bluuebunny/crossref_metadata_2025 huggingface dataset:
A Kinetic Study on the Reaction of (Arylthio)trimethylgermane with Benzoyl Chloride Giving S-Aryl Thiobenzoate and Chlorotrimethylgermane
Authors: Kozuka Seizi , Tamura Shoji , Yamazaki Tetsuya , Yamaguchi Shigeru , Tagaki Waichiro
Published: July 2006

A kinetic study has been conducted on the reactions of (substituted arylthio)trimethylgermanes with aroyl chlorides giving S-aryl thioaroates and chlorotrimethylgermane. The rates of the reactions were distinctly accelerated in polar solvents. Both of the effects due to the substituents of the arylthio and the aroyl moieties gave positive ρ values especially in a polar solvent. A mechanism involving initial 5-coordination, ionic cleavage of the Ge–S bond giving arenethiolate ion, and followed by rate-determining addition of the thiolate to the carbonyl carbon, was suggested for the reaction.
3,3′-(Phenylphosphinylidene)bis[2(3H)-benzoxazolone] and 3,3′-(Phenylphosphinylidene)bis[2(3H)-benzothiazolone]. New Activating Agents
Authors: Ueda Mitsuru , Mochizuki Amane , Hiratsuka Ichir\={o} , Oikawa Hideaki
Published: July 2006

New activating agents, 3,3′-(phenylphosphinylidene)bis[2(3H)-benzoxazolone] (4) and 3,3′-(phenylphosphinylidene)bis[2(3H)-benzothiazolone] (5), were readily prepared by the reaction of phenylphosphonic dichloride (3) with 2(3H)-benzoxazolone (1) and 2(3H)-benzothiazolone (2) respectively in the presence of triethylamine at room temperature. The new activating agents 4 and 5 were found to be useful for the preparation of amides, esters, and dipeptides under mild conditions. Furthermore, the direct poly-condensation of isophthalic acid with aromatic diamines using the activating agent 4 in the presence of pyridine proceeded fast at room temperature to produce polyamides with inherent viscosities up to 0.80 dL/g.
Preparation, Crystal Structure, and Stereochemical Properties of {N,N′-Ethylenebis(1,1,1-trifluoro-4-imino-2-pentanonato)} (l-methioninato)cobalt(III)
Authors: Okamoto Ken-ichi , Matsutani Katsuhiro , Fujii Yuki
Published: July 2006

The (−)435 isomer of the {N,N′-ethylenebis(1,1,1-trifluoro-4-imino-2-pentanonato)}(l-methioninato)cobalt(III) complex, (−)435-[Co(tfac2en)(l-met)], was preferentially crystallized from an equilibrium mixture of the (−)435 and (+)435 isomers in methanol. The crystal structure of the (−)435 isomer was determined by X-ray diffraction. The (−)435 isomer is of a Λ-cis-β2 type in which the quadridentate tfac2en takes a nonplanar configuration, and the l-methioninate is bound to the cobalt atom by nitrogen and oxygen atoms as a bidentate ligand. The electronic absorption, CD, and 1H NMR spectral behaviors of both (−)435 and (+)435 isomers are discussed in relation to their geometrical and absolute configurations.
A Mechanistic Investigation of the Todd Reaction
Authors: Kong Anne , Engel Robert
Published: July 2006

The Todd reaction, involving formation of a dialkyl phosphorochloridate by reaction of a dialkyl phosphonate with tetrachloromethane under basic conditions, has been determined to involve the intermediacy of the trichloromethanide anion.
Solution Properties of Dialkyl Phosphate Salts. Apparent Molar Volumes, Viscosity B Coefficients, Heats of Solution, and Osmotic Coefficients
Authors: Tamaki Kunio , Suga Keita , Tanihara Eiko
Published: July 2006

The apparent molar volumes, viscosity B coefficients, and heats of solution of sodium salts of dialkyl phosphates (methyl, ethyl, and butyl) in water were measured. The limiting apparent molar volumes at 25 °C increased with the number of carbon atoms in the alkyl chains. The viscosity B coefficients of the salts decreased as the temperature was raised from 25 to 35 °C. The changes in heat capacity for dissolution in water, as calculated from the heats of solution at 15, 25, and 35 °C, were positive for the salts. The osmotic coefficients for lithium, sodium, and potassium salts of dimethyl phosphate were also measured. For a given concentration, the osmotic coefficients decreased in the order: Li+<Na+<K+. From the results obtained, the –(–O)2PO2− ionic part may be classified as a structure-maker.
The Enantioface-Differentiating Hydrogenation of the C=O Double Bond with Asymmetrically Modified Raney Nickel. XXXIX. Repeated Uses of the Catalyst in the Hydrogenation of 2-Alkanones
Authors: Osawa Tsutomu , Harada Tadao
Published: July 2006

The durability of tartaric acid-sodium bromide-modified Raney nickel in the hydrogenation of 2-octanone was investigated. A remarkable lowering of the optical yield was observed in the repeated use of the catalyst. A lack of sodium ions in the reaction system was found to be the origin of this phenomenon. The addition of sodium ions to the reaction mixture was useful for attaining high optical yields in the repeated uses of the catalyst.
The Condensation and Decomposition of Phosphoramidates with Acids
Authors: Sato Shoji , Takayanagi Takao , Watanabe Makoto
Published: July 2006

Several phosphoramidates were reacted with dried hydrogen chloride, acetic acid, and oxalic acid. The phosphoramidates reacted with the acids to produce ortho- and polyphosphates, but did not react with them to make polyphosphates containing imino groups, with the elimination of ammonia. The decomposition of the phosphoramidates to orthophosphate by the action of water was considered to be the first step in the production of polyphosphates:

(Remark: Graphics omitted.),

The formation of polyphosphates can be explained, for example, by this equation:

(Remark: Graphics omitted.),

where HA stands for acid.
Medium Effects on the Redox Properties of 12-Molybdophosphate and 12-Molybdosilicate
Authors: Itabashi Eiki
Published: July 2006

The formal redox potentials of 12-molybdophosphate and 12-molybdosilicate up to the twelve-electron reduction per heteropolymolybdate ion were determined by cyclic voltammetry at a glassy carbon electrode in 50% (v/v) water-organic media containing some inorganic acids. These heteropolymolybdates in the presence of 1,4-dioxane (DO) or tetrahydrofuran (THF) display five two-electron reversible cathodic waves, followed by an irreversible two-electron wave, whereas the same heteropolymolybdates in the presence of 1,2-dimethoxyethane, N,N-dimethylformamide, acetonitrile, ethanol, or acetone yield five successive redox couples of 2,2,2,4, and 2e− (electrons) each. The eight-electron reduction species of 12-heteropolymolybdates are stabilized by cyclic ethers such as DO or THF. The stabilization of the eight-electron reduction species by the addition of a cyclic ether has been explained by taking into account the adduct formation between the molecules of the cyclic ether and 12-heteropolymolybdate.
Crystal and Molecular Structures of Two Isomers for Chlorobis-(2-methyl-8-quinolinolato)nitrosylruthenium(III)
Authors: Kamata Yukiko , Kimura Takashi , Hirota Reiko , Miki Eiichi , Mizumachi Kunihiko , Ishimori Tatsujiro
Published: July 2006

Two isomers of [RuCl(2mqn)2(NO)] (2mqn=2-methyl-8-quinolinolate ion) were isolated and their crystal structures were determined by X-ray diffraction. In both the isomers, the Cl atom lies cis to the NO group and the O atom of one of the quinolinolato ligands lies trans to the NO group. One of the two isomers, (1), is in cis(O,O) and trans(N,N) configuration for the two quinolinolato ligands, another, (2), being in cis(O,O) and cis(N,N). Crystal data: 1, space group P21⁄c (monoclinic), a=7.412(1), b=27.241(6), c=9.752(1) Å, β=105.49(1)°; 2, space group P21⁄c (monoclinic), a=7.157(2), b=20.205(4), c=13.359(3) Å, β=107.70(2)°. The final R values for 1 and 2 are 0.044 for non-hydrogen atoms and 0.037 for all the atoms, respectively. The coordination geometries of 1 and 2 are distorted octahedron. The interatomic distances are qualitatively discussed on the basis of π- and σ-bonding abilities of the NO group, the Cl, and the coordinating atoms, N and O, of the quinolinolato ligands.
Solvatochromism of [Diamine-N,N′-polycarboxylato]chromium(III) and -cobalt(III) Complexes
Authors: Miura Naoko , Shimura Makoto , Ogino Hiroshi
Published: July 2006

Visible absorption spectra of [diamine-N,N′-polycarboxylato]chromium(III) and -cobalt(III) complexes were measured in twelve different solvents. The diamine-N,N′-polycarboxylates used in this work were ethylenediamine-N,N,N′,N′-tetraacetate (edta4−), 1,2-cyclohexanediamine-N,N,N′,N′-tetraacetate (cydta4−), N′-(2-hydroxyethyl)ethylenediamine-N,N,N′-triacetate(hedtra3−), and N′-methylethylenediamine-N,N,N′-triacetate (medtra3−). The first d–d absorption maxima of these complexes depend considerably on the solvents. From the solvatochromic behaviors of these complexes, it was concluded that solid complexes, K[Co(edta)]·2H2O, K[Co(cydta)]·3H2O, [Co(hedtra)(H2O)], [Co(medtra)(H2O)]·3H2O, Na[Cr(cydta)]·4.5H2O, and probably K[Cr(edta)]·2H2O, dissolve in the solvents while holding their first coordination sphere intact; in some solvents, however, [Cr(medtra)(H2O)]·1.5H2O and [Cr(hedtra)(H2O)]·1.5H2O undergo substitutions of the coordinated water molecule to form [Cr(medtra)(solvent)] and [Cr(hedtra)(solvent)], respectively.
Preparation and Crystal Structures of Binuclear Copper(II) Complexes of N,N′,N″,N'″-Tetrakis(2-aminoethyl)1,4,8,11-tetraazacyclotetradecane Containing Azide, Cyanate, or Thiocyanate Ion
Authors: Mikuriya Masahiro , Kida Sigeo , Murase Ichiro
Published: July 2006

Three binuclear copper(II) complexes of N,N′,N″,N'″-tetrakis(2-aminoethyl)-1,4,8,11-tetraazacyclotetradecane (taec), [Cu2(taec)N3](ClO4)3 (1), [Cu2(taec)(NCO)](ClO4)3 (2), and [Cu2(taec)(NCS)2](ClO4)2·H2O (3), were prepared and characterized. The crystal structures of these complexes were determined by single-crystal X-ray analysis. In all the complexes taec coordinates to each copper through two ring- and two pendant-nitrogen atoms. Complexes 1 and 2 adopt similar structures, where N3− and NCO− are incorporated into the cavity of taec as a bridging group (end-on fashion). The structure of 3 is substantially different from those of 1 and 2 in that each copper is independently coordinated by NCS−-nitrogen. The spectral and magnetic properties were discussed in relation to the molecular structures.
Reaction of Enohexopyranoside Acetates with Lithium Dimethylcuprate(I) and Its Application to Synthesis of Prelog-Djerassi Lactone
Authors: Kawauchi Nobuya , Hashimoto Hironobu
Published: July 2006

In the reaction of two 2-O-acetyl-3-enohexopyranosides and four 4-O-acetyl-2-enohexopyranosides including 2-C-methyl and 4-C-methyl derivatives, respectively, with lithium dimethylcuprate(I), anti SN2′ substitution was proved to be preferential, giving the corresponding C-methylated derivatives. On the other hand, SN2 substitution occurred in the reaction of the 2-enopyranoside without methyl branch and d-glucal triacetate.
Lithio Styryl Sulfone as an Acyl Anion Synthon
Authors: Yamamoto Makoto , Suzuki Kazuya , Tanaka Seiji , Yamada Kazutoshi
Published: July 2006

Lithio styryl sulfone, which was shown to be an acyl anion synthon, reacted with various electrophiles; the products were rearranged by treatments with m-chloroperbenzoic acid to give acyl benzyl sulfones in good yields.
The Determination of a Small Amount of a Biological Constituent by the Use of Chemiluminescence. X. The Determination of Protein Using a 1,10-Phenanthroline–Hydrogen Peroxide–Ruthenium(III) System
Authors: Hara Tadashi , Tsukagoshi Kazuhiko , Imaki Masakatsu
Published: July 2006

The catalytic activity of ruthenium(III) chloride in a chemiluminescence reaction with 1,10-phenanthroline–hydrogen peroxide has been found to decrease in the presence of protein. On the basis of this phenomenon, bovine serum albumin as a model protein was determined within the concentration range of 5×10−5–1×10−1 g dm−3 and a detection limit of about 1 ng.
Liquid-Phase Hydration of Acrylonitrile to Acrylamide over the Copper–Nickel Alloy Catalysts
Authors: Sugiyama Kazuo , Miura Hiroshi , Watanabe Yoshichika , Ukai Yasunori , Matsuda Tsuneo
Published: July 2006

The liquid-phase hydration of acrylonitrile to acrylamide has been examined over various metal catalysts at 75 °C. Five metal elements-Cu, Ag, Fe, Co, and Ni-showed the catalytic conversion of acrylonitrile. The Cu and Ag catalysts gave the acrylamide with a 100% selectivity, while the other metals, Fe, Co, and Ni, yielded three products: acrylamide, ethylene cyanohydrin, and bis(2-cyanoethyl) ether. The alloying of Cu and Ni led to an increase in the formation of acrylamide with keeping the high selectivity to acrylamide. Especially, Cu–Ni alloys, with a range of 20–70% Cu in their bulk composition, were much more active catalysts than Cu. The maximum yield of acrylamide was obtained on the Cu–Ni alloy catalysts was observed, although such a retardation occurred on the Cu catalyst surface. The maximum synergistic effect was observed over the alloy with the surface component ratio of Cu to Ni of 4; this effect was discussed.
Raman Spectra and Electronic Structure of Alkaline Metal Doped Polyacetylene and β-Carotene
Authors: Tanaka Jiro , Saito Yasuyoshi , Shimizu Masaaki , Tanaka Chizuko , Tanaka Masashi
Published: July 2006

Raman spectra of alkaline metal doped polyacetylene were studied at various levels of doping for (CHMy)x, and (CDMy)x, M=Na and K, with y=0–0.18. Several steps in the doping process can be recognized in changes of the Raman spectra; the initial Raman lines remain for y=0–0.06 but change completely into a new pattern at y=0.13. Raman and ESR spectra of alkaline metal doped β-carotene were measured as a model study of the alkaline metal doping of polyacetylene. The correlation of these spectra together with the ab initio SCF MO calculation on model compounds show that a heavily alkaline metal doped polyacetylene chain does not have a uniform bond length structure but is composed of a charged soliton structure connected by a uniform chain. The new Raman bands were assigned based on this structure, implying that a bond alternation still exists in the metallic state of alkaline doped polyacetylene.
Preparation and Stereochemistry of Cobalt(III) Complexes Containing 3,6-Diphenyl-3,6-diphosphaoctane-1,8-diamine or (2S,9S)-4,7-Diphenyl-4,7-diphosphadecane-2,9-diamine, NH2CHRCH2P(C6H5)CH2CH2P(C6H5)CH2CHRNH2 (R=H, CH3)
Authors: Atoh Masamichi , Sugiura Hirofumi , Seki Yoji , Kashiwabara Kazuo , Fujita Junnosuke
Published: July 2006

Nine new cobalt(III) complexes containing 3,6-diphenyl-3,6-diphosphaoctane-1,8-diamine (NPPN), trans-[CoCl2(rac(P)-NPPN)]+, cisα-[Co(L)(rac(P)-NPPN)]n+ (L=en, n=3; L=acac, n=2) and Δ- and Λ-cisα-[Co(L′)(rac(P)-NPPN)]n+ (L′=R-pn, n=3; L′=S-ala or S-pro, n=2), and five new cobalt(III) complexes containing (2S,9S)-4,7-diphenyl-4,7-diphosphadecane-2,9-diamine (SS(C)-NPPN), Δ- and Λ-cisα-[Co(L)(rac(P)SS(C)-NPPN)]n+ (L=en, n=3; L=acac, n=2) and Δ-cisβ-[Co(acac)(meso(P),SS(C)-NPPN)]2+, were prepared, where en, R-pn, acac, S-ala and S-pro denote ethylenediamine, (R)-1,2-propanediamine, 2,4-pentanedionate, (S)-alaninate and (S)-prolinate ions, respectively. Stereochemistries of the complexes and the chiral phosphorus donor atoms were studied on the basis of the absorption, 1H and 13C NMR, and CD spectra. The rac(P)-NPPN and rac(P),SS(C)-NPPN ligands formed selectively either the trans or cisα isomer, while no stable complex was obtained with the meso(P) isomers of NPPN and SS(C)-NPPN except cisβ-[Co(acac)(meso(P),SS(C)-NPPN)]2+ which slowly decomposes in water.
Fluoride Ion-Induced Horner–Emmons Reaction of α-Silylalkylphosphonic Derivatives with Carbonyl Compounds
Authors: Kawashima Takayuki , Ishii Takafumi , Inamoto Naoki
Published: July 2006

Dimethyl α-trimethylsilylbenzylphosphonate was allowed to react with carbonyl compounds in the presence of fluoride ion to give the corresponding olefins in fairly good yields. Use of CsF in tetrahydrofuran gave the best result. On the other hand, dimethyl trimethylsilylmethylphosphonate was allowed to react similarly with benzophenone to afford 1,1-diphenylethylene, dimethyl methylphosphonate, and dimethyl 2,2-diphenylethenylphosphonate. A similar result was obtained by using O,O-diethyl trimethylsilylmethylphosphonothioate. But, reaction of trimethylsilylmethylphosphonic bis(diethylamide) afforded only the protodesilylation product.
Optically Active Polyamides Having (−)-Anti Head-to-Head Coumarin Dimer Component. 2. Chiroptical Property in the Film State
Authors: Chen Yun , Saigo Kazuhiko , Yonezawa Noriyuki , Hasegawa Masaki
Published: July 2006

The chiroptical property of optically active polyamides (3a–i), derived from (−)-anti head-to-head coumarin dimer (1), was investigated by comparing their UV and circular dichroism (CD) spectra with those of the corresponding model diamides (8a–i) in the film state. The result suggests that the polyamides (3a–c,g) derived from acyclic aliphatic diamines, exist in a random conformation due to the flexibility of the diamine components. The polyamides (3d,h), consisting of piperazine, are assumed to be in a rod-like conformation, resulting from their rigid and fixed main chains. The polyamides (3e,f,i), prepared from aromatic diamines, show reversed and split Cotton effects at 270–300 nm in comparison with those of model diamides. This phenomenon is interpreted by the formation of an ordered conformation of macromolecular asymmetry.
The Magnetic Properties of the Ammonium Chloride Adducts of Copper(II) Fluoroacetate and Copper(II) Bromoacetate
Authors: Emori Shuji , Morishita Nobuhide , Muto Yoneichiro
Published: July 2006

Compounds of formula Cu(XCH2COO)2·nACl (A=NH4, CH3NH3, (CH3)2NH2, (CH3)4N and X=F, Br) have been prepared, and characterized by magnetic susceptibility and IR spectroscopy measurements. Factors affecting the magnetic moments of copper(II) salts of monosubstituted alkanoic acids are discussed.
Chemical Studies on the Lichen. I. The Structure of Isolecanoric Acid, a New ortho-Depside Isolated from Parmelia tinctorum Despr.
Authors: Sakurai Atsushi , Goto Yohko
Published: July 2006

A new ortho-depside, isolecanoric acid was isolated from Parmelia tinctorum Despr. and 2-(2,4-dihydroxy-6-methylbenzoyloxy)-4-hydroxy-6-methylbenzoic acid was assigned to this substance from studies on the hydrolysis products and from analyses of the 1H and 13C NMR spectra. This substance is the first ortho-depside isolated from the genus Lichen.
A Facile Preparation of Flavones Using Nonaqueous Cation-Exchange Resin
Authors: Hoshino Yukio , Takeno Noboru
Published: July 2006

Flavone was prepared from 1-(2-hydroxyphenyl)-3-phenyl-1,3-propanedione by using nonaqueous cationexchange resin in a nearly quantitative yield. Of several reaction media, isopropyl alcohol gave the best result. Eight substituted flavones were also synthesized from the corresponding diketones in satisfactory yields.
Crystal Structure of Bis(2,2′-bipyridine)copper(I) Perchlorate
Authors: Munakata Megumu , Kitagawa Susumu , Asahara Akio , Masuda Hideki
Published: July 2006

The crystal structure of the title complex was determined by X-ray diffraction: Orthorhombic, space group C2221, a=20.553(2) Å, b=11.210(1) Å, c=8.980(2) Å, and Z=4. The structure was solved by the direct method and was refined anisotropically by the full-matrix least-squares method: R was 0.062 for 1206 observed reflections. The [Cu(bpy)2]+ cation has a pseudo-tetrahedral arrangemeni (average Cu–N=2.021 Å). The interligand dihedral angle in [Cu(bpy)2]+, 75.2°, differs significantly from that previously reported [Cu(1,10-phenanthroline)2]ClO4 (49.9°).
Reductive Dimerization of Allyl and Benzyl Halides in Pb/n-Bu4NBr–DMF and PbBr2/Al–DMF Systems
Authors: Tanaka Hideo , Yamashita Shiro , Torii Sigeru
Published: July 2006

Reductive dimerization of allyl and benzyl halides has been performed by treatment with Pb/n-Bu4NBr and catalytic PbBr2/Al in N,N-dimethylformamide.
Preparation of Some Lanthanoid Picrates and the Behavior of Their Water of Hydration
Authors: Nakagawa Kazuharu , Amita Kayoko , Mizuno Hifumi , Inoue Yoshihisa , Hakushi Tadao
Published: July 2006

Lanthanoid(III) picrates (Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, and Yb) were prepared from picric acid and the corresponding lanthanoid carbonates in good yields. Combustion analyses, ICP emission analyses, and UV spectrophotometry have shown that the light lanthanoid picrates, i.e. Ln=La–Gd, are all undecahydrates, while the heavy ones, Dy and Yb, are octahydrates. An examination by TG-DTA has revealed that these hydrates, being fairly stable in air at ambient temperature, are quite labile to give partially or completely dehydrated samples upon drying under vacuum, in a desiccator, and/or at elevated temperatures just above 30°C.
Synthesis of 1,2-Di-O-alkyl-sn-glycero-3-phosphatidylcholine Using 2-Methoxyethoxymethyl and 2-(Trimethylsilyl)ethoxymethyl Protective Groups
Authors: Yamauchi Kiyoshi , Hihara Mitsuyoshi , Kinoshita Masayoshi
Published: July 2006

2-Methoxyethoxymethyl (MEM) and 2-(trimethylsilyl)ethoxymethyl (SEM) groups were used to protect the sn-3-OH of optically active glycerols in the synthesis of 1,2-di-O-octadecyl-sn-glycero-3-phosphatidylcholine. Both MEM and SEM protective groups had advantages of a classical benzyl group by virtue of (i) the facile preparation of 1,2-O-isopropylidene-3-O-(2-methoxyethoxymethyl)-sn-glycerol and its sn-3-O-SEM analog as starting materials and (ii) the rapid demasking of the MEM and SEM moieties in lipid precursors, especially by means of titanium tetrachloride.
Fast Reactions of Organic Anion Radicals with Organic Halides in Hexamethylphosphoric Triamide Studied by Pulse Radiolysis
Authors: Honda Eiji , Tokuda Masao , Yoshida Hiroshi , Ogasawara Masaaki
Published: July 2006

Fast reactions of diethyl fumarate anion radical (DEF−) and fluorenone anion radical (Fl−) with various organic halides (RX) in hexamethylphosphoric triamide have been studied by means of ns pulse radiolysis at room temperature. Reactions of acetophenone anion radical were also studied for comparison. It was found that the reaction rate of Fl− was subject to the steric and resonance effects of R groups of RX in accord with the classical concept of SN2 reactions: the rate constant was reduced by 2 orders of magnitude by the steric effect when R was changed from ethyl to bulky isopropyl or t-butyl, and it was still large by the resonance effect of R even if R was changed from ethyl to an allyl or a benzyl group. While the reaction rate of DEF− was not much affected when R was changed to more bulky groups, the rate constant was correlated to the reduction potential of RX. The results were interpreted in terms of a VB correlation diagram approach or rate-equilibrium relationship within a framework of SN2 reactions.
The Role of COad in the Oxidation of Methanol at a Platinum Electrode in an Acid Solution
Authors: Matsui Hiroshi , Hisano Takeo
Published: July 2006

The role of the adsorbate COad in the oxidation of methanol was studied under a variety of experimental conditions on the basis of the rate-ratio of the path of CO2 formation via COad to the overall oxidation of methanol at a platinum electrode in 0.5 mol dm−3 of H2SO4. The results: (a) At potentials below 0.55 V and with a short time of oxidation, COad inhibited its own formation; (b) at 0.60–0.75 V and with a long time of oxidation, COad was a poison to parallel reactions; (c) at above 0.8 V and at θ1>0.15, the formation of CO2 via COad was predominant, and the COad never hindered parallel reactions. There was no difference between the role of the COad formed from dissolved CO and that of the COad formed from methanol, though, in the absence of dissolved CO, the oxidation of methanol was, for some reason, inhibited at small coverages close to the respective limiting values. When the coverage was larger than about 0.85, COad remarkably inhibited all the parallel reactions in the methanol oxidation.
Studies of the Hydrous Zirconium(IV) Oxide Ion Exchanger. I. Ion-Exchange Properties and Effect of Heat Treatment
Authors: Inoue Yasushi , Yamazaki Hiromichi
Published: July 2006

A satisfactory method was established for synthesizing a hydrous zirconium(IV) oxide ion exchanger; also, its ion-exchange properties and thermal stability were studied. The exchanger was synthesized reproducibly by hydrolyzing a ZrOCl2 solution at pH 9.3 with the addition of NH3 aq. This material was an amphoteric ion exchanger possessing an isoelectric point close to pH 6.5. The order of affinity for the cations was, transition metal> alkaline earth metal>alkali metal. Transition metal ions form a coordinate bond with OH groups in the exchanger. The OH groups, which were easily condensed by a heat treatment, were not restored even when the samples subjected to thermal treatment were immersed in water: Thirty percent of the initial ion-exchange capacity was lost when the exchanger was heat-treated at a temperature as low as 70 °C, and the exchange sites were completely destroyed between 400 and 550 °C.
A Method of Calculation for d.c. Polarographic Catalytic Wave
Authors: Kikuchi Kenji
Published: July 2006

A new numerical method for theoretical analysis of polarographic catalytic current is proposed and applied to well-studied systems to prove that the method is dependable. In this method, a system of partial differential equations of diffusion is transformed to finite-difference form by using Crank–Nicolson difference scheme, and the latter is solved by using both Gauss–Seidel and successive over relaxation methods. Chemical kinetics terms in the diffusion equations is substituted by ones rewritten by three alternative procedures. The method has been applied to a system of copper(II) and hydrogen peroxide. Resulted rate constant of participating chemical reaction agrees with the rate constant obtained from bulk solution experiments. This and other results show that the method is a useful tool for theoretical analysis of catalytic waves.
NAD(P)+–NAD(P)H Model. 62. The Mechanism of the Silica Gel-Catalyzed Reduction with an NAD(P)H Model
Authors: Yasui Shinro , Fujii Masayuki , Nakamura Kaoru , Ohno Atsuyoshi
Published: July 2006

The reduction of diethyl acetylenedicarboxylate, diethyl fumarate, and diethyl maleate as well as several α,β-unsaturated carbonyl compounds by a model of NAD(P)H on silica gel was examined. The order of the reactivity for the reduction was reverse to that of the degree of adsorption of the substrates onto the surface of silica gel. Semiquantitative analysis of the results suggests the possibility that silanol groups on the surface of silica gel act as general acid catalysts in the course of the reduction.
Synthesis and Properties of Cyclohepta[hi]pyrrolo[2,1,5-cd]indolizines
Authors: Noguchi Michihiko , Tamai Ryoichi , Tanigawa Noriyuki , Okumura Hiroyuki , Kajigaeshi Shoji
Published: July 2006

The oxidation of the methylene moiety of 4,5,6,7-tetrahydrocyclohepta[hi]pyrrolo[2,1,5-cd]indolizines with NBS gave 5-bromo-6,7-dihydro- (4) and 5-bromo-cyclohepta[hi]pyrrolo[2,1,5-cd]indolizines. The dehydrobromination of 4 with DBU afforded cyclohepta[hi]pyrrolo[2,1,5-cd]indolizines in good yields. The characteristic electronic features of these cycloheptapyrroloindolizines are discussed on the basis of the MO calculations and the spectroscopic properties.
Infrared Spectra of Nitrogen Adsorbed on Ion-Exchanged ZSM-5 Zeolite
Authors: Yamazaki Tatsuya , Watanuki Isao , Ozawa Sentaro , Ogino Yoshisada
Published: July 2006

Amounts of nitrogen adsorbed by ion-exchanged ZSM-5 zeolites (H+, Li+, Na+, K+, Rb+, and Cs+) and silicalite have been measured under various conditions; pressure=6.7×102–6.7×104 Pa, temperature=196–273 K. IR spectra of adsorbed nitrogen have also been measured at 226 K under various nitrogen pressures (1.3×102–4.0×104 Pa). The adsorption capacity, the specific surface area, and the heat of adsorption have been evaluated from the adsorption data. These quantities coupled with the IR peak shifts observed have revealed that the nitrogen molecule adsorbed on a small and strong cationic site (Li+, Na+) has an orientation in which the longer molecular axis lies in parallel with the direction of the electric field of the cation site. It has also been revealed that the nitrogen molecule adsorbed on a large (K+, Rb+, Cs+) or weak (H+) cationic site takes on no special orientation. The electric field evaluated by analyzing the IR intensity is consistent with the adsorption model obtained.
Micellar Catalytic Effect on the Base Dissociation of Methylamine Studied by the Ultrasonic Absorption Method
Authors: Harada Shoji , Sano Takayuki , Yamashita Teruyo , Yano Hiroshige , Inoue Tadaomi , Yasunaga Tatsuya
Published: July 2006

Micellar catalytic effects on the base dissociation of methylamine have been studied by ultrasonic absorption method. The dissociation constant, the rate constants, and the volume change of the reaction were obtained in the absence and in the presence of SDS. The micellar catalytic effects observed for methylamine was smaller than those for amines of long alkyl chain, which was ascribed to the facts that the former is incorporated into the micellar ionic atmosphere in the concentrated micellar solution while the latters are solubilized into micelles.
A Through Space/Bond Interaction Analysis of the Shape of the Band Structure of Polyacetylene
Authors: Aoki Yuriko , Imamura Akira , Sasaki Takae
Published: July 2006

The band structure of all-trans-polyacetylene is examined by using through space/bond interaction analysis. It is found that the cross-term in the perturbation expansion between two kinds of interactions governs the band shape near the gap: One kind is the interaction within the backbone, and the other is that between the backbone and the side chain. The relationship between the band structure and the symmetry of the interacting orbitals is also discussed.
Studies of the Rate of the Formation of Talc under Hydrothermal Conditions at 400–460 °C
Authors: Muraishi Haruto
Published: July 2006

The rate of the formation of talc from brucite powders with soluble silica under hydrothermal conditions was investigated in the temperature range of 400–460 °C, a range including the equilibrium temperature for the reaction: brucite+serpentine\ightleftarrows2 forsterite+3H2O. Serpentine appeared as an intermediate phase below 415 °C, while above 430 °C forsterite appeared in addition to serpentine. The apparent reaction can be represented as:

(Remark: Graphics omitted.)

The reaction was apparently expressed as a pseudo-first-order reaction. The overall rate of the reaction did not increase with the increase in the temperature. Arrhenius plots of the rate constants for the overall reaction showed a curve with a maximum at about 415 °C and a minimum at about 445 °C which was caused by the alteration of the reaction by the appearance of forsterite at 430 °C.
Rate of Solvent Extraction of Chromium(III) with Acetylacetone into Carbon Tetrachloride
Authors: Sekine Tatsuya , Inaba Kazuho , Morimoto Tatsumu , Aikawa Hidehiko
Published: July 2006

The rate of solvent extraction of chromium(III) in aqueous perchlorate solutions into carbon tetrachloride as the tris(acetylacetonato) complex has been determined. The rate was first order with respect to the acetylacetone concentration and inverse first order with respect to the hydrogen-ion concentration. From this information, the rate-controlling reaction is concluded to be the formation of the first complex in the aqueous phase by a reaction between [Cr(OH)]2+ and HA.
Dynamic NMR as a Nondestructive Method for Determination of Rates of Dissociation. XV. Dissociation of Thioether and Ether Ligands in Tin(IV) and Boron Complexes and Significance of Entropy of Activation Therein
Authors: Oki Michinori , Yamada Yasuhisa
Published: July 2006

The rates of dissociation of thioether ligands which are imbedded in organotin(IV) compounds, such as trichloro[o-(ethylthiomethyl)phenyl]stannane, were determined by the dynamic NMR method. The dynamic processes of the corresponding ether ligands was too fast to detect as the change in line shapes in 1H NMR spectra. All the boron compounds examined, which possessed similar structures to the stannane and were of the boronate type, failed to show dissociation of a thioether or ether ligand due to their large rates of dissociation. The rates of dissociation of a thioether–tribromoboron complex were determined by the same technique. The feature of the activation parameters was that the compounds examined exhibited fairly large positive entropy of activation in accordance with other results that involve dissociation of ionic species into covalent species.
Disulfide Linkages in a Heat-Stable Enterotoxin (STp) Produced by a Porcine Strain of Enterotoxigenic Escherichia coli
Authors: Hidaka Yuji , Kubota Hirokazu , Yoshimura Shoko , Ito Hideaki , Takeda Yoshifumi , Shimonishi Yasutsugu
Published: July 2006

Heat-stable enterotoxins, produced by various enteric bacteria such as enterotoxigenic Escherichia coli, Yersinia enterocolitica, and Vibrio cholerae non-01, have common segments consisting of 13 amino acid residues (T. Takao et al., FEBS Lett., 193, 250 (1985)). These segments have full enterotoxigenic activity and are bound by three intramolecular disulfide bonds. The linkages of these three disulfide bonds in a heat-stable enterotoxin (STp) produced by a porcine strain of enterotoxigenic E. coli were determined to be

(Remark: Graphics omitted.)

by stepwise and selective formation of disulfide bonds using different types of removable protecting groups for Cys residues. These disulfide linkages were identical with those of a heat-stable enterotoxin (STh) produced by a human strain of enterotoxigenic E. coli (Y. Shimonishi et al., FEBS Lett., 215, 165 (1987)).
Equilibrium and Kinetic Studies of the Interaction between Orange I and Bovine Serum Albumin
Authors: Murakami Kiyofumi
Published: July 2006

The interaction between Orange I (sodium 4-[(4-hydroxy-1-naphthalenyl)azo]benzenesulfonate) and bovine serum albumin (BSA) at pH=7.0 and 25 °C has been studied by equilibrium dialysis, spectrophotometry, and the temperature-jump method. Equilibrium dialysis has revealed the existence of sixteen equivalent binding sites with the binding constant of K=9.7×103 M−1. All of them were found to be equivalent also in the sense of spectrophotometry. That is, Orange I interacts with BSA in a typically nonspecific manner. Five relaxations were found by the temperature-jump measurements. These relaxation times, distributed over the time range from 10 μs to 0.1 s, were determined over a wide range of reactant concentrations. The fastest relaxation becomes slow, but the four slower ones become fast, with the increase in the concentration of the free ligand. The data were interpreted by means of a combination of the bimolecular binding processes and the four isomerization modes of BSA. The results were discussed in the light of the role of the configurational adaptability of albumin molecules in the ligand-binding mechanism.
Synthesis, Ion-Exchange Properties, and Analytical Applications of Anilinium Tin(IV) Phosphate
Authors: Singh Dhruv Kumar , Darbari Anjana
Published: July 2006

A new inorganic ion-exchanger anilinium tin(IV) phosphate (ATP) has been synthesized under varying conditions. The effects of mixing ratio of reagents and the pH of the mixture on the properties of the material have been studied. The sample ATP1 has been chosen for detailed studies, such as ion-exchange capacity, chemical and thermal stabilities, chemical composition, pH titration, break-through curve, and IR analysis. Distribution coefficients of 16 metal ions have been studied in water, hydrochloric acid and acetone–hydrochloric acid media. On the basis of Kd values some analytically important separations of metal ions have been achieved on the small columns of anilinium tin(IV) phosphate.
Alkylation of Phenol by C9 and C12 Olefins
Authors: Rajadhyaksha Rajeev Anand , Chaudhari Dilip Devidas
Published: July 2006

Alkylation of phenol by 1-dodecene, propylene tetramer and trimer is investigated using a variety of acid catalysts. The catalytic activity of perfluorinated sulfonic acid resin Nafion-H, the recently described ‘sulfate treated’ zirconia and trifluoromethanesulfonic acid is compared with that of cation exchange resin (CER) catalyst which is commonly employed in industrial practice. The activity of zirconia is observed to be comparable to CER and Nafion-H. In view of its low cost and higher thermal and structural stability, this catalyst shows considerable promise for practical application.
Synthesis of [52](1,2)Ferrocenophane
Authors: Hisatome Masao , Yamashita Rin-ichi , Watanabe Jun , Yamakawa Koji
Published: July 2006

The title compound 1 has been synthesized via bridge enlargement of compound 2 which was formed by cyclization of [5]ferrocenophane-2-propionic acid. By this study the structure of 2, which was discrepantly described by two groups, has been established as [5]-α-oxo[3](1,2)ferrocenophane.
Halogenation Using Quaternary Ammonium Polyhalides. IX. One-Step Syntheses of Acylureas and Carbamates from Amides by Use of Tetrabutylammonium Tribromide and DBU
Authors: Fujisaki Shizuo , Tomiyasu Kazushi , Nishida Akiko , Kajigaeshi Shoji
Published: July 2006

The reaction of amides with tetrabutylammonium tribromide (TBA Br3) (0.5 equiv) and DBU (one equiv) in dichloromethane at room temperature gave N-substituted acylureas in fairly good yields. In the presence of alcohols, the reaction of amides with TBA Br3 (one equiv) and DBU (two equiv) gave N-substituted carbamates.
Effects of Aryl Substituents on Electron-Transfer-Mediated Photochemical Addition of Alcohol to 1,1,2-Triarylcyclopropanes
Authors: Tomioka Hideo , Inoue Osamu
Published: July 2006

Direct irradiation of 1,1,2-triarylcyclopropanes in alcohol resulted in the formation of all possible products arising from trimethylene biradicals, while DCB-sensitized irradiation gave a novel ”anti-Markownikoff“ addition product of alcohol almost exclusively. In order to get insight into the nature and fate of intermediates in the reactions, the effects of nucelophiles and aryl substituents are examined.
New Description of the Substituent Effect on Electronic Spectra by Means of Substituent Constants. V. n–π* Transition of Aliphatic Carbonyl Groups
Authors: Uno Bunji , Kano Kenji , Hosoi Noriya , Kubota Tanekazu
Published: July 2006

The substituent (X) effect on the carbonyl n–π* band of CH3COX is discussed on the basis of a general equation, theoretically derived in order to express the substituent effect on electronic spectra using substituent constants. The results have been successful and are supported by MO calculations.
Reactions of Cobalt Complexes of 5,10,15,20-Tetraphenylporphyrin with Peroxide Radicals Generated from Organic Peroxides and Unsaturated Fatty Acids
Authors: Kohno Masahiro
Published: July 2006

The title reactions in aerated benzene solutions were investigated by using ESR and optical-absorption spectrometers. It was found that (1) a benzyl peroxide radical, bpox·, generated photochemically from dibenzoyl peroxide (DBPO) oxidizes [CoII(tpp)] to produce, successively, a five-coordinate cobalt(III) complex, [CoIII(bpox)(tpp)]; a π cation radical, [CoIII(tpp)\underset.+](bpox)2, and isoporphyrin; (2) a t-butyl peroxide radical, bupox·, generated from di-t-butyl peroxide (DBuPO) oxidizes [CoII(tpp)] to give only a six-coordinate cobalt(III)complex, [CoIII(bupox)(tpp)(dbupo)]; (3) lipid peroxide radicals (lpox·: oapox·, lapox·, lnapox·, and aapox·) produced from unsaturated fatty acids, oleic acid (OA), linoleic acid (LA), linolenic acid (LNA), or arachidonic acid (AA), do not react with [CoII(tpp)]; (4) all the peroxide radicals (pox·: lpox·, bpox·, bupox·) react with [CoIII(Cl)(tpp)] to produce π cation radicals, [CoIII(tpp)\underset.+](Cl)(pox), and (5) bpox· and lapox· react further with the π cation radicals to give isoporphyrins. Finally, the present reactions were compared with the reactions of horseradish peroxidase.
Effect of Counterionic Species on the Adsorption of Tetradecyltrimethylammonium Ion at the Polarized Nitrobenzene–Water Interface
Authors: Kakiuchi Takashi , Kobayashi Miki , Senda Mitsugi
Published: July 2006

The effect of counterions, F−, Cl−, and Br− on the adsorption of the hexadecyltrimethylammonium ion (HTMA+) at the polarized nitrobenzene–water interface has been studied by measuring electrocapillary curves. The interfacial tension in the negative branch of the electrocapillary curve, where the interface is polarized such that the potential in the aqueous phase is negative with respect to that in the nitrobenzene phase, was lowered due to the specific adsorption of HTMA+ ion at the interface. The magnitude of interfacial tension depression in the negative branch became larger in the order F−, Cl−, and Br−, indicating a specific counterion binding at the interface in this order. The adsorption free energy of the HTMA+ ion, ΔGa0, for the adsorption of HTMA+ ion at the interface from the nitrobenzene phase was found to depend markedly on the anionic species present in the aqueous side of the interface. This ΔGa0 values can be taken as a quantitative measure of the counterion specificity at the interface. The meaning of the fact that the change in the shape of the electrocapillary curves depends on the counterion species is discussed in detail in terms of the thermodynamics of the oil–water interface.
An Ab Initio Molecular Orbital Study on the Conformations of Bicyclo[3.1.0]hexane Derivatives
Authors: Okazaki Renji , Niwa Jun , Kato Shigeki
Published: July 2006

Ab initio calculations have been carried out for 2,4-dithia- (5), 2,4-dioxa- (6), 6-oxa- (8), 6-thiabicyclo[3.1.0]hexanes (9), bicyclo[3.1.0]hexane (7), and some of the corresponding cyclohexane derivatives 10–12 using 3-21G, 3-21 G(*) and 6-13G* basis sets. Relative total energies and geometries have been obtained for both boat and chair forms of these compounds. The calculated geometries are in good agreement with observed ones for 7–9. The boat form is more stable than the chair form in the bicyclic systems 7–9, while both the forms have almost equal stability for 5 and the chair form of 6 is slightly more stable than the boat form. The relative stability of the boat form in the bicyclic systems compared with that in the monocyclic cyclohexane derivatives can be explained in terms of the stabilizing orbital interaction. Inversion barriers between the boat and chair forms for 5–7 have also been estimated and are briefly discussed. A similar calculation for bicyclo[3.2.0]hept-6-ene also shows that the boat form is much more stable than the chair form contrary to the conclusion derived from the analysis of experimental results.
Magnetism and Electronic Structure of a Cubane-Type Mo4S4 Cluster
Authors: Sugano Tadashi , Shibahara Takashi , Kobayashi Hanako , Uryû Norikiyo , Kinoshita Minoru
Published: July 2006

The static magnetic susceptibilities of the stable cubane-type compounds of [Mo4S4]m+ with a set of consecutive oxidation numbers have been measured in the temperature range from 2 to 300 K at the field strength of 0.5 T. Na3[Mo4S4(edta)2]·10H2O (m=5) has been found to be paramagnetic with S=1⁄2, whereas Mg2[Mo4S4(edta)2]·22H2O (m=4) and Mg[Mo4S4(edta)2]·12H2O (m=6) to be diamagnetic. The electronic structure of the [Mo4S4]m+ clusters is discussed on the basis of the MO theory from the magnetic properties of these compounds.
A New Reaction of Tris(alkylthio)cyclopropenium Salt with m-Substituted Anilines Affording Quinoline Derivatives
Authors: Yoneda Shigeo , Kojima Hideo
Published: July 2006

The reaction of tris(alkylthio)cyclopropenium salt with m-substituted anilines gave quinoline derivatives.
The Electrocapillary Curves of the Phosphatidylcholine Monolayer at the Polarized Oil–Water Interface. I. Measurement of Interfacial Tension Using a Computer-Aided Pendant-Drop Method
Authors: Kakiuchi Takashi , Nakanishi Masatoshi , Senda Mitsugi
Published: July 2006

The conditions for obtaining the electrocapillary curves of the dilauroylphosphatidylcholine (DLPC) monolayer formed at the polarized nitrobenzene–water interface have been studied using the pendant drop method. To facilitate the measurement, the system for the interfacial tension measurement, including the computer software for the data handling, has been developed based on digital image processing of the video image of a pendant drop. The 95% confidence interval of the measured interfacial tension value was ±0.06 mN m−1. The time required to measure an electrocapillary curve with 30 points was 30 min, while the time necessary to convert the image data to the interfacial tension was 1 min. The potential drop across the monolayer has been demonstrated to influence the stability of the monolayer strongly. The DLPC markedly lowered the interfacial tension by forming a stable monolayer when the interface was polarized so that the aqueous phase has a negative potential with respect to the nitrobenzene phase. On the other hand, when the aqueous phase became positively polarized, the adsorbed DLPC molecules started to desorb from the interface, giving rise to the disruption of the monolayer. The electrocapillary curves only in the former potential range were found to be thermodynamically meaningful.
Excited-State Reactions of Coumarins. VII. The Solvent-Dependent Fluorescence of 7-Hydroxycoumarins
Authors: Moriya Tetsuo
Published: July 2006

The excited-state reactions of 7-hydroxycoumarin (7HC) and 7-hydroxy-4-methylcoumarin (7H4MC) have been studied by measuring the absorption and fluorescence spectra in aqueous and organic solvents under acidic and basic conditions. Based on the solvent-dependent fluorescence of the fluorophores, the solvents could be classified into several groups: hydroxylic solvents, nonhydroxylic solvents with low dielectric constants, and those with high dielectric constants. In the hydroxylic solvent, protonation, deprotonation, and tautomerization were the main reactions, while in the nonhydroxylic solvent the formation of hydrogen bonding and ion pairs was essential. The fluorescence in water–ethanol mixtures and in aqueous sodium dodecyl sulfate solutions has also been examined in relation to the solvent-dependent spectra in pure hydroxylic and nonhydroxylic solvents.
Polarized Raman and Infrared Spectra of 2,6-Dichloro-, 2,6-Dibromo-, 3,5-Dichloro-, and 3,5-Dibromopyridines
Authors: Tanaka Katsuharu , Kasasaku Kinichi , Shimada Hiroko , Shimada Ryoichi
Published: July 2006

Assignments of the normal vibrations of 2,6-dichloro-, 2,6-dibromo-, 3,5-dichloro-, and 3,5-dibromopyridines were made based on the polarization behavior of the Raman and infrared spectra in single crystals and the normal coordinate calculations. The effect of halo-substitution on the vibrational frequencies of the normal modes was discussed.
The Structure of the Cyclodextrin Complex. XXI. Crystal Structures of Heptakis(2,6-di-O-methyl)-β-cyclodextrin Complexes with p-Iodophenol and p-Nitrophenol
Authors: Harata Kazuaki
Published: July 2006

Crystal structures of heptakis(2,6-di-O-methyl)-β-cyclodextrin complexes with p-iodophenol and p-nitrophenol were determined by the X-ray analysis. These two crystals were isomorphous with the space group P212121 and cell dimensions: a=14.796(3), b=18.853(5), and c=28.989(6) Å for the p-iodophenol complex, and a=14.779(2), b=18.965(3), and c=28.741(4) Å for the p-nitrophenol complex. The structures were solved by the heavy atom method combined with the phase refinement by the tangent formula and refined by the blockdiagonal least-squares method to the R-values of 0.12 (p-iodophenol complex) and 0.10 (p-nitrophenol complex). The host molecule has a round shape, which is maintained by the intramolecular hydrogen bonds between the O(3)H hydroxyl group and O(2)CH3 methoxyl group of the adjacent residue. The guest molecules in the both complexes are not included within the host cavity but located in the intermolecular space between host molecules. The host cavity includes water molecules and a methoxyl group of the adjacent host. Hydrogen bonds are formed only within the host cavity.