bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of 1-N-[(S)-4-Amino-2-hydroxybutyryl]lividomycin A
Authors: Watanabe Isamu , Tsuchiya Tsutomu , Umezawa Sumio , Umezawa Hamao
Published: July 2006

The title compound (7), which is active against resistant bacteria producing phosphotransferase I, was synthesized from lividomycin A through a cyclic carbamate derivative (3). Selective hydrolysis of the carbamate ring followed by acylation of the free C-1-amino group with (S)-2-hydroxy-4-aminobutyric acid by the active ester method led to 7.
Studies of the Fragment-ion Distribution and Reaction with a Charge Spectrometer. VI. A New Interpretation of the Fragmentation Mechanism in CH3X Based on the Molecular Orbital Method. (2)
Authors: Ikuta Shigeru , Yoshihara Kenji , Shiokawa Takanobu
Published: July 2006

We have proposed a new fragmentation mechanism and successfully applied it to various monosubstituted alkanes RX. The fragmentation mechanism can be described as follows: (1) The bond scission first occurs where the electrons exist densely in the particular occupied molecular orbital correlated to the particular ionization. (2) Process (1) competes with the electron redistribution. (3) In the higher-energy region, secondary scission also occurs. The breakdown curves of the CH3NH2+, CH3SH+, and CH3Br+ produced by charge-exchange reactions have been obtained by the use of a perpendicular double-mass spectrometer. The experimental results can be satisfactorily explained by the proposed mechanism on the basis of the calculated eigenvectors of the various molecular orbitals.
The Computation of the Thermodynamic Properties of Aqueous Electrolyte Solutions by Means of the Perturbation Theory of Fluids
Authors: Hirata Fumio , Arakawa Kiyoshi
Published: July 2006

A useful method to investigate the thermodynamic properties of aqueous electrolyte solutions was presented on the basis of the perturbation theory of fluids, where a primitive model was used as a reference system. A perturbation potential of a square type was applied. An analytical solution of the mean spherical model (MSM) equation obtained by Waisman and Lebowitz was used as the thermodynamic functions of the reference system, and an ionic distribution function in electrolyte solutions was derived. The values of the energy parameters which represent the depth of the well were determined by a comparison of the observed values of the thermodynamic quantities with the calculated ones.
Some Properties of the Salt between Inosine and l-Lysine
Authors: Suzuki Yoshihisa , Hara Kentaro , Hirahara Tsuneo
Published: July 2006

Among several basic amino acids, only the l-lysine free base was found to form a crystalline salt with inosine. A specific stereochemical arrangement of these two molecules, inosine and l-lysine, is considered to be involved in such a crystalline salt-formation on the basis of the fact that d-lysine did not form a crystalline salt with inosine. Part of the equilibria were determined at 10 °C for the inosine–l-lysine–water and inosine–l-lysine-60 w/w % aqueous ethanol systems. The salt was unstable against water, while it was stable against aqueous ethanol (containing more than about 40% ethanol). The solubility of the salt in water was summarized as follows: logS (w/w %) =0.0219t+0.624. The X-ray powder diffraction data of the salt are given.
A Polarographic Cell for the Continuous Monitoring of Column Effluents and Its Application to the Determination of Nitropyridine Derivatives
Authors: Wasa Tamotsu , Musha Soichiro
Published: July 2006

The construction of a microdetector, based on the principle of polarography, for liquid chromatography and its application are described. The characteristics of the flow cells with a horizontal dropping mercury electrode (HDME), a vertical dropping mercury electrode (DME), and a mercury plated platinum electrode (Hg–Pt) are compared with each other. The flow cell has been applied to the analysis of a mixture of nitropyridine derivatives, such as 2-amino-3-nitropyridine (A3N), 2-amino-5-nitropyridine (A5N), 2-hydroxy-3-nitropyridine (O3N), 2-hydroxy-5-nitropyridine (O5N), and 2-nitroaminopyridine (NA), by means of a reversed-phase partition column or an ion-exchange column. In quantitative analysis, a standard deviation of better than 3% can be obtained.
The Reactions of Recoil Tritium Atoms with Water. II. Reactivity Integral- and Moderator-Isotope Effects in H2O–D2O Binary Mixtures
Authors: Tachikawa Enzo , Aratono Yasuyuki
Published: July 2006

The HT and DT yields from the nuclear transformation of 6Li(n,α)T in H2O–D2O binary mixtures were studied in the liquid phase. The (HT/H2O)/(DT/D2O) ratio was nearly constant at 1.60±0.08 over the whole range of mol fractions of D2O in the presence of I2 as a scavenger. Using the kinetic model with reasonable assumptions, the relative efficiencies for the kinetic moderation of H2O, HDO, and D2O were determined. The results indicate that the collision of recoil T atoms with HDO, with a large fractional energy loss, must occur as frequently as with H2O.
An Analysis of the Surface Composition of Passive Film on Cu–Ni Alloys by means of Auger Electron Spectroscopy and X-Ray Photoelectron Specroscopy
Authors: Takasu Yoshio , Maru Shun-ichi , Matsuda Yoshiharu , Shimizu Hazime
Published: July 2006

A potentiostatic polarization method, Auger electron spectroscopy (AES), and photoelectron spectroscopy (XPS) were used to examine the composition of the passive films formed on Cu–Ni alloys anodized in an acid. The Flade potential of pure nickel in 0.5 M HClO4 at 25 °C was −0.085 V (vs. SCE), while those of the alloys varied linearly from 0.180 V at 95%Ni to 0.310 V at 47%Ni. Analysis by AES and XPS revealed that (a) the passive region contained nickel and copper in the same ratio as the alloy, and (b) the chemical species of the film were made of NiO and copper oxide (Cu2O and/or CuO). The Flade potential was assumed to be governed by the mixed potential of the formation of such oxides.
X-Ray Study of the Compound Obtained by the Reaction of Nδ-Salicylidene-l-ornithine and Palladium(II) acetate. The Crystal Structure of (Nα-Salicylidene-d-ornithinato) (Nα-Salicylidene-l-ornithinato)dipalladium(II)-Dimethyl Sulfoxide
Authors: Kojima Yoshitane , Matsui Masanori , Matsumoto Keiji
Published: July 2006

X-Ray structure analysis has elucidated that the reaction of Nδ-salicylidene-l-ornithine and palladium(II) acetate in DMF results in the amine exchange and racemization of the ligand, yielding (Nα-salicylidene-d-ornithinato)(Nα-salicylidene-l-ornithinato)dipalladiuna(II). The yellow crystals are monoclinic, a=15.15(2), b=9.80(1), c=15.67(2) Å, β=111.3(1)°, space group P21⁄c, and Z=2. The structure was solved by the Patterson and Fourier techniques and was refined by the least-squares method to R=0.105. The complex molecule has a center of symmetry by which d- and l-Schiff-base ligands are interrelated. Each Pd atom has a square-planar coordination by means of two O and Nα atoms of one ligand, and the Nδ atom of the other one, the two N atoms being in the trans position. The H2Nδ–(CH2)3–CH–Nα fragments of the two ligands bridge the two Pd atoms, giving a 14-membered ring.
Catalytic Activities of a Polyoxime–cobalt Complex for the Addition Reaction of an Alcohol to Acrylaldehyde and for the Polymerization of Styrene
Authors: Kim Sung Jho , Takizawa Takeo
Published: July 2006

A new polymeric cobalt-chelate complex was prepared from cobalt acetate and a polyoxime consisting mainly of 1,2-bis(hydroxyimino)trimethylene units. The polymeric complex in the solid state at 77–300 K, both in air and under a vacuum, gives an ESR signal with a g-value of about 2 and can initiate the polymerization of styrene and catalyze the “Michael”-type addition reaction of an alcohol to acrylaldehyde, yielding exclusively β-alkoxypropionaldehyde, after being treated with phenylthiol and sodium borohydride. The catalytic activities depend greatly on the cobalt content and are much greater than those of its monomeric analogue in composition, bis(dimethylglyoximato)cobalt. The absorption spectrum of the polymeric complex treated with the reagents is similar to that of monomeric or polymeric analogues containing monovalent cobalt atoms.
Oxidation of a Conductive Polymer-TCNQ Salt with Atmospheric Oxygen
Authors: Nakatani Kenji , Sakata Tadayoshi , Tsubomura Hiroshi
Published: July 2006

The oxidation reaction of conductive poly-4-vinylpyridinium (P4VP+) tetracyano-p-quinodimethanide(TCNQ\ewdot) with oxygen has been studied. The main product of this reaction is found to be α,α-dicyano-p-toluoylcyanide. An interesting difference in reactivity was observed between the polymer salt and the ethanol solution of the monomer salt.
A Facile Synthesis of 6-Chloro-d-tryptophan
Authors: Moriya Tamon , Hagio Katsuaki , Yoneda Naoto
Published: July 2006

A nonnutritive sweetener, 6-chloro-d-tryptophan (4), was synthesized from d-tryptophan (1) by nitration, hydrogenation and diazotization, followed by a reaction with cuprous chloride. The optical rotation of 4 agreed with that of an authentic sample which had been prepared by the resolution of racemic 4 methanesulfonate.
Synthesis of Succin-as-eins. II. Dyes Derived from β-(2-Fluoroyl) propionic, β-(3-Phenanthroyl)propionic Acids and Carbazole-3,6-bis(γ-ketobutyric Acid)
Authors: Gopal R , Gupta P C
Published: July 2006

A number of succin-as-eins have been prepared by condensing β-(2-fluoroyl)propionic, β-(3-phenanthroyl) propionic acids and carbazole-3,6-bis(γ-ketobutyric acid) with phenol, resorcinol, catechol, quinol, phloroglucinol, pyrogallol, and orcinol.
Calculation of the Ionization Yield in He by Incident Ar+ and H+Ions with the Initial Energies of 1 and 0.1 MeV
Authors: Ohno Shin-ichi
Published: July 2006

The classical binary-encounter theory was used to calculate the G(He+) due to the direct action of incident particles and that due to the secondary electrons. The results show that both values depend greatly on the quality of the radiation used.
Ranges and Lifetimes of Electrons in Irradiated Liquid Hydrocarbons. Application of the Modified Exponential Distribution Function
Authors: Baba Masatoshi , Fueki Kenji
Published: July 2006

A modified exponential function is developed for the description of the spatial distribution of electrons in irradiated liquid hydrocarbons. This distribution function is applied to calculations of ranges and lifetimes of electrons in a number of hydrocarbons. The temperature dependence of electron ranges is also investigated for some of the hydrocarbons. A calculation is made of electron scavenging in cyclohexane using this distribution function and the forced diffusion approximations.
A Study of the Exchange Reaction between Water and Surface Hydroxyl Groups on Magnesium Oxide by Means of Infrared Diffuse Reflectance Spectroscopy
Authors: Takezawa Nobutsune , Kobayashi Haruo
Published: July 2006

Infrared diffuse reflectance spectroscopy was applied to the study of the exchange reaction between water and surface hydroxyl groups on magnesium oxide. The results led to the conclusion that (i) no reaction occurs via the combination of hydroxyl groups, and (ii) the hydroxyl groups react with adsorbed water reversibly. Two types of hydroxyl groups present on the surface are involved in the rate determining step.
Complex Formation between the Uranyl Ion and Citric Acid
Authors: Ohyoshi Emiko , Oda Junko , Ohyoshi Akira
Published: July 2006

A method to facilitate the analysis of the complex formation by a polybasic acid has been applied to the study of uranyl citrate complexes. The amount of the uranyl ion in equilibrium with the complexing agent was determined by the cation-exchange method. In this experiment, the uranyl-ion concentration was kept within a 105–106 M range in order to eliminate polymeric species. By using a series of solutions prepared so as to keep [H3Cit−] nearly constant and to vary [H2Cit2−] and [HCit3−] in the 2.2–2.9 pH range, it has been found that three kinds of complexes, UO2H3Cit+, UO2H2Cit, and UO2HCit−, were present in the solution. Approximate values of their formation constants were obtained.
The Syntheses and Spectroscopic Investigation of Copper(II), Nickel(II), and Cobalt(II) Complexes of 8-Quinolinecarboxamide
Authors: Noji Masahide , Kidani Yoshinori , Koike Hisashi
Published: July 2006

The syntheses of the bivalent metal complexes of 8-quinolinecarboxamide (abbreviated as 8-QCA) were attempted; the complexes obtained have the compositions of M(8-QCA)2X2 (M=Cu(II), Ni(II), and Co(II) ions; X=Cl−, Br−, I−, and NO3−) and Cu(8-QCA)Cl2. The diffuse reflectance, the infrared and far-infrared spectra, and the magnetic moments of these metal complexes were measured. The coordination sites of 8-QCA have been suggested for the amide oxygen and the quinoline nitrogen from the diffuse reflectance spectra and the infrared spectra. The values of 3.13–3.21 B.M. and 4.81–5.03 B.M. were observed for Ni(8-QCA)2X2 and Co(8-QCA)2X2 respectively. From these magnetic moments, an octahedral structure has been proposed for the nickel and the cobalt complexes, whose far-infrared spectra (600–200 cm−1) also supported this structure, with a trans-planar coordination of the 8-QCA molecules around the metal ions. Since the Cu(8-QCA)2X2 complexes are of the mononuclear form, judging from the magnetic moments of 1.87–1.93 B.M., and since the far-infrared spectra suggested a structure belonging to the C2h point group, a distorted octahedral configuration is conceivable.
Use of a Glass Electrode in the Potentiometric Study of Acid-Base Equilibria of Zinc and Cadmium Acetates in Acetic Acid
Authors: Sawada Kiyoshi , Nakano Mitsuji , Mori Hidenari , Tanaka Motoharu
Published: July 2006

Potentiometric study of acid-base equilibria of zinc and cadmium acetates in acetic acid was undertaken with a glass electrode filled with a LiCl–HClO4 acetic acid solution. Potentiometric titration of 0.1 m LiClO4 acetic acid solution with perchloric acid and lithium acetate reveals that the glass electrode gives rise to the Nernstian response. The equilibrium constant of the reaction, HClO4+LiOAc \oversetKf\ightleftharpoons LiClO4+HOAc is found as logKf=7.86. The titration of zinc and cadmium acetate with perchloric acid and lithium acetate points to the following equilibria: M(ClO4)2+LiOAc \oversetβ1\ightleftharpoons M(OAc)(ClO4)+ LiClO4, M(ClO4)2+2LiOAc \oversetβ2\ightleftharpoons M(OAc)2+2LiClO4, M(ClO4)2+3LiOAc \oversetβ3\ightleftharpoons LiM(OAc)3+2LiClO4. Logarithmic overall formation constants of the acetato complexes, β1, β2 and β3 were determined as 4.04, 7.00 and 9.2 respectively for zinc, and 3.43, 5.46 and 8.0 respectively for cadmium. In addition zinc forms tetraacetate complex with the overall formation constant of logβ4=12.4.
Synthesis of Chloro(organo-oxy)tin(IV) from Organo-hydroxylic Compound and Tin(II) Chloride
Authors: Masaki Mitsuo , Fukui Kiyoshi , Uchida Izuhiko , Yasuno Hiroshi
Published: July 2006

The reaction of an organo-hydroxylic compound and tin(II) chloride with a chlorine compound containing positively polarizable chlorine was found to yield trichloro(organo-oxy)tin(IV) or its disproportionation products, dichlorobis(organo-oxy)tin(IV) and tin(IV) chloride. The reaction of tin(II) chloride and N-chlorosuccinimide (NCS) with methanol or ethanol afforded methoxy- or ethoxy-trichloro(succinimide)tin(IV) (1), while the reaction with n-butanol led to the formation of dibutoxydichlorotin(IV) (2) and tetrachlorobis(succinimide)tin(IV) (3). The reaction of tin(II) chloride and NCS with alcohols in the presence of cyclohexanone oxime gave dialkoxydichloro(cyclohexanone oxime)tin(IV) (6). Cyclohexanone oxime and hexahydro-2H-azepin-2-one(3,4,5,6-tetrahydro-2H-azepin-7-ol) could be used as the organo-hydroxylic reagent in the reaction, while 1-chloronitrosocyclohexane and N-chlorohexahydro-2H-azepin-2-one were also useful as the chlorine compound. Thus, dichlorobis(cyclohexanone oximato)tin(IV) (9), dichlorobis(hexahydro-2H-azepin-2-onato)tin(IV) (13), and an adduct of 9 with tetrachlorobis(hexahydro-2H-azepin-2-one)tin(IV) (1 : 1) were prepared. Two stable complexes, bis(benzophenone oximato)dichlorobis(hexahydro-2H-azepin-2-one)tin(IV) (15) and dichlorobis(2-pyridinethiolato)tin(IV) (11), were synthesized by the reactions of 13 with benzophenone oxime and 2-pyridinethiol respectively. The complex 13 was also synthesized by the reaction of N-trimethylsilylhexahydro-2H-azepin-2-one with tin (IV) chloride.
The Crystal and Molecular Structure of cis-2,2-Diphenyl-3,4-dichlorothietane
Authors: Kumakura Shigekazu , Kodama Toshiko
Published: July 2006

The crystal structure of cis-2,2-diphenyl-3,4-dichlorothietane has been determined from three-dimensional X-ray data collected by the photographic method. The compound forms monoclinic crystals with a=9.94(1), b=12.56(1), c=12.96(1) Å, β=120.66(8)°, and Z=4 in the space group of P21⁄c. The structure has been refined by the block-diagonal least-squares method to a final R value of 0.10, based on 1578 observed reflections. The conformation of the C–Cl bonds with respect to the thietane ring is (3e4a), consistent with that in solution derived from the dipole moments. The thietane skeleton of the compound is puckered, with a dihedral angle of 151.1°. The two C–S distances are 1.81 Å and 1.89 Å, and the average distance between the C–Cl bonds is 1.785 Å. The C–S and C–Cl bond characters are discussed in terms of the CNDO/2 method. The intermolecular S···S contact of 3.32 Å is remarkably short; it may be explained as a consequence of an attractive interaction between the dipole moments of the molecules.
Studies of 4-Diethylenetriaminemonoacetatocobalt(III) Complexes. I. The Preparation and Identification of 4-Diethylenetriaminemonoacetatocobalt(III) Complexes with Ethylenediamine, Oxalate Ion, or Acetylacetonate Ion as the Additional Ligand
Authors: Kuroda Kashiro , Mori Yoshio , Matsunaga Hitoshi , Kunigita Kazufumi , Watanabe Kiyokatsu
Published: July 2006

The fac(N)- and mer(N)-isomers of 4-diethylenetriaminemonoacetatocobalt(III) complexes with ethylenediamine, the oxalate ion, or the acetylacetonate ion as the additional ligand have been obtained by means of reactions between chloro(4-diethylenetriaminemonoacetato)aquocobalt(III) chloride and the bidentates under different conditions. The geometrical configuration of each isomer has been identified by means of the PMR spectra and the electronic absorption spectra. The methine hydrogen in the acetylacetonato complexes has been replaced with bromine, and the resulting complexes have also been characterized.
Group Interactions in Polyelectrolytes. XI. The Kinetics of N-Methylation of Poly(ethyleneimine)
Authors: Kawabe Hiroshi
Published: July 2006

The N-methylation of polyethyleneimine (PEI) of low and high molecular weights as well as that of diethylenetriamine was investigated kinetically in 50% aqueous ethanol; during the procedure we observed deceleration due to the electrostatic effect of the neighboring charged groups. The rate equation was derived for the N-methylation of PEI, which proceeded in three steps with a marked deceleration beyond quarter-conversion and also beyond half-conversion. In the second and third steps of the N-methylation of PEI, additional energies equivalent to the electrostatic free energies due to the one and the two nearest-neighboring charged groups were required respectively, in addition to the intrinsic activation energy of the first step.
Gas-chromatographic Behavior of C1, C2, and C3-Halocarbons Containing Iodine
Authors: Makide Yoshihiro , Fukumizu Takefumi , Tominaga Takeshi
Published: July 2006

The regularity of the specific retention volume (Vg) in gas chromatography was investigated on a number of C1, C2, and C3 halocarbons containing iodine. The log Vg value was found to correlate with the number of halogen and carbon atoms in the molecule.
The Synthesis of Flemichapparin-A and Its Derivatives
Authors: Yamada Shigetoshi , Ono Futara , Katagiri Takao , Tanaka Juntaro
Published: July 2006

Some chromenochalcones including Flemichapparin-A were synthesized in 53–63% yields from 6-acetyl-5,8-dihydroxy-2,2-dimethylchlomene and benzaldehydes.
Photolysis of Aromatic Oxime Esters. Finding of Aromatic Substitution by Diphenylmethyleneimino Radicals
Authors: Ohta Hiroyuki , Tokumaru Katsumi
Published: July 2006

Diphenylmethyleneimino radicals, Ph2C=N·, generated from photolysis of benzophenoxime benzoates undergo aromatic substitution on benzene as well as dimerization into azine. On the other hand, phenylmethyleneimino radicals, PhCH=N·, generated from photolysis of benzaldoxime benzoate are oxidized to benzonitrile in preference to dimerization.
A Convenient Synthesis of 2,3-Benzotropone from α-Tetralone by Ring-expansion
Authors: Sato Masaru , Tanaka Takashi , Tsunetsugu Josuke , Ebine Seiji
Published: July 2006

2,3-Benzotropone (1) has conveniently been prepared from easily available α-tetralone (2) in good overall yield by the following successive reactions: dihalocarbene addition to enol-ether (3) derived from 2, ring-expansion of the adduct (4) to halobenzocycloheptadienone (5), and dehydrohalogenation of 5 giving 1.
Synthesis of Acyl Derivatives of β-Lysine for Peptide Synthesis
Authors: Wakamiya Tateaki , Uratani Hiroshi , Teshima Tadashi , Shiba Tetsuo
Published: July 2006

Dibenzyloxycarbonyl- and di-t-butyloxycarbonyl-l-β-lysine were synthesized from corresponding diacyl-l-ornithine by modified Arndt-Eistert reaction involving diazoketone preparation via the mixed carbonic carboxylic anhydride. These diacyl-β-lysine derivatives are required for total- or semi-syntheses of peptide antibiotics, tuberactinomycins or streptothricins.
Solvent Effect of Methanol on the Rate of Formation Reaction of Monochloroiron(III) Complex in Aqueous Solution
Authors: Wada Goro , Kobayashi Yaeko
Published: July 2006

The rate constants of the formation reaction of FeCl2+ complex from Fe(III) and Cl− ion were measured in water-methanol mixed solvents by use of a stopped-flow spectrophotometer. The apparent rate constant k is dependent upon the acid concentration of the medium, indicating that the reaction can proceed through two parallel paths, Fe3++Cl− (k1) and Fe(OH)2++Cl− (kH). Both k1 and kH increase with the increase in the mole fraction of methanol in the medium, xM. Since kH is much larger and is consequently much more accurately determined than k1 considerations were mainly made on the nature of kH. According to the dependence of kH on the dielectric constant of the medium, it was found that the activation free energy of the Fe(OH)2++Cl− reaction consists of the electrical and non-electrical parts and that the dimension of the activated complex corresponds approximately to the distance of the outer-sphere approach between the reacting species. These facts are therefore in favor of an outer-sphere mechanism in the anation reactions of iron (III) by simple anions.
Preparation and Some Properties of Triorganosiloxy Derivatives of Cyclopentadienyl Titanium
Authors: Suzuki Hideo , Takiguchi Toshio
Published: July 2006

Several triorganosiloxy derivatives of cyclopentadienyl titanium were synthesized by the reactions of dicyclopentadienyl titanium dichloride or cyclopentadienyltitanium trichloride with triorganosilanols or their sodium salts. The products obtained include π-Cp2TiClOSiMe3, π-CpTi(OSiMe3)3, π-CpTi(OSiMe2Ph)3, π-CpTi(OSiPh2Me)3, π-CpTi(OSiPh3)3, π-CpTi(OSiPh3)2Cl and π-CpTi(OSiPh3)Cl2. Some correlations were found to exist between the substituents on silicon atoms and cyclopentadienyl ring protons in NMR spectra and the Ti–O–Si bond absorptions in IR spectra. The chemical stabilities of the Ti–O–Si bonding in the products were dependent on the nature of the organic groups attached to the silicon atoms. The chemical resistance of the products against hydrolytic cleavage was regularly increased with successive replacement of methyl groups by phenyl groups.
The Carbonyliron Complexes of Some Chlorocarbons
Authors: Matsukura Takefumi , Mano Koichi , Fujino Akira
Published: July 2006

The (tetracarbonyl)iron complexes of perchloro-(3,4-dimethylenecyclobutene) and perchlorofulvene, and the (tricarbonyl)iron complex of the former chlorocarbon were synthesized. The structural evidences for those complexes were given on the basis of the DSC, their chemical behaviors, and the UV, IR and other spectral data. Particularly, their mass-, NQR- and 13C-NMR-spectra were discussed in detail by comparing them with those of the substrate chlorocarbons.
Optical Activity and Absolute Configuration of 2,3 :6,7-Dibenzobicyclo [3.3.1]nona-2,6-diene Derivatives
Authors: Tatemitsu Hitoshi , Ogura Fumio , Nakagawa Yasuhiro , Nakagawa Masazumi , Naemura Koichiro , Nakazaki Masao
Published: July 2006

2,3 : 6,7-Dibenzobicyclo[3.3.1]nona-2,6-diene-4,8-diol was synthesized and resolved via (−)-menthoxyacetate. Several kinds of optically active derivatives with the same absolute configuration were prepared from the (−)-diol and their chiroptical properties were recorded. The absolute configuration of this series of compounds was determined to be 1R, 5R by a chemical correlation with (R)-(−)-3-phenylbutanoic acid via (−)-1,3-diphenylglutaric acid and (−)-2,4-diphenylpentane.
Chemical Studies on Tuberactinomycin. IX. Nuclear Magnetic Resonance Studies on Tuberactinomycins and Tuberactinamine N
Authors: Wakamiya Tateaki , Shiba Tetsuo
Published: July 2006

Conformational analyses of peptide antibiotics tuberactinomycins were performed by NMR spectroscopy of 100 MHz. Studies on temperature dependence and deuterium exchange in amide proton resonances revealed the presence of an intramolecular hydrogen bond participated with α-amide proton of the guanidino amino acid residue in the cyclic part of each molecule. The same result was obtained in tuberactinamine N, which is the cyclopeptide moiety without amino acid side chain in tuberactinomycins N and O. The common rigid structure fixed by hydrogen bonding in the cyclic part seems to be a requisite for the exhibition of microbial activity in tuberactinomycin family.
Racemization Catalyst for Amino Acid. IV Enantiomer Differentiating Racemization with (S)-2′-Nitro-5-nitroso-6,6′-dimethylbiphenyl-2-ol
Authors: Hirota Kazuhiro
Published: July 2006

The racemizations of both enantiomers of alanine were carried out with (S)-2′-nitro-5-nitroso-6,6′-dimethylbiphenyl-2-ol (1) in the presence of cupric ion. In time course studies, the apparent half-life of d-alanine is longer than that of l-alanine. Such an enantiomer differentiating ability is explained by a mechanism involving a reactive product formed from the preferred conformation of the diastereomeric cupric complexes, consisting of 1 and d- or l-alanine, respectively. Synthesis of 1  via the resolution of 2′-nitro-6,6′-dimethylbiphenyl-2-amine is also presented.
Relative Determination of the Soret Coefficients of Electrolytes. V
Authors: Ikeda Toshio , Takatsuka Yoshihiro , Watanabe Takeshi
Published: July 2006

The Soret coefficients of aqueous solutions of some transition metal chlorides were determined by use of combined thermocells. The following values (in 10−3 K−1) were obtained in 0.005 M solutions at 25°C: −7.01 for MnCl2, −4.61 for CoCl2, −2.67 for NiCl2, and −3.43 for CuCl2. It was concluded that ion paramagnetism does not affect thermal diffusion.
Proton Magnetic Resonance in Some Triarylaminium Salt Free Radicals
Authors: Yoshioka Toshio , Watanabe Kohji , Ohya-Nishiguchi Hiroaki
Published: July 2006

The static magnetic susceptibilities from 77 to 300 K and the proton NMR spectra from 1.5 to 77 K have been measured on powder samples of tris-p-chlorophenylaminium perchlorate and chloroantimonate, and tris-p-tolylaminium perchlorate and chloroantimonate. The Weiss constants have been determined to be −2.0, −40, −0.5, and −10 K respectively. A broad maximum which indicates an antiferromagnetic interaction has been observed in the electron susceptibilities of the chloroantimonates obtained from the paramagnetic shift. The magnetic behavior is interpreted assuming the linear-chain model. On the other hand, the perchlorates obeyed the Curie-Weiss law down to 1.5 K. The isotropic hyperfine coupling constants of these four aminium salts have been estimated from the proton NMR spectra, from which the cations of these crystalline aminium salts can be expected to have similar configurations.
α,β-Unsaturated Carboxylic Acid Derivatives. IX. The Cyclization of α-(N-Acyl-hydroxyamino) Acid Esters with Ammonia or Hydroxylamine
Authors: Shin Chung-gi , Nanjo Katsumi , Kato Masaki , Yoshimura Juji
Published: July 2006

A new type of cyclization reaction of α-(N-acyl-hydroxyamino) acid esters to imidazolidine-4-one derivatives and the synthesis of several 2,5-piperazinedione derivatives are described. The treatment of β-methoxy-α-(N-chloroacetyl- or N-phthaloylglycyl-hydroxyamino) acid esters with ammonia gave 2-carbamoyl-2-(1-methoxy)alkyl-or aralkyl-imidazolidine-4-ones, while a similar cyclization of α-(N-haloacetylamino) or α-(N-haloacyl-hydroxyamino) acid esters with ammonia or hydroxylamine gave 2,5-piperazinedione, 1-hydroxy-2,5-piperazinedione or 1,4-dihydroxy-2,5-piperazinedione derivatives. The difference in the formation mechanisms between the imid-azolidine-4-one and 2,5-piperazinedione and their structural assignment were discussed.
Syntheses of Photosensitive Poly(amino acids)
Authors: Nanasawa Masato , Kamogawa Hiroyoshi
Published: July 2006

New poly(amino acids) (l-glutamic acid, l-tyrosine and l-lysine) containing photosensitive acryloyl, methacryloyl, and cinnamoyl groups in their side chains were synthesized from the corresponding amino acid NCAs. Their photosensitivities under UV irradiation were also investigated as to kind of functional group and the skeleton portion of the poly(amino acids). As regards the effect of the former, the sensitivities were in the order: acryloyl\simeqmethacryloyl>cinnamoyl; as regards the effect of the latter, the sensitivities were in the order: poly-glutamate>poly-lysine>poly-tyrosine.
Restricted Rotation Involving the Tetrahedral Carbon. XVI. Isolation of Stable Rotamers about an sp3-sp3 Carbon Bond
Authors: Yamamoto Gaku , Nakamura Mikio , Oki Michinori
Published: July 2006

Both antiperiplanar and synclinal rotamers resulted from the restricted rotation about a C–C single bond between the bridgehead t-alkyl group and the skeleton of 9-(1,1-dimethyl-2-phenylethyl)-11-methoxycarbonyl-9,10-dihydro-9,10-ethenoanthracene-12-carboxylic acid are isolated. Optical resolution of the synclinal rotamer is successfully performed by way of the mono-(−)-menthyl esters and a pair of enantiomers of the acid, [α]D32±24.7°, are isolated as stable entities. Activation energy for the interconversion between the rotamers of dimethyl esters is found to be 33.2 kcal/mol with a frequency factor of 1013.3 s−1.
Measurement of Singlet-Triplet Absorption Spectrum of Pyridazine by a Sensitized-Phosphorescence Excitation Method
Authors: Yamamoto Kohzaburo , Takemura Takeshi , Baba Hiroaki
Published: July 2006

The S0→T absorption spectrum of pyridazine was measured by means of sensitized-phosphorescence excitation in EPA rigid-glass solution at 77 K. Its intensity was found to be much lower than that of the corresponding spectrum of pyrazine.
Note on the Preparation and Catalytic Properties of Dichlorotris[tris(p-methoxyphenyl)phosphine]ruthenium
Authors: Nishimura Shigeo , Yumoto Osamu , Tsuneda Kiyoshi , Mori Hiromu
Published: July 2006

The procedure for the preparation of RuCl2[(p-MeOC6H4)3P]3 was improved, resulting in a higher catalytic activity. The complex was thirteen and five times as active as RuCl2(Ph3P)3 in the hydrogenation of 1,4-androstadiene-3,17-dione (I) and 4-androstene-3,17-dione (II), respectively, indicating that the methoxy complex is more selective for formation of II in the consecutive hydrogenation pathway of I.
Smiles-Type Rearrangement of N-trans-Styrylsulfonyl) and N-(4-Phenyl-1,3-butadienylsulfonyl)thioureas and Isothioureas
Authors: Hasegawa Kiyoshi , Hirooka Syuzi , Sasaki Tadashi
Published: July 2006

Treatment of N-(trans-styrylsulfonyl)- (1) and N-(4-phenyl-1,3-butadienylsulfonyl)-N′-methylthiourea (2), and the corresponding S-methylisothioureas (6 and 7), with strong base afforded the Smiles-type and Michael-type products. Effects of substituents at C-2 and nucleophiles on the products are discussed.
Monolayers and Built-up Films of N,N′-Disubstituted Dithiooxamide Cu(II) Coordination Compounds
Authors: Suzuki Asahi , Ohkawa Kuwako , Kanda Seiichi , Emoto Masanori , Watari Shunichi
Published: July 2006

N,N′-Disubstituted dithiooxamide-Cu(II) as compound semiconductors prepared by the usual method have been liable to be an isomeric mixture of coordination polymers. Syntheses of the stereospecific coordination polymers were attempted by an interfacial technique. The dithiooxamides with two hydrophobic substituents, R’s, on nitrogen atoms of a ligand molecule could be spread on a water surface to form the monomolecular film, where its possible structure is cis isomers of the ligands. Some coordination compounds, i.e. the stereospecific coordination polymers, between the cis isomers and Cu2+ ions were found to be produced at the air-water interface by employing the substrate solution containing Cu2+ ions. This was established by the surface pressure vs. area measurements for their ligand molecules with C6H5CH2–, C6H11–, C12H25–, and C12H25OCOCH2– as hydrophobic substituents, and by the effects of various spreading solvents, pH in substrate solutions and temperatures on their monolayers. Furthermore, built-up films of these polymers were examined for thickness.
13C Nuclear Magnetic Resonance Studies of the Hindered Internal Rotation and the Molecular Association of N,N-Dimethylacetamide
Authors: Ando Isao , Jinno Naomi , Nishioka Atsuo
Published: July 2006

The concentration and temperature dependences of the 13C chemical shifts of N,N-dimethylacetamide (DMA) in CCl4, H2O, and H2SO4 solutions were measured by means of a 13C FT-NMR spectrometer at 25.15 MHz. From the temperature dependence of the chemical-shift difference between the cis- and trans-NCH3 carbons, the activation energy, Ea, for the hindered internal rotation about the C–N bond was obtained to be 10–17.5 kcal/mol; it was also found to be ca. 10 kcal/mol at an infinite dilution in a CCl4 solution. The chemical shift of each carbon in the DMA molecule was calculated using Pople’s expression under the average excitation-energy approximation by means of the CNDO/2 method. The calculated finding that each carbon in DMA appears in the order of carbonyl, trans-NCH3, cis-NCH3, and acetyl carbons from the low field agrees with the order assigned by McFarlane. Further, as for the molecular association in neat liquid, various models are discussed on the basis of quantum-chemical calculations, and a model is proposed which has antiparallel oriented carbonyl groups in associated states of the molecules of more than two. The observed differences between the chemical shifts of the carbonyl carbons at dilutions in CCl4 and H2O solutions, and between those in CCl4 and H2SO4 solutions, are found to agree well with the results calculated using the model in which the DMA molecules at dilutions in CCl4, H2O, and H2SO4 exist as monomer, hydrogen-bonded DMA with H2O, and protonated DMA respectively.
The Crystal and Molecular Structure of Versicolorin C, A Metabolite of Aspergillus versicolor
Authors: Fukuyama Keiichi , Tsukihara Tomitake , Katsube Yukiteru , Hamasaki Takashi , Hatsuda Yuichi
Published: July 2006

The crystal structure of versicolorin C, C18H12O7, has been determined by the X-ray diffraction method. The crystals are monoclinic, with the space group P21/a, and with four molecules in a unit cell with dimensions of a=24.918(7), b=7.922(3), c=7.003(3) Å, and β=92.85(4)°. The structure was refined by the least-squares method to R=0.053 for 1693 non-zero reflections. There are two intramolecular hydrogen bonds. A pair of molecules related by a center of symmetry forms a dimer by means of intermolecular hydrogen bonds.
Temperature Effects on the Electronic Spectra of 2-Methyl-1-aceanthrenone
Authors: Hirayama Satoshi
Published: July 2006

The absorption, fluorescence, and excitation spectra of 2-methyl-1-aceanthrenone (I) were investigated in several solvents in the temperature range of 77–298 K. The results show that the hydrogen-bonded (fluorescent) and non-hydrogen-bonded (very weakly fluorescent) molecules of I coexist in ethanol to a comparable extent. This is the reason why its absorption spectra are very broad in alcoholic solvents. With a decrease in the temperature, the apparent fluorescence quantum yield in ethanol at first rises to a maximum (0.37) at 197 K and then decreases. Below ca. 113 K, a new fluorescence band due to the non-hydrogen-bonded molecule appears. In 2-methyltetrahydrofuran (MTHF), the temperature dependence of the fluorescence quantum yield of I is significant only at low temperatures. The yield varies monotonously from 0.014 at 132 K to 0.30 at 77 K. A behavior intermediate between those in ethanol and in MTHF is observed in EPA. The rise and fall of the fluorescence quantum yield in ethanol or in EPA may be interpreted in terms of the temperature-dependent concentration change in the hydrogen-bonded molecule. From the results in MTHF, the maximum rate constant of the intersystem crossing between the S1ππ* and Tnπ* states is estimated to be of the order of 1013 s−1.
Photosensitized Decomposition of Trioxalatocobaltate (III) Ion by Organic Triplet Sensitizers
Authors: Sakuraba Shukichi , Kakuta Akio , Matsushima Ryoka
Published: July 2006

Sensitized decomposition of the trioxalatocobaltate(III) ion was studied in deoxygenated aqueous solution at room temperature, using biacetyl as an n-π* triplet sensitizer and 9-carboxyanthracene as a π-π* triplet sensitizer. In the presence of one of these sensitizers the photodecomposition rate of the complex was increased, and the plot of the reciprocal of the sensitization quantum yield as a function of the concentration of the complex gave a straight line for each sensitization system. On the other hand, the complex quenched the phosphorescence without affecting the fluorescence of the sensitizers, indicating a triplet energy transfer mechanism. A photokinetic treatment of the data for both the sensitized photolysis and the quenching process gave a result in line with proposed mechanism for bimolecular triplet energy transfer.
A Conformational Study of the NOx(x=1 or 2)-catalyzed Isomerization of cis-2-Butene Using the INDO-UHF Method
Authors: Ohkubo Katsutoshi , Ikebe Hiromichi , Okada Masahide
Published: July 2006

The NOx(x=1 or 2)-catalyzed isomerization of cis-2-butene was investigated by means of the INDO-UHF theory, with a particular view to the energetic and conformational aspects of the reaction. The NO2-addition process to form the intermediate radical (R1) had no appreciable activation barrier, although the NO2-fission process from the intermediate radical (R2) had the C-NO2 dissociation energy of 44.6 kcal/mol. Some characteristic features of the stretched C-C bond in the intermediate radical (R1) were; (1) rcc=1.45 Å, which was roughly equal to the value (1.481 Å) in cis-2-butene at the transition state of its thermal isomerization; (2) a pseudo π-conjugation with a small π-character (about 13% of ECCR) in comparison with that (about 29% of ECCR) in cis-2-butene, and (3) approximately the same magnitude of the hfsc value (34.40–34.47 G) for the sp2-hydrid carbon as that (experimental value of 39.07 G) for the said atom in the ethyl radical. The calculated internal-rotation barrier of the intermediate radical (R1) around the C–C bond (1.75–3.01 kcal/mol in the two rotating directions) was smaller than that (around 4 kcal/mol) obtained from the thermodynamic estimations. The energetically most stable or unstable rotamer was found in the staggered or the eclipsed configuration respectively; a hydrogen-bonding effect on the stabilization was observed in staggered configuration, although a remarkable effect of the homoconjugation or the repulsive interaction of unpaired and lone-paired electrons can be disregarded in the present internal-rotamer.
Refinement of the Crystal Structure of Sodium Hexahydroxoantimonate(V), NaSb(OH)6
Authors: Asai Takeshi
Published: July 2006

The crystal structure of sodium hexahydroxoantimonate (V), NaSb(OH)6, has been refined. The previous structure given by Schrewelius was confirmed, but the positional parameters of oxygen atoms were shifted significantly. Both antimony and sodium atoms are surrounded by six oxygen atoms octahedrally. The interatomic distances are: Sb–O=1.972–1.999 Å (mean 1.98 Å), O–O=2.758–2.834 Å (2.80 Å) for an SbO6 octahedron, Na–O=2.375–2.406 Å (2.39 Å) and O–O=3.229–3.526 Å (3.38Å) for an NaO6 octahedron. Two types of sequences of hydrogen bonds were recognized. They were compared with the sequences of hydrogen bonds in In(OH)3 and MnSn(OH)6.
The Photobleaching: of Trapped Electrons and the Electron Capture of Radicals in γ-Irradiated Hydrocarbon Matrices at 77 K
Authors: Ishikawa Yo-ichi , Oka Ko-ichi , Sato Shin
Published: July 2006

The rate of the photobleaching of the trapped electrons in the 3-methylhexane and methylcyclohexane matrices at 77 K was measured by means of ESR as a function of the concentration of the 3-methylhexyl or methylcyclohexyl radicals present in the matrices. The quantum yield of the photobleaching at the wavelength of 1300 nm increased with the increase in the radical concentration. The stable products such as olefins formed during the γ-irradiation did not affect the quantum efficiency. These results support the suggestion made by Willard et al. that the 3-methylhexyl and methylcyclohexyl radicals capture the electrons released from the trapping sites by the irradiation of the infrared light. A comparison showed that the radicals are comparable with sulfur hexafluoride in electron capture.
Distribution of Trapped Electron-Cation Distance in γ-Irradiated 2-Methyltetrahydrofuran Glassy Matrix
Authors: Ichikawa Tsuneki , Yoshida Hiroshi , Hayashi Koichiro
Published: July 2006

An approach was presented to elucidate the distribution of trapped electron-cation distance from isothermal decay of the trapped electron by numerically solving the Smoluchowski equation and was applied to the observed isothermal decay of trapped electron at 92.2–95.0 K in 2-methyltetrahydrofuran glass irradiated by γ-rays at 77 K. The distribution curve (the probability density of finding initially the electron at the distance r) thus obtained was close to a Gaussian function.
Quantitative Estimates of π-Contact-term Contributions to the Lanthanideinduced Paramagnetic 1H Shifts in Aniline and m-Toluidine
Authors: Hirayama Masatoshi , Sato Michihiko , Takeuchi Makoto , Saito Makoto
Published: July 2006

The paramagnetic proton chemical shifts induced by a series of Ln(FOD)3(Ln=Pr, Eu, Dy, Ho, Er, and Yb) were observed for aniline and m-toluidine in CCl4. In an attempt to separate the pseudo-contact(pcs) and contact shift(cs) contributions, the spin-density distributions of the π-cation radicals or the Ni(AcAc)2-induced shifts were used for the cs pattern in a molecule, as well as the geometric factors for the pcs pattern. The appropriate regions of the two geometric parameters were determined by the computer-search method for the least-squares fits of the observed to the calculated shifts. Thus, the intramolecular average value of the ratio of cs-to-pcs contributions was evaluated. The variation in this ratio with an Ln ion corresponds relatively well to that of the theoretical ratio, |〈SZ〉⁄|δ|, where 〈Sz〉 has been calculated by Golding et al. and where δ is the relative pcs predicted by Bleaney et al.
Interpretation of Shake-up Satellites in the X-Ray Photoelectron Spectra of Small Hydride Molecules by One-Center-Expansion ab initio Calculation with Equivalent-Core Approximation
Authors: Fujikawa Takashi , Aoyama Tomoo , Ohta Toshiaki , Kuroda Haruo
Published: July 2006

One-center-expansion ab initio calculations with STO basis set were carried out on H2O, NH3, CH4 and BH3, to estimate the energies and probabilities of shake-up processes accompanying the photoionization of a core level. A method based on equivalent-core approximation and that based on configuration interaction procedure were applied to obtain wave functions of core-hole ions. It is shown that the calculations by the former method yield very satisfactory results, not only for the core ionization potential, but also for the energies and intensities of shake-up satellites.
Anodic Wave Polarography of N-2-Aminoethyl-N-2-hydroxyethylcarbodithioic Acid
Authors: Sugawara Masao , Kambara Tomihito
Published: July 2006

N-2-Aminoethyl-N-2-hydroxyethylcarbodithioic acid (Hahdtc) in an alkaline medium gives at the dropping mercury electrode an adsorption prewave due to the two-electron oxidation of mercury. The electrode reaction at pH=13.1–10.1 was inferred to proceed according to

Hg+2ahdtc^-\ightleftarrowsHg(ahdtc)_2+2e\labeleq1

The surface excess of the mercury(II) chelate was estimated to be 3.0×10−10mol cm−2.
The Pressure Broadening of the Cadmium-resonance Line at 326.1 nm in Ammonia and Argon
Authors: Umemoto Hironobu , Yamamoto Shunzo , Sato Shin
Published: July 2006

The ratio of the collison-broadening cross-section of ammonia to that of argon for the cadmium-resonance line at 326.1 nm has been estimated to be 2.1 by comparing the experimental data of the transmission measurement with the theoretically calculated numerical table. The table shows the relation between the transmission of a resonance line passing through the system containing absorbing atoms and the ratio of the Lorentz half-breadth to the Doppler half-breadth at different values of two parameters; the optical density, and the ratio of the Doppler half-breadth of the emission line to that of the absorption line. This table may have universal importance for the study of the absorption of atomic spectra.
A Study of Catalysis by Uranium Oxide and Its Mixed Catalysts. IX. A Catalytic Reduction of Nitric Oxide with Carbon Monoxide
Authors: Nozaki Fumio , Matsukawa Fumio , Mano Yoshikazu
Published: July 2006

The reduction of NO with CO over the uranium oxide catalyst and its mixed catalysts with alkali metal oxide or alkaline earth metal oxide has been investigated using conventional flow and pulse reactors at temperatures of 250 to 450 °C under atmospheric pressure. The activity of the uranium oxide catalyst without any additive was higher than that of the Fe2O3 catalyst, although it was inferior to that of the CuO–Cr2O3 catalyst. The addition of alkali metal oxide or alkaline earth metal oxide to uranium oxide, particularly in the case of Cs2O or K2O, was effective in enhancing the catalyst activity. The W/F-conversion curves revealed that the reduction of NO to N2 proceeds consecutively, passing through N2O as a gas-phase intermediate. The reaction rates were formulated as r=kPCO1.0PNO0.4. The kinetic study suggested a redox reaction sequence. The oxidation states of the catalysts were discussed on the basis of X-ray diffractograms.
Ultra-thin Layer of Lipids in Polymer Film and Its Electric Properties. New Sorption Method to Prepare a Model Biomembrane System
Authors: Yoshida Tadayoshi , Ogura Shin-ichiro , Okuyama Masataka
Published: July 2006

The ultra-thin layer of glycerol α-cis-9-octadecenate (glycerol α-monooleate:GMO) could be formed by impregnating nitrocellulose (NC) film with GMO and by then filling microscopically the interstices of the network structure of NC with microdrops of GMO. The dielectric dispersion characteristic of this film was found to be similar to that observed for bimolecular films. In a concentrated KCl solution (100 mM), however, an anomalous dielectric dispersion phenomenon was observed below 10 kHz. The low-frequency dispersion was attributed to surface conductance along the planes of contact between the GMO microdrops and the NC network. The ultra-thin film of di(cis-9-octadecenyl)phosphate (dioleyl phosphate: DOPH) could also be formed by this method. When a constant DC voltage (50 mV) was applied across the film in a 20 mM KCl solution, the electric current through the whole system changed periodically.