bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Ion-Association Sorption and Extraction of Metal Thiocyanate Complexes to Cellulose Acetate Polymer and Organic Solvents. Similarity in Distribution Mechanisms
Authors: Hayashita Takashi , Takagi Makoto 
Published: July 2006

Abstract
The sorption and extraction of heavy metal thiocyanate complexes from an aqueous solution were studied for a cellulose acetate polymer and conventional organic solvents. The ease of metal sorption to solid cellulose acetate correlated well with the ease of metal extraction to liquid glycerol triacetate. The distribution behavior of ammonium thiocyanatozincate complexes was studied in detail and compared among cellulose acetate, isobutyl methyl ketone, and glycerol triacetate. The chemical processes involved in the metal distribution to the organic phase were found to be essentially the same for these three media. Thus, cellulose acetate was conveniently considered a polymer solvent. The results were discussed in relation to metalselective hyperfiltration through cellulose acetate membranes.
Rearrangement Approaches to Cyclic Skeletons. III. Practical Route to cis-Bicyclo[4.3.0]non-4-en-7-ones Based on Photochemical [1,3] Acyl Migration of Bicyclo[3.2.2]non-6-en-2-ones
Authors: Uyehara Tadao , Kabasawa Yasuhiro , Furuta Toshiaki , Kato Tadahiro 
Published: July 2006

Abstract
1-Methoxybicyclo[3.2.2]non-6-en-2-ones and the related compounds were derived I) from the Diels-Alder type 1,4-addition products of tropones with ethylene by selective reduction of the α,β-unsaturated carbonyl part (hydrosilylation followed by hydrolysis) and/or II) from bicyclo[2.2.2]oct-5-en-2-ones a) by the ring-enlargement utilizing Tieffeneau-Demjanov type conditions (1, TMS–CN; 2, LiAlH4; 3, NaNO2–AcOH) and/or b) by the related ringexpansion using trimethylsilyldiazomethane and boron trifluoride etherate. These bridged compounds were transformed into the respective [1,3] acyl migration products, cis-bicyclo[4.3.0]non-4-en-7-ones, in practical yields by direct irradiation through a Pyrex filter.
Catalytic Hydration of Unsaturated Nitriles to Unsaturated Amides Using Colloidal Copper Dispersions
Authors: Hirai Hidefumi , Wakabayashi Hidehiko , Komiyama Makoto 
Published: July 2006

Abstract
Homogeneous hydrations of unsaturated nitriles such as acrylonitrile, methacrylonitrile, and crotononitrile to the corresponding unsaturated amides have been carried out in water at 80°C by use of colloidal copper dispersions as catalysts. The dispersions are prepared by reduction of copper(II) sulfate, copper(II) chloride, and copper(II) acetate with sodium tetrahydroborate in the presence of various polymers. The dispersions with poly(N-vinyl-2-pyrrolidone), poly(vinyl alcohol), methylamylopectin, methylcellulose, ethylcellulose, and (2-hydroxyethyl)cellulose exhibit much larger catalytic activities than the copper precipitates prepared by reduction of the copper salts with sodium tetrahydroborate in the absence of the polymers. For all the catalytic reactions with the colloidal dispersions, selectivity for the unsaturated amides is 100% and formation of any by-products is not detected at all. Electron microscopy shows that no significant structural change occurs in the dispersions during the catalytic hydration. The catalytic activity monotonously increases with increasing amount of poly(N-vinyl-2-pyrrolidone) up to the charged ratio 20 of the monomeric residue to copper(II) ion, showing saturation at the ratio larger than 20. When the degree of the polymerization of poly(N-vinyl-2-pyrrolidone) is varied at a fixed residual molar ratio 40, the activity shows a maximum at the degree of polymerization 1440. The results are interpreted both by the change in the size of the colloidal copper particles and by the difference in the magnitude of the interactions between the polymers and the copper particles.
Electrolytic Recovery of Silver from Photographic Fixing Solutions with a Fluidized Bed Electrode
Authors: Sekine Isao , Ishii Hiroyuki 
Published: July 2006

Abstract
For an effective electrolytic recovery of silver from photographic fixing solutions, polarization measurements and potentiostatic electrolysis were carried out using active carbon as a fluidized bed electrode. The optimum conditions, determined by the electrolytic recovery, required a static bed height was 4 mm, a bed expansion rate 14%, and an initial set potential −0.84 V vs. SCE. The current efficiency in this case was about 75%, and the limiting concentration for recovery of silver was about 5 ppm. The electrolytic duration for recovery of the silver was reduced to about half by enlarging the electrolytic cell. Other products formed during the electrolysis were hydrogen sulfide (H2S) and silver sulfide (Ag2S). When silver deposited under the optimum conditions was dissolved in 5M-HNO3 (1M=1 mol dm−3) of 100 ml, the recovery efficiency of the silver was about 75%.
Crystal Structures of Trimethylammonium Hexaiodotellurate(IV) and Heptaiodotellurate(IV)
Authors: Kiriyama Hideko , Mizuhashi Yukiko , Ootani Junji 
Published: July 2006

Abstract
Crystal structures of the title compounds were determined by X-ray diffraction method. The crystal data and the final R values are: [(CH3)3NH]2TeI6, cubic, Pa3, a=13.210(2) Å, V=2305.2(9) Å3, Z=4, R=0.057 for 263 observed unique reflections and [(CH3)3NH]2TeI7, tetragonal, P4⁄nmm, a=13.921(3), c=6.224(2) Å, V=1206.4(8) Å3, Z=2, R=0.051 for 553 reflections. The structure of hexaiodo complex is a modified K2PtCl6 type. The discrete[TeI6]2− octahedra are practically regular with a Te–I distance of 2.952(2) Å. The trimethylammonium cations lie on the unit cell triad axes and form trifurcated, weak hydrogen bonds of NH···3I. In contrast, the TeIV coordination in the heptaiodo complex is an elongated octahedron with Te–I(1)=2.934(1) and Te–I(2)=3.124(4), 3.100(4) Å. These TeI6 octahedra form linear trans TeI5 chains running along c by sharing each pair of opposite vertices. Extra iodine atoms also stack along c with nearly equidistant I–I separations of 3.091(6) and 3.133(6) Å. The trimethylammonium cation is distributed randomly over four configurations in a cavity formed by two [TeI5]nn− and two [I]2nn− columns. Thus, the chemical constitution of the heptaiodo complex can be expressed as di-trimethylammonium catena-μ-iodo-tetraiodo tellurate(1-) catena-diiodide(1-), [(CH3)3NH]2n2n+[TeI5]nn−[I]2nn−.
Effects of Bivalent Metal Cations on the Conformation and Aggregation of Poly(l-glutamic acid)
Authors: Maeda Hiroshi , Hiramatsu Tsuyoshi , Ikeda Shoichi 
Published: July 2006

Abstract
In the solution of fully neutralized poly(l-glutamic acid) in the absence of supporting electrolytes, the α-helix was induced by the addition of five transition metal chlorides in the following order: CuCl2\gtrsimCdCl2&gt;ZnCl2&gt;NiCl2&gt;CoCl2. The induction did not occur by the addition of BaCl2, CaCl2, or MgCl2. The induction by transition metal cations was inhibited in the presence of a supporting electrolyte (NaCl). Distortion of circular dichroism (CD) spectra occurred as the induction of the α-helix proceeded, which was shown to be recognizable when apparent aggregation number m exceeded about 100. Conformation of the polypeptide in these aggregates was expected to be the α-helix based on the conformation in the precipitates obtained at these mixing ratios which gave distorted CD spectra, which was determined by infrared absorption spectra.
Chemistry of 1,2-Thiaphosphole 2-Sulfides. II. Reactions of 1,2-Thiaphosphole 2-Sulfides with Some Nucleophiles
Authors: Tanaka Hideyuki , Saito Takao , Motoki Shinichi 
Published: July 2006

Abstract
5-t-Butyl-1,2-thiaphosphole 2-sulfides reacted with alcohols, thiols, and amines to give the 1,4-adducts, 2-alkoxy-, 2-(p-tolylthio)-, and 2-alkyl(aryl)amino-1,2-thiaphosphol-3-ene 2-sulfides, respectively. However, the reactions of 5-phenyl-1,2-thiaphosphole 2-sulfides with cyclohexyl- and arylamines afforded 1,2,3-dithiaphosphorins.
Electrochemical Behavior of p-Type Indium Selenide Single Crystal Electrodes in Dark and under Illumination
Authors: Uosaki Kohei , Kaneko Susumu , Kita Hideaki , Chevy A 
Published: July 2006

Abstract
The electrochemical behaviors of van der Waals face of p-InSe single crystal electrodes in 0.5M H2SO4 and 1M NaOH (1M=1 mol dm−3) with and without illumination have been thoroughly investigated. In 0.5M H2SO4, relatively large cathodic dark current was observed and the onset potentials for the current in dark and under illumination were ca. −0.8 V (vs. Ag/AgCl) and ca. −0.5 V, respectively, at as-prepared electrode. The current seemed to be mainly due to hydrogen evolution reaction. The dark current decreased significantly and the photo-current increased by removing surface steps. These results and impedance analyses show that the surface steps create surface states which act as recombination centers and mediators for charge transfer. Both the dark- and photocurrent onset potentials in 1M NaOH were more negative than those in 0.5M H2SO4 by ca. 0.5 V. The dark current was quite large and the photocurrent was small in 1M NaOH even after removing surface steps. By depositing Pt on p-InSe, the photocurrent onset potential shifted towards positive by several hundred mV. The reaction mechanism of photoelectrochemical hydrogen evolution was discussed by considering the above results.
Preparation and Coercivity of Cobalt Ultrafine Particles by Reduction of Multilayered CoO–SiO Films
Authors: Bando Yoshichika , Terashima Takahito 
Published: July 2006

Abstract
Films containing Co ultrafine particles were prepared by hydrogen reduction of periodically multilayered CoO–SiO films which were formed by alternating deposition of CoO and SiO. The films containing Co particles maintained the periodicity similar to the original films. Using samples of CoO single layer sandwiched between SiO layers, highly dispersed Co particles in the reduced sample were observed by transmission electron microscopy. The average size of the Co particles was almost as large as the thickness of CoO layer. The coercivities of the multilayered films containing Co particles were measured at room temperature and 77 K; they decreased with decreasing particle size from 20 nm to 3nm. Superparamagnetism was observed for the Co particles with average sizes below 4nm at room temperature. The formation and the magnetic property of the Co ultrafine particles in the Co–SiO system is dicussed.
Kinetics and Mechanism of Replacement of Glycinate in Bis(glycinato)oxovanadium(IV) by Oxalate
Authors: Kim Jung-Sung , Jung Woo-Sik , Tomiyasu Hiroshi , Fukutomi Hiroshi 
Published: July 2006

Abstract
The kinetics of formation of bis(oxalato)oxovanadate(IV) [VO(ox)2(H2O)]2− (hereafter water molecule will be omitted) from the reaction of bis(glycinato)oxovanadium(IV) [VO(gly)2] with oxalate has been studied by the stopped-flow method. The reaction was found to consist of two consecutive steps, a relatively slow step (k1) and a fast one (k2). The values of rate constants k1 and k2 were independent of the concentration of free oxalate and of the pH of solution ranging from 4.2 to 6.5. Similar behavior was also observed in the acid decomposition of [VO(gly)2]. A mechanism passing through an intermediate, [VO(ox)(gly)]−, was proposed.
New Multi-Sulfur 1,2-Dithiolene Complexes. Preparation, Structure, and Electrochemical Properties
Authors: Kato Reizo , Kobayashi Hayao , Kobayashi Akiko , Sasaki Yukiyoshi 
Published: July 2006

Abstract
New multi-sulfur 1,2-dithiolene complexes in which the 1,2-dithiolene moiety is extended by incorporating heterorings have been prepared and characterized by IR spectroscopy, X-ray diffraction method, and cyclic voltammetry. Partial oxidation of these complexes are expected to provide the multi-dimensional molecular conductors. Electrochemical properties of these complexes are compared with those of the dmit-complexes (dmit=2-thioxo-1,3-dithiole-4,5-dithiolate).
Aftereffects of Nuclear Decay in 57CoCl2·nH2O (n=2 and 6) Investigated by γ-X Ray Coincidence Mössbauer Spectroscopy
Authors: Kobayashi Takayuki , Friedt Jean M 
Published: July 2006

Abstract
The anomalous states produced by electron capture decay of 57Co in CoCl2·2H2O and CoCl2·6H2O are investigated using conventional Mössbauer emission spectroscopy and a γ-X ray coincidence method which allows to isolate events with a reduced influence of the Auger electron self-irradiation. The formation of the anomalous electronic and structural configuration is assigned to the self-radiolysis of the water ligands. The mechanism involves both the nearest and the next nearest H2O coordination shell according to the densities of these ligand molecules in the respective shells.
The Crystal and Molecular Structure of Δ-(8-Methyl-1,3,6,10,13,16,19-heptaazabicyclo[6.6.6]icosane)cobalt(III) Perchlorate Monohydrate
Authors: Sakaguchi Ushio , Ito Tasuku 
Published: July 2006

Abstract
The structure of Δ-(8-methyl-1,3,6,10,13,16,19-heptaazabicyclo[6.6.6]icosane)cobalt(III) perchlorate monohydrate, Δ-[Co(C14H33N7)](ClO4)3·H2O, has been determined by single crystal X-ray diffraction techniques. Crystal data are the following: space group P212121, a=16.379(2) Å, b=16.388(2) Å, c=9.753(1) Å, V=2617.9(5) Å3, Z=4, 3983 nonzero structure factors (|Fo|&gt;3σ(|Fo|)), R=0.0447, and Rw=0.0491. The geometry of the cation can be approximated very closely by a composite of [Co(sen)]3+ and [Co(sep)]3+, where sen=1,1,1-tris(4-amino-2-azabutyl)ethane and sep=1,3,6,8,10,13,16,19-octaazabicyclo[6.6.6]icosane.
EXAFS Studies of the Behavior of Rh6(CO)16 Supported on γ-Al2O3 Surface
Authors: Asakura Kiyotaka , Iwasawa Yasuhiro , Kuroda Haruo 
Published: July 2006

Abstract
The structural change of Rh6(CO)16 supported on γ-Al2O3 surface during a decarbonylation–recarbonylation cycle was studied by means of EXAFS (extended X-ray absorption fine structure) spectroscopy. Rh6(CO)16 cluster framework was found to be decomposed into Rh(CO)2(OAl(Remark: Graphics omitted.))2 after the reaction with a mixture of O2 and H2O, and reversely regenerated by the subsequent treatment with a mixture of CO and H2O.
Crystal and Molecular Structure of a Potentially Five-Coordinate Palladium(II) Complex Containing 1,10-Phenanthroline. Chlorobis(triphenylphosphine)(1,10-phenanthroline)palladium(II) Tetrafluoroborate
Authors: Taira Zenei , Yamazaki Shinsaku 
Published: July 2006

Abstract
The X-ray crystal structure of a potentially five-coordinate palladium(II) complex containing 1,10-phenanthroline, [PdCl(PPh3)2(phen)][BF4]·(CH3)2CO has been determined. The structure was solved by the heavy-atom method and refined to R=0.051.
Total Synthesis of (±)-Zeylena
Authors: Ogawa Seiichiro , Takagaki Tohei 
Published: July 2006

Abstract
Zeylena, isolated from the roots of Uvaria zeylanica L. (Annonaceae), has been synthesized as a racemic modification by an intramolecular cyclo-addition reaction of Dl-trans-2,3-dihydroxy-1-(benzoyloxymethyl)cyclohexa-4,6-diene 3-(E)-cinnamate or its acetate.
Stereoselective Synthesis of Allyl- or Alkynyl-Substituted (Z)-Vinylsilanes via Organoboranes
Authors: Hoshi Masayuki , Masuda Yuzuru , Arase Akira 
Published: July 2006

Abstract
Copper(I) iodide-catalyzed cross-coupling reactions of (Z)-(1-trimethylsilyl-1-alkenyl)dicyclohexylboranes with allyl bromide or 1-bromo-1-hexyne gave stereoselectively (Z)-1,4-dienes or conjugated (Z)-enynes having a trimethylsilyl group on the internal carbon atom of the double bond.
The Structure of Bis(dibenzyl sulfoxide)tris(O,O′-diethyl dithiophosphato)lanthanum(III), La{(C2H5O)2PS2}3{(C6H5CH2)2SO}2
Authors: Imai Takashi , Shimoi Mamoru , Ouchi Akira 
Published: July 2006

Abstract
The crystal and molecular structure of the title complex has been determined by the use of the single-crystal X-ray diffraction method. The crystal of LaC40H58O8P3S8, F.W.=1155.20, is triclinic; space group P\bar1, a=13.300(5), b=19.816(8), c=11.257(4) Å, α=92.79(4), β=114.92(3), γ=75.40(4)°, U=2598(2) Å3, Z=2, Dm=1.48(3), Dx=1.48 g cm−3, and μ(Mo Kα)=1.29mm−1. Each lanthanum(III) atom is octa-coordinated and is in a dodecahedral geometry. The oxygen atoms of dibenzyl sulfoxide molecules are ligated at both ends of the base of a trapezia, and the chelating O,O′-diethyl dithiophosphates span two m edges and one a edge.
Platinum-Catalyzed Oxidation of Cholesterol
Authors: Akihisa (ne Itoh) Toshihiro , Matsumoto Taro , Sakamaki Hiroshi , Take Masa-aki , Ichinohe Yoshiyuki 
Published: July 2006

Abstract
Cholesterol was oxidized (12% conversion) with platinum and oxygen to give several 7-oxygenated products, cholest-5-en-3-one, and cholest-4-en-3-one accompanied with its further oxygenation products at C-6. The pathways and mechanisms of the catalytic oxidation are discussed.
Preparation of Solid Catalysts for Vapor-Phase Decomposition of Carbonyl Sulfide
Authors: Akimoto Masamichi , Suto Hirotoshi , Niiyama Hiroo 
Published: July 2006

Abstract
The vapor-phase catalytic decomposition of COS (COS→CO+1/xSx and 2COS→CO2+CS2) has been mechanistically investigated so as to prepare solid catalysts which are active and selective for the first reaction. The comparison of the catalytic activity and selectivity of a series of Al2O3 catalysts with their acid-base properties and the different behavior of these two catalytic decomposition reactions in the poisoning of an Al2O3 catalyst with SO2 demonstrate that electron-donating sites catalyze the first reaction whereas Lewis acidic sites do so the second reaction. CaO catalysts are prepared by thermal decomposition of CaCO3 at elevated temperatures and their catalytic activity is compared with their amount of electron-donating sites. The greatest catalytic activity and selectivity for the first reaction(yield of CO+Sx=21.4%, selectivity=80.2% at 873 K) are obtained over CaO catalyst prepared at 1123 K which has the greatest electron-donating ability. These values of the yield and selectivity to CO+Sx are much greater than those obtained over Al2O3 catalysts.
Catalysis by Transition-Metal Carbides. VII. Kinetic and XPS Studies of the Decomposition of Methanol on TiC, TaC, Mo2C, WC, and W2C
Authors: Orita Masahiro , Kojima Isao , Miyazaki Eizo 
Published: July 2006

Abstract
The catalytic decomposition of methanol was investigated on a series of powdered transition-metal carbides, such as TiC, TaC, Mo2C, WC, and W2C, which had been catalytically activated by evacuation at high temperatures. WC was found to produce methyl formate (HCOOCH3) with a high selectivity (above 80%), whereas CO and H2 were mainly produced on clean TaC, Mo2C, and W2C surfaces. XPS measurements combined with an analysis of the peak intensities revealed that the catalytic activation of WC and TaC was attributable to the removal of surface oxygen and the subsequent formation of monocarbide surfaces. On the other hand, the minor activities leading to the formation of methyl formate on W2C and Mo2C were concluded to be due to the formation of oxycarbide surfaces. The deuterium distributions in the products during the reaction of CH3OD suggest that the methyl formate is produced via the dimerization of the intermediate adspecies, CH2O.
Kinetic Study of Liquid-Phase Esterification with Sulfonic Acid Cation-Exchange Resin of the Macroreticular Type. I. Heterogeneous–Pseudohomogeneous Resin Catalysis
Authors: Shimizu Shoichi , Hirai Choichiro 
Published: July 2006

Abstract
The rates of the esterification of octanoic acid with 1-butanol catalyzed by macroreticular sulfonated ion-exchange resin were measured by the use of a batch reactor. The effects on the rate were investigated for variations in the amount of the catalyst, the temperature, and the reactant alcohol concentrations as well as those of water and butyl octanoate. From these data, it is considered that alcohol and water solvate the matrix-bound sulfo groups, and so this esterification system consists of a heterogeneous reaction catalyzed by un-ionized sulfo groups and a pseudo-homogeneous reaction catalyzed by solvated protons; in other words, catalysis by sulfonic acid resin is both heterogeneous and pseudo-homogeneous in liquid-phase esterification.
Pulse Radiolysis Study of Reaction of OH Radicals with Triose Reductone
Authors: Horii Hideo , Abe Yasuo , Taniguchi Setsuo 
Published: July 2006

Abstract
The reaction between the hydroxyl radical (OH) and triose reductone (2,3-dihydroxy-2-propenal) in an aqueous solution has been studied by spectrophotometric pulse radiolysis. The OH radical adds to triose reductone (TRH2) to form the transient OH adduct (TRH(OH)−·) with an absorption maximum at 398 nm, ε=3150 M−1 cm−1 (1 M=1 mol dm−3) in a neutral solution. The OH adduct decays by second-order kinetics in the pH range 2–12. The rate constants for the reactions of the OH radical with dissociated and undissociated triose reductone are 1.4×1010 M−1 s−1 and 9.9×109 M−1 s−1, respectively. The dependence of the transient absorption on the pH shows that the OH adduct has a pKa value of 4.7.
Electrocatalysis in Metal Hydride Electrode. I. Hydrogen Electrode Reaction on Group-IB and VIII Metals Deposited on Palladium Substrates
Authors: Machida Ken-ichi , Enyo Michio 
Published: July 2006

Abstract
Hydrogen electrode reactions (HER) on thin-layer electrodes of group-IB and VIII metals (Cu, Ag, Au, Ni, and Pt) prepared by electro-deposition on Pd foil substrates were studied (together with the Pd foil itself) in 0.5 M H2SO4 and 1.0 M NaOH (M=mol dm−3) at 303 K by a transient technique. The reactions on these metals were concluded to proceed via a Volmer-Tafel reaction route and the exchange current densities of the elementary steps, ioV and ioT, were then evaluated. The electrocatalytic activities towards the Volmer step were observed to be in the order Pt&gt;Pd&gt;Au&gt;Ag&gt;Cu in an acidic solution and Pt&gt;Pd&gt;Ni≥Ag≥Au≥Cu in an alkaline solution. The activities towards the Tafel step were Pt≥Pd&gt;Au&gt;Cu&gt;Ag in an acidic solution and Pd&gt;Pt&gt;Au&gt;Cu=Ag&gt;Ni in an alkaline solution. The results were summarized in terms of the parameter mo (=ioV⁄ioT). This parameter was used to describe the electrochemistry of the energy efficiency of a hydride-type hydrogen-storage electrode, when the metals were employed for the purpose of modifying the electrode surface. Pt and Ag (among the group-IB metals) in both acidic and alkaline solutions were revealed to be suitable electrocatalysts.
Geometrical Isomerism of Phenylhydrazones of α-Keto Esters. II. p-Substituted Phenylhydrazones of Ethyl Pyruvate and 2,4-Dinitrophenylhydrazones of Some α-Keto Esters
Authors: Ishibashi Fumihide , Nashima Takeo , Nishino Junko , Kobayashi Ikuko , Ichihara Yoshinori , Kitagawa Yoshimi , Sasaki Shigeko , Yoshikawa Masako , Matsuoka Atsuko , Yamamoto Keiko 
Published: July 2006

Abstract
Each geometrical isomer of various substituted phenylhydrazones of ethyl pyruvate and 2,4-dinitrophenylhydrazones of some α-keto esters was isolated in a pure state. Partial isomerizations of the E-isomers of the former hydrazones to the Z-isomers took place by keeping solutions of the hydrazones in organic solvents containing C, H, and Cl in the dark. An E- or Z-structure was assigned to each molecule on the basis of IR and 1H NMR spectra. In all cases, isomers with higher Rf-values on a silica gel TLC (using benzene as a developing solvent) involved an intramolecular hydrogen bonding between the imino hydrogen and the ester carbonyl oxygen. Thus, the Z-structure was assigned. An E-structure was assigned to other isomers with lower Rf-values. The present assignment is, thus, entirely the same as that proposed in a previous investigation.