bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Halide Ions on Micelle-Enhanced Chemiluminescence Reaction of Lucigenin with Adrenaline
Authors: Kamidate Tamio , Kaneyasu Tetsutoshi , Segawa Tadashi , Watanabe Hiroto 
Published: July 2006

Abstract
A remarkable lowering of chemiluminescence (CL) emitted from the CL reaction of lucigenin (Luc) with adrenaline (AD) was observed in cationic micellar assemblies containing halide ions, when their concentrations were above 5×10−3 mol dm−3. These results could be explained in terms of the quenching of the Luc CL reaction by halide ions. The quenching by chloride ions was dependent on the carbon number in the alkyl group of surfactant reagents.
Palladium-Catalyzed Carbonylative Cross-Coupling Reaction of 1-Halo-1-alkenes with 9-Alkyl-9-BBN Derivatives. A Direct Synthesis of α,β-Unsaturated Ketones
Authors: Ishiyama Tatsuo , Miyaura Norio , Suzuki Akira 
Published: July 2006

Abstract
The synthesis of α,β-unsaturated ketones by means of the palladium-catalyzed cross-coupling reaction between 9-alkyl-9-borabicyclo[3.3.1]nonanes (9-R-9-BBN) and 1-halo-1-alkenes under carbon monoxide atmosphere is described.
Dielectric Relaxation Studies of Oligether of Ethylene Glycol at Microwave Frequencies
Authors: Purohit Hari Dutt , Sengwa Ram Jeewan 
Published: July 2006

Abstract
Dielectric relaxation studies of dialkyl ethers of ethylene glycol and of diethylene glycol have been carried out at microwave frequencies in benzene solutions. Dipole moment and relaxation times corresponding to overall and group rotations and their weight factors have been determined. The configuration of these molecules and the mechanism of the rotation of end alkoxyl groups have been discussed.
Observation of Propagation Speed of Conductive Front in Electrochemical Doping Process of Polypyrrole Films
Authors: Tezuka Yoshihiko , Ohyama Shigeru , Ishii Tadahiro , Aoki Koichi 
Published: July 2006

Abstract
According to the propagation theory of a conductive zone for the electrochemical doping process of conducting polymer films, an oxidized conductive zone works as an electrode for oxidizing the reduced non-conductive region and is propagated throughout the film under charge transfer control. This theory was verified for polypyrrole films by tracing the temporal and spatial variations of conductive regions in a film. An exhaustively reduced polypyrrole film was laid on an insulating glass plate and connected electrically to an ITO electrode at the marginal part. The film absorbance to a monochromatic light beam was monitored with a photodiode array detector at 14 segments of the film. When the potential of the ITO electrode was stepped to an oxidation potential of the film, an electrochemically oxidized conductive zone was propagated through the film with a manifest phase boundary. The distance from the edge of the ITO electrode to the front of the conductive zone increased linearly with time. The logarithmic slope of the propagation speed exhibited a linear relation to the applied potential.
Pressure-Induced Neutral–Ionic Phase Transition of a Tetrathiafulvalene–Iodanil Crystal
Authors: Matsuzaki Susumu , Hiejima Toshihiro , Sano Mizuka 
Published: July 2006

Abstract
The pressure dependence of IR spectra measured for a mixed-stack neutral charge-transfer (CT) crystal, tetrathiafulvalene–iodanil (TTF–IA), showed an occurrence of a neutral–ionic (N–I) transition at 1.9 GPa. The N-I transition is accompanied by gradual dimerization of the crystal lattice and a small ionicity jump, in contrast to the case of TTF–chloranil (TTF–CA). Such a quasi-continuous N–I transition is attributable to stronger electron–lattice interaction in TTF–IA than that in TTF–CA.
Direct Epoxidation of Olefins Catalyzed by Nickel(II) Complexes with Molecular Oxygen and Aldehydes
Authors: Yamada Tohru , Takai Toshihiro , Rhode Oliver , Mukaiyama Teruaki 
Published: July 2006

Abstract
In the presence of a bis(1,3-diketonato)nickel(II) complex, various olefins are directly monooxygenated into the corresponding epoxides on treatment with atmospheric pressure of oxygen or air and aldehydes. Especially, it is noted that bis[1,3-bis(p-methoxyphenyl)-1,3-propanedionato]nickel(II) behaves as an excellent catalyst in the present epoxidation.
Asymmetric Reactions of Enamines with Methyl (E)-4-Oxo-4-(2-oxo-1,3-oxazolidin-3-yl)-2-butenoate by the Use of a Chiral Titanium Reagent
Authors: Hayashi Yujiro , Otaka Ken , Saito Nobuo , Narasaka Koichi 
Published: July 2006

Abstract
Asymmetric Michael and [2+2] cycloaddition reactions between enamines and methyl (E)-4-oxo-4-(2-oxo-1,3-oxazolidin-3-yl)-2-butenoate proceed with a chiral titanium reagent generated in situ from dichlorodiisopropoxytitanium and a tartrate-derived chiral 1,4-diol. In the presence of excess amounts of the chiral titanium reagent, good to moderate enantioselectivity is attained. The reactions are also well catalyzed even with a catalytic amount of the titanium reagent.
One-Step Hydroamidation of a Schiff Base with Trichlorosilane
Authors: Okamoto Hidenori , Kato Shozo 
Published: July 2006

Abstract
We have found that the treatment of a Schiff base (2) with trichlorosilane and chloroacetyl chloride results in a highly active chloroacetamide herbicide (1) in an excellent yield. This one-step hydroamidation reaction of a Schiff base is a useful synthetic method.
Crystal Structures and Electrical Conductivities of TXCn-TTF (X=Sulfur, Selenium, Tellurium; n=2,3)·TCNQ Charge-Transfer Complexes
Authors: Imaeda Kenichi , Mori Takehiko , Nakano Chikako , Inokuchi Hiroo , Iwasawa Naoko , Saito Gunzi 
Published: July 2006

Abstract
The crystal structures and the electrical conductivities have been studied for tetrakis(alkylchalcogeno)tetrathiafulvalene (TXCn-TTF (X=sulfur, selenium, tellurium; n=2,3)) complexes with tetracyanoquinodimethane (TCNQ). All the complexes with a composition of 1 : 1 had the same crystal system (triclinic) and the same space group (P\bar1). The donor and acceptor molecules were alternately stacked in their crystals. (TSeC2-TTF)TCNQ was obtained as plate and needle crystals. The molecular structure of TSeC2-TTF and the overlapping mode between TSeC2-TTF and TCNQ molecules of the two complexes were subtly different. All the complexes were semiconductors because of their mixed-stack structures. (TTeC2-TTF)TCNQ showed the lowest resistivity (5 Ω, cm at room temperature). Its good conductivity was brought about by the effective degree of charge-transfer and the favorable overlap between TTeC2-TTF and TCNQ molecules. An overall discussion on the structural and physical properties of a series of TCNQ complexes with TXCn-TTF (X=sulfur, selenium, tellurium; n=1,2,3) is presented.
ESR Studies at High Pressures. III. Spin-Exchange Reactions of Some Nitroxide Radicals in Acetone and Hexane
Authors: Sueishi Yoshimi , Kuzukawa Masahiro , Yamamoto Shunzo , Nishimura Norio 
Published: July 2006

Abstract
Pressure effects on the rate of spin–spin exchange of some nitroxide radicals in acetone and hexane at 298.2 K have been studied by means of a high-pressure ESR technique. It was found that this exchange reaction is diffusion-controlled. The rate of the spin exchange is related to that of diffusion, the probability of the spin exchange, P=f(J, τ1), and steric factor fs. The values of P and hence τ1 were estimated as a function of pressure. A method for evaluating the steric factor and the exchange integral is proposed.
The Number of Organic Radicals on a Decationated Y-Type Zeolite before, during, and after Irradiating with Ultraviolet Light or Heating
Authors: Kashiwagi Hiroshi 
Published: July 2006

Abstract
A decationated Y-type zeolite (HY) was adsorbed by a single organic compound from a heptane solution, and dried in vacuo. The numbers of the radicals in these binary systems before, during, and after irradiating with ultraviolet (UV) light or heating were followed by electron paramagnetic resonance spectroscopy and then compared. During UV irradiation, the number of radicals increased from the constant number of spins before illumination (C1) to the second constant number of spins (C2). After stopping the illumination, the C2 decreased up to the third constant number of spins (C3). The C3 value was smaller than C2, but was significantly greater than C1. The enhancement of radicals induced by UV light, expressed quantitatively in terms of the C3/C1 ratio, was pronounced when either a weak donor or a weak acceptor was adsorbed on HY calcined at a low temperature. C1 was proportional to the amount of adsorption up to the maximal amount of adsorption, whereas C2 and C3 were proportional only at a considerably decreased amount of adsorption. A similar tendency was observed when the binary systems were heated at 40 or 80 °C. A quantitative determination of the mechanically induced enhancement of radicals would prompt either an improvement in the reproducibility of physicochemical data or an elucidation of the solid acidity or basicity.
VUV Photoionization Efficiency Curves and Appearance Energies of N,N-Dimethylformamide Ion and Its Fragment Ions
Authors: Arimura Masana , Yoshikawa Yozaburo 
Published: July 2006

Abstract
Ionization efficiency curves of N,N-dimethylformamide (DMF) ion and of its fragment ions, C3H6NO+, C2H4NO+, and C2H6N+ were obtained by use of vacuum ultraviolet photoionization method. The appearance energy of the parent ion was 9.12±0.06 eV. The appearance energies of C3H6NO+, C2H4NO+, and C2H6N+ were very close (10.77±0.08 eV for C3H6NO+ and C2H4NO+, 10.59±0.08 eV for C2H6N+). The relative intensity curve of C2H6N+ normalized by the sum of fragment ions vs. photon energy has the second rise at 12.2±0.3 eV, which implies that another fragmentation process appears at the photon energy above 12.2 eV. The second fragmentation process is ascribed to a channel through DMF cation in an excited electronic state.
Additional Formation of Brønsted Acid Sites on Silica–Alumina Catalyst Surfaces by Depositing Silica Component
Authors: Sato Satoshi , Hiratsuka Masahiro , Sodesawa Toshiaki , Nozaki Fumio 
Published: July 2006

Abstract
The chemical vapor deposition (CVD) of silica onto an amorphous silica–alumina was investigated using tetraethoxysilane in order to create Brønsted acid sites on the surface of original silica-alumina. Silica loading could be readily controlled by the CVD time at 160 °C; the silica covered an internal wall of mesopore of the support of silica–alumina. The resulting CVD silica–alumina was catalytically more active than the original silica–alumina support for such test reactions as the cracking of cumene and the isomerization of 1-butene. The characteristic changes in the amount of Brønsted acid sites were clarified by means of the temperature-programmed desorption of adsorbed 2,6-dimethylpyridine. Strong Lewis acid sites of the original silica–alumina were converted into strong Brønsted acid sites upon depositing the silica component.
Pillared Tetrasilicic Mica Catalysts Having Fixed Interlayer Ca Ions. Comparison with Other Clays
Authors: Sakurai Hiroaki , Urabe Kazuo , Izumi Yusuke 
Published: July 2006

Abstract
Three kinds of Ca2+-modified pillared clays (TSM, taeniolite, and montmorillonite) were prepared from Ca2+-exchanged clays. The cumene cracking activity over the TSM-based catalyst was greatly dependent on the calcination temperature before pillaring, and gave a maximum at 300–400 °C. In contrast, no appreciable increase in the activity with the calcination temperature before pillaring was observed in montmorillonite- and taeniolite-based catalysts. The amount of residual Ca in the modified pillared TSM was increased with a rise in the calcination temperature before pillaring, whereas the amount of Al incorporated through pillaring was decreased, showing the progress of Ca2+ fixation during the stage of thermal treatment of Ca2+-exchanged unpillared TSM. Thus, the cracking activity was greatly enhanced by the fixation of Ca2+. The cracking activity, however, dropped due to a pretreatment above 400 °C, since the Al-pillars which prop silicate layers are reduced while causing a decline in the surface area of the resulting pillared TSM; also, the strong acid sites were decreased due to excessive packing of Ca2+ fixed over the surface of silicate layers. In the cases of montmorillonite and taeniolite, the remaining amounts of Ca and Al were almost constant, irrespective of the calcination temperature before pillaring. This indicates that Ca2+ fixation does not occur in these clays.
Reaction of Tris(t-butylthio)cyclopropenylium Perchlorate with Arylmagnesium Bromides
Authors: Kojima Hideo , Ozaki Kazuyoshi , Matsumura Noboru , Inoue Hiroo 
Published: July 2006

Abstract
The reaction of tris(t-butylthio)cyclopropenylium perchlorate with phenyl-, o-tolyl-, or 1-naphthylmagnesium bromide in tetrahydrofuran at room temperature gave t-butylthio-substituted allenes and indenes. The reaction with 2,6-xylylmagnesium bromide gave only the corresponding allene derivative.
Resonance Raman Study on Phot on eduction of Iron–Porphyrins. A Novel Insight into the Ligand-Aided Process
Authors: Fidler Vlastimil , Ogura Takashi , Sato Shin-ichiro , Aoyagi Katsuhiro , Kitagawa Teizo 
Published: July 2006

Abstract
Photoreduction of Fe(OEP) (OEP: octaethylporphyrin) in organic solvents by visible light was demonstrated to be a ligand-aided process in which simultaneous coordinations of a base such as 2-methylimidazole (2MeIm) and of an aliphatic alcohol to two axial positions of the iron ion were required. Coordination of an alcohol was evidenced from the observation of the Fe–alcohol stretching (νFe–alcohol) resonance Raman (RR) band. Since this band exhibited an appreciable frequency shift between ROH and ROD, coordination of the alcohol in a protonated form was suggested. When a primary or secondary alcohol was added to the CH2Cl2 solution of FeIII (OEP)Cl in the presence of 2MeIm, a new absorption band appeared around 560–590 nm and the νFe–alcohol RR band was most intense for excitation at the maximum of the new absorption band. The new absorption was therefore assigned to the alcohol to FeIII charge transfer (CT) band. A tertiary alcohol gave neither the CT band nor the νFe–alcohol RR band, although some spectral changes were noticed after long laser illumination at 441.6 nm, and the photoreduction as seen for other alcohol solutions did not take place. This photoreduction was not apparently recognized in the presence of oxygen. However, flash photolysis experiments demonstrated that the photoreduction occurs irrespective of the presence or absence of oxygen but rapid reoxidation results in apparent no effect.
Reaction of Thioaldehydes with Amines
Authors: Okuma Kentaro , Komiya Yasuo , Ohta Hiroshi 
Published: July 2006

Abstract
The reaction of phosphonium ylides with elemental sulfur gave thioaldehydes, which changed to the corresponding thioamides in good yields when treated with amines. When thioaldehydes containing α-hydrogens were treated with secondary amines, the corresponding enamines or reduction products were obtained.
Catalysis by Heteropoly Compounds. XVIII. Oxidation of Methacrylaldehyde over 12-Molybdophosphoric Acid and Its Alkali Salts
Authors: Mizuno Noritaka , Watanabe Tetsuji , Misono Makoto 
Published: July 2006

Abstract
The reaction scheme for the methacrylaldehyde oxidation over heteropoly compounds proposed previously (M. Misono et al., Proc. 7th Intl. Congr. Catal., 1980) was confirmed by 18O tracer experiments using the Pulse-MS method (combination of pulse reactor/mass spectrometer). The occurrence of direct and rapid oxygen exchange between methacrylaldehyde and the polyanion of MxH3−xPMo12O40 (M=Na, Cs, x=0–3.15) was verified under the reaction conditions. The results also suggested that this reaction is catalyzed by Brønsted acid sites of the catalysts via such intermediates as (I) and/or (II) in scheme 1. It was shown that the methacrylaldehyde oxidation is a surface-tyepe reaction and the catalytic activity is controlled by the oxidizing ability of the catalyst surface.
Raman Phonon Spectroscopic Study of Phase Transition in trans-Stilbene Crystal
Authors: Chakrabarti Subhasis , Misra Tridibendra Narayan 
Published: July 2006

Abstract
Raman phonon spectroscopy in the 10–170 cm−1 range has been used to study phase transition in trans-stilbene crystal. At 77 K, eight distinct phonon modes and an internal mode are observed whereas at 300 K the spectrum shows only four phonon bands and an internal mode. The temperature dependence of spectral pattern and some phonon band width suggest that the phase transition in this crystal is quasi-continuous over a small temperature range 215–225 K. The absence of a soft mode and a strong increase of the phonon band width, when approaching the Tc from below, suggest that the phase transition is of order-disorder type. The well established disordered structure of trans-stilbene crystal at room temperature attains an ordered structure at low temperature at least through one, possibly two order–disorder transitions.
Structure and Properties of (NEt4)[MoVO(α,2-toluenedithiolato)2]. Distorted Tetragonal-Pyramidal MoOS4 Core
Authors: Ueyama Norikazu , Yoshinaga Naoto , Kajiwara Atsushi , Nakamura Akira , Kusunoki Masami 
Published: July 2006

Abstract
An oxomolybdenum(V) complex with two chelating ligands of alkane- and arenethiolate parts, (NEt4)[MoVO(α,2-toluenedithiolato)2], was prepared and characterized by visible, ESR, IR, and Raman spectroscopies. Four distinct ligand-to-metal charge transfer absorption bands were observed in visible region. The complex crystallizes in the space group P21 with a=9.535(2), b=16.582(9), c=8.085(1) Å, β=90.757(4)°, V=1278.3(8) Å3, Z=2, and dcalcd=1.431 g cm−3. The structure was solved and refinement based on 2102 reflections converged at R=0.089 and Rw=0.100. The complex takes an apical oxo and trans bis(α,2-toluenedithiolato) structure with a distorted MoOS4 core from a tetragonal-pyramidal geometry.
Dipeptide Side Chain–Side Chain Hydrophobic Interactions as Conformational Core for Chymotrypsin Inhibition
Authors: Sakamoto Hiroshi , Shimohigashi Yasuyuki , Ogawa Tomohisa , Kawano Keiichi , Ohno Motonori 
Published: July 2006

Abstract
A series of dipeptides with the sequence of H–d-Leu–l-Phe–R, where R denotes 4-phenylpiperidide, 4-phenylpiperazide, and their derivatives, have been synthesized to examine their ability to inhibit chymotrypsin. Dipeptide phenylpiperidide and phenylpiperazide inhibited chymotrypsin fairly strongly (Ki=7.5×10−4 M and 1.4×10−3 M, respectively) (1 M=l mol dm−3), while their phenyl-substituted analogs were inactive. In high resolution 3H NMR measurements, it was found that the proton signals of d-Leu γ-CH and β-CH2 shifted considerably to the upfield when compared with those of H–d-Leu–l-Ala–OH, suggesting that these upfield shifts are due to the magnetic anisotropy effect by the benzene ring of the Phe residue. This was confirmed by measuring NOE between d-Leu–isobutyl and l-Phe–phenyl groups. These NMR data indicate that the side chains of both d-Leu and l-Phe are in close proximity, resulting in formation of a hydrophobic complex. It was suggested that, in the inhibitory conformation of dipeptides against chymotrypsin, the phenyl group of phenylpiperidide or phenylpiperazide moiety fits the S1 site, while the side chain-side chain hydrophobic complexing core fits the S2 site.
Studies on Mixed Chelates. XIX. 5-Coordinate Nickel(II) Complexes with N,N,N′,N″,N″-Pentamethyldiethylenetriainine and β-Diketonates
Authors: Shintani Noriko , Sone Kozo , Fukuda Yutaka , Ohashi Yuji 
Published: July 2006

Abstract
Mixed Ni(II) chelates with N,N,N′,N″,N″-pentamethyldiethylenetriamine (pmdt) and a β-diketonate (dike) such as acetylacetonate(acac), dipivaloylmethanate(dipm), pivaloyltrifluoroacetonate(pfac), trifluoroacetylacetonate(tfac) or hexafluoroacetylacetonate(hfac) were prepared, and their structure and properites were studied. X-Ray crystal analysis confirmed that [Ni(acac)(pmdt)]ClO4 is a distorted square pyramidal complex, and the solid reflection spectra of the remaining chelates indicated that most of them are also essentially square pyramidal. This structure is retained in a nonpolar solvent like 1,2-dichloroethane, but in strong donor solvents like DMSO or DMF it is converted into a 6-coordinated structure, [Ni(dike)(pmdt)(Solvent)]+, containing a solvent molecule. The formation of this species is favored by increasing donor number(DN) of the solvent, and in the following order of dike:dipm&lt;acac&lt;&lt;tfac, pfac&lt;&lt;hfac, which is almost opposite to the order of their pKa values.
The Excited-State Dipole Moment of Nitrobenzene Estimated from Solvent Spectral Frequency Shifts
Authors: Abe Takehiro 
Published: July 2006

Abstract
The excited-state dipole moment of nitrobenzene has been estimated to be 33.7×10−30 Cm from solvent spectral frequency shifts. This value agrees well with that ((31.7±3.3)×10−30 Cm) determined from an electrooptical absorption measurement.
A Fusarubin Isomer
Authors: Tanoue Yasuhiro , Terada Akira , Umezu Yasuo 
Published: July 2006

Abstract
An isomer of fusarubin, 2-acetonyl-5,8-dihydroxy-7-hydroxymethyl-3-methoxy-1,4-naphthoquinone, was prepared from 2-hydroxymethyl-7-(2-hydroxypropyl)-1,4,5,6,8-pentamethoxynaphthalene.
EXAFS Investigation of Pentasil-Structured Gallium-Containing Metallosilicates
Authors: Okabe Kiyomi , Matsubayashi Nobuyuki , Sayama Kazuhiro , Arakawa Hironori , Nishijima Akio 
Published: July 2006

Abstract
Pentasil-Structured bimetallosilicates were prepared by adding Ga and Fe (or Sr) salts simultaneously during the hydrothermal synthesis of a pentasil silicate, and local structures around Ga were directly elucidated by means of EXAFS for the first time. It was found that Fe and Ga independently substituted the silicate framework, and that the local structure around Sr was the same as that in Sr2+-exchanged gallosilicate.
Thermodynamic Study of Brij 35 in Aquo-Polyethylene Glycol Solvents
Authors: Koshy Leena , Rakshit Animesh Kumar 
Published: July 2006

Abstract
The critical micelle concentrations of Brij 35 in aquo PEG 200 solutions were determined by the iodine solubilization method at five different temperatures at various PEG percents. The thermodynamic quantities of micellization as well as the free energies of micellization at infinite dilution were computed and rationalized.
Spectrophotometric Detection for Flow Injection Analysis of Tertiary Alkylamines in Terms of the Intermolecular Charge-Transfer Interaction with Iodine
Authors: Uno Bunji , Nakajima Kiho , Kawai Satoshi 
Published: July 2006

Abstract
Spectroscopic studies of the intermolecular charge-transfer interaction with iodine have been extended in order to develop a new spectrophotometric detection method for flow injection analysis (FIA). Tertiary alkylamines, as a model compound of spectroscopically inactive species, have been determined with high detection sensitivity by FIA using the present detection method.
Entropy Change Associated with the Charge Transfer Reation of Various Quinones in Aprotic Solvents
Authors: Komaguchi Kenji , Hatsusegawa Yasuhiro , Kitani Akira , Sasaki Kazuo 
Published: July 2006

Abstract
Temperature dependence of the cathodic reduction potentials of various p-benzoquinone derivatives have been determined in five aprotic solvents, benzonitrile, acetonitrile, propylene carbonate, N,N-dimethylformamide, and dimethyl sulfoxide. As for the first electron transfer reactions, the free energy of transfer between any two of solvents has been found to be less than 1.0 kcal mol−1, which is much smaller than the solvation enthalpy of ordinary anions. As a result, the transfer entropy is compensated almost perfectly by the transfer enthalpy. The compensation effect also appears in the transfer energies of the second electron transfer reaction though not perfect.