bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radical Formation through Curing Reaction of Epoxy Resins with 2,4,6-Trinitrophenol or 2,4,6-Trinitroresorcinol
Authors: Kawamura Kazuro 
Published: July 2006

Abstract
Radicals formed spontaneously during the cure reaction of epoxy resins with 2,4,6-trinitrophenol (TNP) or 2,4,6-trinitroresorcinol (TNR) have been investigated using electron spin resonance (ESR) technique. The ESR spectrum of the radicals stabilized in the epoxy resins cured with TNP was a triplet and the other spectrum of the radicals in the epoxy resins cured with TNR was a triplet with high anisotropy. The triplet splittings and g-values were attributed to radicals of the type (Remark: Graphics omitted.). The asymmetric line shapes of the triplet splittings caused by the 14N coupling constant are induced by the slow motion of the radicals in the polymer. The presence of radicals of this type suggests the transfer of an oxygen of a nitro group of TNP or TNR during the cure reaction.
Association of β-Diketones with Trioctylphosphine Oxide in Solvent Extraction Systems
Authors: Sekine Tatsuya , Saitou Takashi , Iga Hiroto 
Published: July 2006

Abstract
Distribution of six β-diketones between hexane, benzene, carbon tetrachloride, or chloroform and 0.1 mol dm−3 aqueous perchlorate solutions has been measured in the presence of trioctylphosphine oxide (TOPO). The distribution ratio was, in many cases, enhanced by TOPO; this was explained in terms of association of the β-diketones and TOPO. The association constants were greater when the β-diketone was stronger as an acid and also in the following order of the diluent: CHCl3&lt;CCl4&lt;C6H6&lt;C6H14. It was concluded that, even though the effect was not very large, still correction for the decrease in the concentrations of both the β-diketone and TOPO is necessary for an accurate estimation of the equilibrium involved in solvent extraction of metal ions containing these two reagents, as in the synergistic solvent extraction of metal ions.
An Electron Transfer Chain Mechanism for Photoinduced Oxidative Addition of Alkyl Iodide to a Dimeric Rhodium(I) Complex under Low Energy Irradiation (553 nm)
Authors: Fukuzumi Shunichi , Nishizawa Nobuaki , Tanaka Toshio 
Published: July 2006

Abstract
A dimeric RhI complex, [Rh2(dicp)4]2+ (dicp=1,3-diisocyanopropane) was found to undergo a photoinduced oxidative addition with butyl iodide and isopropyl iodide in MeCN by 553 nm irradiation in high quantum yields, Φ=25.2 and 22.6, respectively. Electron acceptors (p-dinitrobenzene, p-benzoquinone, and chloranil) and radical scavengers (oxygen and isopentyl nitrite) act as inhibitors for the photoinduced oxidative addition, providing unambiguous evidence for a chain character of this reaction. The fluorescence quenching of [Rh2(dicp)4]2+ by the electron acceptors as well as butyl iodide has also been examined. Based on the kinetics of the photochemical reactions in the absence or the presence of electron acceptors and radical scavengers, an electron transfer chain mechanism has been proposed. The formation of butyl radicals in the photoinitiation step was confirmed by the trap with oxygen to yield equimolar amounts of 1-butanol and butyraldehyde. The nature of the excited state of [Rh2(dicp)4]2+*(1A2u or 3A2u) involved in the photoinitiation step has also been discussed.
Binuclear Metal Complexes. LI. Synthesis and Characterization of the Tetrachloro-o-benzoquinone Adducts of Binuclear Iron(II) Complexes with 2-(Salicylideneamino)phenol and Its Substituted Homologs
Authors: Kanda Wakako , Nakamura Masaaki , Okawa Hisashi , Kida Sigeo 
Published: July 2006

Abstract
Binuclear iron(III) complexes Fe2(R-R′-sap)2(tcoq) have been prepared by the oxidation of binuclear iron(II) complexes Fe2(R-R′-sap)2 with tetrachloro-o-benzoquinone (TCOQ), where H2(R-R′-sap) represents 2-(salicylideneamino) phenols with the substituent R on the salicylaldehyde ring and the R′ on the o-aminophenol ring. Magnetic measurements indicated the operation of an intramolecular antiferromagnetic spin-exchange interaction between the iron(III) ions, the exchange integrals being evaluated at −6–−10 cm−1. In both polarograms and cyclic voltammograms of these complexes, two redox processes attributable to Fe(III)–Fe(III)\ightleftharpoonsFe(III)–Fe(II)\ightleftharpoonsFe(II)–Fe(II) were observed.
Studies of Bitter Peptides from Casein Hydrolyzate. I. Synthesis of Bitter Peptide BPIa Corresponding to Arg–Gly–Pro–Pro–Phe–Ile–Val from Casein Hydrolyzate by Alkaline Proteinase of Bacillus subtilis
Authors: Fukui Hiroshi , Kanehisa Hidenori , Ishibashi Norio , Miyake Ichizo , Okai Hideo 
Published: July 2006

Abstract
A bitter heptapeptide BPIa was synthesized and compared with the natural peptide, isolated by Minamiura et al. from casein hydrolyzate, by means of thin layer chromatography, paper electrophoresis, and carboxymethylcellulose column chromatography. All results for the two peptides matched very closely each other. The synthetic BPIa has an extremely bitter taste with its threshold value 0.05 mM. It is one of the most bitter compounds such as phenylthiourea and quinine.
Stereochemistry of the Palladium-catalyzed Hydrogenation of 3-Oxo-4-ene Steroids. V. A Kinetic Study in Basic and Acidic Media
Authors: Nishimura Shigeo , Momma Yasuhiro , Kawamura Hideo , Shiota Michio 
Published: July 2006

Abstract
Effects of the β-methyl group at C-10 and some oxygen functions (=O, OH, OAc) at C-11, C-17, and C-20 on the rates of hydrogenation of 3-oxo-4-ene steroids have been studied with palladium catalyst in pyridine or THF/HBr as solvent. In contrast to the hydrogenation in pyridine, the rate in THF/HBr was greatly depressed by the presence of 10β-methyl group. The reactivity of the steroids was enhanced by the oxygen functions, in particular, by 11, 17-dioxo group. The effects of the substituents are discussed from a mechanistic consideration based on the obtained results.
Viscosities of Aqueous Solutions of Alkanoic Acids
Authors: Miyajima Koichiro , Sawada Masahiro , Nakagaki Masayuki 
Published: July 2006

Abstract
Viscosities of aqueous solutions of alkanoic acids including formic acid were measured by an Ostwald type viscometer at 15, 25, and 35 °C, and the viscosity B-coefficient and the temperature dependence of B-coefficient, dB⁄dT, were calculated. From the signs and the magnitudes of Bst, increment of B-coefficient arising from the change of water structure, and dB⁄dT, it was concluded that formic acid was a hydrophilic structure breaker, while acetic acid was neither a structure maker nor a structure breaker. Both propionic acid and butyric acid were the hydrophobic structure makers. The mechanism of structure breaking effect of carboxyl group was briefly discussed.
Mechanism of Chlorine Catalytic Oxidation of CO in the Gas Phase
Authors: Ohta Tomohiro 
Published: July 2006

Abstract
The mechanism of the title reaction is determined under steady state conditions by the irradiation of the mixtures of Cl2, CO, O2, and N2 at 300 K with black blue fluorescence lamps using infrared spectroscopy. The pressure dependence of the ratio of the formation rate of carbon dioxide to that of phosgene (COCl2) and the other results indicated that the oxidation of CO proceeded via intermediates ClCO and ClC(O)O2 as the termolecular process rather than the bimolecular oxidation by ClOO and/or ClO. The ratio of the competitive reactions of chloroformyl radicals, k8⁄k9a, was found to be (6.5±0.4)×10−2 in the total pressure range from 30 to 755 Torr (1 Torr=133 Pa); ClCO+Cl2→COCl2+Cl (8), ClCO+O2→ClC(O)O2* (9a). And also, the ratio of the competitive reactions of the vibrationally excited intermediates, k9b⁄k9c, was (3.4±0.3)×1018 molecule/cm3; ClC(O)O2*→ClCO+O2 (9b), ClC(O)O2*+M→ClC(O)O2+M (9c). The role of this reaction in the stratosphere is discussed and estimated to be unimportant.
Catalytic Alkylation, Sulphonation, and Heteroarylation of Some Bicyclic Pyrazolines in Solid-Liquid Two Phase Systems
Authors: El-Shafei Ahmed Kamal , El-Sayed Ahmed Mahmoud , Khalaf Ali Ali 
Published: July 2006

Abstract
The reaction of some bicyclic pyrazolines with alkyl halides, aryl sulphonyl chlorides as well as with some N–H and S–H containing heterocycles is affected in solid-liquid two phase systems using a catalyst. The catalytic cycle is described, the purity of the obtained products is checked using TLC and their structure is confirmed by a combination of chemical and spectroscopic methods.
Absorption Intensity of Charge-transfer Transition between Ion Radicals in One-dimensional System of Crystalline Ion Radical Salts
Authors: Iida Yôichi 
Published: July 2006

Abstract
The charge-transfer interaction between ion radicals in crystalline ion radical salts was examined with one-dimensional Hubbard model. The intensity of charge-transfer absorption in crystal electronic spectra was estimated with both simple and complex ion radical salts. This approach was then applied to simple cation radical salt of Phenothiazine+·Br− and complex cation radical salt of (Phenothiazine)2+·Br−.
The Quenching of the OH (2Σ+) Produced in the H2–O2 Reaction by Collision with Ar
Authors: Hidaka Yoshiaki , Kawano Hiroyuki , Suga Masao 
Published: July 2006

Abstract
H2–O2 mixtures highly diluted with Ar were heated to temperatures in the range of 1200–1800 K behind reflected shock waves. The OH*-emission intensity was then measured to determine its quenching-rate constant upon collision with Ar; this constant was found to be about 1/164 of that in the case of H2O.
An Odorless Preparative Method of Sulfides and Thiocarboxylic S-Esters Using 3-(Alkylthio)-1,2-benzisothiazole 1,1-Dioxide
Authors: Yamada Hiroyuki , Kinoshita Hideki , Inomata Katsuhiko , Kotake Hiroshi 
Published: July 2006

Abstract
It was found that sodium salt of 1,2-benzisothiazole-3(2H)-thione 1,1-dioxide (thiosaccharin) readily reacted with alkyl halide affording 3-(alkylthio)-1,2-benzisothiazole 1,1-dioxide (3). Treatment of 3 with piperidine produces the corresponding alkanethiol in situ quantitatively and subsequent treatment with various electrophiles gives the corresponding sulfides and thiocarboxylic S-esters in good yields.
Catalytic Activity of PdCl2 Complexes Having Sulfur Compounds as Ligands
Authors: Ogura Katsuyuki , Aizawa Teruki , Uchiyama Koichiro , Iida Hirotada 
Published: July 2006

Abstract
The PdCl2 complexes coordinated with methyl p-tolyl sulfoxide (1:2), methylthiomethyl p-tolyl sulfoxide (1:2), and 1,3-bis[(p-tolylsulfinyl)methylthio]propane (1:1) as ligands were prepared. Among these complexes, bis(methyl p-toly sulfoxide)palladium dichloride catalyzed effectively cyclotrimerization of diphenylethyne and rearrangement of 3-acetoxy-1-tridecene to 1-acetoxy-2-tridecene.
Palladium-catalyzed Reaction of 4′-Iodobenzocrown Ethers with Acetylenes. Convenient Synthesis of Alkyl-substituted Benzocrown Ethers and Bis(benzocrown ether)s via Alkynyl-substituted Benzocrown Ethers
Authors: Kikukawa Kiyoshi , Abe Akito , Wada Fumio , Matsuda Tsutomu 
Published: July 2006

Abstract
4′-Iodobenzo-15-crown-5 and -18-crown-6 were alkynylated by heptyne, propargyl alcohol, 1,7-octadiyne and acetylene in good yields with use of Pd(PPh3)2Cl2 and Cul as catalysts. The latter two acetylenes gave bis(crown ether)s in one step. Hydrogenation of the alkynylated benzocrown ethers gave 4′-heptyl, 4′-(3-hydroxypropyl)benzocrown ethers and bis(benzocrown ether)s connected with ethylene or octamethylene linkage.
Importance of Work Terms in the Free Energy Relationship for Electron Transfer
Authors: Fukuzumi Shunichi , Kochi Jay K 
Published: July 2006

Abstract
The rates of arene and alkene brominations and mercurations, Diels-Alder cycloaddition as well as alkylmetal cleavages by electrophiles, electron acceptors and free atoms can be quantitatively analyzed in terms of the driving force for electron transfer. The single, unified free energy relationship for all of these rather disparate chemical processes relates the activation free energy to the standard free energy change for electron transfer and the work term for ion-pair formation. The latter is evaluated from charge transfer spectral data of the electron donoracceptor complexes formed as transient intermediates. The large variations in the apparent Brönsted slopes from unity to even negative values in these systems can be readily attributed to changes in the work terms arising from steric effects in ion-pair formation.
Effects of Alkyl Chain Length on Molecular Interactions. I. Solid Complex Formation in the Pyrene–N-Alkyl-2,4,6-trinitroaniline Systems
Authors: Togashi Atsushi , Matsunaga Yoshio 
Published: July 2006

Abstract
Phase diagrams were prepared for the fifteen binary systems consisting of pyrene as an electron donor and N-alkyl-2,4,6-trinitroanilines as electron acceptors. The thermal stability of the orange 1:1 complex between pyrene and the unsubstituted 2,4,6-trinitroaniline (mp 236 °C) is drastically decreased by N-alkylation; e.g., the N-pentyl-2,4,6-trinitroaniline complex melts at 97 °C. The systems with the N-hexyl and N-heptyl derivatives give two peritectics each, while most of the higher homologues produce a single peritectic or a eutectic. Unstable red solids were formed on rapid cooling of the molten pyrene–N-hexyl-2,4,6-trinitroaniline mixtures. This red complex becomes relatively more stable with increase of the alkyl chain length, possibly because of the enhanced tendency for chain alignment. In the systems with the N-pentadecyl and N-heptadecyl derivatives, the stable existence of the red 1:1 complex could be demonstrated.
Preparation of Aluminum Fluoride Film with Graphite Fluoride
Authors: Watanabe Nobuatsu , Ohara Hidehiko , Nakajima Tsuyoshi 
Published: July 2006

Abstract
An aluminum fluoride film covered by graphite fluoride on metallic aluminum was prepared by reaction in the ternary system of aluminum, graphite and fluorine gas at 450–550 °C. The film consisted of a large amount of aluminum fluoride covered by thin graphite fluoride layers. The contact angle of a water drop on the film was around 120°, which decreased to 85–95° during 45 d probably due to reaction with moisture and/or water drop. Almost no oxygen was detected in the film. The film formation would be based on the reduction of oxide layer on aluminum by carbon radical produced by thermal decomposition of graphite fluoride.
Ion Radicals of Organometallic Compounds. III. Positional Effects on the Thermodynamics of Formation and the Kinetics of Decomposition of (Methyl-substituted Benzene)tricarbonylchromium Cation Radicals
Authors: Ikeshoji Tamio , D. Parker Vernon 
Published: July 2006

Abstract
Reversible oxidation potentials, rate constants, and activation parameters are reported for the formation and decomposition reactions of all isomers of (methyl-substituted benzene)tricarbonylchromium cation radicals. The reversible potentials were observed to depend both on the number and the positions of the methyl substituents. It was found that the effects on the reversible potentials of adding single methyl substituents to similar structures were additive. The activation energies and entropies for the decomposition reactions were found to be grouped into four different categories depending upon the numbers of adjacent unsubstituted positions on the methylarene ligands. Within each group the deviations from the averages were less than experimental error. The differences in activation parameters are explained in terms of how effective bonding is between the chromium atom and the arene ligands in the cation radicals.
Copper(II)-Catalyzed Transamination of Hydrophobic Pyridoxamine with Pyruvic Acid in Functionalized Bilayer Vesicles
Authors: Murakami Yukito , Kikuchi Jun-ichi , Nakano Akio , Akiyoshi Kazunari , Imori Toru 
Published: July 2006

Abstract
The copper(II)-catalyzed transamination of 2-methyl-3-hydroxy-4-aminomethyl-5-(dodecylthiomethyl)pyridine (C12SPM) with sodium pyruvate was investigated in an aqueous medium at pH 6.8, μ 0.10 (KCl), and 30.0±0.1 °C in the presence of molecular aggregates of N,N-ditetradecyl-Nα-[6-(trimethylammonio)hexanoyl]-l-alaninamide bromide (N+C5Ala2C14), N,N-ditetradecyl-Nα-[6-(trimethylammonio)hexanoyl]-l-histidinamide bromide (N+C5His2C14), or hexadecyltrimethylammonium bromide (CTAB). The reaction afforded the corresponding pyridoxal analogue (C12SPL) and alanine as the final products upon addition of edta which liberates the copper(II) ion from the coordination sites of the aldimine Schiff-base. The coordination interaction between the copper(II) ion and C12SPM, which takes place prior to the transamination, was clarified by electronic spectroscopy. The reactivity of the 2:1 (ketimine:CuII) complex was found to be much larger than that of the 1:1 complex in the molecular assemblies of N+C5Ala2C14 and CTAB, and the formation of the former species was more pronounced in the N+C5Ala2C14 vesicle. The bilayer vesicle formed with N+C5His2C14 allowed the formation of the 1:1 complex in preference to that of the 2:1 complex, and the coordination-free imidazolyl group of the amphiphile effectively catalyzed the isomerization as a general base.
Rate and Equilibrium of the Hydration of 1,3-Benzodithiolylium Ion
Authors: Okuyama Tadashi , Fueno Takayuki 
Published: July 2006

Abstract
Rates and the equilibrium constant of hydration of 1,3-benzodithiolylium ion were spectrophotometrically measured at 30 °C in aqueous acidic solutions. The hydrate was stable below pH 5 and pKR+=−0.40. The cation does not seem to be very stable as compared with the corresponding dithiolanylium ion.
Quinazoline Derivatives from 2-Phenyl-4-quinazolinylhydrazine
Authors: El-Sherief Hassan Ahmed , Mahmoud Abdalla Mohamed , Esmaiel Ahmed Ahmed 
Published: July 2006

Abstract
Formic acid and acetyl and benzoyl chloride were treated with 2-phenyl-4-quinazolinylhydrazine (1) under mild conditions to afford the corresponding hydrazides which were converted into 5-phenyl[1,2,4]triazolo[1,5-c]quinazoline, 2-methyl-5-phenyl[1,2,4]triazolo[1,5-c]quinazoline, and 2,5-diphenyl[1,2,4]triazolo[1,5-c]quinazoline (3a) respectively by heating over their melting points. Reaction of 1 with aldehydes produced the corresponding hydrazones which give the corresponding [1,2,4]triazolo[1,5-c]quinazolines (3a–i) on pyrolysis. Carbon disulfide underwent ring closure with 1 to 5-phenyl-1,2,4-triazolo[4,3-c]quinazoline-3-thiol which was readily converted into the corresponding alkylthio compounds by treatment with alkyl halides. Further, 4-(4-arylmethylene-5-oxo-2-phenyl-2-imidazolinylamino)-2-phenylquinazolines were obtained via the condensation of 4-arylmethylene-2-phenyl-2-oxazolin-5-ones with 1.
Paramagnetic Cobalt(III) Complexes with Organic Ligands. VIII. The NMR Spectra of Paramagnetic Tetraammine(5-nitrosalicylato)cobalt(III) Chloride Nitrate Hydrate and the Related Compounds
Authors: Yamamoto Yoshihisa , Shimokawa Shigezo , Yamada Eiji 
Published: July 2006

Abstract
The ring proton signals have been assigned for the 1H NMR spectra of the green paramagnetic tetraammine(5-nitrosalicylato)cobalt(III) chloride nitrate hydrate and (quadridentate amine)(5-nitrosalicylato)cobalt(III) chloride nitrate hydrate, [Co(5-NO2sal)L]Cl·NO3·nH2O (L: (NH3)4, trien, 2,3,2-tet, and 3,2,3-tet). The 1H NMR spectra indicate that the unpaired electron on the coordinated 5-nitrosalicylato ligand of the title complexes is located over the π-orbital of the chelated ligand
Photoelectrochemical Oxidation of Alcohols on Polycrystalline Zinc Oxide
Authors: Lee Ju-seong , Kato Tamihiko , Fujishima Akira , Honda Kenichi 
Published: July 2006

Abstract
The current doubling behavior of alcohols was studied on an n-type ZnO polycrystalline electrode. The increase in photocurrent due to alcohols on the ZnO depended on pH of the solution. The photocurrent was almost doubled in alkaline solution. It was found that the ZnO photoanode dissolved in the neutral aqueous solution but the dissolution reaction of ZnO was completely suppressed in alkaline solution at a sufficiently large pH. From the experimental results obtained by the rotating ring disk electrode and gas chromatographic and mass spectrometric analyses, a mechanism of the current-doubling reaction is proposed.
The Willgerodt-Kindler Reaction between Polycyclic Aromatic Amines and Benzaldehyde. Formation of 1,3-Thiazines
Authors: Nomura Yujiro , Hayama Takashi , Takeuchi Yoshito , Tomoda Shuji , Kato Yuko 
Published: July 2006

Abstract
The title reaction performed under typical conditions of the Willgerodt-Kindler reaction afforded “abnormal” product 1,3-thiazines. A mechanism involving the Diels-Alder reaction between N-benzylidenearyl-amine and thiobenzaldehyde has been suggested to explain the formation of 1,3-thiazines.
NMR Study of Protonated Halothiophenes. II. An ab Initio Self-consistent Field Calculation of the Protonation of Chlorothiophenes
Authors: Yamashita Yukihide , Kobayashi Hiroyuki , Yoshino Akihiro , Takahashi Kensuke , Sone Tyo 
Published: July 2006

Abstract
The STO-3G method was applied to the protonation of thiophene and chlorothiophenes. The optimized structures and charge densities thus obtained are consistent with the experimental results obtained from the 1H NMR spectral data. In the neutral molecule, the β-chloro substituent lowers the total energy more than the α-one; however, the latter stabilizes the protonated state more than the former.
Manufacture of Pure Titanium(IV) Oxide by the Chloride Process. III. Precipitation of Hydrous Titanium(IV) Oxide in Hydrochloric Acid Solution at Elevated Temperatures
Authors: Narita Eiichi , Takeuchi Hitoshi , Horiguchi Naoto , Okabe Taijiro 
Published: July 2006

Abstract
Thermal hydrolysis of titanium(IV) in hydrochloric acid solutions (0.2 mol dm−3 in Ti(IV); 2 mol dm−3 in HCl) was carried out at temperatures up to 110 °C to investigate the effects of heating rate, heating temperature, aging time, and coexisting ions on the particle shape, size, crystal form, crystalline size, and content of water of the hydrous titanium(IV) oxide precipitated. The resulting polycrystalline particles having rutile structure were all distorted ellipsoids at the beginning of the hydrolysis, and gradually changed to spheres with rising temperature or with the duration of time. However, no effects of heating rate on the particle shape and size distribution were observed at the beginning of the hydrolysis. On the other hand, the precipitation rate of titanium(IV) measured at a constant temperature remarkably depended on the temperature; marked changes in the particle size distribution and mean particle size were observed during the reaction. The precipitation rate was well expressed by the rate equation based on the rate-determining step of the surface chemical reaction. The apparent activation energy was 111 kJ mol−1. Although no effects of coexisting cations such as iron(III) and aluminium(III) were recognized, the presence of sulfate and fluoride ions significantly affected the particle shape and size of such precipitates. Anatase-type hydrous titanium(IV) oxide consisting of spherical particles of narrow size distribution was also obtained in the presence of fluoride ion.
Stereoselective Formation of Rotaxanes Composed of Polymethylene-bridged Dinuclear Cobalt(III) Complexes and α-Cyclodextrin. II
Authors: Yamanari Kazuaki , Shimura Yoichi 
Published: July 2006

Abstract
[2]-[[(en)2Co{XCH2S(CH2)nSCH2Y}Co(en)2]Clm]-[α-CDX]-rotaxanes (n=8, 10, and 12 for X=Y=CO2− (m=4); n=10 for X=CO2− and Y=CH2NH2(m=5); α-CDX=α-cyclodextrin) were prepared with partial stereoselectivity and characterized from their visible-UV absorption, circular dichroism(CD), and 13C NMR spectra, and elemental analysis. The rotaxane formation could be identified by the down field shift of the chemical shift due to α-CDX in the 13C NMR spectra and the increase of the CD intensity in the ligand-to-metal charge transfer band region in the CD spectra. The rotaxanes always showed apparently ΔΔ-rich CD spectra, the highest selectivity(10% ΔΔ-rich) being found in the case of n=10.