bluuebunny/crossref_metadata_2025 huggingface dataset:
Electronic Excited States of the Intramolecular Exciplex and Charge-transfer Complex in (9,10-Dicyanoanthracene)(CH2)3-(Naphthalene)
Authors: Itoh Michiya , Mimura Tsutomu , Okamoto Toshihiko
Published: July 2006

In the previous paper two kinds of fluorescences due to the intramolecular exciplex (above ∼200 K) and the charge-transfer complex (below ∼160 K) were reported in a nonpolar solution of the (9,10-dicyanoanthracene)(CH2)3-(naphthalene) systems. The fluorescence quantum yields as well as the fluorescence lifetimes of the exciplex and CT complex determined at several temperatures show a discontinuous change from room temperature to 77 K. The radiative and nonradiative decay constants of these fluorescent states suggest that the radiative decay in the exciplex is comparable with the nonradiative decay, while the nonradiative process is predominant in the excited state of the CT complex.
The Electronic Structures of Cu(II) Complexes as Determined by Means of the Configurational Interaction Method
Authors: Kobinata Shunsuke
Published: July 2006

The electronic structures of Cu(II) complexes with D4h effective molecular symmetry have been investigated by means of the configurational interaction method. The locally-excited configurations of the central metal ion and the charge-transfer configurations corresponding to an electron transfer from the ligand system to the central metal ion have been taken into account. A correspondence with the crystal-field treatment has been obtained using the partitioning technique of solving the secular equation. The energies of the charge-transfer configurations, the resonance integrals, and the electrostatic contribution, Dsion, were determined so as to fit the observed d-d spectra.
Acid Dissociation Constants of Some Histidine-containing Peptides and Formation Constants of Their Metal Complexes
Authors: Yokoyama Akira , Aiba Hiroji , Tanaka Hisashi
Published: July 2006

Glycyl-l-histidine, l-histidylglycine, glycylglycyl-l-histidine, glycyl-l-histidylglycine, and l-histidylglycylglycine were synthesized by the carbobenzoxy azide procedure. The acid dissociation constants of these peptides and their related compounds were determined from the potentiometric titration curves of 0.01 M solutions at 21°C. The dissociation of one ionization group is greatly influenced by the charge on the other groups. The formation constants of metal complexes of l-histidylglycine, l-histidylglycylglycine, and l-3-benzylhistidine were calculated by the least-squares method from the titration curves of the solution containing the ligand (0.01 M) and metal in the molar ratio 2: 1, assuming the formation of 1: 1 and 2: 1 normal complexes (ML+ and ML2), and the results were compared with those of l-histidine-metal complexes. For any metal ion, the order of formation constants was found to be histidine≈3-benzylhistidine>histidylglycine>histidylglycylglycine, in agreement with that of the basicity of amino and imidazole groups. In these metal complexes, metal ion is considered to bind through amino, imidazole, and carboxyl or carbonyl groups of histidine residue.
The Reaction of α-Ethoxybenzyl t-Butyl Peroxide with Grignard Reagents
Authors: Okubo Masao , Sait\={o} Hiroshi , Tomiyoshi Toshiaki
Published: July 2006

Effect of the ethoxyl group of the peroxide in the title was examined. Reactivities of some peroxides having oxygen- and nitrogen-atom adjacent to O-O linkage against magnesium compounds and alkali iodide were compared, and effect of the coordination of heteroatoms to the cationic species was discussed.
Vibrational Spectra and Normal Coordinate Analysis of Bis(methylthio)mercury
Authors: Iwasaki Noriko , Tomooka Jo , Toyoda Koichi
Published: July 2006

The IR and Raman spectra of bis(methylthio)mercury and methyl(methylthio)mercury were studied. Fundamental vibrations were assigned as follows: frequencies 698, 330, 530 and 174 cm−1 to C–S stretching, S–Hg stretching, C–Hg stretching and C–S–Hg bending vibrations, respectively. The fundamental vibrations were confirmed by normal coordinate analysis. The force constants of S–C and S–Hg stretching vibrations were estimated to be 2.16 and 1.5 md/Å, respectively.
A Study of Quenching of Triplets by Ferrocene
Authors: Kikuchi Masae , Kikuchi Koichi , Kokubun Hiroshi
Published: July 2006

Rate constants for quenching of several triplets by ferrocene have been determined in ethanol. Most triplets have been found to be deactivated by ferrocene, yielding no observable transient absorption. The rate constant increases with increasing triplet energy in the range 8000–17000 cm−1. The quenching mechanism has been discussed, the lowest triplet level of ferrocene being estimated to be 15000±1000 cm−1.
Copper(II) Complexes of l-Histidylglycine and l-Histidylglycylglycine in Aqueous Solution
Authors: Aiba Hiroji , Yokoyama Akira , Tanaka Hisashi
Published: July 2006

Equilibrium constants were determined in the complex formations of l-histidylgylcine (HG) and l-histidylglycylglycine (HGG) with copper(II) ion in aqueous solution by potentiometric titration, and the structures of the complexes were discussed based on the observations in the titration and infrared and electronic absorption spectra. In the acid region, a cationic chelate, in which copper(II) binds to nitrogen atoms of amino and imidazole groups, is formed. In the neutral region, deprotonation of the peptide amide group occurs to form a dimer, in which four coordination positions of copper(II) are occupied by nitrogen atoms of deprotonated amide and amino groups and an oxygen atom of carboxyl or carbonyl group in one molecule and a nitrogen atom of imidazole group of another molecule. In HGG–Cu(II) system, the dimer is decomposed in the alkaline region with further deprotonation of the second peptide amide group to form an anionic chelate as in the case of the glycylglycylglycine–Cu(II) complex.
ESR Study on Transient Radicals in Plastic Crystals under
Authors: Shiraishi Hirotsugu , Kadoi Hajime , Hasegawa Kenichi , Tabata Yoneho , Oshima Keichi
Published: July 2006

An apparatus was constructed for ESR measurements during electron irradiation, and the behavior of transient radicals in the plastic crystals of cyclohexane (CyH) and 2,2,3,3-tetramethylbutane (TMB) was investigated. It was found from the experiment that cyclohexyl radical produced by irradiation of CyH decays with a rate constant of 2×10−8 exp (−7.9 kcal/RT) cm3/s. The rate constant is in good agreement with the results reported by Buben et al. On the other hand, radicals formed in irradiated TMB were assigned to be

(Remark: Graphics omitted.)

from the present results. It was shown from the results that the assignment made by Marx et al. before should be corrected to some extent. In the plastic crystals of CyH and TMB, it was suggested that the decay reactions of the observed radicals are controlled by the diffusional migration of the radicals. The analysis of radiolytic products of TMB was also made, and the results were compared with the results of ESR observation.
A Solubility Study of Coacervates of Magnesium, Calcium and Aluminum Highpolyphosphates in Acid Solutions
Authors: Kanazawa Takafumi , Umegaki Takao , Kitajima Y\={o}z\={o} , Ogawa Takeshi
Published: July 2006

Dissolution of the highpolyphosphate coacervates of magnesium, calcium and aluminum was studied in order to understand the conformational feature of polyphosphate chains in the coacervates. Electrical conductivity and viscosity of the coacervate solutions were measured. Paper chromatographic technique was employed for the analysis of the solutions. It was concluded that the polyphosphates dissolve into acid solvents without cleavage of phosphate chains, the degree in the extension of the chains being considerably small. Dissolution processes of the three coacervates were compared. Optimum conditions on the syntheses of the threadforming coacervates are given.
Copper(II) Complexes of Glycyl-l-histidine, Glycyl-l-histidylglycine, and Glycylglycyl-l-histidine in Aqueous Solution
Authors: Aiba Hiroji , Yokoyama Akira , Tanaka Hisashi
Published: July 2006

The complex formation of glycyl-l-histidine, glycyl-l-histidylglycine, and glycylglycyl-l-histidine with copper (II) ion in aqueous solutions containing equimolar amounts of copper(II) and the respective ligand was investigated by potentiometric and visible spectrophotometric methods. The presence of the following copper (II) complex species was assumed: CuLH2+, CuX, and CunYnn− for glycyl-l-histidine-copper(II) and glycyl-l-histidylglycine–copper(II) systems, and CuLH2+, CuY−, and CuZ2− for glycylglycyl-l-histidine-copper(II) system, where LH is the neutral species of the ligand and LH=XH2=YH3=ZH4. The formation and ionization constants were obtained graphically, and the distribution of copper(II) among the complex species was calculated for each system. The results indicate that copper(II) ions are bound to the imidazole and carboxyl (or carbonyl) groups in CuLH2+ and to the amino, imidazole, and deprotonated amide groups in CuX, CuY−, and CuZ2−. The spectral blue shift accompanying a deprotonation in the region from a=4 to 5 in the glycyl-l-histidine and glycyl-l-histidylglycine copper(II) systems indicates the formation of a polymer complex CunYnn− in which the imidazole ring acts as a bridge to connect copper atoms, where a represents moles of KOH added per completely protonated ligand.
Total Syntheses of Holomycin, Thiolutin, and Aureothricin
Authors: Hagio Katsuaki , Yoneda Naoto
Published: July 2006

The reactions of 4-benzylthio-5-benzylthiomethyl-3-hydroxy-2-oxo-2,5-dihydrofuran with ammonia and primary amines gave 3-amino-4-benzylthio-5-benzylthiomethyl-3-pyrrolin-2-one derivatives. 3-Acylamino-4-benzylthio-5-benzylthiomethylene-3-pyrrolin-2-one derivatives, including the intermediate of the synthesis of holomycin by Büchi, were prepared by the treatment of the 3-acylaminolactams derived from the 3-aminolactams with chloranil or DDQ. Thiolutin and aureothricin were also synthesized from 3-acetamido- and 3-propionamido-4-benzylthio-5-benzylthiomethylene-1-methyl-3-pyrrolin-2-one respectively.
A New Lanthanoid Double Trifluoride Compound (Er0.3Nd0.7)F3
Authors: Okamura Kiyohito , Yajima Seishi
Published: July 2006

A new compound, (Er0.3Nd0.7)F3, in the ErF3–NdF3 system was prepared by the solid state reaction of NdF3(hexagonal LaF3-type) and ErF3 (orthorhombic YF3-type). It was found to be of an isostructure with ErF3 of the space group Pnma. Structural data are compared with those of ErF3.
Reaction Paths in the Photochemical Isomerization between cis-Butadiene and Cyclobutene
Authors: Kikuchi Osamu
Published: July 2006

During the disrotatory process of the photoinduced cycloaddition of cis-butadiene, two lower symmetric states play an important role and the ground state of cyclobutene is formed directly through a radiationless transition between these two states.
On the Behavior of O2− and O− Radicals over V2O5–SiO2 Catalyst
Authors: Yoshida Satohiro , Matsuzaki Tokuo , Kashiwazaki Tomonori , Mori Kozo , Tarama Kimio
Published: July 2006

The behavior of oxygen, O2− and O− radicals adsorbed on the partially reduced V2O5–SiO2 catalysts has been investigated. Oxygen is adsorbed mainly in a molecular state at room temperature, the sum of amounts of paramagnetic adsorbed species O2− and O− being less than 10% of total amount of adsorbed oxygen. High degree of reduction, high content of V2O5 and low pressure of oxygen at adsorption equilibrium are favorable for the formation of O− radical. It was confirmed by the quantitative analysis of reaction products and the adsorbed species that O2−, not O−, is the active species in the oxidation of propylene at room temperature. A mechanism involving an intermediate of an epoxide structure was proposed.
Extrinsic Photoconductivity of N-Ethylcarbazole Single Crystals
Authors: Kato Keishi , Yokoyama Masaaki , Mikawa Hiroshi
Published: July 2006

An extrinsic photocurrent was observed in pure N-ethylcarbazole single crystal, contrary to the current view that it does not exist in N-isopropylcarbazole. It was reduced to a great extent in anthracene-containing crystal due to the decrease in carrier quantum yield caused by the energy transfer from N-ethylcarbazole (host) to anthracene (guest) molecules.
The Kinetics and Mechanism of Hydrogen Adsorption and Hydrogen–Deuterium Equilibration on the Copper Surface
Authors: Kiyomiya Makoto , Momma Naohiro , Yasumori Iwao
Published: July 2006

The mechanism of H2–D2 equilibration reaction over the copper surface was studied in the 40–90 °C range of temperature and in the pressure range of 4–45 Torr. From the studies of the hydrogen adsorption and the reaction between gaseous deuterium and preadsorbed hydrogen, the reaction was confirmed to proceed via combination between hydrogen and deuterium atoms on the surface. The rate constants for the adsorption and the desorption were optimized by a computer simulation of the reaction-time course and were found to be in satisfactory agreement with the observed results. A marked isotope effect was found in these rates; its influence on the partial pressure dependence of the reaction was discussed.
The Crystal and Molecular Structure of β-Lactose
Authors: Hirotsu Ken , Shimada Akira
Published: July 2006

The crystal structure of β-lactose (C12H22O11) was solved by direct phasing methods with integrated photographic intensity data. The structure was refined by the anisotropic least-squares method to give a final R value of 0.068 for the observed reflections. The space group is P21 with Z=2 and with unit cell dimensions of a=10.839 (6), b=13.349 (6), c=4.954 (5) Å, and β=91.31 (9)°. All the hydrogen atoms were located on different syntheses. The crystals are nearly isostructural with those of β-cellobiose except for the axial O(4) atom. The exocyclic C(5)–C(6) and C(5′)–C(6′) bonds are significantly shorter than the other C–C bonds. The lengths of the two ring C–O bonds are unequal in the galactose unit and equal in the glucose unit. The C(1)–O(1) and C(1′)–O(1′) bond lengths are shorter by 0.015 Å and 0.030 Å than the mean exocyclic C–O length of 1.417 Å. The structure contains an intramolecular hydrogen bond and exhibits an asymmetrical twist about the bridge bond. All the oxygen atoms, except the bridge oxygen atom, are involved in the hydrogen-bonding network, which comprises two terminating chains.
Vibrational Energy Transfer of Some X2CO-type Molecules on Collision with Argon
Authors: Yonezawa Yoshiro , Fueno Takayuki
Published: July 2006

Vibrational excitation of X2CO-type polyatomic molecules (X=F, Cl, Br, and H) on collision with an argon atom at temperatures 1000–3000 K was treated by the SSH-Tanczos method with a more tractable formula of average vibrational factor. Bending modes are more easily excited than bond-stretching modes in carbonyl halides. Excitation of the carbonyl stretching mode, the most difficult to occur in T–V process, becomes realizable when coupled with other modes to satisfy the near-resonance conditions.
Asymmetric Synthesis in the Oxymercuration Reaction Using Optically Active Mercuric Salts
Authors: Sugita Toshio , Yamasaki Yasuo , Itoh Osamu , Ichikawa Katsuhiko
Published: July 2006

The oxymercuration-demercuration of styrene with optically active mercuric tartrate, 2-phenylpropionate, mandelate, camphorate, menthoxyacetate, and monomethyl tartrate resulted in a partial asymmetric synthesis of 1-phenylethanol. When mercuric tartrate was used, exceptionally high optical yields (25–32%) were observed. The mechanisms for the asymmetric synthesis are discussed.
Crystal and Molecular Structure of ω-Amino Acids, ω-Amino-Sulfonic Acids and Their Derivatives. VII. The Crystal and Molecular Structure of Dl-Carnitine Hydrochloride
Authors: Tomita Ken-ichi , Urabe Keiko , Kim Yang Bae , Fujiwara Takaji
Published: July 2006

The crystal structure of Dl-carnitine hydrochloride, C7H15NO3·HCl, was determined by the heavy atom method using X-ray diffraction data on a Weissenberg photograph, and refined by the least-squares method to an R-factor of 0.13 for 1969 independent reflections. The crystals are monoclinic space group P21⁄c, Z=4, with a=6.77(1), b=11.41(2), c=15.10(3) Å and β=120.1(1)°. By protonation at carboxyl oxygen atom, carnitine molecule has the cationic form, N+(CH3)3CH2CH(OH)CH2COOH, with trans-zigzag skeletal configuration as similar as γ-amino-β-hydroxybutyric acid. The Cl− ion mediates between adjacent carnitine cations by two O–H···Cl− hydrogen bonds to form infinite chain elongated along the c-axis. The correlation between molecular structure and biological activity was also discussed.
Codimerization of Butadiene and Ethylene Catalyzed by σ-Arylnickel(II) Compound in the Presence of Boron Trifluoride Etherate
Authors: Kawata Noboru , Maruya Ken-ichi , Mizoroki Tsutomu , Ozaki Atsumu
Published: July 2006

The codimerization of butadiene with ethylene was studied with use of the catalyst system consisting of bis(triphenylphosphine)σ-arylnickel(II) halide and boron trifluoride etherate in methylene dichloride. The codimerization took place readily at 15 °C under 20 kg/cm2 to give trans- and cis-1,4-hexadiene and 3-methyl-1,4-pentadiene. A catalytic amount of water significantly enhanced the catalytic activity. The reaction path to form the codimers is discussed in terms of the variation in product distribution with time and the reaction kinetics.
A Polarographic Study of the Rates of the Dissociation Reactions of Aminopolycarboxylato–zinc(II), –lead(II), and –cadmium(II) Complexes
Authors: Kodama Mutsuo , Namekawa Kyoko , Horiuchi Takashi
Published: July 2006

The rates and the mechanisms of the dissociation reactions of aminopolycarboxylato zinc(II), lead(II), and cadmium(II) complexes were studied by analyzing their kinetic waves by conventional DC polarography. The dissociations of the zinc(II)–HIDA and–NTA complexes and the cadmium(II)– and lead(II)–HIDA complexes in an acetate buffer solution, and those of protonated lead(II)–EDTA and –EDTA–OH complexes were found to proceed through the following direct dissociation mechanisms:

i) HIDA and NTA systems

2&MX_2^2-2m\ightleftharpoonsMX^2-m+X^m-& &in a rapid equil.

&MX^2-m\ightleftharpoonsM^2++X^m-& &r.d.s.

\intertextii) EDTA and EDTA-OH systems

&MHY^3-n\ightleftharpoonsM^2++HY^1-n& &r.d.s.

On the other hand, the dissociation of the zinc(II)-EDTA-OH and its protonated DTPA complexes gave this rate law: -d[MHiY2+i−m]/dt (i=0 or 1)=kdH·[H+]·[MHiY2+i−m]. From a comparison of the observed rate constants, the zinc(II)–HIDA and –NTA, lead(II)- and cadmium(II)–HIDA and protonated lead(II)–EDTA and –EDTA–OH complexes are concluded to dissociate through a simple glycinate reaction intermediate, and the zinc(II)–EDTA–OH and its protonated DTPA complexes, through a glycinate reaction intermediate which includes polyfurcated hydrogen bonds.
Crystal Structure of Chloro-1-(2-thiazolylazo)-2-naphtholatopalladium(II) Dioxane Solvate
Authors: Kurahashi Masayasu
Published: July 2006

The crystals of chloro-1-(2-thiazolylazo)-2-naphtholatopalladium(II) dioxane solvate, [PdCl(TAN)]·C4H8O2, are orthorhombic and of space group Pbcm, with unit cell dimensions: a=8.44(2), b=30.97(4) and c=6.82(2) Å and Z=4. The structure was determined by the heavy-atom method and refined by the least-squares procedure to give an R value of 0.097 for 1392 observed reflections. The crystallographic mirror plane normal to the c-axis coincides with the molecular plane of [PdCl(TAN)]. The 1-(2-thiazolylazo)-2-naphtholato group, i.e., TAN, is a terdentate ligand; the phenolic oxygen atom, azo nitrogen atom and thiazole nitrogen atom are coordinated to the palladium atom to form two five-membered chelate rinsgs. The fourth coordination position is occupied by a chlorine atom.
Formation and Collapse of Mixed Monolayers of Trilaurin with Cholesterol and with Tristearin
Authors: Nakagaki Masayuki , Funasaki Noriaki
Published: July 2006

The surface pressure-area curves of mixed monolayers and the equilibrium spreading pressure of solid mixtures were measured at 25 °C for cholesterol and trilaurin as well as tristearin and trilaurin. The phase diagrams of these mixtures were obtained by the measurement of the melting point. From two curves, one representing the relation between the collapse pressure (if the mixed monolayer was not overcompressed) and the composition of mixed monolayer, and the other representing the relation between the equilibrium spreading pressure and the composition of solid mixture, it was shown that the compositions of the mixed monolayer and the solid mixture coexisting in equilibrium were obtained. It was found that when the mixed monolayer of cholesterol and trilaurin was compressed, pure trilaurin began to collapse and deposit, and that the mixed monolayer of tristearin and trilaurin was apt to be overcompressed. It was concluded on the basis of phase rule and thermodynamics for plane interfaces that the equilibrium spreading pressure is constant regardless of the composition of solid mixture if the solid mixture consists of two phases of mixed crystals, and that cholesterol and trilaurin form a regular solution in mixed monolayer.
Effects of the Wavelength and the Matrix on the Photopolymerization of 2,5-Distyrylpyrazine and Its Related Compounds and on Their Photodepolymerization
Authors: Suzuki Yasuzo , Tamaki Takashi , Hasegawa Masaki
Published: July 2006

The solution photopolymerization of 2,5-distyrylpyrazine (DSP) and its related compounds with the general formula of Ar–CH=CH–Ar′–CH=CH–Ar, where Ar and Ar′ represent aryl and arylene groups respectively, have been investigated. All diolefines were converted in good yields into amorphous oligomers with cyclobutane in the main chain on the exclusive excitation of the monomer molecules, while, in the crystalline state, only DSP and 1,4-bis[β-pyridyl-(2)-vinyl] benzene are known to yield highly crystalline oligomers under the same light. All the oligomers were found to be photodepolymerized to the original monomers in the solution on the excitation of the terminal groups of these oligomers. In consequence, a photoreverse scheme has been demonstrated between the diolefinic monomer and the oligomer, depending on the excitation wavelength. Poly-DSP was photodepolymerized into the monomer in tifluoroacetic acid solution, while amorphous poly-DSP in film was readily photooxidized in the air under sunlight. From the photochemical behavior of DSP, oligo-DSP, and poly-DSP, it was found that chemically the same substance, oligo-DSP, behaved in three ways, photopolymerization, photodepolymerization and no photoreaction, according to the physical state. Such a matrix effect is discussed from the point of view of topochemical reaction.
The Temperature Dependence of the G-Values of Nitrogen from the Gas-phase γ-Radiolysis of C3-Hydrocarbons in the Presence of Nitrous Oxide
Authors: Okazaki Kiyoshi , Yugeta Rei , Kowari Ken-ichi , Sato Shin
Published: July 2006

The G-values of nitrogen from the gas-phase γ-radiolysis of the C3-hydrocarbons (propane, propylene, and cyclopropane) in the presence of nitrons oxide have been measured at the temperatures from −35 to 150 °C. The G-values increased with an increase in the pressure of N2O and were saturated at about 4 mol% of N2O. The saturated values, G(N2)max’s showed characteristic temperature dependences. In propane, they scarcely changed with the temperature and stayed at around 2 Ge. Here Ge is the G-value of electrons estimated from the W-value of the hydrocarbon. In propylene, the G(N2)max changed from Ge at −35 °C to about 2 Ge at 150 °C, while in cyclopropane it changed from Ge at −35 °C to 4.5 Ge at 100 °C. Possible reaction mechanisms to explain these results have been discussed.
ESR Studies of the Triplet State Dimers of the Salicylaldehyde Schiff Base Complexes of Copper(II) in Toluene and in Chloroform
Authors: Chikira Makoto , Yokoi Hiroshi , Isobe Taro
Published: July 2006

The ESR spectra of triplet-state dimers have been obtained for various bidentate and quadridentate salicylaldehyde Schiff base complexes of copper(II) in frozen solutions. The spectra have been analysed on the basis of the previously-obtained results concerning the non-coaxial g and fine-structure tensors. The results indicate that the angles between the g|| axis and the copper-copper axis of the dimers for the quadridentate Schiff base complexes are considerably smaller than those for the bidentate ones. Each of the actually-measured ESR spectra, however, consisted of two mutually-overlapping spectra; one is due to dimers (M2), and the other, to monomers (M). The equilibrium constant for 2M\ightleftharpoonsM2 has been estimated by comparing the ESR spectral intensities of the two species. The factors which govern the dimer formations have been discussed in some detail.
The Effect of Pressure on the Diels-Alder Reaction
Authors: Seguchi Kazuyoshi , Sera Akira , Maruyama Kazuhiro
Published: July 2006

The effect of pressure on the Diels-Alder reaction was investigated. The observed activation volume was found to have a significant correlation with the activation free energy of the reaction. A correlation diagram between the activation volume and the activation free energy was proposed. By this diagram, the position of the transition state in the Diels-Alder reaction was discussed, and the activation volume was suggested to be a good diagnostic probe for the position of the transition state. The importance of the contribution of the volume contraction resulting from secondary orbital interaction to the apparent activation volume was pointed out.
Reaction of Sulfilimine and Sulfonium Ylide with Hydroxide or Methoxide Ion in Methanol
Authors: Furukawa Naomichi , Masuda Toshiaki , Yakushiji Masatoshi , Oae Shigeru
Published: July 2006

The reactions of dialkyl and alkyl aryl N-p-tosylsulfilimines with hydroxide or methoxide in methanol afforded either S-substitution products or Pummerer type products or a mixture of both, their distribution being dependent on the structure of the sulfilimine. From the results of analyses, the mechanisms of the formation of these products are discussed. A similar alkaline methanolysis of sulfonium ylides was also investigated.
The Allylic Rearrangement of Linalyl Acetate in the Medium of Acetic Acid, Propionic Acid, or Acetic Acid Containing Dioxane or Sulfuric Acid
Authors: Kogami Kunio , Kumanotani Ju
Published: July 2006

The mechanism of the allylic rearrangement of linalyl acetate in the medium of acetic acid, propionic acid, or acetic acid containing dioxane or sulfuric acid has been investigated. The nature of the carbonium-ion pairs generated from linalyl acetate in low-dielectric-constant solvents or in strong acids, and the behavior of the active intermediate in the transition state were postulated from the kinetic data as well as from the physicochemical properties and distributions of the products.
The Crystal Structure of Tetraiodo-p-benzoquinone
Authors: Kobayashi Hayao , Danno Takaaki , Shirotani Ichimin
Published: July 2006

The crystals of tetraiodo-p-benzoquinone-(iodanil) are monoclinic, with a space group of P21⁄c and with a=7.630(1), b=5.268(1), c=14.222(2) Å, β=113.07(2)°, and Z=2. The iodanil molecules are stacked to form columns along the b axis, with an interplanar distance of 3.694 Å.
Organic Photochemical Reactions. XXII. The Photoaddition of Methyl Pyruvate to Methyl-substituted Olefins
Authors: Shima Kensuke , Kawamura Teruo , Tanabe Koji
Published: July 2006

The irradiation of methyl pyruvate (III) and several methyl-substituted olefins (I) in acetonitrile gives allylic ethers (IV) as well as oxetanes (V) and alcohols (VI), Quenching studies suggest that IV and V are formed from the triplet state of methyl pyruvate, while VI is produced from the excited singlet state.
Microwave Spectrum, Structure and Dipole Moment of Ethanethiol. I. Trans Isomer
Authors: Hayashi Michiro , Imaishi Hisae , Kuwada Kazunori
Published: July 2006

The microwave spectra of trans-ethanethiol and its isotopic species were measured. The rs structure of the trans isomer was determined from the observed moments of inertia. The trans isomer has a symmetrical CH3group, the parameters for the CH2SH part of the molecule being approximately equal to those of methanethiol. The C-C bond length, found to be 1.529±0.006Å, is close to that of propane. The angle α(CCS), obtained as 108°34′±19′, is much smaller than that of analogous molecules. Discussion is given for this anomalously small α(CCS) angle. From the Stark shifts, the dipole moment of the trans isomer was determined to be μa=1.058±0.023, μb=1.146±0.002 and μtotal=1.560±0.032 D, an angle of 28°46′ being made with the bisector of the α(CSH) angle inclining towards the ethyl group. Since the dipole moment of methanethiol makes an angle of 18°30′ with the bisector of the α(CSH) angle, the increase of the angle with the bisector for ethanethiol was concluded to arise from the induction moment of the ethyl group. A brief description is given for the spectra due to the gauche isomer.
Fluorescence Depolarization Study of Hydrogen Bonded 1-Anthrol
Authors: Hamai Sanyo , Kokubun Hiroshi
Published: July 2006

Rotaional depolarization of 1-anthrol fluorescence was studied in liquid paraffin. The molecular volume of 1-anthrol becomes large when it forms a hydrogen bonded complex. The molecular volume of the complex depends on the concentration of acceptor as well as the kind of acceptor. The molecular volume obtained by extrapolation to nil acceptor concentration increases with increasing size of acceptor molecule and is appreciably larger for amines than for ethers. The emitting species in the case of amines is 1-anthrolate ion pair whose strong dipolar nature may cause further interaction with excess amine molecules. It is probable that more than one molecule of amine participate in the rotating unit, leading to a large molecular volume. The rotational relaxation time was evaluated and found to depend on acceptor concentration. Two competitive effects occur by the increase in acceptor concentration, one shortening the relaxation time because of reduction of viscosity, and the other lengthening it because of molecular volume enlargement.
Chemistry of α-Haloaldehyde. VI. Reaction of 2-Chloro-2-methylpropanal with Benzoylacetonitrile in the Presence of Potassium Carbonate
Authors: Takeda Akira , Tsuboi Sadao , Sakai Takashi
Published: July 2006

The reaction of 2-chloro-2-methylpropanal with benzoylacetonitrile in aqueous K2CO3 has been studied. When 2-chloro-2-methylpropanal was added to a stirred suspension of benzoylacetonitrile in aqueous K2CO3, 2-hydroxy-3,3-dimethyl-4-cyano-5-phenyl-2,3-dihydrofuran (7) was obtained. The oxidation of 7 with CrO3gave α,α-dimethyl-β-cyano-γ-phenyl-Δβ,γ-butenolide (8). When benzoylacetonitrile was added to a suspension of 2-chloro-2-methylpropanal in aqueous K2CO3 stirred beforehand for 60 min, the reaction proceeded in a different manner to give the enol tautomer (9b) of 2,4-dibenzoyl-3-(α-hydroxyisopropyl)glutaronitrile (9a) at room temperature, and 2,2-dimethyl-3-(α-carbaminophenacyl)-4-cyano-5-phenyl-2,3-dihydrofuran (11) at 80–90 °C. The alkaline hydrolysis of the nitrile 9 conducted at 70 °C also afforded the amide 11. The nitrile 9 eliminated one mol of benzoylacetonitrile on treatment with H2SO4 to afford 2,2-dimethyl-3-hydroxy-4-cyano-5-phenyl-2,3-dihydrofuran (12). Chromic acid oxidation of 12 gave 2,2-dimethyl-3-oxo-4-cyano-5-phenyl-2,3-dihydrofuran (14), which can be derived from bullatenone in two steps. Structures of compounds 11, 12, and 14, which all possess 2,2-dimethyl-4-cyano-5-phenyl-2,3-dihydrofuran ring, have been confirmed and well correlated by both chemical transformations and spectral data.
Glass Formation in Multicomponent Phosphate Systems Containing TiO2
Authors: Kishioka Akira , Haba Masanori , Amagasa Michio
Published: July 2006

Glass formation was investigated in the Na2O–TiO2–P2O5, K2O–TiO2–P2O5, BaO–TiO2–P2O5,Na2O–BaO–P2O5, and Na2O–BaO–TiO2–P2O5 systems. In the Na2O–TiO2–P2O5 system, glass containing up to 45.5 mol% TiO2 was found to be formed at the composition of Na2O/P2O5=1, whereas in the K2O–TiO2–P2O5 system the glass formation was observed in a narrow region along the composition of K2O/P2O5=1 in a three-component diagram. In the BaO–TiO2–P2O5 system, only the glass containing about 10 mol% TiO2 as a maximum was obtained. In the Na2O–BaO–TiO2-P2O5 system, the region of glass formation extended with an increase of Na2O up to 30 mol%. These results suggested that a certain amount of Na2O is necessary for the formation of glass containing a large amount of TiO2 in the presence of BaO. The three-component diagrams of the Na2O–TiO2–P2O5 and Na2O–BaO–P2O5 systems indicated that the most favorable amount of Na2O for the glass formation in this four-component system is 27 to 28 mol%.
Reactions of Organoboranes with Ferric Chloride and Thiocyanate. Convenient Syntheses of Alkyl Chlorides and Thiocyanates from Olefins via Hydroboration
Authors: Arase Akira , Masuda Yuzuru , Suzuki Akira
Published: July 2006

The reactions of trialkylboranes with ferric chloride and thiocyanate in an aqueous tetrahydrofuran solution give the corresponding alkyl chlorides and thiocyanates in good yields. It was found that two equivalents of ferric salts per alkyl group of organoborane are required, and not only the first alkyl group of trialkylborane but other alkyl groups are also used.
A New Method of Preparing Flavones
Authors: Kasahara Akira , Izumi Taeko , Ooshima Masatoshi
Published: July 2006

The reaction of the sodium salt of 2′-hydroxychalcones with palladium(II) salt led to the formation of flavones, accompanied by a small amount of flavanones. The reaction proceeds via a phenoxypalladation, followed by the elimination of a hydridopalladium(II).
Far Infrared Spectra and Internal Rotation of Ethyl Fluoride and Deuterated Species
Authors: Sugeta Hiromu , Adachi Yoshio , Miyazawa Tatsuo
Published: July 2006

Far infrared spectra were measured of ethyl fluoride CH3CH2F and deuterated species CH3CD2F, CD3CH2F, and CD3CD2F in the gaseous state. The potential barriers hindering the internal rotation were calculated with various models. Possibly because of isotope effects on structure relaxations due to torsional motion and to zeropoint motion of other vibrational modes, the observed potential barriers are slightly different among isotopic molecules; the threefold barrier is lowered on the deuteration of the methyl group. The absorption intensities of the four isotopic species were also measured. The intensity of the torsional vibration of the methyl group is nearly doubled on deuteration of the methyl group but is reduced on deuteration of the methylene group. The observed intensity ratios among isotopic species were in good agreement with the ratios calculated with the intensity theory of our previous study.
Spectroscopic Studies on Some Ketimines
Authors: Abu-Eittah R , Hamed M M
Published: July 2006

The electronic absorption spectra of some ketimines have been investigated using different solvents. Assignment of the obtained transitions was attempted. The N-substituted ketimines did not show a discrete band for the n–π* transition as was obtained with the unsubstituted molecules. Molecular orbital calculations were carried out using the PPP variant of the SCF-MO theory. Agreement between the calculated and experimental transition energies was satisfactory.
The Photoinduced Substitution Reaction of 4-Quinolinecarbonitrile
Authors: Hata Norisuke , Ono Isao , Suzuki Hiroshi
Published: July 2006

The photochemical reactions of 4-quinolinecarbonitrile with alcohol (ethanol, 1-propanol, 2-propanol, or t-butyl alcohol) resulted in the substitution of the 1- and/or 2-hydroxyalkyl group at the 2-position of a quinoline nucleus.
The Stereoselective Reduction of Tropinone to Tropine
Authors: Hayakawa Yoshihiro , Noyori Ryoji
Published: July 2006

The reduction of tropinone with diisobutylaluminum hydride in tetrahydrofuran at −78 °C leads to tropine selectively.
Determination of Conformations of Esters with the Use of Lanthanide Shift Reagents
Authors: Sakamoto Kazuhiko , Oki Michinori
Published: July 2006

Lanthanide shift reagents have been used for diagnosis of s-trans and s-cis conformations of esters. By taking a ratio of lanthanide-induced shift of (H)CH2C=O protons vs. [shift reagent]/[substrate] as a reference, relative ratio of (H)CH2O- of the s-trans form has been found to be almost unity, whereas that of the s-cis ca. 0.5.
An Ultrasonic Method for Determination of the Volume Change Due to Internal Rotation in 1,2-Dichloroethane
Authors: Aoi Masakatsu , Arakawa Kiyoshi
Published: July 2006

A simple method for determining the volume change, ΔV, in conformational isomerism from sound velocity has been worked out from the theory of binary mixtures. The method was applied for obtaining the volume change due to internal rotation in 1,2-dichloroethane. The sound velocity was measured with an ultrasonic interferometer. The method was found useful.
Acetoxythallation of Acetylenes and the Proto- and Halogenodethallation of the Products
Authors: Uemura Sakae , Tara Hideyuki , Okano Masaya , Ichikawa Katsuhiko
Published: July 2006

The trans acetoxythallation of alkylphenylacetylene with Tl(OAc)3 proceeds in acetic acid at 50–75 °C for 1–3 hr to give a mixture of two isomeric vinylthallium(III) compounds in 54–79% yields, 2-acetoxy-1-alkyl-2-phenyl- and 2-acetoxy-2-alkyl-1-phenylvinylthallium(III) diacetates [C6H5C(OAc)=C(R)–Tl(OAc)2 (1) and C6H5C(Tl(OAc)2)=C(OAc)R (2), where R=Me, Et, n-Pr, and n-Bu]. Protodethallation of 1 and 2 in refluxing acetic acid occurs with retention of configuration to afford C6H5C(OAc)=C(R)H (3) and C6H5CH=C(OAc)R (4), respectively. The reaction of 1 and 2 with NaBH4 in protic solvents at pH 6–7 also gives 3 and 4 with retention of configuration, where the hydrogen for replacement of thallium group comes almost completely (>98%) from the solvent. 1 and 2 are relatively stable to water and dilute HCl, while they readily give ketones in alkaline condition. Halogeno-, cyano-, and thiocyanodethallations of 1 is conducted by reactions with the corresponding copper(II) or (I) salts in acetonitrile to give C6H5C(OAc)=C(R)X (X=I, Br, Cl, CN, and SCN) with retention of configuration. Bromodethallation of 1(R=CH3) by bromine gives C6H5C(OAc)=C(CH3)Br stereospecifically in pyridine (retention), while α,α-dibromopropiophenone is obtained in CS2 and acetonitrile.
Synthesis of Streptolidine (Roseonine, Geamine)
Authors: Kusumoto Shoichi , Tsuji Shinichi , Shiba Tetsuo
Published: July 2006

Streptolidine (roseonine, geamine) (1), a guanidino amino acid component of the streptothricin group antibiotics, was synthesized starting from d-ribose (8). The epimino compound (11b) was prepared from 8 in five synthetic steps. Azidolysis of 11b gave the arabino-type compound (12b), which in turn was converted to the key intermediate tribenzyloxycarbamido lactone (23b) by oxidation of C-1. The lactone 23b was rearranged to the free lactam (4) after deprotection, and then guanidinated with cyanogen bromide. The identity of the hydrolysis product of this guanidino lactam with natural streptolidine in all respects certified the proposed structure involving the steric configurations.
Enthalpies of Hydrogen Bond Formation between Diphenylamines and Dimethyl Sulfoxide
Authors: Hirota Minoru , Shinozuka Kazumasa , Hamada Yoshiki
Published: July 2006

Enthalpies of hydrogen bond formation for the diphenylamine–dimethyl sulfoxide systems were determined by infrared spectroscopic method. The ΔH values for 4-methoxy, 4-methyl, unsubstituted, 3-methoxy, 3-chloro, 3-nitro, and 4-nitro-diphenylamines are −9.6, −10.1, −11.1, −11.2, −12.8, −13.9, and −13.9 kJ mol−1, respectively. The substituent effects are discussed in relation with those on N–H stretching frequencies.
Reaction of Group IV Organometallic Compounds. XXXI. The Reaction of N-Trimethylsilyl- and -stannyl(diphenylmethylene)amine with Diketene
Authors: Suzuki Hiroharu , Matsuda Isamu , Itoh Kenji , Ishii Yoshio
Published: July 2006

Linear 1/1 adducts and oxazinone derivative were obtained by the reaction of N-trimethylsilyl- and -stannyl(diphenylmethylene)amine; Ph2C=N–MMe3 (M=Si, Sn) with diketene. Consecutive demetallation reaction by ethanethiol for the organostannyl 1/1 adduct, and by methanol for the organosilyl 1/1 adduct gave a piperidine derivative and an oxazinone derivative, respectively.
The Reaction of Alkyl Halides with Mercuric Thiocyanate
Authors: Watanabe Nanao , Okano Masaya , Uemura Sakae
Published: July 2006

The reaction of secondary and tertiary alkyl halides with mercuric thiocyanate in less-polar solvents e.g., n-hexane, di-n-butyl ether, and 1,2-dichloroethane) was found to afford predominantly N-alkylation products, alkyl isothiocyanates, in contrast to the reaction with potassium salt in DMF. Especially, from t-butyl bromide, α-phenethyl bromide and benzhydryl chloride, the corresponding pure isothiocyanates were obtained in good yields. A most probable reaction mechanism is suggested, based on the relative rate data, the stereochemical result of the reaction with optically active α-phenethyl bromide, and the well-known catalytic effect of silver or mercury salt in SN1 reaction.
Kinetics of Ligand Isotopic Exchange of Tris(acetylacetonato)gallium(III) and Related β-Diketonato Complexes in Tetrahydrofuran
Authors: Chatterjee Chinmoy , Matsuzawa Kazuyo , Kido Hiroaki , Saito Kazuo
Published: July 2006

The rate of isotopic exchange of tris(acetylacetonato)gallium(III)[Ga(acac)3] and acetylacetone-14C(Hacac) in tetrahydrofuran (THF) is expressed by the formula R=[complex](k1+k1+[H2O]+k3[Hacac]) and the k1, k2, and k3 are ≤2×10−6 s−1, 0.31×10−3 M−1s−1 and 0.71×10−4 M−1 s−1, at 0 °C, respectively. The activation enthalpies and entropies are 18±2 and 19±2 kcal-mol−1, and −13±6 and −20±6 cal·K−1 mol−1, for k2 and k3 respectively. Trichloroacetic acid gives acid catalysis. A dissociative mechanism through an intermediate containing a unidentate ligand is suggested. The isotopic exchange rate decreases in the sequence In>Ga>Al for a given β-diketonato complex, and with increase in pKa of the β-diketone for given central metal ions.
The Thermal Reactions of Azido-1,3,5-triazines
Authors: Kayama Ryuichi , Hasunuma Shigeru , Sekiguchi Shizen , Matsui Kohji
Published: July 2006

Azido-s-triazines containing –Cl, –OCH3, and –N(CH3)2 groups were synthesized, and their thermal reactions with some hydrocarbons were investigated with respect to the reaction products and the reaction kinetics. With non-olefinic hydrocarbons the reactions were found to proceed via a nitrene inteimediate; in the reactions with cyclohexane, cydohexylamino-s-triazines and amino-s-triazines were obtained. On the other hand, with olefinic hydrocarbons the reactions took place via a. bimolecular mechanism involving a formation of an intermediate of the triazoline type; in the reactions with cyclohexene, cyclohexenylamino-s-triazines were obtained along with amino-s-triazines; In both cases, the yields of alkylamino and alkenylamino-s-triazines increased with the electron-withdrawing power of the substituents in the s-triazine nucleus.
The Synthesis of 2,4-Dehydrohomoadamantane
Authors: Yamaguchi Ryohei , Katsushima Takeo , Kawanisi Mituyosi
Published: July 2006

A synthesis of 2,4-dehydrohomoadamantane (I) is described. a) The UV irradiation of a solution of 4-homoadamantene (IV) in xylene containing a small amount of methanesulfonic acid under nitrogen gave a 2: 1 mixture of I and IV after 7 day; this mixture afforded pure I in a 40% isolation yield. b) The oxidation of 4-homoadamantyl hydrazone (XI) by Pb(OAc)4, NiPO, and MnO2 (active) gave a 7–11: 1 mixture of I and IV respectively. It was observed that the ratio of I to IV depends on the reaction temperature, and that the oxidation of XI by Pb(OAc)4 at −78 °C gave thirty times as much I as IV. The addition of MeOH as a proton source reduced the ratio of I to IV in the cases of NiPO and MnO2. The Bamford-Stevens reactions of 4-homoadamatyl tosylhydrazone (II) were effected in aprotic as well as in protic solvents. The ratio of I to IV was inverted under aprotic and protic conditions. The selectivities in the oxidation of XI and the Bamford-Stevens reactions of II were explained by considering the conformations of 4-homoadamantyIidene (XII) and the 4-homoadamantyl cation (VIII).
Determination of the Optical Purity of Amino Acids by Complex Formation. Determination of Optimum Condition for Rotational Measurement
Authors: Fujii Yuki
Published: July 2006

A new method has been established for the determination of the optical purity of a small amount of amino acids (alanine, valine, leucine, and glutamic acid). The method utilizes the fact that when an optically active amino acid is dissolved in an alkaline solution of K[Co(acac2en)(gly)2], the solution shows much larger optical rotation than the free amino acid in the visible region. 1/50 to 1/100th the amount of an amino acid (about 0.1– 0.05 grams) suffices for the determination of optical purity as compared with that needed in the usual method. The optimum conditions for measurement are: wavelength, 500 nm; pH, 10.00; time required to establish the substitution equilibrium, 6–8 hours; concentration of the complex, (4–5)×10−3 mol l−1; concentration of amino acid, (2–1)×10−2 mol l−1
The Selectivity Evaluation of an Ion-selective Electrode with a Liquid Membrane by Electrode Response to a Foreign Ion
Authors: Jyo Akinori , Torikai Masanori , Ishibashi Nobuhiko
Published: July 2006

The potential responses of liquid-membrane electrodes to foreign ions were examined. The electrode response obeyed the Nikolsky equation when the selectivity for the foreign ion was nearly equal to or higher than that for the objective ion and when the concentration of the foreign ion in the sample solution was sufficiently higher than that of the ion-exchanger in the liquid membrane. The Nikolsky equation, however, did not hold for the response when the selectivity for the foreign ion over the objective ion was extremely low or when the concentration of the sample was not so high. Such a non-ideal response was ascribed to the variation in the ionic composition at the membrane-solution interface caused by the ion-exchange. From the measurement of the electrode potential under conditions when the response obeyed the Nikolsky equation, the selectivity coefficient for the foreign ion over the objective ion could be obtained successfully as an intrinsic value of the electrode membrane. The selectivity value thus obtained was in good agreement with the value estimated from the Sandblom-Eisenman-Walker theory on the electrode selectivity. The additivity of the membrane potential was also described.
Binuclear Copper(II) Propionate Complexes with N-Arylsalicylideneamines
Authors: Tokii Tadashi , Emori Shuji , Muto Yoneichiro
Published: July 2006

Two copper(II) propionate complexes with N-arylsalicylideneamines have been prepared. The magnetic and spectral properties of these complexes indicate that they have a carboxylate-bridged binuclear structure.
Synthesis of Methyl Isobutyl Ketone from Acetone and Hydrogen Catalyzed by Palladium Supported on Zirconium Phosphate
Authors: Watanabe Yoshiaki , Matsumura Yoshito , Izumi Yusuke , Mizutani Yukio
Published: July 2006

The one-step synthesis of methylisobutyl ketone from acetone and hydrogen was investigated by using palladium supported on zirconium phosphate, a bifunctional catalyst. Effects of reaction variables on both the conversion of acetone and the selectivity of methylisobutyl ketone were examined. The experiments were carried out with a continuous flow unit at 110–140°C and 7–25 kg/cm2 over a range of liquid hourly space velocity of acetone for 2–15 hr−1 with a mole ratio of hydrogen to acetone in the range 0.2–1.45. Under these conditions, the conversion of acetone was 20–40%, the selectivity of methylisobutyl ketone being as much 90–97 mol%. It is suggested that the one-step reaction proceeds via a consecutive mechanism.