated. It was found that mass spectra measured by direct inlet system gave characteristic retro-Diels-Alder fragmentations, while indirect introduction of the samples afforded intense peaks at m/e 159 and m/e 145 containing the furan moiety. Fragmentation patterns of other poly-functional derivatives were examined by measurements of accurate masses and metastable ions.
Effects of Mechanical and Electrical Anharmonicities on Local Mode Spectrum
Authors: Tamagake Keietsu , Hyodo Shi-aki , Fujiyama Tsunetake
Published: July 2006

The first and second order dipole moment parameters along the CH bond in benzene, chloroform, and cyclohexane were obtained by deducing the local mode intensities on the basis of the one-dimensional Morse oscillator model. The validity of the one-dimensional model is discussed according to a newly introduced formula which helps us to understand the nature of local mode absorptions. The relative intensities of the first overtones to the other bands were found to be crucially important in determining M2/M1 together with its sign, because the contributions of the mechanical and electrical anharmonicities to M1/M2 are often cancelled out each other accidentally. The M2/M1 values for benzene, cyclohexane, and chloroform were 2.3, 1.45, and −0.93 Å−1 respectively. These values for benzene and cyclohexane were excellently reproduced by the ab initio calculations for benzene and methane respectively.
Salting-out Phenomenon and Clathrate Hydrate Formation in Aqueous Solution of Polar Nonelectrolyte
Authors: Kato Tadashi , Yudasaka Masako , Fujiyama Tsunetake
Published: July 2006

The Salting-out Phenomenon has been carefully observed by adding ammonium chloride into aqueous solutions of t-butyl alcohol, acetone, dioxane, and 2-butoxyethanol. The experimental results have been well explained by considering the formation of a clathrate hydrate-like local structure in the aqueous solution of each nonelectrolyte. In addition, the role of the chloride ion has been found to be the promotion of the aggregation of the clathrate hydrate-like local structures. The line-width measurement of 35Cl-NMR spectra has been shown to be an extremely powerful method for studying the state of mixing of ions in solutions.
An Ion-impact Study of Singlet-Triplet Transitions in Ethylene and Alkyl-substituted Ethylenes
Authors: Sato Yukinori , Satake Kazuki , Inouye Hokotomo
Published: July 2006

The T←N (π→π*) transitions in ethylene, all of its methyl derivatives, and 1-butene were observed by means of He+-impact energy-loss spectroscopy. With a resolution of better than 0.1 eV, a vibrational structure was just resolved in the T←N excitation spectrum of ethylene. The T←N transition energy was measured for the alkylethylenes with a lower resolution. The results are in good agreement with the electron-impact data, indicating that the vibro-rotational excitation due to the impulsive momentum transfer is negligible in the present method. The T←N excitation cross-sections were found to decrease by half upon the unit substitution of alkyls. The relative invariance of the T←N transition energy and the decrease in the T←N cross-sections upon alkyl substitution may be attributable to the decrease in the intra- and intermolecular Coulomb and exchange interactions between π- and π*-orbitals.
The Raman Spectra of Cobalt(III) Complexes. IV. Differentiation between cis and trans Isomers of Bis(trimethylenediamine)cobalt(III) Complexes
Authors: Kanamori Kan , Ichinose Hiroko , Kawai Kiyoyasu
Published: July 2006

The Raman and the infrared spectra of bis(trimethylenediamine)cobalt(III) complexes have been studied to establish a definite distinction between the cis and trans isomers. A differentiation between the isomers can be made on the bases of the number of the Raman bands in the region of 480–550 cm−1 and of the mutual exclusion in the region of 400–500 cm−1.
Calculation of the Pair Correlation Functions for Fluids Composed of Diatomic Polar Molecules Based on the Interaction Site Model
Authors: Ohba Masaharu , Arakawa Kiyoshi
Published: July 2006

A reference hypernetted chain (RHNC) like approximation of the interaction site model is proposed, which is the extension of Lado’s RHNC equation of simple fluids to the case of molecular fluids. By using the proposed RHNC like integral equation, pair correlation functions, structure factors and some thermodynamic quantities for fluids composed of diatomic polar molecules are calculated, where the molecules consist of two fused hardspheres with each center located at a distance l, and at each center charges +q and −q are sited. Calculated pair correlation functions are successful in showing well-marked characteristics of the fluid, such as cusps, not observed for simple fluids like argon. The isothermal compressibility at a constant reduced density and dipole moment has a weak l-dependence in sharp contrast to the total internal energy showing a strong l-dependence.
Effect of Polar Group on the Polypeptide–Lipid Interaction at the Air-Water Interface
Authors: Shibata Akira , Yamashita Shinsuke , Yamashita Takuya
Published: July 2006

The effect of polar group on the interaction of synthetic polypeptides with lipids at the air-water interface was investigated. Methyl stearate interacts with benzyloxycarbonyl derivative of basic poly(α-amino acid) or benzyl ester of acidic poly(α-amino acid) on distilled water and KF, KSCN, and urea subsolutions. No interaction between polypeptide and stearamide on various subsolutions was observed except for the mixed system of stearamide with benzyl ester of acidic poly(α-amino acid) in α-helical conformation. The components in mixed monolayers exhibit characteristic miscibilities depending upon the flexibility of polymer side chain, the conformation of polymer and the steric factor of head group in lipid molecules. All of the mixed polypeptide–lipid monolayers spread on the subsolution containing SCN− as a breaker of water structure become miscible. The dipole-dipole interaction between stearamide and benzyl ester of acidic poly(α-amino acid) in α-helical conformation is weakened by the action of urea.
Isomerism of the Metal Complexes Containing Multidentate Ligands. IX. Structure of the meso Isomer of [Co(hexaen)]3+ (hexaen=1,4,7,10,13,16-Hexaazacyclooctadecane)
Authors: Yoshikawa Yuzo , Toriumi Koshiro , Ito Tasuku , Yamatera Hideo
Published: July 2006

The crystal and molecular structure of meso-[Co(hexaen)]Cl3 has been determined by single crystal X-ray diffractometry. The crystals are rhombohedral with space group R\bar3, a=9.2976(10), c=16.851(2) Å, and Z=3. The structure has been refined by least-squares calculations to an R value of 0.021 for 952 observed reflections. The complex ion has S6 symmetry. The Co–N distance is 1.9966(8) Å and the N–Co–N angle in the chelate ring is 83.62(3)°. The molecular dimensions are in good agreement with those obtained from the conformational analysis.
The Sensitization Effect in the Laser-induced Infrared Fluorescence Spectroscopy by Addition of a Second Component. II
Authors: Kagawa Yasuhiro , Higuchi Seiichiro , Tanaka Shigeyuki
Published: July 2006

A considerable degree of the sensitization is realized in the laser-induced infrared fluorescence spectra when some of the alkene compounds are mixed with an objective sample in the gas phase. This sensitization effect has been examined quantitatively for diethyl ether when ethylene or propylene is added as a second component. The 8.7 μm band of ether is used as a key band. The degree of sensitization is abruptly enhanced with lowering the concentration of diethyl ether, and at about 0.1 Torrt of the sample the intensities per unit concentration become about 150 and 50 times greater for ether–ethylene and ether–propylene systems, respectively compared with that without ethylene or propylene. A possibility of a new vibrational spectroscopy with high sensitivity and its applications to microanalysis are suggested.
Preparation, and Structural and Spectroscopic Characterization of Cobalt(III) Phosphine Complexes of the Type, [Co(CN)4−2n(acac)n(P)2](n−1)+ (acac=Acetylacetonate Ion, n=0,1,2, and P=P(CH3)x(C6H5)3−x, x=0,1,2,3)
Authors: Kashiwabara Kazuo , Katoh Katsuaki , Ohishi Tomoji , Fujita Junnosuke , Shibata Muraji
Published: July 2006

A series of the complexes, [Co(CN)4−2n(acac)n(P)2](n−1)+ (acac=acetylacetonate ion, P=P(CH3)x(C6H5)3−x) and several related complexes were prepared. For [Co(acac)2(P)2]+, the P(CH3)3 and P(CH3)(C6H5)2 complexes afford only the cis and the trans isomers, respectively, while the P(CH3)2(C6H5) complex forms both cis and trans isomers. No P(C6H5)3 ligand gave the bis(acac)-type complex. The trans isomers show a strong absorption band in the region of the first absorption band, which is assumed to involve charge transfer transitions between the cobalt(III) ion and a phosphine, while the cis isomers give usual absorption spectra, exhibiting the first d-d absorption band of medium intensity. The methyl and phenyl groups on a phosphorus atom in both cis and trans isomers show triplet signals in the 1H and 13C NMR spectra due to virtual coupling. A trans(P,P) configuration was assigned to all the complexes of [Co(CN)2(acac)(P)2] on the basis of the NMR and electronic spectra. For [Co(CN)4(P)2]−, a trans configuration was assigned from the electronic spectra.
Synthesis of Biotin-containing Peptides Representing the Biotin Binding Site of E. coli Acetyl–CoA Carboxylase
Authors: Kondo Hiroki , Moriuchi Fumio , Sunamoto Junzo
Published: July 2006

Two biotin-containing peptides, Ac–Met–Bct–Met–Met–OMe (1) and Boc–Met–Bct–Met–Met, that correspond to the local sequence of biotin carboxyl carrier protein subunit of E. coli acetyl–CoA carboxylase have been synthesized. The precursor tetrapeptide Boc–Met–Lys(Cbz)–Met–Met–OMe was prepared first by the stepwise elongation method and biotin was incorporated subsequently by the active ester method. Another biotin-containing peptide, HCO–Met–Bct–Met–Met–OMe, has also been prepared. Magnesium ion binding to peptide 1 in acetonitrile has been studied by means of 13C NMR spectroscopy. The metal interacts principally with the amide carbonyls rather than sulfide moieties, as deduced from a significant downfield shift of the former carbon signals in 13C NMR.
The Biosynthesis of Protoanemonin in Ranunculus glaber. The Pivotal Biosynthetic Intermediate and the Stereospecific Hydrogen Elimination from the Intermediate
Authors: Suga Takayuki , Hirata Toshifumi
Published: July 2006

The pivotal biosynthetic intermediate directly leading to protoanemonin was established to be 2-oxoglutarate on the basis of the labeling patterns in protoanemonin biosynthesized from sodium acetate-1-14C, sodium malonate-2-14C, sodium succinate-2,3-14C2, sodium glutamate-5-14C, and sodium 2-oxoglutarate-5-14C by Ranunculus glaber. Also the 3H/14C ratio in protoanemonin biosynthesized from (3R)-2-oxoglutaric-3-3H1-3,4-14C2 and 2-oxoglutaric-3-3H2-3,4-14C2 acids demonstrated that the formation of the double bond at the 3-position of protoanemonin involves the stereospecific elimination of the pro-3S hydrogen atom from 2-oxoglutaric acid.
The Total Syntheses of (−)-Occidentalol and Its C7-Epimer. The Stereochemical Assignment of (+)-Occidentalol
Authors: Ando Masayoshi , Asao Toyonobu , Nakagawa Toru , Nanaumi Ken , Takase Kahei
Published: July 2006

The total syntheses of (−)-occidentalol and its C7-epimer are reported with the object of establishing the structure of naturally occurring (+)-occidentalol.
A Convenient Synthesis of 4- and 5-Acetyltropolone
Authors: Yamamoto Hiroshi , Hara Atsushi , Noguchi Ayashi , Kawamoto Heizan , Inokawa Saburo , Nozoe Tetsuo
Published: July 2006

4-Acetyltropolone is derived from hinokitiol (β-thujaplicin) in four steps, with an overall yield of 60%, via readily available 8-azidohinokitiol. γ-Thujaplicin almost quantitatively forms its difluoroboron complex, which, upon bromination, provides an 85% yield of the 8-bromo-γ-thujaplicin difluoroboron complex. This bromo compound readily gives γ-dolabrin (87% with triethylamine) and 8-azido-γ-thujaplicin (88% with sodium azide), from which 5-acetyltropolone is derived in an 80% yield by ozonolysis or in a 40% yield with sulfuric acid. The considerable differences in the reactivities observed between these 4- and 5-substituted tropolones are discussed. The pKa values of 4- and 5-acetyltropolone and 4- and 5-(3,4,5-trimethoxycinnamoyl)tropolones are also reported.
Electron Spin Resonance Studies of Manganese(II) Doped in Cd(NH3)2Ni(CN)4·2C6H6. Angular and Temperature Dependency of Fine Structures
Authors: Nakano Taku
Published: July 2006

ESR measurements on Mn(II) ion doped in single crystals of Cd(NH3)2Ni(CN)4·2C6H6 confirmed the structure of the Hofmann-type clathrate predicted before. Spin Hamiltonian parameters obtained are g=2.0033±0.0010, A=(−84.9±1.0)×10−4 cm−1 (123 K) and (−84.3±1.0)×10−4 cm−1 (room temp), D=(67.5±1.0)×10−4 cm−1 (123 K) and (17.3±1.0)×10−4 cm−1 (room temp), and a=(16.5±1.0)×10−4 cm−1. The environment of Mn(II) ion has a tetragonally distorted cubic symmetry. While the parameter a is independent of temperature, the parameter D is found to be dependent on temperature obeying to D∝(T0–T)2 where T0 is 473 K. The nuclear forbidden lines, Δm=±1, were also detected, intensities of which vary in terms of D squared.
Solvent Effect on the Nonradiative Deactivation of the Excited State of Tris(2,2′-bipyridyl)ruthenium(II) Ion
Authors: Nakamaru Katsumi
Published: July 2006

Emission quantum yields and lifetimes of the [Ru(bpy)3]2+ ion were measured in various solvents at 25 °C. Nonradiative rate constants (knr) were calculated from these data. A plot of knr  vs. the Gutmann’s acceptor number was found to be linear. This result can be explained in terms of the contributions of charge transfer to solvent (CTTS).
Studies of Aromatic Sesquiterpenes. III. The Synthesis of 4-Methoxyisocadalene
Authors: Adachi Kazuo , Taniguchi Naoki
Published: July 2006

Starting from p-cresol, the title sesquiterpene was synthesized through 4-methoxy-1,6-dimethylnaphthalene as a key intermediate.
Chemical Property of 1-Dialkylamino-2-phenylthioethylene
Authors: Agawa Toshio , Ishikawa Minori , Komatsu Mitsuo , Ohshiro Yoshiki
Published: July 2006

The olefins which are vicinally substituted by amino and phenylthio groups showed the reactivity as an enamine in the reactions with heterocumulenes and in cycloadditions with a 1,3-dipole and a 2-propenimine, giving a pyrazole derivative and a pyridine derivative, respectively.
Photocatalytic Dehydrogenation of 2-Propanol over TiO2 and Metal/TiO2 Powders
Authors: Teratani Shousuke , Nakamichi Junichi , Taya Kazuo , Tanaka Kazunori
Published: July 2006

A series of TiO2 catalysts loaded with transition metals were prepared by photodeposition. The activity order for these catalysts in the title reaction was as follows: Pt/TiO2>Rh/TiO2>Pd/TiO2>Ru/TiO2>Ir/TiO2>TiO2. Upon heat treatment the activities of all the metal/TiO2 catalysts were enhanced, but the above sequence was unaltered.
Liquid Crystal Formation in Binary Systems. V. Liquid Crystals Induced in N-[4-(Dimethylamino)benzylidene]-4-ethoxyaniline-N-(4-Nitrobenzylidene)-4-nitroaniline and Related Mixtures
Authors: Araya Kotaro , Matsunaga Yoshio
Published: July 2006

The induction of liquid crystals was demonstrated with binary mixtures comprising N-(4-nitrobenzylidene)-4-nitroaniline and N-[4-(dimethylamino)benzylidene]-4-alkoxyaniline or N-(4-alkoxybenzylidene)-4-(dimethylamino)aniline. Both nematic and smectic phases were observed with the ethoxy derivatives, but only a smectic A phase with the propoxy derivatives. The mesophases appear in the region centered around 30 mol% of the dinitro compound. Similarly, liquid crystals could be induced in several mixtures of N-[4-(dialkylamino)benzylidene]-4-(dialkylamino)aniline with N-(4-nitrobenzylidene)-4-alkoxyaniline or N-(4-alkoxybenzylidene)-4-nitroaniline. The bis(dialkylamino) and dinitro derivatives of azoxybenzene were also shown to be efficient as one of the component compounds in producing binary liquid crystals.
Selective Reduction of Nitrogen Monoxide with Hydrogen on Pt/Al2O3 Containing a Metal Oxide
Authors: Kosaki Yukio , Miyamoto Akira , Murakami Yuichi
Published: July 2006

By using a three-way catalyst containing a metal oxide, NO can be selectively converted to N2 and N2O without the formation of NH3 even at the “rich” side of the air/fuel ratio. In order to elucidate the mechanism of this action of the added metal oxide, the NO–H2 reaction on Pt–V2O5/Al2O3 catalyst was investigated using the pulse reaction technique. In the NO–H2 reaction on Pt/Al2O3 catalyst, a significant amount of NH3 was formed in the “rich” region of the reactants (H2/NO>1), although NO was completely removed. In the NO–H2 reaction on the Pt–V2O5/Al2O3 catalyst, on the other hand, no NH3 was formed even in the “rich” region of the reactants; in addition, NO was completely removed. During the NO–H2 reaction on the Pt–V2O5/Al2O3 catalyst, the V2O5 in the catalyst was found to be reduced from V5+ to V4+. The reaction of NO with NH3 and the reaction of NH3 or H2 with Pt–V2O5 mixed catalysts for various states of mixing were also investigated. From these results, the NO–H2 reaction on the Pt–V2O5/Al2O3 catalyst has been shown to be composed of the following three main steps: Step I, the formation of NH3 by the reduction of NO with H2 on Pt; Step II, the NO–NH3 reaction on Pt to form N2 or N2O; and Step III, the reduction of V2O5 in the catalyst by H2 which is accelerated by the “hydrogen spil-lover.” In the NO–H2 reaction on Pt/Al2O3 catalyst, NO is first reduced to NH3 in Step I and the NO–NH3 reaction in Step II follows. In the “rich” region, the formation of NH3 takes place more readily than the subsequent NO–NH3 reaction. In the NO–H2 reaction on the Pt–V2O5/Al2O3 catalyst, the formation of excess NH3 is suppressed by the removal of hydrogen from Pt in Step III, and the NH3 thus produced reacts with NO to form N2 or N2O selectively in Step II. The rates of Steps I, II, and III were also discussed in terms of the structure of the catalysts and composition of the reactants.
Electric Birefringence and Electric Dichroism of Sonicated DNA in Aqueous Solutions with Various Additives. Electro-optical and Hydrodynamic Properties
Authors: Matsuda Koichiro , Yamaoka Kiwamu
Published: July 2006

Electric birefringence (EB) and electric linear dichroism (ED) of a sonicated DNA (Mw=1.24×105) sample were studied in solutions containing various additives at 7 °C. Signals of EB at 535 nm and of ED at 260 nm were measured in the electric field range 0–ca. 19 kV/cm. Both signals obeyed the Kerr law at low field strengths (E<ca. 5 kV/cm) and showed a saturating trend at high fields. The mean relaxation time, <τ>EB, obtained from the decay of EB, was field-strength dependent, indicating the effect of the polydispersity of sDNA. The field strength dependence of steady-state EB signals was nearly identical with that of ED signals. These results were analyzed with the “classical” orientation functions derived for mono- and polydisperse systems. The optical anisotropy factor (g3–g1) of sDNA was ca. −2.0×10−2, while the average angle between the orientation axis of sDNA and the transition moment of the base pair was ca. 70° at 260 nm. The electric moment of sDNA was influenced by ionic strength, counterions, and other additives. The weight-average length lw of sDNA decreased in this order: 0.2 mM NaCl**>9-aminoacridinium chloride (P⁄D=10)>1.0 mM NaCl>0.33 mM MgCl2> 20 vol% glycerol. Values of lw/base pair were 2.8−2.7 Å in the glycerol and 3.6−3.4 Å in the 1.0 mM NaCl.
Multi-ionic Potential and Membrane Permeability Matrix. I. NaCl–CsCl Bi-ionic System with a Cation Exchange Membrane
Authors: Kaibara Kozue , Kimizuka Hideo
Published: July 2006

This paper is concerned with analysis of membrane transport processes on the basis of nonequilibrium thermodynamics. Inter-ionic correlations between permeating ions are quantitatively estimated by applying the membrane permeability matrix theory to the system in which the NaCl and CsCl solution phases are divided by a highly selective cation exchange membrane. The membrane permeability matrix of the system may be expressed by four ionic correlation terms concerning with Na+ and Cs+. The electroconductive and diffusional membrane permeabilities are expressed as a function of the matrix elements having the dimension of permeating speed of ions. The conductive and diffusional permeabilities as well as the matrix elements are estimated from membrane potential, conductance, and ionic flux data. The external electrolyte concentration dependence of these permeability parameters is discussed. The conductive and diffusional permeabilities considerably differ from each other and their ratio changes with the external electrolyte concentration, whereas the permeability ratio of Na+ to Cs+ is constant. Electroconductive and diffusional characteristics of membrane transport processes are consistently analyzed in terms of the memberane permeability matrix theory.
Kinetic Studies of Spin Trapping Reactions. III. Rate Constants for Spin Trapping of the Cyclohexyl Radical
Authors: Doba Takahisa , Yoshida Hiroshi
Published: July 2006

In order to give a quantitative basis for the spin trapping technique, the spin trapping rate constants for the reactions between commonly-used spin traps and cyclohexyl radicals have been determined. The cyclohexyl radicals were generated by γ-irradiating cyclohexane solutions of the spin traps. The rate constants for nitrosobenzene, nitrosodurene, pentamethylnitrosobenzene, 2,4,6-tri-t-butylnitrosobenzene, and α-phenyl-N-t-butylnitrone at 299 K are 9×107, 1.4×107, 1.6×107, 2.4×104, and 8×103 mol−1 dm3 s−1, respectively. The results are qualitatively in accordance with previous data for t-butyl, 1-methyl-5-hexenyl radicals.
The Estimation of the Liquid-Liquid Distribution Coefficients of Acetylacetone by Means of the Group Solution Theory
Authors: Kato Masanao
Published: July 2006

The estimation of the liquid-liquid distribution coefficients of acetylacetone tautomers was attempted on the basis of the UNIFAC equation, and it was found that the calculated values of the reciprocals of the activity coefficients of tautomers in organic phases were linearly related to the distribution coefficients. It was verified that the estimation by the UNIFAC equation could be extended to the organic solvents with no characteristic parameter.
Electron Spin Resonance and Some Spectral Studies on Coordination Behaviors of Paramagnetic Metal Ions for Chelating Resins
Authors: Nakashima Akira , Isobe Toshiyuki , Tarutani Toshikazu
Published: July 2006

Coordination behaviors of VO(II), Cr(III), Mn(II), Fe(III), Cu(II), and Gd(III) ions for the iminodiacetato group in the chelating ion-exchange resin Dowex A-1 were studied with the aid of ESR, infrared absorption, and M\ddotossbauer spectroscopies. A comparative investigation also was made with the o-hydroxybenzyliminodiacetato group in the chelating resin Unicellex UR-50. The iminodiacetato group in Dowex A-1 is considered to coordinate as a tridentate ligand and form 1 : 1 chelates with metal ions, whereas the o-hydroxybenzyliminodiacetato group in Unicellex UR-50 coordinates as a quadridentate ligand in alkaline media and forms 1 : 1 chelates. Elucidation of spin-spin exchange interaction has led to a conclusion that the iminodiacetato groups present in the coordination pore of Unicellex UR-50 are closer to one another than those of Dowex A-1. For Fe(III) ions adsorbed in concentrated HCl media, besides the species [FeCl4]−, lower symmetric species are considered to be adsorbed with the anion exchange effect, from results of resin phase ESR and Mössbauer spectra.