bluuebunny/crossref_metadata_2025 huggingface dataset:
The Use of Different Figure-Inventories in the Enumeration of Isomers Derived from Non-Rigid parent Molecules
Authors: Fujita Shinsaku
Published: July 2006

Inevitable use of different figure-inventories is discussed in the enumeration of non-rigid isomers derived from 2,2-diphenyl-(1) and 2,2-dimethylpropane (2) by means of unit subduced cycle indices (USCIs). Such a parent non-rigid molecule is divided into a rigid skeleton and mobile moieties. Thus, the molecule (1) consists of a rigid skeleton of C2v symmetry, a methyl moiety of C3v symmetry and a phenyl moiety of C2v symmetry. The molecule (2) contains a Td rigid skeleton and a C3v moiety. The USCIs are used in the first enumeration of mobile moieties as well as the subesequent enumeration based on a rigid skeleton. A general procedure for enumerating non-rigid isomers is discussed.
Electrosorption of Tetraethylene Glycol Monododecyl Ether at the Polarized Nitrobenzene–Water Interface
Authors: Kakiuchi Takashi , Usui Taketoshi , Senda Mitsugi
Published: July 2006

The adsorption of tetraethylene glycol monododecyl ether, C12E4, has been studied by measuring the electrocapillary curves at the polarized interface between the nitrobenzene solution of 0.1 mol dm−3 tetrapentylammonium tetraphenylborate and the aqueous solution of 0.05 mol dm−3 lithium chloride. C12E4 adsorbed at the interface over the entire polarized potential range of 250 mV. Although C12E4 itself is a neutral molecule, its surface activity was greatly affected by changing the potential drop across the interface; an increase in the potential of the aqueous phase with respect to the potential in the nitrobenzene phase markedly enhanced the adsorption. The complex formation between the adsorbed C12E4 molecules and Li+ ions in the aqueous side of the interface was shown to play a decisive role in determining the dependence of adsorption on the electrical potential difference across the interface. A proposed model for complex formation at the interface based on the Gouy–Chapman double-layer theory well-explained the observed trend in the adsorption Gibbs energy when the potential drop across the interface was changed.
Preparation and Characterization of Cobalt(III) Complexes Containing 3,7-Diphenyl-3,7-diphosphanonane-1,9-diamine, NH2CH2CH2P(C6H5)CH2CH2CH2P(C6H5)CH2CH2NH2
Authors: Jung Minho , Atoh Masamichi , Kashiwabara Kazuo , Fujita Junnosuke
Published: July 2006

New cobalt(III) complexes with the titled ligand and its analog, cisα-[Co(L)(rac(P)-232NPPN)]n+ (L=2,4-pentanedionate (acac) and oxalate(ox) ions, and ethylenediamine(en)), cisβ-[Co(L)(rac(P)-or meso(P)-232NPPN)]n+ (L=acac and ox) and cisα-[Co(acac)(rac(P)-222NPPN)]2+ and cisβ-[Co(acac) (meso(P)-222NPPN)]2+ were prepared and characterized by 1H and 13C NMR,. and absorption spectra, where rac(P)-and meso(P)-232NPPN and -222NPPN denote recemic(P)-and meso(P)-NH2CH2CH2P(C6H5)(CH2)nP(C6H5)CH2CH2NH2 with n=3 and 2, respectively. All the cisα isomers except the en complex react with concd hydrochloric acid at room temperature to yield the corresponding cisα-dichloro complexes. For the cisβ isomers, the acac complexes dissociate one amino group of NPPN reversibly depending on the acidity of solution, yielding [Co(acac)(H2O)(NPPNH+)]3+, while the ox complexes of rac(P)-and meso(P)-232NPPN yield the cisα and trans-dichloro complexes, respectively in hydrochloric acid. All the cisβ isomers except [Co(ox)(rac(P)-232NPPN)]+decompose slowly in coned hydrochloric acid to give Co(II) species.
Studies of the Acidity and Ionic Conductivity of Silica-Supported Heteropoly Compounds. II. Acidity and Catalytic Activity of Supported Heteropoly Compound Catalysts
Authors: Ohtsuka Reiji , Morioka Yoshio , Kobayashi Jun-ichi
Published: July 2006

The acidity function, H0, of silica-supported heteropoly compounds (HPC) such as H3PMo12O40, H3PW12O40, and their sodium, potassium, ammonium, cesium, and bismuth oxide salts has been examined in connection with their catalytic activity for the dehydration of t-butyl alcohol (TBA). The values of H0 for the respective catalysts have been determined spectrophotometrically utilizing adsorbed dicinnamylideneacetone (DCA) as a probe molecule. A linear relationship has been established between the amount of HPC supported (logm) and its H0. Also, for the dehydration of TBA in the liquid-phase all plots of logk1′ vs. H0 fall on a straight line with a slope of −1, independent of the kind of catalyst. In this case k1′ is the apparent rate constant of the dehydration of liquid TBA. On the other hand, for the gas-phase dehydration of TBA the plots yield straight lines with different slopes, depending on the type of catalyst. The dependence of the catalytic activity on the H0 supports the previous conclusion that the dehydration of liquid and gaseous TBA proceeds through pseudo-liquid and outer-surface mechanisms, respectively.
Conformational Adaptation: A New Aspect of Substitutent Effects
Authors: Inagaki Satoshi , Okajima Takehiko , Yamamura Kimiaki , Miyake Hideyoshi , Nakasuji Kazuhiro , Murata Ichiro
Published: July 2006

Methoxyl (CH3O–) substituent on unsaturated molecules was suggested by ab initio molecular orbital calculation and qualitative orbital interaction theory to change from coplanar to vertical conformation on electron acceptance. The conformational adaptation can make it possible that methoxyl group is less electron-donating than methyl group.
Structures Optimized by Molecular Mechanics for 15-Crown-5 and Its Water-Accommodating Species
Authors: Fukushima Kunio
Published: July 2006

Optimization of the structure for 15-crown-5 and its water-accommodating species was carried out by a molecular mechanics calculation. Molecular deformation presumed from the Raman spectral feature of 15-crown-5 in aqueous solutions was confirmed by the results of the calculation.
Photocatalytic Reaction on Layered Cs–Nb–Ti Complex Oxide
Authors: Sekine Toshiko , Yoshimura Joji , Tanaka Akira , Domen Kazunari , Maruya Ken-ichi , Onishi Takaharu
Published: July 2006

Ion-exchangeable layered titano-niobates, CsNbTi2O7 and CsNbTiO5, were prepared and the photocatalytic properties of those oxides as well as of the H+-exchanged forms were investigated. H2 or O2 evolution reaction from an aqueous methanol solution or from an aqueous silver nitrate solution was carried out under a high pressure mercury lamp irradiation. For H2 evolution, Pt (0.1 wt%)-loaded H+-exchanged forms showed remarkable activity both for CsNbTi2O7 and CsNbTiO5, while higher rates of O2 evolution were obtained for H+-exchanged forms than those for the original forms.
1H NMR Study of the Motion of Guanidinium Ions in Guanidinium Dichloroiodate(I) and Tetrachloroiodate(III)
Authors: Furukawa Yoshihiro , Nakamura Daiyu
Published: July 2006

The temperature dependence of the 1H NMR spin-lattice relaxation time, T1, was measured for C(NH2)3ICl2 and C(NH2)3ICl4. For the dichloro complex, three T1 minima were observed and assigned to the reorientations of crystallographically inequivalent C(NH2)3+ ions about the three-fold axes, each of which has an activation energy of 21, 15, and 8.4 kJ mol−1. The tetrachloro complex yielded a single T1 minimum with an activation energy of 33 kJ mol−1. A phase transition in C(NH2)3ICl2 was found at 399 K by NMR and differential thermal analysis.
MNDO RHF CI and MINDO/3 RHF CI Calculations of Hyperfine Coupling Constants of π Radicals
Authors: Morihashi Kenji , Takase Hideto , Kikuchi Osamu
Published: July 2006

MNDO RHF CI and MINDO/3 RHF CI calculations, in which one type of singly-excited configuration is included, were shown to give hyperfine coupling constants of π radicals which are in better agreement with the experimental values, as compared with the UHF method.
Highly Diastereoselective 1,2-Asymmetric Addition of Dialkylzincs to Chiral 2-Phenylpropanal Catalyzed by Amino Alcohol
Authors: Soai Kenso , Niwa Seiji , Hatanaka Toshihiro
Published: July 2006

Diastereoselective addition of dialkylzinc reagents to 2-phenylpropanal using amino alcohol as catalyst afforded erythro alcohols (Cram-selectivity) in high diastereomeric excess (up to 88% d.e.).
Evidence of Conversion from Carbon Dioxide to Unstable Carbon Oxides
Authors: Akiyama Fuminori
Published: July 2006

A reaction of reduction products of carbon dioxide by benzoin carbanion with sodium dithionite gave a substance showing only one 13C NMR absorption signal at 75.4 ppm, which was tentatively attributed to a signal of an oligomer having a –C(SO3Na(H))2– structure as a repeating unit.
Synthesis of 4,4-Disubstituted 2,3-Dicyano-5-imino-2-pyrrolines. Reaction of Alkylidenemalononitriles with Trimethylsilyl Cyanide
Authors: Chatani Naoto , Hanafusa Terukiyo
Published: July 2006

The reaction of alkylidenemalononitriles with trimethylsilyl cyanide in the presence of KCN/18-crown-6 gave 4,4-disubstituted 2,3-dicyano-5-imino-2-pyrrolines in high yields.
Electronic Structures of 2,7-Bis(methylthio)-1,6-dithiapyrene (MTDTPY) Charge Transfer Complexes
Authors: Kawamoto Atsushi , Tanaka Jiro , Sasaki Mitsuru , Murata Ichiro , Nakasuji Kazuhiro
Published: July 2006

Polarized reflection spectra were measured on two charge-transfer complexes of 2,7-bis(methylthio)-1,6-dithiapyrene (MTDTPY) with chloranil and 7,7,8,8-tetracyanoquinodimethane (TCNQ), which showed metallic conductivity. In spite of short intercolumnar S–S contacts, the spectra showed a strong one-dimensional character. The optical conductivity spectra, σ(ω), and real part of the dielectric constant, ε′(ω), along the stack axis were obtained by means of Kramers–Kronig transformation. The conductivity spectra and the dielectric constant of both complexes substantially differ from the simple Drude model. These results were analyzed with a one-dimensional electron localization model in a disordered system with the optical parameters: ωp=13500 cm−1, τi=1.6×10−15s (τi−1=3300 cm−1) for chloranil complex and ωp=12000 cm−1, τi=2.5×10−15s (τi−1=2100 cm−1) for TCNQ complex.
Modification of an Ion-Exchange Membrane Surface by Plasma Process Part 3: Interfacial Resistance of Monovalent Cation Perm-Selective Membrane from Nafion®
Authors: Ogumi Zempachi , Uchimoto Yoshiharu , Tsujikawa Masanori , Yasuda Kazuaki , Takehara Zen-ichiro
Published: July 2006

The monovalent cation perm-selectivity of Nafion® 117, perfluoro-sulfonate cation-exchange membrane, was enhanced by depositing on its surface an ultrathin anion-exchange layer prepared by plasma polymerization. The anion exchanger was deposited from a 4-vinylpyridine monomer vapor followed by quaternarization with 1-bromopropane. The resulting anion-exchange layers were found to be pinhole-free and of uniform thickness. The monovalent cation perm-selectivity of the plasmamodified Nafion membrane was determined by measuring the Fe 2+ ion transference number, tFe in a Li+–Fe2+ system. The influence of the thickness of the plasma layers on the tFe and the membrane resistance was investigated. The tFe decreased with increasing thickness of the plasma polymer layer, but at the cost of enhanced membrane resistance. The resistance of treated Nafion was separated into bulk resistance and interfacial resistance. A large interfacial resistance was observed between Nafion and the plasma polymer layer, and was ascribed to the implantation of cation species.
Effects of Phenyl Groups on Thermodynamic Parameters of Lanthanoid(III) Complexation with Aromatic Carboxylic Acids
Authors: Hasegawa Yuko , Yamazaki Nobuhiko , Usui Satoko , Choppin Gregory R
Published: July 2006

The enthalpy changes as well as the stability constants of the complexes between a series of lanthanoid(III) cations and phenylacetate, 3-phenylpropionate, and salicylate ions have been measured using a potentiometer and an isothermal calorimeter, respectively. The data were compared with the data with benzoate ions. The enthalpy changes for formation of the heavier lanthanoid(III) complexes are larger than those for the complexation of the lighter lanthanoids. Also, the complexation heat changes by the carboxylate ions having methylene group(s) between the carboxyl and the phenyl groups are more endothermic than by the anions in which these two groups are joined directly. The results are explained in terms of the differences in the dehydration of the lighter lanthanoid(III) from that of the heavier ones upon complexation and also the different basicities of the carboxylate ions of the ligands.
Solvent Extraction of Palladium(II) and Platinum(IV) with N,N-Dioctylsuccinamic Acid from Aqueous Chloride Media
Authors: Yoshizuka Kazuharu , Baba Yoshinari , Inoue Katsutoshi , Wada Fumio , Matsuda Tsutomu
Published: July 2006

N,N-Dioctylsuccinamic acid was synthesized to examine the selectivity for various metals in extractions from hydrochloric acid. It was found to be highly selective for palladium(II), platinum(IV), and mercury(II) over other base metals including copper(II), nickel(II), cobalt(II), zinc(II), iron(III), aluminum(III), and gallium(III). A quantitative study was conducted on the extraction equilibria of palladium(II) and platinum(IV) from aqueous chloride media with N,N-dioctylsuccinamic acid in toluene, together with measurement of the apparent molecular weight of the extractant. It was elucidated that the extractant (HR) dimerizes in toluene and that palladium(II) and platinum(IV) are extracted according to the following reactions:

&PdCl_4^2-+‾H_2R_2 \oversetK_e,Pd\ightleftharpoons ‾PdR_2+2H^++4Cl^-

& PtCl_6^2-+‾H_2R_2 \oversetK_e,Pt\ightleftharpoons ‾PtCl_4·2HR+2Cl^-

The extraction equilibrium constants of palladium(II) and platinum(IV) with the extractant were evaluated as follows: Ke,Pd=0.11±0.03 (mol·dm−3)5 and Ke,Pt=27.7±3.7 mol·dm−3, respectively.
Synthesis of a Homostatine-Containing Renin Inhibitor Which Incorporates a Sulfonemethylene Isostere at Its N-Terminus
Authors: Nakano Masato , Atsuumi Shugo , Koike Yutaka , Tanaka Seiichi , Funabashi Hiroshi , Hashimoto Junko , Ohkubo Mitsuru , Morishima Hajime
Published: July 2006

A homostatine analogue, (2RS,4S,5S)N-isobutyl-5-amino-2-ethyl-4-hydroxy-7-methyloctanamide, was synthesized starting from natural statine. The modified Horner–Wadsworth–Emmons reaction of (4S,5R)-3-benzyloxycarbonyl-5-formyl-4-isobutyl-2,2-dimethyloxazolidine is a key reaction for the synthesis of a homostatine analogue. Stereoselective and stereospecific syntheses of a N-terminal precursor, N-[(2R)-3-hydroxy-2-(1-naphthylmethyl)propionyl]-l-norleucine t-butyl ester and a total synthesis of a highly active renin inhibitor, (2RS,4S,5S)-N-isobutyl-5-[[N-[(2S)-2-(1-naphthylmethyl)-3-(2-pyrimidinylsulfonyl)propionyl]-l-norleucyl]amino]-2-ethyl-4-hydroxy-7-methyloctanamide are described.
Multi-Dimensional Stacking Structures in Phthalocyanine-Based Electrical Conductors, K[Co(phthalocyaninato)(CN)2]2·5CH3CN and Co(phthalocyaninato)(CN)2·2H2O
Authors: Inabe Tamotsu , Maruyama Yusei
Published: July 2006

Two kinds of electrically conducting crystals have been obtained by the electrochemical oxidation of potassium dicyanophthalocyaninatocobalt(III), KCo(Pc)(CN)2. Oxidation in acetonitrile gives K[Co(Pc)(CN)2]2·5CH3CN, in which the phthalocyanine rings are two-dimensionally stacked. Since some of the acetonitrile molecules can be easily removed from the lattice, the crystal is not stable outside of the solution. Mosaically distorted crystals, which are exposed to air, show relatively high conductivities (≈10 Ω−1cm−1 at room temperature). On the other hand, oxidation in benzonitrile in the presence of dibenzo-18-crown-6 yields Co(Pc)(CN)2·2H2O, in which the phthalocyanine rings are three-dimensionally stacked. The water molecules in this crystal form hydrogen bonds, and the crystal is stable against drying. The conductivity of this crystal is ≈1 Ω−1cm−1 at room temperature. The multi-dimensionalities observed in these two kinds of crystals arise from a slipped stacking of phthalocyanine, due to steric interactions of the axial substituents.
The Crystal and Band Electronic Structures of Bis[4,5-ethylenedithio-4′,5′-(vinylenedithio)tetrathiafulvalenium] Hexafluorophosphate, and Hexafluoroarsenate [EVT2PF6 and EVT2AsF6]
Authors: Nakano Hideyuki , Miyawaki Kenji , Nogami Takashi , Shirota Yasuhiko , Harada Shigeharu , Kasai Nobutami , Kobayashi Akiko , Kato Reizo , Kobayashi Hayao
Published: July 2006

The molecular and crystal structures of EVT2PF6 and EVT2AsF6 [EVT=4,5-ethylenedithio-4′,5′-(vinylenedithio)tetrathiafulvalene] were determined by an X-ray diffraction method. Tight-binding band-structure calculations were made, and the results were compared with those of closely resembling conducting salts, α-(BEDT-TTF)2PF6 and VT2PF6 [BEDT-TTF=bis(ethylenedithio)tetrathiafulvalene; VT=bis(vinylenedithio)tetrathiafulvalene]. It was concluded that the extent of the two-dimensional nature of the band electronic structure increased systematically in the order VT2PF6, EVT2PF6, and α-(BEDT-TTF)2PF6; this result was analysed in terms of their crystal structures.
Studies of Aqueous Resins. I. Water-Dispersed Polyesters Containing Polar Groups
Authors: Kotera Nobukazu , Takahashi Kensuke
Published: July 2006

Water-borne polyesters which can provide a flexible film having a high resistance to water have been designed. Such hydrophobic polyesters can be dispersed into water by introducing small amounts of hydrophilic groups. When a few mol% of sodium 5-sulfonatoisophthalic acid is used as a hydrophilic group and some water-soluble organic compounds, such as 2-butoxyethanol, are used as additives, stable aqueous dispersions of polyester resins are obtained, having a fine particle size under 1.0 μm.
Studies of a Hydrous Tin(IV) Oxide Ion Exchanger. VI. Rate of the Isotopic Exchange of Cobalt Ions between the Exchanger in the Cobalt Form and Aqueous Solutions
Authors: Yamazaki Hiromichi , Itami Akira , Inoue Yasushi
Published: July 2006

The isotopic exchange rate of cobalt ions between a hydrous tin(IV) oxide ion exchanger and aqueous solutions was radiochemically measured in order to obtain fundamental data which could be useful for elucidating the ion-exchange kinetics of the material for the transition metal elements. This rate can be understood by considering that the cobalt in an exchanger exists as three species: (A1) dissociated ions which can diffuse in the exchanger particles; (A2) weakly bound ions to the exchange sites, which are in local equilibrium with A1; and (B) covalently fixed ions to the exchange sites, which are exchanged very slowly with A1. At a small ratio of the amount of B to the total amount of cobalt sorbed on the exchanger, the rate is controlled by the diffusion of A1, with effective diffusion coefficient, \barDeff, a value which depends on the concentration ratio of A2 to A1. When B predominates over A, the concentration ratio of B to A1 greatly affects \barDeff. The values of \barDeff and their activation energy (20 kJ mol−1) were also estimated.
First Synthesis of [Fe4(η5)-C5H5)4S4](PF6)3 and Improved Syntheses of [Fe4(η5-C5H5)4S4](PF6)n (n=1,2)
Authors: Ogino Hiroshi , Satoh Asako , Shimoi Mamoru
Published: July 2006

[Fe4(η5)-C5H5)4S4](PF6) and [Fe4(η5-C5H5)4S4](PF6)2 were prepared in 81 and 82% yields, respectively, by bulk electrolysis of [Fe4(η5-C5H5)4S4] at the requisite potentials according to the results of voltammetric studies. [Fe4(η5-C5H5)4S4](PF6)3 was prepared and isolated first by electrolysis of [Fe4(η5-C5H5)4S4](PF6)2 in acetonitrile at +0.95 V vs. SCE in 83% yield. The electronic spectral data for [Fe4(η5-C5H5)4S4]n (n=0, 1+, 2+, 3+) were collected.
Amphiphilic Porphinatoirons Having Steroid Groups and Their Oxygen-Adduct Formation in an Aqueous Medium
Authors: Tsuchida Eishun , Komatsu Teruyuki , Babe Takeshi , Nakata Taisaku , Nishide Hiroyuki , Inoue Hidenari
Published: July 2006

Amphiphilic heme derivatives having four steroid groups (steroid-heme), 5,10,15,20-tetrakis[α,α,α,α-o-[2,2-dimethyl-8-(3α-hydroxycholan-24-oyloxy)octanamido]phenyl]porphinatoiron (1b) and 5,10,15,20-tetrakis[α,α,α,α-o-(3-acetoxycholan-24-oylamino)phenyl]porphinatoiron (2b), were synthesized as a model of an oxygen carrier. They were efficiently embedded in the bilayer of a phospholipid liposome based on their high compatibility with the lipid. The oxygen-binding ability of 1b was compared with those of hemoglobin (Hb) and myoglobin (Mb). The dioxygen adduct of 1b was also characterized by Mössbauer and infrared spectroscopy.
Improvements of the Empirical π* Solvent Polarity Scale
Authors: Abe Takehiro
Published: July 2006

The famous empirical π* (or π1*(N)) solvent polarity scale has been improved for nonassociating solvents by introducing newly presented solvent polarity parameters of π1* and π2* Here, the π1* parameter is a modified form of the π1*(N) scale. The shortcoming that the π* scale does not correlate to solvent spectral shifts of nonpolar and less polarized solutes has been overcome by introducing the new supplementary π2* solvent scale. The present parameters of π1* and π2*, the physical meanings of which are clarified on the basis of their theoretical background, are more successfully applied to the solvent frequencies of both nonpolar and less polarized solutes and to the logarithmic rate constants for organic reactions than is the π1*(N) scale.
Radiation-Induced Polymerization of Isobutyl Vinyl Ether by Diphenyliodonium Hexafluorophosphate. Contribution of Free Radicals to Cationic Polymerization
Authors: Teramoto Mitsuhito , Yamamoto Yukio , Hayashi Koichiro
Published: July 2006

The radiation-induced cationic polymerization of isobutyl vinyl ether by Ph2IPF6 was investigated in dichloromethane solution. The polymerization occurs in the aerated solution containing the salt and is extremely accelerated when the solution is degassed. Contribution of radiolytically produced radicals to the cationic initiation is described. Results for the polymerization by Ph3SPF6 are also presented for the sake of comparison.
The Determination of a Small Amount of a Biological Constituent by the Use of Chemiluminescence. XVII. Experimental Consideration on the Chemiluminescence Detection of Protein Using the 1,10-Phenanthroline-Hydrogen Peroxide–Copper(II) System
Authors: Hara Tadashi , Tsukagoshi Kazuhiko , Kimoto Hideshi , Imai Toshihito , Nakajima Riichirou
Published: July 2006

With an objective to clarify the relationship between chemiluminescence intensity and the reaction time in the flow injection analysis of a small amount of protein using a 1,10–phenanthroline-hydrogen peroxide–copper(II) chemiluminescence system, an apparatus was newly set up for continuously measuring the chemiluminescence intensity. With this apparatus a lowering of the catalytic activity of copper(II) was observed in the presence of α-amino acids, polyamines, polypeptides, and proteins. In addition, the effect of heating on the reaction between copper(II) and protein was examined, and the reaction rate was found to markedly increase. Heating was therefore indispensable for the rapid and sensitive detection of proteins.
Type II Photoreaction of 2-Benzoylcycloalkanones: Conformational Control in the Biradical Formation and in the Behavior of Biradicals
Authors: Hasegawa Tadashi , Hojo Fusao , Yoshioka Michikazu
Published: July 2006

The photoreactivities of 2-benzoylcycloalkanones were shown to be controlled by their ring conformation; 2-benzoylcycloalkanones underwent the Type II elimination and/or cyclization, and/or the α-cleavage reaction.
An Efficient Synthesis of 5,7-Dihydroxy-4-methylisobenzofuran-1(3N)-one, a Metabolite of aspergillus flavus and a Key Intermediate in the Synthesis of Mycophenolic Acid
Authors: Kobayashi Kazuhiro , Shimizu Hideki , Itoh Masahito , Suginome Hiroshi
Published: July 2006

An efficient new synthesis of 5,7-dihydroxy-4-methylisobenzofuran-1(3H)-one, a metabolite of aspergillus flavus and a key intermediate in the synthesis of mycophenolic acid, is reported. The new synthesis involves the preparation of 1,2-dihydro-4,6-dimethoxy-3-methylbenzocyclobuten-1-ol and a regioselective β-scission of alkoxyl radical generated from it with lead tetraacetate as the key steps.
Stereochemistry of Thermal Chlorine-for-Bromine Substitution in Diastereomeric 3-Bromo-4-fluorohexane
Authors: Sharma Ram B , Meyer Richard J , Rack Edward P
Published: July 2006

The stereochemistry of thermalized chlorine-for-bromine substitution was studied in gaseous (3RS,4SR)- and (3RS,4RS)-3-bromo-4-fluorohexane. While energetic chlorine-for-bromine substitution occurs by a two-channel substitution mechanism, one leading to retention, the other to inversion of configuration, thermal chlorine-for-bromine substitution at the sp3-hybridized carbon of the diastereomers proceeds extensively, if not exclusively, via stereochemical inversion.
On the Volume Flow in Nonequilibrium Membrane Systems
Authors: Garrido Javier , Compañ Vicente
Published: July 2006

The volume flow definitions of the different formulations which describe irreversible proccesses in isothermal membrane systems are critically analysed. We show that only one of these definitions can be considered as the volume change observed in each compartment. The study carried out considers the general case of multicomponent systems with arbitrary dissociation degrees.
Transportation of Monosaccharides by Electrodialysis with Ion-Exchange Membranes. I
Authors: Shigemasa Yoshihiro , Yamasaki Osamu , Sashiwa Hitoshi , Saimoto Hiroyuki
Published: July 2006

The effects of voltage, electrolytes, monosaccharides, and pH on the transportation of monosaccharides by electrodialysis were investigated. Transportation was strongly affected by the formation of monosaccharide-borate esters. It was possible to separate saccharides using an electrodialysis technique.
Rotational Effect on Radiationless Transition I: Fluorescence Depolarization in Pyrimidine
Authors: Kanamaru Nobuaki
Published: July 2006

Fluorescence depolarization after R branch excitation of 000  1B1 pyrimidine was interpreted by utilizing ΔJ=0 and/or ±1 coupling schemes within a singlet manifold through triplet rovibronic levels where spin-orbit, vibration-rotation, and hyperfine interaction terms are involved. These schemes are suggested to be useful interpreting the intermediate-case phenomena observed in this kind of molecules.
Photophysics on Solid Surfaces. Time-Resolved Fluorescence Spectra of Pyrene Adsorbed on Calcinated Vycor Glass
Authors: Fujii Tsuneo , Ishii Akira , Satozono Hiroshi , Suzuki Satoshi , Che Michel , Anpo Masakazu
Published: July 2006

The fluorescence, fluorescence excitation, and time-resolved fluorescence spectra of pyrene molecules adsorbed on calcinated (773 K) Vycor glass (average pore diameter, 40 Å) have been investigated as a function of the amount of adsorbed pyrene. The results of the analyses of these spectra and multi-component decays of fluorescence suggest that there are three fluorescent species with different decay times on the surface of Vycor glass. Their lifetimes are determined to be 303–355, 100–145, and 19–48 ns. These decay components are reasonably assigned to the emissions of monomeric, dimeric, and excimer-like species in the order of decreasing the lifetimes. A 26600 cm−1 peak appearing at the first stage of the time-resolved fluorescence spectra is assingned to the 0–0 hand of dimeric pyrene based on the results reported by Yamazaki et al. in the Langmuir-Blodgett monolayer.
Crystal and Molecular Structure of the Crystalline Host-Guest Complex between (R)-(+)-2,2′-Dihydroxy-1,1′-binaphthyl and (S)-(−)-(Ethyl m-Tolyl Selenoxide)
Authors: Fujiwara Takaji , Tanaka Naoki , Ooshita Ryuzou , Hino Ryoji , Mori Koji , Toda Fumio
Published: July 2006

The crystal and molecular structure of the title complex was determined by X-ray method. The absolute configuration of the host (+)-2,2′-dihydroxy-1,1′-binaphthyl (1) was determined to be R and the guest (−)-(ethyl m-tolyl selenoxide) (2) to be S. Two Se–C and one S-O bond lengths are 1.926(7), 1.970(8), and 1.677(5) Å, respectively, and the arrangement around Se atom is roughly tetrahedral. There are O(guest)···HO(host)OH···O(guest) hydrogen bonds between the host and the guest molecules.
Electron Paramagnetic Resonance Study of the Dimer Formation of Bis(acetylacetonato)oxovanadium(IV)
Authors: Kawata Satoshi , Yokoi Hiroshi , Iwaizumi Masamoto
Published: July 2006

Dimer formation of the title complex in toluene and benzene mixed solvents has been demonstrated by the EPR spectroscopy. The dimer structure and the spin-exchange energy have been examined by spectral simulation for ΔMs=2 transitions and the temperature dependence of their spectral intensities, respectively. It has been found that the structure and the magnetism are similar to those of the inversion pair of bis(benzoylacetonato)oxovanadium(IV) in a crystal which is known to show dimeric interactions in its EPR spectra. The formation constant of the dimer, K, for 2 [monomer] \ightleftharpoons dimer has been determined by analyzing the concentration dependence of the dimer and the monomer EPR signals, indicating that K is remarkably solvent-dependent.
ESR Studies at High Pressure. II. Spin Exchange of 2,2,6,6-Tetramethyl-4-oxo-1-piperidinyloxyl in Protic and Aprotic Solvents
Authors: Sueishi Yoshimi , Nishimura Norio , Hirata Koichi , Kuwata Keiji
Published: July 2006

The activation volumes for the spin exchange of 2,2,6,6-tetramethyl-4-oxo-1-piperidinyloxyl (Tanone) in protic and aprotic solvents were determined from the pressure dependence of the rate constants, and were compared with those for the diffusive process. It was concluded that the rate process for the spin exchange in aprotic solvents is a diffusion-controlled one, and in protic solvents an encounter complex as intermediate is formed. The average reaction volume for the complex formation in protic solvents was estimated to be −3.6 cm3 mol−1.
Homoconjugated Diene as a Dienophile to Troponoid Compounds: The Stereoselective Addition Reactions of Tropone and 8,8-Dicyanoheptafulvene with Tricyclo[3.2.2.02,4]nona-6,8-diene Derivative and Thermal and Photochemical Isomerizations of the Adducts
Authors: Ito Kazuaki , Noro Yukie , Saito Katsuhiro , Takahashi Kensuke
Published: July 2006

Thermal addition reactions of tropone and 8,8-dicyanoheptafulvene with a homoconjugated diene, dimethyl 3-cyanotricyclo[3.2.2.02,4]nona-6,8-diene-6,7-dicarboxylate derivative, proceeded stereoselectively to give endo-[4+2]-type cycloadducts, where the troponoids acted as 4 π components. Upon photo-irradiation the adducts afforded intramolecular [2+2]-type addition products to verify the endo-form of the adducts. Molecular orbital caluculations suggested that the stereoselectivity could be explained by secondary orbital interactions between the HOMO of the troponoid compounds and the LUMO of the tricyclic compound. A thermal reaction of the adducts gave three-membered ring opened products, which further proceeded through an intramolecular [2+2]-type reaction upon photo-irradiation.
Diphenylsilane Reduction of C=O and C=N Bearing Electron-Withdrawing Group in the Presence of Aluminum(III) Chloride
Authors: Hojo Makoto , Hojo Masahiro , Inoue Yoshihiko , Tanimoto Shigeo
Published: July 2006

Several α-keto esters and methyl N-p-tolylsulfonyl-2-aryl-2-iminoacetates were reduced to the corresponding α-hydroxy esters and methyl N-p-tolylsulfonyl-2-arylglycinates in high yields by a combination of aluminum(III) chloride and diphenylsilane under operating conditions in which diphenylsilane was added to the pre-formed substrate-aluminum(III) chloride complex in dichloromethane and the mixture stirred. The case of an exactly equivalent amount of aluminum(III) chloride as the substrate resulted in good results.
Preparation of Fluoroamminecobalt(III) Complexes
Authors: Mitsutsuka Yoshihiro , Tursun Erkin , Nakahara Masayoshi
Published: July 2006

New preparation methods are reported for some fluoroamminecobalt(III) complexes. The polarized spectra were measured by microspectrophotometry for some complexes. Coordination geometries of the complexes were predicted from the spectral data.
Effect of Solvent on the Electrochemical Properties of Chromotropic Copper(II) Mixed Chelates
Authors: Labuda Jan , Mafune Kumiko , Fukuda Yutaka
Published: July 2006

Electrochemical and electronic spectral bahaviors of complexes [Cu(acac)(tmen)]ClO4 and [Cu2(taet)(tmen)2](ClO4)2, where acac=acetylacetonate ion, tmen=N,N,N′,N′-tetramethylethylenediamine, taet=1,1,2,2-tetraacetylethanediide ion, were investigated in six solvents by cyclic voltammetry, constant potential coulometry, and visible absorption spectroscopy. Copper(II) undergoes electrolytic reduction to copper(I) coupled with the complex decomposition. The values of reduction potential vs. \ ildeν max of the d-d absorption band show linear correlation in accordance with coordination ability of the solvent.
Voltammetric Investigation of the Response Mechanism of the Ion-Selective Electrodes Based on the Polymer Modified with Poly(oxyethylene) Derivatives in Acetonitrile
Authors: Nakamura Toshio , Nakamura Yasuyuki , Kojima Teruhito , Izutsu Kosuke
Published: July 2006

The voltammetric behavior of barium and lithium ions in acetonitrile (AN) was studied at polymer membrane ion-selective electrodes which showed Nernstian responses to those metal ions in AN, in order to elucidate the mechanism of their potentiometric responses. The membrane electrodes consisted of polyacrylamide coupled to such poly(oxyethylene) derivatives as tetraethylene glycol monododecyl ether, dibenzo-18-crown-6, and cryptand222B and coated on platinum or gold disk. The cyclic voltammograms for barium and lithium ions, recorded repeatedly after setting the electrodes at the rest potentials, showed a cathodic peak at −1.5±0.2 V vs. Ag/0.01 M Ag+ (AN). The cathodic peak current (icp) decreased markedly between the first and second scans, but reached a steady value after the third scan. The icp values after the third scan were diffusion controlled and considered to be due to a transfer of the metal ions from the solution into the membrane. The differences in icp between the first and the third scans were proportional to the potential scan rate and attributed to a transfer of the metal ions which had been accumulated at or near the surface of the membrane by combining with the functional groups of the polymer. The accumulation occurred rather slowly and saturated with time. Based on the fact that the response processes of the ion-selective electrodes were very much similar to the accumulation processes, the response mechanism of the ion-selective electrodes is discussed.
Preparation and Characterization of Optically Active Schiff Base-Oxovanadium(IV) and -Oxovanadium(V) Complexes and Catalytic Properties of These Complexes on Asymmetric Oxidation of Sulfides into Sulfoxides with Organic Hydroperoxides
Authors: Nakajima Kiyohiko , Kojima Katsuhide , Kojima Masaaki , Fujita Junnosuke
Published: July 2006

Oxovanadium(V) complexes, VVO (Schiff base)Y (Y=ClO4, Cl, NO3), with quadridentate Schiff base ligands derived from optically active 1,2-diamines and salicylaldehyde or its derivatives were prepared by oxidizing the corresponding VIVO (Schiff base) with CeIV in acetonitrile followed by the addition of HY. The complexes were characterized by their 1H NMR, IR, UV-Vis, and circular dichroism spectra, and electrochemistry. Reversible reduction potentials (V5+/V4+) obtained by cyclic voltammetry for a series of oxovanadium(V) complexes with Schiff base ligands derived from 5-substituted salicylaldehydes showed a linear dependence on the Hammett parameter. Both the vanadium(IV) and the vanadium(V) complexes catalyze asymmetric oxidation of sulfides into the corresponding sulfoxides with organic hydroperoxides. The oxovanadium(IV) complex catalysts gave much better asymmetric induction than the oxovanadium(V) complex catalysts and in most cases the enantiomeric excess (ee) ranged between 20 and 40%. In the reaction of VIVO (Schiff base) with an organic hydroperoxide the complex is finally converted into the oxovanadium(V) species, and a dark brown intermediate is suggested to be the catalytically active species.
Polarographic Study of the Rates of the Dissociation Reactions of the Eu(III)-HAHA Complex and of the Eu(III)-, Gd(III)-, and Ho(III)-PAPA Complexes
Authors: Kodama Mutsuo , Mahatma Anung Budhi , Koike Toru , Kimura Eiichi
Published: July 2006

Polyaza macrocycles carrying acetate groups, HAHA and PAPA, were found to form solely 1:1 ratio complexes with Eu(III), Gd(III), or Ho(III) ions. The PAPA complexes of the Eu(III), Gd(III), and Ho(III) ions and the HAHA complex of the Eu(III) ion in acetate buffer solutions containing an excess of the Eu(III), Gd(III), or Ho(III) ion produce anodic waves, which are kinetic in nature. They can be ascribed to the free macrocycles formed upon the dissociations of the complexes preceding electron-transfer steps at the electrode surface. From an experimental examination of the nature of these kinetic waves, the reaction mechanisms and rates for the dissociation reactions were determined. The dissociation reactions for the HAHA and PAPA complexes were found to proceed through (A) and (B), respectively. The (kd)o values for the Eu(III)-HAHA and -PAPA complexes were 5.1×10−1 and 3.9×10−2 (sec−1), respectively, and those for the Gd(III)- and Ho(III)-PAPA complexes, 4.04×10−2 and 1.2×10−2 (sec−1).

(Remark: Graphics omitted.)

The (kd) values for the Eu(III)-HAHA abd -PAPA complexes were 3.70×102 and 4.24×105 (mol−1dm3s−1) and those for the Gd(III)-and Ho(III)-PAPA complexes, 2.45×104 (mol−1dm3s−1).
The Headspace Gas Chromatographic Study on (Biphenyl, Naphthalene)–(Benzene, Cyclohexane, 1-Octanol) Binary Mixtures at 298.15 K
Authors: Sanemasa Isao
Published: July 2006

The vapor pressure of each constituent of the title binary mixtures, except for 1-octanol, was measured by the headspace gas chromatography as a function of biphenyl or naphthalene mole fraction in a relative scale taking the vapor pressure of the pure component as unity.
Electrochemical Calorimetry of D2O Electrolysis Using a Palladium Cathode—An Undivided, Open Cell System—
Authors: Oyama Noboru , Ohsaka Takeo , Hatozaki Osamu , Kurasawa Yuko , Yamamoto Nobushige , Kasahara Seiji , Ohta Naoki , Imai Yuko , Oyama Yukio , Nakamura Tomoo , Shibata Tokushi , Imamura Mineo , Uwamino Yoshitomo , Shibata Seiichi
Published: July 2006

The electrochemical calorimetry of the electrolysis of D2O has been carried out using a Pd cathode in an undivided, open cell fashion, together with measuring the total volume of the evolved gases. The excess heat production, observed using a Pd cathode pretreated by a special procedure, can not be explained as a result of the D2–O2 recombination alone. However, the present data certainly do not confirm “cold fusion”, because no evidence has yet been obtained for neutron, gamma-ray, tritium or helium production during our electrolysis of D2O with Pd cathodes.
A New Photochromic Spiro[3H-1,4-oxazine]
Authors: Kawauchi Susumu , Yoshida Haruo , Yamashina Naoko , Ohira Manabu , Saeda Shigeru , Irie Masahiro
Published: July 2006

A new photochromic spiro[3H-1,4-oxazine] 4 is described. The absorption spectra of 4 have been examined and compared with those of spiro[indoline-naphthoxazine] 1. The colored form of 4 has the absorption maximum shorter than that of 1. Compound 4 showed excellent light fatigue-resistant property.
Analysis of Two-Year Results of Acid Precipitation Survey within Japan
Authors: Hara Hiroshi , Ito Ei-ichi , Katou Takunori , Kitamura Yoko , Komeiji Tetsuhito , Oohara Mayumi , Okita Toshiichi , Sekiguchi Kyoichi , Taguchi Keisuke , Tamaki Motonori , Yamanaka Yoshio , Yoshimura Kenichiro
Published: July 2006

Precipitation chemistry within Japan has been assessed in order to judge both the magnitudes of the concentrations and the deposition of major ions: H+, NH4+, Ca2+, K+, Mg2+, Na+, SO42, NO3−, and Cl−. A data set was obtained through an acid precipitation survey by Japan Environment Agency at 14 stations from April 1984 to March 1986. The annual average pH at each site ranged from 4.5 to 5.1 with a mean value of 4.7. The free acidity was derived both from sulfuric and nitric acids; sulfuric acid was found to contribute to 67–83% of the free acidity. The acidity was apparently lower than that expected from SO42− and NO3− levels, mainly because alkaline species, such as NH3, and Ca2+ species neutralized a certain fraction of the original acidity. This neutralization would certify the fact that SO42− and NO3− deposition were comparable to, or smaller than those in eastern North America, but the Ca2+ and NH4+ deposition within Japan exceeded that within the U. S.
Ultrasonic Absorption Studies of the Micellar Catalyzed Reaction of the Base Dissociation of Ammonia
Authors: Harada Shoji , Doi Teruhiko , Sano Takayuki , Yamashita (Isoda) Teruyo , Yano Hiroshige
Published: July 2006

The base dissociation of ammonia has been studied by an ultrasonic absorption method in both the absence and presence of SDS micelle in aqueous solution, and kinetic parameters were obtained. The micellar catalyzed reaction mechanism, including the interactions of ammonium ion with SDS micelles, are discussed.
Reactions of Ozone with 1-Methylcyclohexene and Methylenecyclohexane in Air
Authors: Hatakeyama Shiro , Akimoto Hajime
Published: July 2006

Reactions of ozone with 1-methylcyclohexene and methylenecyclohexane were studied for the purpose of obtaining the reaction mechanism as a prototype of the reaction of ozone with pinenes. The similarity of the yields of corresponding gaseous products between 1-methylcyclohexene and α-pinene and between methylenecyclohexane and β-pinene indicates the similarity of the reaction mechanisms.
Excited Triplet States of Dimethyl Ether Studied by Electron Energy-Loss Spectroscopy
Authors: Ogawa Teiichiro , Yoshidome Toshifumi , Kawazumi Hirofumi
Published: July 2006

The elecron energy-loss spectrum of dimethyl ether was measured at electron energies of 50, 20 and +2(residual energy) eV and at scattering angles of 0–90°. Six new bands were observed at about 6.4, 7.0, 7.5, 7.8, 8.2, 8.9 eV and assigned as the singlet-triplet and/or symmetry-forbidden transition.
Some Multinuclear NMR Solution and Solid State Studies on 1,8-Bis(dimethylamino)naphthalene and Its Complex with Tetrazole
Authors: Grech E , Stefaniak L , Ando Isao , Yoshimizu Hiroaki , Webb Graham A , Sobczyk L
Published: July 2006

13C and 15N NMR spectra are measured for 1,8-bis(dimethylamino)naphthalene and its complex with tetrazole in both solution and the solid state. On the basis of the solution and solid state 15N results, an equilibrium involving the half protonated form of the base in the solution of the complex salt was identified. On the other hand, it is found that the 13C results for the solutions are closely similar to those found for the solid state, and are rather insensitive to salt formation.
Aluminium-Bearing Ferrite Formation from γ-FeOOH in an Aqueous Suspension
Authors: Ito Kazuo , Tamaura Yutaka , Katsura Takashi
Published: July 2006

Stoichiometric Al-bearing ferrites[AlxFe3-xO4 (x=0.05–0.46)] are formed by a transformation reaction from γ-FeOOH in an aqueous suspension. The transformation reaction proceeds in a suspension containing γ-FeOOH, Fe(II) and Al ions without oxidation at 25°C and a pH of 9.5–11.0.
Preparation of Optically Active (S)-2-Aminoalkylphosphonic Acids from (S)-Amino Acids without Racemization
Authors: Oshikawa Tatsuo , Yamashita Mitsuji
Published: July 2006

Optically active (S)-2-aminopropylphosphonic and (S)-2-amino-4-methylpentylphosphonic acids were synthesized from commercially available chiral α-amino acids [(S)-(+)-alanine and (S)-(+)-leucine] without racemization.
Photolysis of Tetraarylmethanes and 3-(Triarylmethyl)pyridines
Authors: Shi Min , Okamoto Yoshiki , Takamuku Setsuo
Published: July 2006

Upon UV irradiation in benzene–methanol (1:2) tetraarylmethanes or 3-(triarylmethyl)pyridines underwent an α,α-elimination of two aryl groups to give biaryls or 3-arylpyridine, and two corresponding carbene intermediates. The latters afforded methyl ethers by the O–H insertion to methanol.
Preparation and Hydrolysis of Some Sterically Protected 1-Aza-3-phosphaallenes
Authors: Niitsu Takashi , Inamoto Naoki , Toyota Kozo , Yoshifuji Masaaki
Published: July 2006

Some sterically protected 1-aza-3-phosphaallenes carrying 2,4,6-tri-t-butylphenyl group were prepared and the hydrolysis reactions of these azaphosphaallenes were studied.
A New, Highly Efficient, and Simple Procedure for the Construction of Medium-Sized Nitrogen Heterocyclic Ring System
Authors: Babu B Ramesh , Goto Mutsuo , Higaki Masato , Sugiyama Takashi , Nakamura Kaoru , Ohno Atsuyoshi
Published: July 2006

Two types of sulfur- and nitrogen-containing heterocycles have been synthesized from a tetrahydro-4-oxothiophene derivative.
Preparation and Characterization of Activated Carbon Tablets for Electric Double Layer Capacitors
Authors: Tanahashi Ichiro , Yoshida Akihiko , Nishino Atsushi
Published: July 2006

Two types of activated carbon tablets (AC tablets) were prepared and characterized by adsorption methods for electric double-layer capacitors. The tablets were prepared from either the activation or carbonization of molded mixtures comprising phenolic resin-based activated carbon powders and phenolic resins. The specific surface area of the tablets (a) prepared from activation was 2010 m2g−1 and the bulk density was 0.45 gcm−3. The area of tablets (b) from carbonization was 1400 m2g−1 with a yield of 83% (weight of obtained tablets/weight of molded mixtures). The capacitance of the capacitors with tablets (a) showed 7.3–12.5 F/(cm3 of AC tablets). The reliability of the capacitors with AC tablets (a) and (b) was improved in comparison with that of capacitors with polarizable electrodes comprising activated carbon powders and binders.
Unit Subduced Cycle Indices and the Superposition Theorem. Derivation of a New Theorem and Its Application to Enumeration of Compounds Based on a D2d-Skeleton
Authors: Fujita Shinsaku
Published: July 2006

A combination of the concept of unit subduced cycle indices (USCIs) and the Redfield–Read superposition theorem affords a new methodology of enumerating geometrical objects such as molecules and polyhedra. This method allows us to enumerate such objects with respect not only to their constitutions but also to their symmetries, in which subduced cycle indices (SCIs) derived from USCIs play an important role. Further derivation of a cycle index from the SCIs and its incorpotation with the superposition theorem are also discussed. The inverse of the mark table and the table of USCIs for D2d point group are presented for further applications of the USCI approach.
Conductometric Study of Calcium(II), Strontium(II), and Barium(II) Perchlorates in Methanol–Ethylene Glycol Mixtures
Authors: Doe Hidekazu , Ohe Hiroshi , Matoba Hiroyuki , Ichimura Akio , Kitagawa Toyokichi
Published: July 2006

The ion-association constants, K1A, of an ion pair, M2+ClO4− (M=Ca, Sr, Ba), have been determined by conductometric measurements in methanol–ethylene glycol mixtures of 0, 20, 40, 60, 80, and 100 wt% of ethylene glycol at 5, 15, 25, 35, and 45 °C. The conductometric data were treated by an improved Fuoss and Edelson method. The thermodynamic functions of ΔH1A\ominus and ΔS1A\ominus have also been determined at 25 °C from the temperature dependence of K1A. In 60–80 wt% of ethylene glycol the K1A values of these metal perchlorates are similar to each other, since the characteristics of individual metal ions are probably depressed by the strong solvations of those cations. The results are discussed while considering the cation solvation and structure of a bulk solvent.