bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis for the Oligomerization Mechanism of Styrene by Field Desorption Mass Spectrometry
Authors: Saito Jun , Hara Junji , Toda Shozo , Tanaka Shigeyuki 
Published: July 2006

Abstract
Measurements were made of field desorption mass spectra of normal and deuterated styrene oligomers synthesized in various alkylbenzenes. Several series of molecular ion peaks are observed in both the spectra. From a comparison between them we have identified oligomers’ end groups and derived formation mechanisms for individual molecular species. It has been clarified that molecular species independent of solvents are produced through chain transfer of propagating radicals to styrene dimers. Analysis for the polymerization mechanism of styrene as well as characterization of polymer molecules has been successfully performed by field desorption mass spectrometry.
Aromatic Nucleophilic Substitution. XVI. Stopped-flow Kinetics of Formation and Decomposition of 1,3- and 1,1-Disubstituted Anionic σ Complexes in Reactions of 1-Dimethylamino-2,4-dinitronaphthalene with Potassium Alkoxides in Dimethyl Sulfoxide–Alcohol
Authors: Sekiguchi Shizen , Tone Noboru , Takei Toshio , Tomoto Noboru 
Published: July 2006

Abstract
Reactions of 1-dimethylamino-2,4-dinitronaphthalene with potassium methoxide or ethoxide were carried out in DMSO–CH3OH or DMSO–C2H5OH (90:10 v/v), respectively, where the 1,3-disubstituted anionic σ complexes were first rapidly formed, undergoing isomerizations to the 1,1-disubstituted anionic σ complexes. Rates and activation parameters were determined by kinetic studies using stopped-flow and conventional spectrophotometers. The rate constant (25 °C) for the formation of 1,3-disubstituted one in DMSO–CH3OH is about half that in DMSO–C2H5OH, whereas the rate constant (25 °C) for its decomposition is more than twice that in DMSO–C2H5OH. The apparent pseudo-first-order rate constant for the formation of 1,1-disubstituted anionic σ complex in DMSO–CH3OH depends upon the methoxide ion concentration, whereas that in DMSO–C2H5OH is almost independent of the ethoxide ion concentration. The mechanism is discussed on the basis of activation parameters.
Aryliminodimagnesium Reagents. V. The Reaction with Bifunctional Nitroarenes
Authors: Okubo Masao , Aratani Hiroyuki , Gond\={o} Takayuki , Koga K\={o}ji 
Published: July 2006

Abstract
The reactions of p-methylphenyliminodimagnesium reagent (p-MeC6H4N(MgBr)2) with p- and m-dinitrobenzenes, bis(p-nitrophenyl) methane, bis(p-nitrophenyl) sulfide and ether, p- and m-nitrobenzaldehydes as well as 4-nitro-4′-methylbenzophenone were investigated. p-Dinitrobenzene, which is the strongest electron-acceptor among the substrates used, gave ca. 30% combined yield of bis(azoxy) and azoxy azo products. The oxidative coupling product, 4,4′-dimethylazobenzene, was isolated in 20–30% yields. About 60% combined yield of the bis(azoxy) and azoxy azo products was obtained in the same reaction with m-dinitrobenzene, which is less electron-accepting than the p-isomer. In the reaction of bis(p-nitrophenyl)methane, bis(p-nitrophenyl) sulfide and ether with five molar amounts of the reagent, ca. 70% combined yields of bis(azoxy), azoxy azo, and bis(azo) products were obtained. On the treatment of the nitrobenzaldehydes and the nitrobenzophenone, in contrast, the reaction took place exclusively on the nitro group. The results are discussed in terms of the electron-accepting ability of substrates.
The Effect of Temperature on the Formation of Benzyl Radical-Halide Ion Complexes in γ-Irradiated Organic Glassy Matrices
Authors: Izumida Tatsuo , Fujii Kuniaki , Ogasawara Masaaki , Yoshida Hiroshi 
Published: July 2006

Abstract
Broad structureless charge-transfer (CT) bands of benzyl radical-halide ion (\dotBz- - -X−) complexes have been observed in 3-methylhexane (3MHx) and 2-methyltetrahydrofuran (MTHF) matrices containing BzCl and BzBr irradiated with γ-rays at 4.2 K. 3MHx and ethanol matrices containing BzI also showed the CT band when warmed from the irradiation temperature to 77 K. These observations are in marked contrast with previous ones in which the CT band was found to be present only in alkane matrices when irradiated at 77 K. The CT band has been found to shift to the blue with increasing matrix polarity, as expected from a large contribution of the solvation of the ion to the CT transition energy of the radical-anion complex. The observed nature and behavior of the CT bands indicates that the dissociative electron attachment reaction in the matrices is a stepwise process: The formation of a \dotBz- - -X− complex and its dissociation. These steps proceed readily in more polar environments and for lighter ions. For the electron attachment to BzI at 4.2 K, an even earlier step, an ionic entity prior to the C–I bond dissociation, was indicated.
Conductimetric Study of the Ion Pair Formation in Mixtures of Bivalent Metal Nitrates and Sodium Sulfate in Aqueous Solutions
Authors: Katayama Shunzo , Tanaka Kazuko , Tamamushi Reita 
Published: July 2006

Abstract
The conductance behavior of electrolyte mixtures was investigated for the systems of bivalent metal nitrates and sodium sulfate in aqueous solutions of high ionic strengths (I≥0.3 mol dm−3) at 25 °C. Significant deviations of the measured conductivities from the additivity were observed in all the systems, which can be attributed to the ion pair formation of the bivalent metal ion with sulfate ion. The conditional formation constants, Kc, were determined by means of computer analysis of the deviation; Kc-values at each ionic strength were found to decrease in the sequence Cd&gt;Mn\simeqNi\simeqCo\simeqZn&gt;Mg.
Hydrates of Organic Compounds. VII. The Effect of Anions on the Formation of Clathrate Hydrates of Tetrabutylammonium Salts
Authors: Nakayama Haruo 
Published: July 2006

Abstract
Phase diagrams of the binary mixtures of tetrabutylammonium salt [(n-C4H9)4N]nX (X=NO2, NO3, BrO3, ClO3, IO3, ClO4, MnO4, and NCS for n=1; X=CO3, SO4, WO4, and CrO4 for n=2; and X=PO4 for n=3) with water were determined over the temperature range between −10 and +50 °C. From these diagrams the following results were obtained: (1) the formation of a clathrate-like hydrate for salts having such anions as NO2−, NO3−, BrO3−, ClO3−, IO3−, SO42−, and PO43− was newly confirmed; (2) the melting point of the clathrate hydrate of the salt with monovalent anion was appreciably influenced by the kind of anion; (3) in the hydrates of the salt having either di- or trivalent anions, the melting points were relatively high and were only slightly affected by the kind of anion; (4) the crystal structure of these hydrates was essentially the same as that of the tetrabutylammonium fluoride hydrate, judging from the hydration numbers; (5) the solubilities in water of both permanganate and perchlorate were markedly lower than that of the iodide; and (6) in the thiocyanate system a phase separation into two liquid phases was observed at temperatures higher than +3.5 °C. The effect of a monovalent anion on the stability of the clathrate hydrate was discussed in connection with the conventional partial molal volume of the anion.
Hydrogen Evolution from Alkaline Formaldehyde Solution
Authors: Okamoto Hiroshi , Katsumoto Masayuki , Kudo Tetsuichi 
Published: July 2006

Abstract
Hydrogen is evolved from an alkaline solution of formaldehyde in the presence of a tungsten carbide catalyst at room temperature under atmospheric pressure. Neither platinum nor palladium shows any catalytic activity to this reaction. The hydrogen evolution competes with the Gannizzaro reaction.
Intensity Enhancement Caused by Complex Formation between Pyrene and Alcohols
Authors: Nakajima Akira 
Published: July 2006

Abstract
The enhancement of the weak 0-0 band in the absorption spectrum of pyrene has been observed using various mixtures of cyclohexane and alcohols. The relations of the absorption coefficients with the alcohol concentrations have been studied on the assumption of 1:1 complex formation between pyrene and alcohols. The association constants for the hydrogen-bonded complexes have been estimated to be of a reasonable order of magnitude(0.1–0.4 mol−1 dm3).
Wetting of Coal by Aqueous Surfactant Solutions
Authors: Esumi Kunio , Meguro Kenjiro , Honda Hidemasa 
Published: July 2006

Abstract
The rates of wetting of coals of various carbon content by aqueous anionic surfactant solutions were measured. It was found that the rates of wetting increased with increasing concentration of the anionic surfactant in solution and further, the addition of electrolyte significantly promoted the rates of wetting. The presence of the electrolyte on the surface of coal after wetting was confirmed by the zeta potential measurement.
The Preparation and Some Properties of Cobalt(II) Schiff Base Complexes and Their Molecular Oxygen Adducts
Authors: Kasuga Kuninobu , Nagahara Takeo , Tsuge Akira , Sogabe Kunihisa , Yamamoto Yasuo 
Published: July 2006

Abstract
Seven new cobalt(II) complexes with a tetradentate Schiff base and their three oxygen adducts were synthesized. The adducts were stable at room temperature for several weeks. The isolated oxygen adducts showed intense new bands in the 1130–1150 cm−1 range characteristic of superoxide-like 1:1 oxygenated metal complexes. The ESR spectra of the adducts showed eight-lined, hyperfine structures with a very small splitting (10–20 G) at 77 K. The adducts obtained were identified as monomeric 1:1 oxygen species, two complexes of which showed a reversible oxygenation in a 1,2-dichloroethane solution at 6 °C.
Syntheses and Properties of Dinuclear Copper(II) Complexes with 2,6-Bis[bis(2-pyridylmethyl)aminomethyl]-4-methylphenol
Authors: Suzuki Masatatsu , Kanatomi Hajime , Demura Youichi , Murase Ichiro 
Published: July 2006

Abstract
The dinucleating ligand, 2,6-bis[bis(2-pyridylmethyl)aminomethyl]-4-methylphenol](Hbpmp), formed two types of dinuclear copper(II) complexes, [Cu2(bpmp)X2]n+(X=Cl−, N3− py(pyridine), or Him(imidazole), and n=1 or 3), and [Cu2(bpmp)X]2+(X=CH3COO− or im−). On the basis of the dinucleating nature of the ligand (bpmp), the elemental analyses and the conductivity measurements in acetonitrile, it is concluded that the complexes have dimeric unit of [Cu2(bpmp)X2]n+ or [Cu2(bpmp)X]2+. In [Cu2(bpmp)X2]n+ type complexes, two copper(II) ions are linked only by a single phenolate bridge. Magnetic susceptibilities of those complexes obey Curie-Weiss law in the temperature range 80–300 K with the Weiss constants ≈−4 K, indicating that weak antiferromagnetic interactions are present in these complexes. In [Cu2[bpmp)X]2+ type complexes, however, two copper(II) ions are bridged by phenolate and acetate, or phenolate and imidazolate. Cryomagnetic measurements of the acetato and the imidazolato complexes showed antiferromagnetic interactions with the −2J values of 82 and 66 cm−1, respectively. All the complexes exhibited absorption bands at 20000–22000 cm−1 except for the azido complex. The origin of those bands are discussed.
Kinetics of the Racemization of Tris(1,10-phenanthroline)nickel(II). Hydrophobic Interaction of the Complex Ion with 1-Alkanesulfonate Ions
Authors: Tachiyashiki Satoshi , Yamatera Hideo 
Published: July 2006

Abstract
The kinetics of the racemization of [Ni(phen)3]2+ were investigated in the presence of 1-alkanesulfonate ions (n-CnH2n+1SO3−; n=8, 10, 12, and 14). The racemization rate decreased with the increase in the alkanesulfonate concentrations in the region of low sulfonate concentrations; then, in the region of higher concentrations, it began to increase, but it never exceeded the rate in water. The rate changes at low and high alkanesulfonate concentrations were related to the formation of the 1:1 and 1:m aggregates of the complex ion with alkanesulfonate ions respectively. A comparison of the aggregate formation constants of [Ni(phen)3]2+ with those of [Fe(phen)3]2+ confirmed that hydrophobic interaction is responsible for the aggregate formation. The energy of hydrophobic interaction between [Ni(phen)3]2+ and an alkanesulfonate ion was estimated to be 1.0±0.1 kJ mol−1 per methylene group of the latter. The kinetic behavior of the racemization of [Ni(phen)3]2+ in the aggregates was also compared with those of the racemization and dissociation of [Fe(phen)3]2+, and it was discussed in relation to the racemization mechanism of [Ni(phen)3]2+. The reaction rates of the complexes in D2O solutions were also reported.
Kinetics of the Racemization and Dissociation of Tris(1,10-phenanthroline)iron(II) and Tris(2,2′-bipyridine)iron(II) in Sodium Dodecyl Sulfate Solutions
Authors: Tachiyashiki Satoshi , Yamatera Hideo 
Published: July 2006

Abstract
The kinetics of the racemization and dissociation of [Fe(phen)3]2+ (phen=1,10-phenanthroline) and [Fe(bpy)3]2+ (bpy=2,2′-bipyridine) was investigated in aqueous sodium dodecyl sulfate (SDS) solutions. The racemization and dissociation rates of the complexes increased with the increase in the SDS concentration to reach limiting values at concentrations above the critical micelle concentration (cmc). The rate changes occurring below the cmc were explained in terms of the formation of at least three kinds of premicellar aggregates of the complex ion with dodecyl sulfate ions. In the region slightly above the cmc, where the concentration of the complex ion is larger than that of the micelle, the rates continued to increase with the increase in the micellar concentration, suggesting that the complex ions interacted with the micelles. A comparison of the kinetic behavior in aqueous micellar solutions with that in organic solvents revealed that the complexes were located inside the micelle–water interface. The mechanisms of the acceleration in the micelle were discussed.
Mössbauer Study of Tin(II) Chloride Hydroxide and Tin(II) Hydroxide Oxide
Authors: Ichiba Sumio , Takeshita Mitsuru 
Published: July 2006

Abstract
The precipitates obtained by addition of a solution of NaHCO3 to a solution of SnCl2 at various pH were studied by thermal analysis, Mössbauer spectroscopy, and X-ray powder diffraction. The formula of the tin(II) chloride hydroxide precipitate obtained in the range of pH 1.9–2.5 was determined as 2SnO·SnCl2·H2O, or Sn3O(OH)2Cl2, and the formula of the hydroxide oxide obtained in the range of pH 7.0–7.7 was 3SnO·2H2O, or Sn3(OH)4O. In the intermediate pH range, the chloride ions were gradually replaced by hydroxide ions. The dehydration of hydroxide oxide to produce SnO occurred in two stages and the disproportionation reaction of SnO to SnO2 and β-tin proceeded via Sn2O3.
Oxidation of S,S-Diaryl-N-(p-tolylsulfonyl)sulfilimines and N-Unsubstituted S,S-Diaryl-sulfilimines with Potassium Hyperoxide Anion Radical (O2\ewdot) in the Presence of 1-Bromopropane, Benzoyl Chloride, p-Tolylsulfonyl Chloride, Carbon Tetrachloride, Chloroform, or Dichloromethane in Aprotic Media
Authors: Akutagawa Kunihiko , Furukawa Naomichi , Oae Shigeru 
Published: July 2006

Abstract
The reaction of S,S-diaryl-N-(p-tolylsulfonyl)sulfilimines and N-unsubstituted diaryl-sulfilimines with hyperoxide anion radical (O2\ewdot) in the presence of 18-crown-6 as a catalyst together with 1-bromopropane/benzene, benzoyl chloride/benzene, p-tolylsulfonyl chloride/benzene, carbon tetrachloride, chloroform, or dichloromethane, gave the corresponding sulfoximines, through nucleophilic oxidation with an intermediary dioxy species formed upon treatment of organic halides with potassium hyperoxide (KO2).
ESR Studies of Spin-Spin Dipolar Interaction in Pure and Diluted Phenoxyl Radical Solids
Authors: Mukai Kazuo , Ueda Kyozo , Ishizu Kazuhiko , Yamauchi Seigo 
Published: July 2006

Abstract
ESR studies have been carried out on powder samples of pure phenoxyl (2,6-di-t-butyl-4-phenylphenoxyl) and 3% phenoxyl diluted in its diamagnetic corresponding phenol matrix. The dipolar splittings due to the spin pairs in closest approach have been observed for both the pure and 3% phenoxyl.
Silver Ion-induced Allylation of Furan with Cyclopropyl Halides
Authors: Shimizu Nobujiro , Watanabe Kenji , Tsuno Yuho 
Published: July 2006

Abstract
Allyl species generated from 1-bromo-2-phenylcyclopropane and seven different 1,1-dihalocyclopropanes with the aid of silver perchlorate reacted with furan in a regio- and stereoselective manner to give a series of 2-allylfuran derivatives in fair to good yields.
Aqueous Dispersion of Iron Oxide by Acrylic Oligomer Surfactants
Authors: Esumi Kunio , Ogihara Kimihiko , Meguro Kenjiro 
Published: July 2006

Abstract
The aqueous dispersion of iron oxide by acrylic oligomer surfactants was examined by particle size and zeta potential measurements. Iron oxide particles were suspended in an aqueous iron(III) chloride solution to render the surface positively charged. The iron oxide particles so prepared were then flocculated by the addition of a small amount of acrylic oligomer surfactant. The floes of iron oxide could be redispersed by further addition of acrylic oligomer surfactant. The flocculation and the redispersion processes can be explained in terms of a “two-fold adsorption layer” mechanism of the acrylic oligomer surfactant. The concentrations of acrylic oligomer surfactants needed to achieve flocculation and redispersion decreased with an increase in acrylic content of the oligomer surfactants.
Catalytic Activity of MoO3 and V2O5 Highly Dispersed on TiO2 for Oxidation Reactions
Authors: Ono Takehiko , Nakagawa Yoshiro , Miyata Hisashi , Kubokawa Yutaka 
Published: July 2006

Abstract
The structure of Mo–Ti oxide catalysts has been investigated by using IR and XRD techniques. At a low Mo content, MoO3 is highly dispersed on TiO2, an amorphous phase being formed. Simultaneously, a shift of the Mo=O band from 995 cm−1 to 950 and 905 cm−1 takes place. The maximum rate of the oxidation of C2H5OH and C3H6 over Mo–Ti-6(atom% of Mo) is attributable to the weakening of the Mo=O bond. The 18O tracer and kinetic studies of the oxidation of C3H6 over Mo–Ti and V–Ti oxides suggest that a redox mechanism is applicable, the rate constants of reduction and reoxidation step being determined. The promoter action of TiO2 support is attributed mainly to the increase in the rate of reduction step.
Synthesis and Isomerism of Mixed (Amine)(carboxylato) Complexes with the [Pd(N)n(O)4−n]-type (n=1–4) and Their Circular Dichroism Spectra
Authors: Nakayama Kazuhiko , Komorita Takashi , Shimura Yoichi 
Published: July 2006

Abstract
A large number of mixed-ligand [Pd(N)n(O)4−n]-type complexes (n=1–4) which contain at least one optically active ligand were synthesized and isolated in a systematic manner. (S)-Propylenediamine, (2S)-N1,N1-diethyl-1,2-propanediamine, and (S)-amino carboxylates were employed as one ligand, which is optically active; ammonia, diamines, amino carboxylates, acetates, and dicarboxylates as the other ligand occupying the remaining coordination sites. Isomerism could be detected in the mixed complexes of an unsymmetrical diamine and an amino carboxylate and has been discussed on the basis of 13C NMR and CD spectra. Moreover, the influence of optically inactive ligands on the vicinal CD spectra has been examined, and also the additivity of vicinal CD contributions of two different optically active ligands has been demonstrated.
Oxidation of Lipids. V. Oxidation of Methyl Linoleate in Aqueous Dispersion
Authors: Yamamoto Yorihiro , Haga Shunichi , Niki Etsuo , Kamiya Yoshio 
Published: July 2006

Abstract
The rate and products of oxidation of methyl linoleate dispersed in water by Triton X-100 were measured at 50 °C. The oxidation was initiated by water- or oil-soluble azo-initiators. The oxidation proceeded smoothly by both types of initiators without any noticeable induction period and a constant rate of oxygen uptake was observed. Conjugated diene hydroperoxides were formed almost quantitatively. The oxidizability for methyl linoleate in aqueous dispersion was obtained as kp/(2kt)1⁄2=0.032(s·mol/L-oil)−1⁄2 where kp and kt are the rate constants for propagation and termination reactions, respectively. This value was similar to that observed in the homogeneous oxidation in chlorobenzene. l-Ascorbic acid inhibited the oxidation initiated by water-soluble initiator but it could not inhibit the oxidation initiated by oil-soluble initiator. 2,6-Di-t-butyl-4-methylphenol inhibited the oxidation initiated by both initiators. On the other hand, α-tocopherol was effective for the oxidation initiated by oil-soluble initiator and it incompletely inhibited the oxidation initiated by water-soluble initiator.
The Formation of the Main Skelton of Bicyclomycin by the Cyclization of 6-Hydroxy-3-(3-hydroxypropyl)-2,5-piperazinedione Derivatives
Authors: Sato Yoshiaki , Shin Chung-gi , Sumiya Satoshi , Nakajima Yoshiharu , Yoshimura Juji 
Published: July 2006

Abstract
This paper describes the synthesis of 3-(3-t-butoxypropyl)-6-hydroxy-2,5-piperazinedione derivatives by the hydroxylation of the corresponding 2,5-piperazinedione with N-bromosuccinimide (NBS) in the presence of water and the subsequent cyclization to 2-oxa-7,9-diazabicyclo[4.2.2]decane-8,10-dione derivatives (11). The reversible interconversion between the spiro[oxolane-2,2′-piperazine]-3′,6′-dione prepared previously and the bicyclo compound 11 was established. The formation mechanisms and the structural confirmation of 11 and the other products are discussed.
NAD(P)+-NAD(P)H Models. 49. Proximity Effect of a Phenyl Group on the Electron Transfer Process
Authors: Ohno Atsuyoshi , Kobayashi Hisami , Goto Takehiko , Oka Shinzaburo 
Published: July 2006

Abstract
1-Propyl-1,4-dihydronicotinamide (PNAH), 1-(3-phenylpropyl)-1,4-dihydronicotinamide (1a), 1-(2-phenylthioethyl)-1,4-dihydronicotinamide (1b), and 1-(4-phenylthiobutyl)-1,4-dihydronicotinamide (1c) and their 4-deuterated analogs are synthesized as NAD(P)H-models and subjected to the reduction of m-nitro-α,α,α-trifluoroacetophenone in the presence or absence of magnesium ion in acetonitrile. Kinetics at 323 K have been studied. Kinetic isotope effect is small (2.33) only when 1a or 1b is employed for the reduction in the presence of magnesium ion, whereas it appears large (≈3.2) under other conditions. The result has been interpreted in terms of steric interference by a proximate phenyl group on the approach of the substrate to form a binary (in the absence of magnesium ion) or ternary (in the presence of magnesium ion) complexes. Thermodynamic parameters for the formation of complexes between the models and magnesium ion have been studied. It has been elucidated that enthalpy of complexation is small for 1a than others. However, the small enthalpy of complexation is compensated by small entropy of complexation affording almost constant free-energy of complexation throughout the models studied.
The Crystal Structure of N,N,N′,N′-Tetramethylpiperazinediium Bis(2,4-dinitrophenolate) Dihydrate
Authors: Iwasaki Fujiko , Mutai Kiyoshi 
Published: July 2006

Abstract
The crystal structure of N,N,N′,N′-tetramethylpiperazinediium bis(2,4-dinitrophenolate) dihydrate has been determined by the X-ray method. The crystals are triclinic, space group P\barl, a=11.504(2), b=8.239(2), c=7.119(2) Å, α=106.22(2), β=99.67(2), γ=92.31(2)°, Z=1. The final R is 0.067 for 2743 reflections. Two dinitrophenolate anions are connected by hydrogen bonds, via the water molecules, forming a dimeric unit related by the center of symmetry. N,N,N′,N′-Tetramethylpiperazinediium ion has a chair conformation.