bluuebunny/crossref_metadata_2025 huggingface dataset:
Pulse Radiolysis of HgBr2 in Aqueous Solutions
Authors: Fujita Shin-ichi , Horii Hideo , Mori Toshiaki , Taniguchi Setsuo
Published: July 2006

Pulse radiolysis of aqueous HgBr2 solutions was investigated in the range from visible to 260 nm. HgBr2 is reduced by eaq−, H, CO2−, and some alcohol radicals except t-butyl alcohol radical to yield a transient species, HgBr, having an absorption spectrum with a maximum at 350 nm (ε350=(4.3±0.2)×103 M−1 cm−1) . k(eaq−+HgBr2) was determined by the pseud-first order decay of eaq− observed at 500 nm as (4.0±0.3)×1010 M−1 s−1. The reactivities of the other reducing species toward HgBr2 were estimated to be in the order eaq−>CO2−>\dotEtOH≈i-\dotPr-OH>MeOH by comparing the absorption yields of HgBr in equimolar HgBr2 solutions containing the parent substances of the respective species. HgBr was found to decay following a second order rate law (2k=(1.0±0.1)×1010 M−1 s−1), producing Hg2Br2. HgBr2 reacts also with the OH radical to give a transient species which shows a similar spectrum to that of Br2−. It is considered that the transient may be HgBr3 instead of Br2−.
The Crystal Structure and the Absolute Configuration of (−)-Argemonine Methiodide
Authors: Kaneda Tsuguhiro , Sakabe Noriyoshi , Tanaka Jiro
Published: July 2006

The crystal structure of (−)-argemonine methiodide has been investigated by the X-ray method. The crystal system is orthorhombic, and the space group is P212121. The cell dimensions are a=13.443, b=20.838, and c=8.485Å. The structure parameters were refined by the block-diagonal least-squares method, and the final R-value was 0.055. The absolute configuration was determined by the MoKα anomalous scattering to be 1S5S, which is consistent with the CD result.
Indium(III) Complexes of Dl-Penicillamine in Aqueous Solution. Evidence for the Formation of Protonated and Hydrolyzed Complexes
Authors: Kojima Nakao , Sugiura Yukio , Tanaka Hisashi
Published: July 2006

The penicillamine–In(III) system has been investigated with potentiometric titration over a wide range of metal concentration at 21°C and I=0.1 (KNO3). In dilute concentration of metal (0.00025–0.0005 M) and ligand (free base), single species (InL and InL2) are predominantly formed. In higher concentration of metal (0.0025–0.005 M) and ligand (with an equimolar HCl), the protonated and hydrolyzed complexes (InLH, InL(LH), and InL(OH)) are also formed together with the simple species. The formation constants calculated with non-linear least-squares program were found to be: logβ110=15.330, logβ120=29.789, logβ11−1=18.858, logβ12−1=33.391, and logβ111=11.25 for InL, InL2, InLH, InL(LH), and InL(OH) species, respectively. The formation constants and ultraviolet spectra indicate that the proton in the protonated complex is attached to the amino-group of penicillamine.
The Structure of Ion-pairs of Λ- and Δ-[Co(en)3]3+ Ions with l-Tartrate and Related Anions as Deduced from Circular Dichroism Spectra
Authors: Fujita Miho , Yamatera Hideo
Published: July 2006

The circular dichroism (CD) spectra of optical antipodes of [Co(en)3]3+ and [Co(pn)3]3+ were measured in the presence of l-tartrate, l-tartranilate or related dicarboxylate ions. l-Tartrate(2−) ions gave a large and stereoselective effect on the CD spectra; the CD change was greater for the Λ-complex than for the Δ-complex. Hydrogen-l-tartrate(1−) and l-tartranilate(1−) ions also caused stereoselective CD changes. On the other hand, succinates-(2−) and l-malate(2−) ions gave small and non-stereoselective CD changes, and undissociated tartaric acid gave no CD change. From a comparison of the results, it was concluded that two hydroxyl and one carboxylate groups of the L-tartrate ion form hydrogen bonds with three N–H groups of the tris(diamine)cobalt(III) ion of the lel form.
Complexation between Copper(II) Ion and Large Excess Histidine in Aqueous Solution
Authors: Aiba Hiroji , Kuroda Yoshihiro , Tanaka Hisashi
Published: July 2006

The complexation between copper(II) ion and large excess histidine has been studied by visible absorption, proton and C-13 NMR spectral methods, in comparison with histamine–copper(II) system. The predominant species were considered to be ML2H+ and ML2H22+ at a=0 and ML2 at a=1 and 2, respectively from the spectral data in visible region, where a represents moles of base added per mole of diprotonated ligand. In ML2H+, one histidine is bound histamine-like with a carboxylate coordinated in apical position and the other glycine-like with a protonated imidazolium group, and in ML2H22+, both histidine molecules are bound glycine-like. Two histidine molecules are both tridentate with apical carboxylates in ML2. In histamine–copper(II) system, the coordination of the third histamine molecule in the apical position was suggested at a=1 and 2. The proton and the G-13 NMR spectra were reasonably interpreted in view of the above situation. A difference in the line-broadening of PMR signals was observed between histidine–copper(II) and histamine–copper(II) systems. This is mainly due to the difference in the exchange rates of the coordinated ligands of two systems.
Identification of Stereoisomers of Methyl Hexopyranosides by Mass Spectrometry of Their Trifluoroacetates
Authors: Ando Susumu , Ariga Toshio , Yamakawa Tamio
Published: July 2006

The mass spectra of the trifluoroacetates of methyl hexopyranosides and their partially deuterated derivatives were measured. The trifluoroacetyl derivatives were found to be very useful for identification of some stereoisomeric hexoses. The mass spectra were characterized by abundant peaks in the high mass range, the presence of a recognizable molecular ion, and sensitive spectral differences due to different stereoisomers. Glucose, galactose and mannose were distinguished from each other by comparing the intensities of the fragment ions due to the loss of trifluoroacetyl groups or cleavage of the pyranose ring. Alfa and β-anomers were distinguished by differences in the abundance of fragment ions produced by the loss of glycosidic methoxyl groups.
13C NMR Spectra of Some Methyl Cyclohexanecarboxylates
Authors: Senda Yasuhisa , Ishiyama Jun-ichi , Imaizumi Shin
Published: July 2006

13C NMR spectra of a series of stereoisomeric-substituted methyl cyclohexanecarboxylates have been obtained. The resonances for ring carbons of the isomers, in which both the methoxycarbonyl and the other groups have equatorial orientations, usually appear at a field lower than those of the isomers in which one of the two substituents has an axial orientation. No appreciable difference in shift due to the configurational change is observed in the resonances for the substituents. Observed chemical shifts are compared with predicted values.
Thermal Cis-to-Trans Isomerization of Substituted Azobenzenes II. Substituent and Solvent Effects
Authors: Nishimura Norio , Sueyoshi Toshinobu , Yamanaka Hideyuki , Imai Etsuko , Yamamoto Shunzo , Hasegawa Shigeo
Published: July 2006

The thermal cis-to-trans isomerization rate of various azobenzenes was followed by means of spectrophotometric and flash photolysis techniques. For para-donor/para′-acceptor-substituted azobenzenes such as 4-nitro-4′-dimethylaminoazobenzene, the rate was distinctly accelerated, the activation energy decreasing with the increase in the polarity of solvents. Introduction of substituents in para positions with respect to azo group increased the rate irrespective of substituent. The effect is additive and a Hammett-type equation holds. For 4-dimethylamino-and 4-nitroazobenzenes, while the 2-methyl group accelerated the rate, the 2′-methyl group did not. The results suggest that the isomerization proceeds via inversion mechanism and the rate is controlled mainly by the resonance stabilization in the coplanar transition state. The inversion center for asymmetric azobenzenes is discussed.
The Oxygen Gas Permselectivity of Dried Cellulose Acetate Membranes
Authors: Taniguchi Yoshio , Horigome Shinkichi
Published: July 2006

The oxygen gas permselectivity of annealed cellulose di- and triacetate membranes were investigated. We have suggested that the permeation ratios of oxygen to nitrogen gases of these membranes attain 7–8 by annealing in air at 180 °C.
The Synthesis of Single Crystals of HgX2·2HgS (X=Halogen)
Authors: Takei Kunio , Hagiwara Hitoshi
Published: July 2006

Single crystals of HgI2·2HgS (3×1.2×0.2 mm3), HgBr2·2HgS and HgCl2·2HgS were prepared by means of a high-temperature vapor-phase reaction. X-Ray experiments showed that the crystal of HgI2·2HgS, the unit cell of which has dimensions of a=9.36 Å, b=9.69 Å, and c=18.5 Å, belongs to the rhombic system.
Aromaticity of Monocyclic Ions
Authors: Aihara Jun-ichi
Published: July 2006

The infinitely-large annulenes with additional formal charges were employed as reference structures to evaluate the reference energies of monocyclic ions. On this basis, the Hiickel (4r+2) rule of aromaticity was verified within the framework of the HMO theory. The results obtained agree well with the available experimental evidence.
The Photoreduction of o-Methoxycarbonylbenzophenone
Authors: Tsujimoto Yuji , Shigemitsu Yasuo , Miyamoto Takuji , Odaira Yoshinobu
Published: July 2006

The photoreduction of o-methoxycarbonylbenzophenone (I) in a hydrogen-donating solvent, such as isopropyl alcohol and toluene, was shown to give diphthalidyl (II) or/and a coupling product (IV).
Kinetic Parameters of Thermal Dehydration and Decomposition of Zeise’s Salt Hydrates
Authors: Sen\={o} Manabu , Iwamoto Kazutoshi , Asahara Teruzo
Published: July 2006

The kinetic parameters of the dehydration of Zeise’s salt hydrates, K[PtCl3 (olefin)]·H2O, (olefin; CH2=CH2, CH3CH=CH2, C2H5CH=CH2, n-C3H7CH=CH2 and n-C4H9CH=CH2) and the thermal decomposition of Zeise’s dimers were determined by using DTA and TG. By comparing the kinetic parameters with the data of IR and the enthalpy change of dehydration, it was shown that the important factor in determining the kinetic behavior of the dehydration is an extent of deformation of lattice at the transition state. Similarly, it was suggested that the bulkiness of ligand olefin is an important factor in governing the kinetics of the thermal decomposition reactions.
Conductivity, Emf, and Spectrophotometric Study on the Participation of Na+ and Cl− into Acridine Orange-Poly(α,l-Glutamic Acid) Complex
Authors: Watanabe Fumiyuki
Published: July 2006

Conductivity, emf and spectroscopic investigations were made for the dimerization process of Acridine Orange (AO) and for the complex formation of AO with poly(α,l-glutamic acid) (PLG) in water. The increase of the dimer species of AO by adding the neutral salt was quantitatively explained, taking the ionic strength into account. From the emf measurements, the inclusions of Cl− into PLG–AO complex were concluded to be negligible, whereas Na+ was included into this complex to a fairly appreciable extent. The association of Na+ with carboxylate groups in the PLG–AO complex was described on the basis of the ordinary law of mass actions. The association constant Ki was unaffected by the presence of AO even in the helical region of PLG. These results strongly support Schwarz’s theory on cooperative binding.
Coulomb Interactions and Optically-active Vibrations of Calcite-type Carbonates
Authors: Yamamoto Akio
Published: July 2006

Polarizable-ion model calculations are made for optically-active vibrations of five carbonates with calcite structures: calcite, magnesite, dolomite, rhodochrosite, and smithsonite. The fit to the experimental TO-LO splittings of the internal modes is found to be greatly improved by the introduction of ionic polarizabilities. It is also ascertained that the electronic polarizabilities of constituent atoms must be regarded as anisotropic in order to interpret the optical anisotropy. The resulting force constants for non-bonded oxygen-oxygen interactions can give the correct orders of magnitude for the Lennard-Jones potential constants.
X-Ray Photoelectron Spectroscopy of the Molecules Containing the C≡N Group
Authors: Fujikawa Takashi , Ohta Toshiaki , Kuroda Haruo
Published: July 2006

The gas-phase X-ray photoelectron spectra (with MgKα radiation) were observed on acetonitrile, propionitrile, acrylonitrile and fumaronitrile. The ionization potentials were determined for all valence-electron levels of the above molecules by using the data derived from the observed valence-electron bands of X-ray photoelectron spectra and the reported data of ultraviolet photoelectron spectroscopy. It is shown that there is a linear relation between the observed ionization potential (IP) and the CNDO/2 orbital energy (ε): IP=0.61(−ε)+3.2[eV], for σ-orbitals; IP=0.38(−ε)+6.0[eV], for π-orbitals. The observed binding energies of the C ls levels were analyzed by means of the electrostatic potential model and the charge densities calculated by CNDO/2 method. Discussion is given also on the shake-up satellite of core-electron peak.
Predictions of Molecular Geometries and Electronic Spectra of Complex Unsaturated Molecules from MC-LCAO-MO Method. II. 1,3-Butadiene and Cyclobutadiene
Authors: Nakayama Mitsunobu , Nishihira Moriyuki , I’Haya Yasumasa J
Published: July 2006

A multi-configuration (MC)-LCAO-MO method is applied to 1,3-butadiene and cyclobutadiene, predicting their molecular geometries and electronic spectra. The molecular ground state geometry, electronic spectrum and stabilization energy of the trans- to the cis-isomer of 1,3-butadiene are predicted to be in good accord with experiments and with those derived from the ordinary semi-empirical SCF-CI method. The results obtained for cyclobutadiene indicate that (a) the Jahn-Teller distortion occurs to favor a rectangular (D2h) form, the stabilization energy being 0.3–0.9 eV depending on approximations, and (b) even in a square (D4h) form a singlet (ground) state is more stable than a triplet state by ca. 0.3 eV. It is also shown that the lowest excited singlet and triplet states (3A2g and 1B1g) in the square form are not subjected to the Jahn-Teller effect. A discussion is given on a possible error in a CI treatment arising when degenerate molecular orbitals are expressed by real coefficients of atomic orbitals.
Interactions of Calcium Ions with Carbohydrates: Crystal Structure of Calcium d-Glucarate Tetrahydrate
Authors: Taga Tooru , Osaki Kenji
Published: July 2006

The crystal structure of calcium d-glucarate tetrahydrate has been determined from three dimensional X-ray data, and refined by the least squares method including an anisotropic temperature factor. The crystals are orthorhombic, space group P212121 with a=16.09, b=11.36 and c=6.68Å. The calcium ion is bound to two glucarate molecules and three water molecules. The eight oxygen atoms form the calcium coordination shell of a distorted square-antiprism geometry. The carboxyl group including C(1) of d-glucarate has an eclipsed conformation relative to C(2) and O(2), and is coordinated with one calcium ion through the carboxyl oxygen O(1) and the α-hydroxyl oxygen O(2), and with the other calcium ion through the carboxyl oxygen O′(1) and the hydroxyl oxygens O(3) and O(4). The other carboxyl group including C(6) has an unusual staggered conformation relative to C(5) and O(5), and is not coordinated with calcium ions. However the oxygen atoms of the latter carboxyl group are attached by hydrogen bonds to a number of hydroxyl groups and water molecules, all of which are coordinated with calcium ions.
Electronic Population Analysis Based on the Electron Pair Concept
Authors: Okada Takashi , Fueno Takayuki
Published: July 2006

The electronic population in molecular systems is analyzed on the basis of the spin coupling matrix. A proposal is made to define the pair-coupling population which is directly related to the electron pair concept. The theory is applied to the examinations of various types of wave functions used for three-centered two-, three-, and four-electron systems. The results permit clear comparisons of the characteristics of the various wave functions examined.
The Crystal and Molecular Structure of (Acetylacetonato)(carboxymethyl)(triphenylphosphine)palladium(II)
Authors: Zenitani Yukio , Inoue Kaoru , Kai Yasushi , Yasuoka Noritake , Kasai Nobutami
Published: July 2006

The molecular structure of (acetylacetonato)(carboxymethyl)(triphenylphosphine)palladium(II) [(acac)-(PPh3)PdCH2COOH] has been determined by means of X-ray diffraction. The crystal belongs to the triclinic system, space group P\bar1, with two formula units in a cell with dimensions of a=10.433(2), b=12.746(2), c=10.224(2) Å, α=106.62(1), β=112.41(2), and γ=75.13(2)°. R=0.032 for 4972 non-zero reflections. The palladium atom, σ-bonded to the methylene group of the acetic acid moiety (Pd–C=2.063(4) Å), has a square-planar geometry. The molecule forms a dimer with the adjacent molecule related by a center of symmetry through an inter-molecular hydrogen bonding between acetic acid moieties, O–H···O=2.621(4) Å.
Bivalent Metal Complexes of N,N-Bis(2-hydroxyethyl)glycine
Authors: Inomata Yoshie , Takeuchi Toshio , Moriwaki Takao
Published: July 2006

Complexes of N,N-bis(2-hydroxyethyl)glycine(BHEG) with a bivalent cation (Cu(II), Ni(II), Co(II), Zn(II), Fe(II), Cd(II), and Pb(II)) have been prepared and investigated by means of infrared absorption spectra, powder surface diffuse reflection spectra, electronic spectra, magnetic susceptibility, and thermal analysis. They can be classified into two types: (A) ML2·nH2O and (B) ML·X·nH2O, (M: metal, L: BHEG−, X: Cl− or NO3−). Ni(II), Co(II), Zn(II), and Fe(II) complexes are of type A, and those of Cd(II) and Pb(II) of type B. In the case of Cu(II) complexes, a blue A type complex (Cu(II)-A) has been prepared from a basic solution and a green B type one (Cu(II)-B) from an acidic solution. From detailed assignments of IR spectra, BHEG is found to have a zwitter ion structure. From magnetic moment data and reflection spectra, we presume that the A type complexes have a trans octahedral structure and the B type complexes a tetrahedral structure.
Photoreactions of Cyclic Benzylidene Acetals with Ketones in the Presence and Absence of Dissolved Oxygen
Authors: Suzuki Morio , Inai Toshimi , Matsushima Ryoka
Published: July 2006

Photoreactions of 2-phenyl-1,3-dioxane (1) and 4,6-O-benzylidene-1,2,3-tri-O-acetylglucopyranose (10) in the presence of benzophenone, acetophenone, or acetone have been studied in both deoxygenated and aerated benzene solutions at room temperature. Photolysis of 1 with ketone in deoxygenated solution gave a dimeric product of 1 (8), cross adduct, and pinacol, while in aerated solution an oxidative ring cleavage product, i.e., trimethyleneglycol monobenzoate (9), was obtained instead of 8, besides smaller amounts of pinacol and cross adduct. The yields of pinacol and cross adduct decreased with the change in ketone in the order benzophenone>acetophenone>acetone, while the yield of 8 or 9 was in the reverse order. Photolysis of 10 with ketone led to results parallel to those of 1: photolysis under nitrogen atomosphere gave pinacol, cross adduct, and a dimeric product of 10 (14), while under bubbling air 4-O-monobenzoate and 6-O-monobenzoate derivatives of 10 were obtained instead of 14, besides pinacol and cross adduct. The effects of temperature, oxygen, and structure on the course of the reaction, to produce dimeric or ring opening products, have been discussed.
A Study on the Photochemistry of α,β-Unsaturated γ-Lactones. III. Photodimerization of 2-Penten-4-olide
Authors: Ohga Kazuya , Matsuo Taku
Published: July 2006

Irradiation of 2-pentene-4-olide (I) with 254 nm light afforded three and dimers; two head-to-tail isomers and one head-to-head isomer. The photodimerization proceeds via the lowest triplet state. The quantum yields for the formation of the photodimers were determined as a function of the concentrations of I. Addition of I in the excited state to cyclopentene gave two isomeric cyclobutane derivatives. The photocycloaddition took place more rapidly than the photodimerization of I. The photodimerization was also quenched by anisole, probably through formation of an exciplex between I and anisole.
Stereochemistry of the C and D Rings of C-Nor-D-homosteroids. III. The Synthesis of Etiojervane Analogs of Androstan-3β-ol
Authors: Murai Akio , Nishimura Takeshi , Masamune Tadashi
Published: July 2006

The synthesis of C/D trans- and cis-fused C-nor-D-homoandrostan-3β-ol 3-acetates (11a and 34a) from jervine (1) is described. The configurations of both the compounds and the synthetic intermediates are defined clearly on the basis of the chemical and spectral evidence.
The Effect of Steric Condition in Cobalt(II), Nickel(II) and Copper(II) Complexes with Schiff Bases Obtained from Salicylaldehyde Derivatives and Diphenylmethylamine
Authors: Yamanouchi Kuniko , Yamada Shoichiro
Published: July 2006

Cobalt(II), nickel(II) and copper(II) complexes with N-diphenylmethyl-ring-substituted salicylideneiminates (abbreviated as X–Sal–Dpm) have been synthesized, in order to examine the steric and electronic effect of a substituent diphenylmethyl group on the structure of the metal complexes. Compounds of the type M(X–Sal–Dpm)2 and their adducts of the type M(X–Sal–Dpm)2·nL have been isolated in crystals, n being 2 or 4 and L being benzene, acetone or pyridine. Both in the solid state and in non-donor solvents, the complexes Co(X–Sal–Dpm)2 have a tetrahedral configuration, and Ni(X–Sal–Dpm)2 and Cu(X–Sal–Dpm)2 have a square-planar configuration, irrespectively of substituents X. The results so far available seem to indicate that the steric hindrance caused by the substituent diphenylmethyl group against the square-planar configuration of the metal complexes may be smaller than that by isopropyl group.
Ring-opening Reactions of Cyclic Ethers. IX. Molecular Weight Distribution of Adducts in the Acid-catalyzed Reactions of Epichlorohydrin with Alcohols
Authors: Sekiguchi Shizen , Hasegawa Yasushi , Nakamura Kenji , Matsui Kohji , Nagahama Kensuke
Published: July 2006

It was found that the molecular weights of adducts in the acid-catalyzed reactions of epichlorohydrin with alcohols obey the Weibull-Nycander distribution but not the Flory distribution. The distribution constants (C=ki⁄k0) were found to be smaller than 1, indicating that the reaction rate of the initial stage (k0), i.e., the reaction of epichlorohydrin with a starting alcohol, is greater than the rates of the later stages (ki), i.e., the reactions of epichlorohydrin with its adducts. The results indicate that the reaction proceeds via an “borderline” A-2 mechanism.
Thermolysis of Phenyl 3-Guaiazulenecarboxylate and the p-Acetyl and p-Methoxy Derivatives
Authors: Kurokawa Shinji , Anderson Arthur G
Published: July 2006

Thermolysis of p-acetylphenyl 3-guaiazulenecarboxylate (1) results in loss of the ester group. In contrast, thermolysis of phenyl 3-guaiazulenecarboxylate (2) or p-methoxyphenyl 3-guaiazulenecarboxylate (3) gives (i) loss of the ester group, (ii) loss of the 1-methyl group with concomitant rearrangement of the ester group to the 1-position, (iii) interchange of the ester and 1-methyl groups, and (iv) cyclization to 5-isopropyl-7-methyl-1,2-dihydrocyclopenta[c,d]azulen-1-one (9).
Synthesis of Eriostoic Acid and Eriostemoic Acid
Authors: Tsukayama Masao
Published: July 2006

A 1,8-dioxaanthracenepropionic acid derivative (5), after being converted into methyl ester-methyl ether (6), was reduced with sodium borohydride to give methyl eriostate (7). Hydrolysis of the ester (7) with alkali afforded eriostoic acid (1). On the other hand, eriostemoic acid (2) was synthesized from methyl eriostemate (10), which was obtained from a 1,5-dioxaphenanthrenepropionic acid derivative (8) via four steps.
The Photoreaction of Benzyl 1-Cycloalkenyl Ketone in Acidic or Protic Media
Authors: Tada Masaru , Saiki Hiroshi , Miura Kyo , Shinozaki Hiraku
Published: July 2006

Three benzyl 1-cycloalkenyl ketones, I–III, were irradiated in the presence of boron trifluoride-diethyl ether (0.05 mol/1) in benzene to give the products V–VII, formed by the bonding between the β-position of αβ-unsaturated ketone and the ortho position of the benzene ring. Benzyl 1-cyclooctenyl ketone (IV) was inactive to the photocyclization because of the preferential geometrical isomerization of the olefin moiety. Trifluoro-acetic acid promotes the reaction exceedingly, but the reaction takes place also in methanol. The reaction in methanol was deduced from quenching experiments to be a triplet process. The reaction takes both singlet and triplet processes when irradiation is carried out in the presence of boron trifluoride–diethyl ether. The participation of the complex between benzyl 1-cycloalkenyl ketone and boron trifluoride is proposed for the singlet process.
Mixed Ligand Copper(II) Complexes of α-Amino Acids with Ligand-Ligand Interactions
Authors: Sakurai Takeshi , Yamauchi Osamu , Nakahara Akitsugu
Published: July 2006

Synthetic and spectroscopic studies have been made on the ternary copper(II) complexes containing two optically active α-amino acids with charged groups in their side chains. Thus, for all combinations of ligands A and B, where A refers to aspartic or glutamic acid and B to arginine, lysine, or ornithine, the mixed ligand complexes, [Cu(l-A)(l-B)] and [Cu(d-A)(l-B)] except [Cu(l-aspartate)(l-ornithine)], were isolated as crystals. Infrared spectra of the isolated complexes suggested the presence of the geometrical isomers. By comparing the observed circular dichroism spectra of the ternary systems with the spectra estimated from those of the corresponding binary systems, the magnitude enhancements were detected for all the Gu(l-A)(l-B) systems, whereas no such enhancement was observed when one of the ligands was l-alanine or l-valine. The spectral behaviors as well as the solid complexes isolated have been interpreted as indicative of the existence of the intramolecular electrostatic bonding between the oppositely charged groups in the side chains of the ligands and their significance as an effective driving force leading to the ternary complex formation.
Mechanism for Light Induced Hydrogen Isotope Exchange in Benzonitrile
Authors: Yoshida Masayuki , Kaneko Hiroyuki , Kitamura Akihide , Ito Tomiyasu , Oohashi Kunio , Morikawa Naotake , Sakuragi Hirochika , Tokumaru Katsumi
Published: July 2006

Light induced tritiation of benzonitrile with diethylamine[N3H] or triethylamine-tritiated water was studied with respect to quenching of benzonitrile fluorescence by the amines and the tritium distribution in the nucleus. A mechanism involving an exciplex possessing charge transfer nature was proposed.
Preparation of Matsutake Alcohol (1-Octen-3-ol) from a Butadiene Telomer
Authors: Tsuji Jiro , Tsuruoka Katsuhiko , Yamamoto Keiji
Published: July 2006

A simple preparation of 1-octen-3-ol so called Matsutake alcohol using a butadiene telomer is described: selective hydrogenation of the terminal double bond of 2,7-octadienyl acetate gave 2-octenyl acetate which was converted via palladium-catalyzed allylic rearrangement and hydrolysis into 1-octen-3-ol.
The Catalytic Hydroboration of Ethylene with Diborane in the Gas Phase —The Acidity of Catalysts and the Reaction Activity—
Authors: Matsuda Tsuneo , Seto Isao , Tanaka Toyosuke
Published: July 2006

The catalytic hydroboration of ethylene with diborane to triethylborane in the gas phase was studied in the presence of various catalysts. The acidity of catalysts and the reaction activity were measured; the increase in the activity can be related to surface acidity of the catalysts.
The Reaction of a Stable Free Nitrogen-centered Radical, 3,4-Dihydro-2,4,6-triphenyl-2H-1,2,4,5-tetrazin-1-yl, with Organolithium Compounds
Authors: Miura Yozo , Morimoto Yuzo , Kinoshita Masayoshi
Published: July 2006

3,4-Dihydro-2,4,6-triphenyl-2H-1,2,4,5-tetrazin-1-yl (1) reacted with ethyl- and butyllithiums to give 1-ethyl- and 1-butyl-2,4,6-triphenyl-1,2,3,4-tetrahydro-1,2,4,5-tetrazines respectively. On the other hand, biphenyl and 1-benzyl-2,4,6-triphenyl-1,2,3,4-tetrahydro-1,2,4,5-tetrazine were given by the reaction of 1 with phenyllithium in toluene. Thus, the results indicate that these reactions proceed through a homolytic process.
The Thermal Decomposition of Cyanodiphenylmethyl t-Butyl Peroxide An Example of C–O Bond Scission
Authors: Okubo Masao , Iba-Imai Emiko , Mizuta Hiroko , Kawamoto Takumi
Published: July 2006

The thermal decomposition of cyanodiphenylmethyl t-butyl peroxide was investigated. The peroxide is abnormally stable and decomposes slowly at 130–135 °C, and the main reaction product is tetraphenylsuccinonitrile. A main reaction path including the C–O bond scission, in contrast to the case of triphenylmethyl t-butyl peroxide, is proposed.
The Photochemical Reaction of Iron Pentacarbonyl and 1,3-Butadiene-1,1,4,4-d4. The Lack of Secondary Isotope Effects
Authors: Noyori Ryoji , Yokoyama Keiichi
Published: July 2006

No significant deuterium isotope effects have been noticed in the formation of the 1,3-butadiene–iron tricarbonyl complex, in contrast to the olefin complexation of Ag+ or Rh(I) species.
The Catalytic Reduction of Nitrogen Oxide by Carbon Monoxide over Metal Oxide Catalysts —The Correlation of the Activities with the Surface States of Metal Oxides—
Authors: Sakurai Katsumi , Okamoto Yasuaki , Imanaka Toshinobu , Teranishi Shiichiro
Published: July 2006

In the catalytic NO–CO reaction over metal oxide catalysts, the surface states of reduced metal oxides were studied with ESCA, and the correlation of the activities of the reduced metal oxide catalysts for the NO–CO reaction with their surface states was investigated. The surfaces of the catalysts were studied with ESCA after treatments in situ. It was revealed that the surface states of the metal oxides did not always agree with their bulk constituents. For example, it was found that the oxygen in the surface layer of the cobalt oxide after a proper reduction treatment by CO was richer than in its bulk. Moreover, the correlation between the surface states and the activities of those oxides was successfully explained. It was also concluded that, in the NO–CO reaction, the metal states were most active for the cobalt, iron, and nickel oxides, while the Cu+ state was more active than the Gu metal state for the copper oxide.
Photolysis of Formaldehyde in the Presence of Nitric Oxide
Authors: Tadasa Kohji , Imai Naomi , Inaba Tetsuo
Published: July 2006

The photolysis of CH2O has been studied in the absence and presence of NO from room temperature to 300°C. In the photolysis of CH2O alone, the CO and H2 formation rates increase greatly with temperature. When NO is added, these rates vary and reach constant values with an increase in the amount of NO. These limiting rates are independent of the temperature to within the experimental error, in contrast to the rates observed for CH2O alone. It is suggested that the limiting rate of CO formation corresponds to the sum of the rates of the two primary processes, the molecular and radical reactions, and that that of H2 formation corresponds to the rate of the molecular process. For photolysis totally inhibited by NO, the rates of formation of CO, H2, N2, and N2O were examined and a reaction mechanism is proposed which is consistent with that for the photosensitized reaction between hydrogen and nitric oxide previously studied in this laboratory.
Heat of Adsorption from Solution. II. The Heat of Adsorption of Pyridine on Silica–Alumina from the Hexane Solution
Authors: Naono Hiromitu , Moori Kazuko , Morimoto Tetsuo
Published: July 2006

The amounts of physisorbed and chemisorbed pyridine on silica–alumina in the hexane solution were measured at 30°C, and found to be 1.25 and 0.25 molecules/100 Å2 respectively. The number of strong acid sites determined by Benesi’s method are in good agreement with the chemisorbed molecules, which indicates that the ratio of the number of chemisorbed pyridine molecules to that of the strong acid sites on the surface of silica–alumina is equal. The adsorption calorimetry was carried out on the same system by means of a flow microcalorimeter which permits us to differentiate the heats of physisorption and chemisorption: the results showed that the heats of physisorption and chemisorption of pyridine are 11.3±0.3 and 22±4 kcal/mol respectively.
The Primary Process of the Photochemical Isomerization of Azanaphthalene N-Oxides
Authors: Hata Norisuke , Ono Isao
Published: July 2006

The quantum yields for the photochemical isomerization of azanaphthalene N-oxides, such as quinoline N-oxide and isoquinoline N-oxide, into lactam (Process I) or oxazepine (Process II) were determined in benzene (or carbon tetrachloride), in methanol, and in mixtures of the two solvents. Consequently, the reaction was revealed to be closely related to whether or not the N-oxide oxygen atom forms a hydrogen bond with the solvent molecule; that is, a strong hydrogen-bonding interaction between the excited singlet N-oxide and alcohol is essential for Process I, but not for Process II. It was further demonstrated that Process II occurred with the formation of powerful oxidants (probably oxaziridines) from the excited singlet N-oxide, whereas such an oxidizing species was not involved in Process I. The reaction mechanisms of Processes I and II were also discussed on the basis of the present experimental results.
Structure Analysis of a Collagen Model Polypeptide, (Pro–Pro–Gly)10
Authors: Okuyama Kenji , Tanaka Nobuo , Ashida Tamaichi , Kakudo Masao
Published: July 2006

A detailed conformation study of the polypeptide (Pro–Pro–Gly)10, synthesized as a collagen model, has been done using X-ray diffraction. Several structures having the observed helical parameters (unit height=8.61 Å, unit twist=51.4°) together with standard bond lengths and angles were generated and tested in terms of an existence of intermolecular van der Waals contacts and least squares calculations using 49 equatorial reflections. It was found from these studies that three polypeptide chains make a three-stranded rope of which the helical parameters are similar to but significantly different from those of the collagen models proposed so far. There exist two possible models for (Pro–Pro–GIy)10 according to the type of hydrogen bonding. One is the model having a hydrogen bond so-called ‘standard’ structure type, and the other has a hydrogen bond of collagen 11 type. The two-dimensional electron density map, synthesized with the observed structure factors, agrees well with these models. In the least squares calculations, atomic scattering factors were modified by taking into account of effects of amorphous water between the three-stranded ropes.
ESR of Hot Ions: Ni(I) Complex Ions Produced in Rigid Solutions by UV-Exposure
Authors: Amano Chikara , Fujiwara Shizuo
Published: July 2006

It has been shown that univalent nickel complex ions are produced in rigid solutions by electrons released on photo-ionization of N,N,N′,N′-tetramethyl-p-phenylenediamine. These complexes have the same g-values as those obtained by γ-irradiation, suggesting that the univalent nickel complex ions produced on γ-irradiation can be formed as a result of the capture of near-thermal electrons by bivalent nickel complexes. Upon UV-exposure at various sample temperatures between −196 °C and −70 °C, a new chemical species with g⁄⁄ of 2.37 and g⊥ of 2.128 has been observed, which appears to be an exchange-coupled dimer of the univalent hexaaqua nickel complex ions.
Solvent Inclusion Effects on the Structure and Electrical Conductivity of Benzidine-TCNQ Complex
Authors: Takahashi Noriaki , Yakushi Kyuya , Ishii Kikujiro , Kuroda Haruo
Published: July 2006

The solvent-containing modification of benzidine (BD)-tetracyanoquinodimethane (TCNQ) complex is a new type of inclusion compound where solvent molecules are included in the channels of the host lattice formed by hydrogen bonding and charge-transfer interaction between BD and TCNQ. The electrical conductivity at 18 °C is 7×10−10 ohm−1·cm−1 and the activation energy of semiconduction is 0.54 eV in the solvent-free state, but they change to 10−4–10−6 ohm−1·cm−1 and 0.1–0.2 eV, respectively, when an aliphatic solvent is included, and to 10−6–10−9 ohm−1·cm−1 and 0.3–0.5 eV, when benzene or its derivatives is included. By examining the changes of the electrical conductivity and the spin density of BD·TCNQ·[CH2Cl2] system with the pressure change of the ambient dichloromethane vapor, it is concluded that the conductivity of BD·TCNQ·[CH2Cl2] is strongly controlled by the amount of solvent vacancies in the crystal lattice. The correlations between the electrical properties and crystal structures of solvent-containing modifications are discussed.
Silver Ion Catalysed Oxidation of Primary Aliphatic Amines by Potassium Peroxydisulfate — A Kinetic Study
Authors: Babu J Sreekantha , Joshi Km Veena , Bhattacharya A K
Published: July 2006

A detailed kinetic study of the oxidation of propyl-, isopropyl-, butyl- and isobutylamines by potassium peroxydisulfate in presence of silver ions has been carried out in aqueous medium. The effects of silver ion concentration and various neutral salts have been detected and the variation of the order of reaction with respect to amine had been explained. The activity of Ag+ ion has been correlated with the amine structure and probable rate law and the mechanism has been proposed.
π-Electron Structure of Some Nonbenzenoid Hydrocarbons Using β-Variable Method
Authors: Chatterjee Subrata , Das Gupta Nanda K
Published: July 2006

The molecules pentaleno[def]heptalene, cyclohept[fg]acenaphthylene, naphth[cde]azulene and cyclohept[bc]acenaphthylene have been studied using β-variable methods proposed by Dewar et al. and Yamaguchi et al. The predicted results are compared with experimental values and with other theoretical results.
Sterically Controlled Substitution of Copper(II) with 3,3′-Bis[N,N-bis(carboxymethyl)aminomethyl]-o-cresolsulfonphthalein
Authors: Yamada Mutsuo
Published: July 2006

The rate constants for the formation of the diprotonated bimetallic complex of copper(II) with 3,3′-bis[N,N-bis(carboxymethyl)aminomethyl]-o-cresolsulfonphthalein (XO) have been determined by the stoppedflow method. The results are interpreted in terms of the reactions, Cu+LH2\ightleftharpoonsCuLH2 (Remark: Graphics omitted.) Cu2LH2 and Cu+LH3\ightleftharpoonsCuLH2+H (Remark: Graphics omitted.) Cu2LH2+H. The over-all rate constants, k1 and k2 for both reactions are determined to be k1=(3.6±0.3)×106M−1s−1 and k2=(8.7±1.3)×103M−1s−1 and 25.0 °C and I=0.1 M.
The Electrochemical Fluorination of Aliphatic Primary Monohydric Alcohols and Aldehydes
Authors: Abe Takashi , Nagase Shunji , Baba Hajime
Published: July 2006

The perfluorocyclic ethers as well as the perfluoroalkanoyl fluorides were obtained by the electrochemical fluorination of primary monohydric alcohols and aldehydes containing 4–8 carbon atoms. The five-membered rather than the six-membered perfluorocyclic ethers were formed as the cyclic products. The over-all yields of the perfluorocyclic ethers and the perfluoroalkanoyl fluorides from the alcohols were in the range of 10–20%, and 3–12% respectively. Those from the aldehydes were poor because of the formation of a considerable amount of tarry by-products. The physical properties of the perfluorocyclic ethers obtained are also described.
Syntheses of Polymerizable Acetals. I. Vinylbenzaldehyde Acetals with Perfume Alcohols
Authors: Kamogawa Hiroyoshi , Okabe Shinya , Nanasawa Masato
Published: July 2006

Several acetal monomers and a hemiacetal monomer of vinylbenzaldehydes were synthesized from the reaction with some perfume alcohols in the presence of p-toluenesulfonic acid as an acid catalyst. It was found that primary alcohols such as citronellol and geraniol with the exception of cinnamyl alcohol afforded acetal monomers in high yields, secondary alcohols such as borneol and menthol in low yields, with the latter affording only hemiacetal monomer, and linalool, a tertiary alcohol, neither acetal nor hemiacetal monomers. The radical polymerizations of the acetal and hemiacetal monomers synthesized provided soluble polymers which easily release perfume alcohols under mild acidic conditions.
Reactions of 2,4-Dialkoxy-1,3-diphenyl-1,3,2,4-diazadiphosphetidines with Benzil, Benzalacetophenone, and α-Phenyliminobenzyl Phenyl Ketone
Authors: Kawashima Takayuki , Inamoto Naoki
Published: July 2006

2,4-Diethoxy-1,3-diphenyl-1,3,2,4-diazadiphosphetidine (1a) reacted with benzil, benzalacetophenone, and α-phenyliminobenzyl phenyl ketone in refluxing o-dichlorobenzene to give 2-ethoxy-3,4,5-triphenyl-Δ4-1,3,2-oxazaphospholine 2-oxide, 2-ethoxy-1,3,5-triphenyl-Δ4-1,2-azaphospholine 2-oxide, and 2-anilino-3,4,5-triphenyl-Δ4-1,3,2-oxazaphospholine 2-oxide, respectively. Under mild conditions, reaction of 1a with benzil gave a Ramirez type 1:2 adduct, which thermally decomposed to give oxazaphospholine derivatives.
Optical Activation of Racemic α-Substituted Carbonyl Compounds Using Optically Active Amines
Authors: Matsushita Hajime , Noguchi Masao , Yoshikawa Sadao
Published: July 2006

Hydrolysis of immonium salts of enamines consisting of optically active amines and racemic α-substituted carbonyl compounds with hydrochloric acid gave the corresponding optically active carbonyl compounds. The NMR spectra showed that the immonium salt is a mixture of two diastereomeric isomers. The mechanism of the optical activation is discussed on the basis of an isotope labeling experiment and the NMR spectra.
The Oxidation of 3-(2-Hydroxyphenyl)coumarins with Lead Tetraacetate
Authors: Kurosawa Kazu , Nogami Keifumi
Published: July 2006

Five 3-(2-hydroxy-4-methoxyphenyl)coumarins (Ia–Ie) were oxidized with lead tetraacetate to the corresponding 6H-benzofuro[3,2-c][1]benzopyran-6-ones (IIa–IIe) and 3-(1-acetoxy-4-methoxy-2-oxo-3,5-cyclohexadienyl)coumarins (IIIa, IIIb, and IIId). Four 3-(3,4-dimethoxy-2-hydroxy-phenyl)coumarins (If–Ii) gave the corresponding 3-(1-acetoxy-3,4-dimethoxy-2-oxo-3,5-cyclohexadienyl)coumarins (IIIf–IIIi).
Synthesis and Biological Activities of 2-Amino-2-deoxy- and 6-Amino-6-deoxy-α-d-glucopyranosyl-2,5-dideoxystreptamines
Authors: Ogawa Seiichiro , Funaki Yuji , Iwata Keiji , Suami Tetsuo
Published: July 2006

To investigate a relationship between structural features of aminocyclitols and biological activities of aminocyclitol antibiotics, 4-O-(2′-amino-2′-deoxy-α-d-glucopyranosyl)- and 4-O-(6′-amino-6′-deoxy-α-d-glucopyranosyl)-2,5-dideoxystreptamines (8 and 15a) have been synthesized, and their biological activities against several microorganisms were determined.
A Potential Synthetic Intermediate of dl-Carnosic Acid
Authors: Oommen P Kurian
Published: July 2006

The Birch reduction of 2,7-dimethoxy-3-isopropylnaphthalene (IIb), which itself was made from IIa in five steps, followed by acid hydrolysis yielded the tetralone IIIa and the latter was carboxymethylated to IIIb by reaction with dimethyl carbonate and sodium hydride. Michael condensation of IIIb with methyl vinyl ketone yielded the unsaturated ketone IV. The tricyclic ketone IV on methylation followed by thioketalisation gave the thioketal IXa and the latter on Raney nickel desulfurisation yielded Ic.
A Shock-tube Investigation of Ethylene–Oxygen–Argon Mixtures. Chemi-ionization and Apparent Activation Energy
Authors: Hidaka Yoshiaki , Nishi Tomofumi , Suga Masao
Published: July 2006

The reaction of ethylene–oxygen mixtures highly diluted with argon was studied over the temperature range of 1400–1800 K behind reflected shock waves by monitoring the total ionization. A kinetic study of the chemi-ionization in the ethylene oxidation was undertaken. It was inferred that the mechanism of CHO+ formation was dependent on the composition and the temperature, and that the rate-determining step for the chemi-ionization was C2H3+O2→C2H3O+O.
Solvent Effect on the Raman Spectra of Mercury(II) Halides
Authors: Sone Kozo , Aritaki Makiko , Hiraoka Keiko , Fukuda Yutaka
Published: July 2006

Raman spectra show that the Hg–X bond strengths in mercury (II) halides are remarkably weakened by the interaction with certain solvents. Relations between the degree of this weakening and (a) the Lewis basicity (Gutmann’s donor number) of the solvent and (b) the ionic character of the Hg–X bond are pointed out, together with a simple explanation.
Origin of the Oxygen Atom in the Nitrosomesitylene Formed by the Oxidation of Mesidine with Fremy’s Salt
Authors: Takahashi Tomoji , Minato Hiroshi , Kobayashi Michio
Published: July 2006

The mechanism of the oxidation of aromatic amines with Fremy’s salt was investigated by use of 18O-labelled compounds. It was shown that the nitroso-oxygen atom originates not from water but from the nitroxide oxygen and sulfonate oxygen atoms of Fremy’s salt.
Synthesis of 2-Aminonaphthalene-1-thiol and Its Conversion into 8-Nitro-7H-benzo[c]phenothiazine
Authors: Gupta R R , Jain S K
Published: July 2006

Synthesis of 2-Aminonaphthalene-1-thiol by hydrolytic cleavage of 2-aminonaphtho(2′,1′: 4, 5)thiazole and its conversion into 8-nitro-7H-benzo[c]phenothiazine via Smiles rearrangement in situ are reported.
Synthesis of Succin-as-eins. III. Dyes Derived from β-Benzoylpropionic, β-(3-Acenaphthoyl)propionic and β-(α-Thenoyl)propionic Acids
Authors: Gopal R , Gupta P C , Garg S P
Published: July 2006

A number of succin-as-eins have been prepared by condensing β-benzoylpropionic, β-(3-acenaphthoyl)propionic and β-(α-thenoyl)propionic acids with phenol, resorcinol, catechol, quinol, phloroglucinol, pyrogallol and orcinol.
The Effect of Metal Oxides on the Transformation of Copper Phthalocyanine Crystals in Organic Solvents
Authors: Kawashima Norimichi , Suzuki Takao , Meguro Kenjiro
Published: July 2006

The dimorphic transformation of copper phthalocyanine crystals was examined by means of X-ray diffraction analysis and electron-micrograph observation, for α-copper phthalocyayine and metal oxides of various mixing ratios with respect to weight were ground using a grinder and suspended in an organic solvent. The α-β transformation of copper phthalocyanine is accelerated by the presence of metal oxides such as alumina, magnesia, and zinc oxide. Particularly, alumina has a remarkable effect on the acceleration of β-copper phthalocyanine formation. The rate of transformation increases with the amount of metal oxide and the grinding time for a mixture of copper phthalocyanine and alumina. The activation energy for the α-β transformation in a (1 : 1) mixture of copper phthalocyanine and alumina ground for 30 min was calculated to be 12.0 kcal/mol.
Group Interactions in Polyelectrolytes. XII. Amination Kinetics of Chloromethylated Polystyrene in Binary Solvent Systems Composed of Dioxane and Dipolar Aprotic Solvents
Authors: Kawabe Hiroshi
Published: July 2006

The activation parameters (ΔG\eweq, ΔH\eweq, ΔS\eweq) in the amination reaction of chloromethylated polystyrene (CMPS) and benzyl chloride with s-butylamine in N,N-dimethylformamide (DMF)–dioxanes mixtures and with 2 amino-1-butanol in dimethyl sulfoxide (DMSO)–dioxane mixtures were investigated as a function of x1 the mole fraction of DMF or DMSO in the binary mixed solvents. A similar dependence of the parameters on x1 was found in both systems, and the observed values of the parameters were in fair agreement with those calculated on the basis of Kondo and Tokura’s theory concerning reaction rates in binary mixed solvents, assuming that the activated complex is solvated selectively with DMF or DMSO to form an addition product. The solvation in the DMSO–dioxane system was stronger than that in the DMF–dioxane system. Although ΔG\eweq decreases relatively uniformly with the increase in x1, ΔH\eweq decreases sharply and reaches nearly a constant value at x1≈0.2. It was suggested that the increase of TΔS\eweq in the range of x1>0.2, which is approximately proportional to that of x1, may be due to the relative increase in the configurational entropy change of the reaction system on transfer from dioxane to the dipolar aprotic solvents.