bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemically Induced Dynamic Electron Polarization in the Photoreduction of Aromatic Ketones with ππ*-Type Triplet State
Authors: Kawai Akio , Yamamoto Tetsuya , Okutsu Tetsuo , Obi Kinichi 
Published: June 2005

Abstract
Chemically induced dynamic electron polarization (CIDEP) spectra of radicals produced in the photoreduction reaction of aromatic ketone/triethylamine systems were measured by time resolved ESR method. Anion radicals with net absorption (Abs) CIDEP were produced in ethanol with a base such as KOH, while ketyl type radicals with net emissive (Em) CIDEP have been formed in cyclohexane and benzene. Laser power dependence measurement indicates that net Em CIDEP of ketyl radicals is generated by a two-photon process while the production of ketyl radical itself is by one-photon process. Therefore, it was concluded that net Em CIDEP is generated through radical-triplet pair mechanism (RTPM) between the triplet state aromatic ketone and the produced ketyl radical. While RTPM is reasonably considered as an origin of net Em CIDEP for ketyl radicals, it is difficult to determine the CIDEP mechanism of the net Abs polarization of anion radicals in the present systems. Possible mechanisms were tentatively proposed for the present net Abs CIDEP generation.
Time-Resolved Measurements of the Gas-Phase Reaction of Mo2 (X 1Σg+) with Some Simple Molecules at Room Temperature
Authors: Ishikawa Yo-ichi , Matsumoto Yoshitaka , Wakabayashi Tomohiro 
Published: June 2005

Abstract
A multiphoton dissociation (MPD) of volatile metal carbonyl was applied for pulse production of neutral transition metal dimers in a gas-phase kinetic study. Its feasibility was discussed in the reaction systems of Mo2 with small molecules (O2, CO, NO, H2, SF6, NH3, and C2H4). Some potential problems, such as disturbances to the dimer production mechanism from the reactant addition and to neutral reaction kinetics from ionic species inevitably produced in the MPD of metal carbonyls, were experimentally examined. The transient concentration of Mo2 (X 1Σg+, ν = 0) produced by 266-nm MPD of Mo(CO)6 was measured by a laser-induced fluorescence (LIF) at 518.60 nm (A 1Σu+, ν″ = 0 ← X 1Σg+, ν′ = 0). The pseudo-first order decay rates of Mo2 were found to increase with increasing the concentration of some reactive species (O2, NO, and NH3). Our results obtained from time-resolved measurements were found to be almost consistent with the observations of Lian et al. (J. Phys. Chem., 98, 11637 (1994)) who prepared Mo2 by laser vaporization and measured its depletion in a fast-flow reactor.
89Y MAS NMR in Red Phosphor, Eu-Doped Y2O2S. Assignment of Peaks Shifted by Paramagnetic Eu3+, Spin Lattice Relaxation Time, and Eu Distribution
Authors: Harazono Toshie , Adachi Ryuji , Kijima Naoto , Watanabe Tokuko 
Published: June 2005

Abstract
89Y MAS (Magic angle spinning) NMR has been investigated to study the local environment of Y sites in a red phosphor, Eu doped-Y2O2S (Eu–Y2O2S), with varying the Eu content. Despite the presence of paramagnetic Eu3+ ions, high resolution spectra were acquired and a number of local environments were detected. The assignment of the resonances to different Y local environments was made on the basis of signal intensities, chemical shifts, and spin-lattice relaxation times (T1) in conjugation with the crystal structural data which were obtained by the Rietveld method. Besides the main peak in pure Y2O2S, four peaks caused by the –Eu species and ten peaks caused by the Eu––Eu species were distinguished in Eu–Y2O2S, where Y1 is the next nearest-neighbor Y site for the doped Eu atom, and –Eu and Eu––Eu are substituted by one and two Eu, respectively. Y atoms (Y2, Y3, ··· Yn), which are further from the second and more nearest-neighbors from Eu were observed at the same resonance position for all samples investigated with that of pure Y2O2S.
The T1 values of the 89Y signal were reduced from 6.6 h for pure Y2O2S to 230 s (10 mol% Eu–Y2O2S) for Yn (n ≥ 2), to several tens of seconds for Y1–Eu and to several seconds for Eu–Y1–Eu in Eu–Y2O2S. The Eu content to Y in the region where Eu atoms are randomly isolated was estimated from the intensity ratio of the total intensities of the four Y1 peaks to the main peak. T1 reduction and a line-broadening due to paramagnetic Eu3+ ions are discussed in relation to the distribution of Eu ions.
Quantum Control of the Photodissociation of Sodium Iodide
Authors: Hoki Kunihito , Ohtsuki Yukiyoshi , Kono Hirohiko , Fujimura Yuichi , Koseki Shiro 
Published: June 2005

Abstract
A quantum control of photodissocation of NaI to neutral atom fragments, NaI → NaI* → Na + I, was theoretically studied by using a locally optimized control method. The purpose of this control was to obtain as many neutral fragments as possible within one cycle of the nuclear vibration. The control was based on a pump-and-dump scheme. Weak and strong laser-field cases were used. The optimal dump pulses in both cases were shown to be of a linear time-dependent up-chirp type by analyzing their time- and frequency-resolved power spectra. This confirms the result predicted using a non-optimal control method in a previous paper (Chem. Phys. Lett., 231, 50 (1994)). The nuclear wavepacket propagations were also analyzed to see how photodissociation takes place when controlled pulses are used.
Flow-Type Chemiluminescence Detection Cell Using an Optical Fiber for Capillary Electrophoresis
Authors: Hashimoto Masahiko , Nakamura Takeshi , Tsukagoshi Kazuhiko , Nakajima Riichiro , Kondo Kazuo 
Published: June 2005

Abstract
A flow-type chemiluminescence detection cell using optical fiber was designed for capillary electrophoresis. The capillary was set up straight to the optical fiber with a certain distance in a Teflon® tube. Hydrogen peroxide was delivered through a three-way joint by a syringe pump and mixed with analytes at the capillary outlet. Luminol chemiluminescence was adapted for use with this detection cell. Analytical conditions, such as hydrogen peroxide flow rate, distance between the capillary and the fiber, and the reagent concentrations, were examined in detail with the cell. The present flow-type system provided a CL signal with high sensitivity, resolution, and reproducibility. The detection limit (S/N = 3) for luminol was 7.6 × 10−9 M (28 amol; 3.7 nl injected) with theoretical plate numbers of 130000—160000 and a relative standard deviation of 3.3% for the peak height (n = 10). A mixture sample of glycine, glycylglycine, and glycylglycylglycine, which were labeled with isoluminol isothiocyanate (2,3-dihydro-6-isothiocyanato-1,4-phthalazinedione), was also subjected to the present system. They were sensitively detected and represented with high resolution.
Adduct Polymers and Dimers of Rhodium(II) Pivalate with Pyrazine, 4,4′-Bipyridine, 1,4-Diazabicyclo[2.2.2]octane, Triethylamine, and Pyridine
Authors: Handa Makoto , Watanabe Mayumi , Yoshioka Daisuke , Kawabata Seiichiro , Nukada Ryoji , Mikuriya Masahiro , Azuma Hiroshi , Kasuga Kuninobu 
Published: June 2005

Abstract
Adducts of rhodium(II) pivalate with pyrazine (pyz), 4,4′-bipyridine (4,4′-bpy), and 1,4-diazabicyclo[2.2.2]octane (dabco), triethylamine (tea), and pyridine (py) have been prepared. The adducts with pyz, 4,4′-bpy, and dabco are polymers formulated as [Rh2(O2CCMe3)4(L)]n, (L = pyz, 4,4′-bpy, and dabco). A polymer structure with an alternating arrangement of the rhodium(II) dimer and ligands was confirmed by an X-ray structure analysis of the 4,4′-bpy adduct. The Rh–Rh bond distance is 2.395(1) Å which is in the range of those reported for the adducts of rhodium(II) carboxylates with axial aromatic nitrogen-donor ligands. The structure of the adduct dimers, [Rh2(O2CCMe3)4(L)2] (L = tea and py), was also confirmed for a tea-coordinated complex, which has considerably long axial Rh–N (2.391(8) Å) and Rh–Rh (2.413(1) Å) bonds. The reflectance-spectral and thermogravimetric data of all the adducts were obtained to examine the axial interaction between the rhodium(II) dimer core and the ligands.
Synthesis and Characterization of Some Cationic η3-Propargylpalladium Complexes
Authors: Tsutsumi Ken , Kawase Tomohiro , Kakiuchi Kiyomi , Ogoshi Sensuke , Okada Yuji , Kurosawa Hideo 
Published: June 2005

Abstract
Some cationic η3-propargylpalladium complexes were prepared upon treatment of the corresponding η1-propargyl- or η1-allenylbis(triphenylphosphine)palladium(II) chloride with Ag[BF4] or Na[BPh4]. The effectiveness of the latter reagent suggests that a η1-propargyl- or η1-allenyl(chloro)palladium complex equilibrates with a cationic η3-propargylpalladium complex with the liberation of a Cl− ligand. A qualitative comparison of trends in a series of analogous equilibrium systems suggests that the η3-coordination mode is favored to a greater extent when (i) propargyl ligands have an alkyl substituent at the propargylic position, (ii) phosphine ligands are bidentate, such as dppe, (iii) polar solvents are used, and (iv) the liberating ligand is a Cl− one. A possible implication of η3-coordination of propargyl ligands in a catalytic cycle of Pd-catalyzed transformations of propargylic or allenylic substrates is presented.
Extracted Species of Rare Earth Elements Using Bis(1,1,3,3-tetramethylbutyl)phosphinic Acid as an Extractant and Their Effective Mutual Separation by High-Performance Extraction Chromatography
Authors: Wang Qiu-quan , Huang Ben-li , Tsunoda Kin-ichi , Akaiwa Hideo 
Published: June 2005

Abstract
The possible extracted species of rare earth elements (REE) in bis(1,1,3,3-tetramethylbutyl)phosphinic acid (Hmbp)/cyclohexane–HNO3 system was proposed by a log–log plot analysis and a saturated extraction method as being [M(mbp)3(Hmbp)3] (M = REE). It was also verified by IR, 1H NMR spectra and element analysis of lutetium–Hmbp extracted species. The effective mutual separation of REEs was achieved on the Hmbp modified C-18 column by a pH gradient elution. Moreover, the degree of the mutual separation of europium(III) from gadolinium(III) was remarkably improved by adding glycollic acid in the mobile phase. A fine concentrate of Sm2O3, Eu2O3, and Gd2O3 from a rare earths smeltery was analyzed by the present method with the spectrophotometric detection after postcolumn derivatization with Arsenazo III.
Solvent Extraction Equilibria and Kinetics of Gallium(III) with 2-Thenoyltrifluoroacetone in the Absence and Presence of Trioctylphosphine Oxide in Toluene
Authors: Yamada Meri , Suganuma Shinya , Tanaka Ichiro , Sekine Tatsuya 
Published: June 2005

Abstract
The rate and equilibrium of solvent extraction of gallium(III) from aqueous perchlorate solutions into toluene with 2-thenoyltrifluoroacetone (Htta) was measured in the absence and presence of trioctylphosphine oxide (TOPO). A synergistic enhancement of the extraction was found when TOPO was added. When a correction was made for the association of Htta and TOPO in the organic phase which decreased their concentrations available for the extraction, the extracted adducts was found to be in the form of Ga(tta)3(TOPO)2. The rate of extraction was not high and it was dependent on the second order with respect to Htta and the inverse second order with respect to H+ in both the absence and the presence of TOPO. The rate was accelerated by addition of TOPO; the enhancement of the rate was proportional to the TOPO concentration.
Time-Resolved Near-Infrared Surface-Enhanced Raman Spectroscopy of a Surface-Confined Electrochemical Reaction of 9,10-Phenanthrenequinone
Authors: Ishioka Toshio , Uchida Tatsuya , Teramae Norio 
Published: June 2005

Abstract
A measurement system for time-resolved surface-enhanced Raman spectroscopy with a submillisecond time resolution was developed using a step-scan near-infrared Fourier-transform spectrometer and was applied to analyze a redox reaction of 9,10-phenanthrenequinone (PQ) adsorbed on a polycrystalline gold electrode. In the time-resolved surface-enhanced Raman spectra, both quinone and hydroquinone forms of PQ were recognized, but the intermediate species, semiquinone radicals, were not. It was suggested that the lifetime of the intermedeate species was shorter than 0.5 ms, which was the time resolution of the developed system.
Synthesis, Spectroscopy, Electrochemistry, and Mesomorphism of Triple-Decker Porphyrins Consisting of Two Cerium Ions and Three 5,15-Diarylporphyrins
Authors: Miwa Hideya , Kobayashi Nagao , Ban Kazue , Ohta Kazuchika 
Published: June 2005

Abstract
Triple-decker sandwich complexes, which consist of two cerium ions and three strip-like diarylporphyrins, have been synthesized and their spectroscopic and electrochemical properties and mesomorphism are reported and compared with those of the corresponding double deckers and the parent monomers. The Soret band of the triple-deckers lies at longer and shorter wavelengths than those of the double-deckers and monomers, respectively, while a sequence of small absorptions is observed in the Q band region. These are interpreted on the basis of knowledge of triple-deckers made from tetraphenylporphyrin and octaethylporphyrin. Magnetic circular dichroism (MCD) spectroscopy suggests that the Soret bands of the triple-deckers are a superimposition of at least two transitions to orbitally degenerate states. In the MCD spectra, Faraday A-terms are observed corresponding to each absorption band, suggesting that these triple-deckers take D4h or more plausibly D4d structures. Triple-deckers containing dialkoxyphenyl groups at the 5,15-positions of their parent porphyrin show a mesophase possessing both lamellar and columnar structures at lower temperatures and a columnar mesophase at higher temperatures, which differ in stacking distances. On the other hand, those containing tetraalkoxylated terphenyl groups at the 5,15-positions of their parent porphyrin show only a columnar mesophase with a single stacking distance. These differences in the mesomorphism are explained by differences of the magnitude of the steric hindrance of the side chains for rotation along the axis connecting the center of the three porphyrins.
Formation of Lanthanide Complexes with Bipyridine-Functionalized Amide Compounds and Their Unusually High Amide Reactivity
Authors: Kawaguchi Satoshi , Kajikawa Takeshi , Kaneko Mariko , Koshimizu Takahiro , Araki Koji 
Published: June 2005

Abstract
In the presence of a catalytic amount of lanthanide cations (Ln3+), the amide of 6-benzoylamino-6′-l-phenylalanylamino-2,2′-bipyridine (1a) was efficiently cleaved at 30 °C to give l-phenylalanine ester in methanol almost quantitatively. The reaction proceeded in the manner of the Michaelis–Menten type via the 1 : 1 1a–Ln3+ complex ([1a]/[Ln3+] molar ratio = 1); the half-life time of the scissile amide bond of the complex was as short as 2 min for the 1a–Dy3+ system. The reactions were highly specific to the structure of the substrates, requiring 2,2′-bipyridine having two acylamino side chains at the 6,6′-positions and an amino group at the α-position of the scissile carbonyl. The formation and structures of the less-reactive 6,6′-bis(benzoylamino)-2,2′-bipyridine (1d) with lanthanide cations were studied spectrophotometrically. They formed 1 : 1 complexes, and the formation constants (Ka) were on the order of 103—105 mol−1 dm3 in methanol at 30 °C. Coordination of the bipyridine nitrogens and the carbonyl oxygens was indicated in chloroform. However, coordination of the carbonyl oxygens was not observed in methanol. Detailed structures of the complexes are discussed in relation to their reactivity.
Solvolysis of 2,2-Dialkylvinyl Iodonium Salt: Alkyl Participation and Possibility of a Primary Vinylic Cation Intermediate
Authors: Okuyama Tadashi , Yamataka Hiroshi , Ochiai Masahito 
Published: June 2005

Abstract
Solvolysis of (E)- and (Z)-2-methyl-5-phenyl-1-pentenyl(phenyl)iodonium tetrafluoroborate (1·BF4) was carried out in various alcohols, acetic acid, and aqueous solutions at 60 °C. Products (after acid hydrolysis) include iodobenzene and 2-methyl-5-phenylpentanal as well as rearranged ones: 6-phenyl-2-hexanone, 6-phenyl-3-hexanone, 6-phenyl-2-hexyne, 6-phenyl-1,2-hexadiene, and 6-phenyl-2,3-hexadiene. The products of α-elimination, including 1-methyl-3-phenyl-1-cyclopentene, were also obtained in methanol and ethanol. Solvolysis of the E isomer (E)-1 is faster than that of (Z)-1 in every solvent examined. The percentage of rearrangement is higher with (E)-1 than with (Z)-1, and the main rearranged products are those of migration of the alkyl group trans to the iodonio group, but migration of the cis alkyl group is also involved. Theoretical calculations suggest that interconversion between the secondary vinylic cations by 1,2-hydride shift is rapid. These results show that a major heterolysis reaction occurs with β-alkyl participation to directly give a secondary vinylic cation, but stereochemistry of the unrearranged substitution products suggests that formation of the primary vinylic cation is also involved in less nucleophilic solvents like acetic acid and 2,2,2-trifluoroethanol.
Mechanism of the Benzophenone-Sensitized Photolysis of O-Benzoyl-N-(1-naphthoyl)-N-phenylhydroxylamine in Cationic Micellar Media
Authors: Kaneko Tsuyoshi , Tokue Tatsuya , Kubo Kanji , Sakurai Tadamitsu 
Published: June 2005

Abstract
The benzophenone-sensitized photolysis of the title hydroxylamine (1) in hexadecyltrimethylammonium chloride (HTAC) micelles was found to give benzoyloxy(2,3)- and phenyl(4,5)-migrated products, along with fragmentation products, 1-naphthanilide (6) and benzoic acid (7), which were obtained exclusively from the sensitized reaction in organic media. An analysis of the effects of added benzyl alcohol on the quantum yields for the reaction in HTAC micelles showed that the benzoyloxy-migrated products are derived from the amidyl-benzoyloxyl radical pair (that is present at the micellar surface), whereas the amidyl-phenyl radical pair (that is penetrated deeply into the micellar interior) is responsible for appearance of the phenyl-rearranged products. This effect of benzyl alcohol also confirmed that the hydrogen abstraction of the amidyl and benzoyloxyl radicals takes place in competition with the spin inversion of these triplet radicals. These interpretations were substantiated by the finding that the critical micelle concentration for HTAC is reduced in the presence of benzyl alcohol, but that the alcohol exerts only its very small effect on the aggregation number. On the other hand, the use of hexadecyltrimethylammonium bromide (HTAB) micelles instead of HTAC resulted in 2 and 3 in negligible quantum yields with increased quantum yields for the formation of 4—7. This intriguing result was explained in terms of (1) much less efffective hydrogen-bonding solvation of the assumed hot triplet radical pair in the more hydrophobic HTAB micellar surface as well as (2) heavy-atom effects on the intersystem crossing from the singlet amidyl-benzoyloxyl radical pair to the triplet one. Based on the quantum yields for the triplet-sensitized photolysis of 1 in HTAC–HTAB mixed micelles, it was demonstrated that the hydrogen-bonding solvation described above plays a major role in suppressing the benzoyloxy photorearrangement reaction in the HTAB micelle cage.
Different Aggregating Properties of Two Conformationally Frozen Isomers of a Water-Soluble Bridged Calix[6]arene
Authors: Akine Shigehisa , Goto Kei , Kawashima Takayuki , Okazaki Renji 
Published: June 2005

Abstract
Two conformationally frozen isomers (cone and 1,2,3-alternate) of a water-soluble calix[6]arene were synthesized and found to show the critical micelle concentrations quite different from each other, which was explained in terms of their monomer structures with different arrangements of the charged groups.
Simple Determination Method of Degree of Substitution for Starch Acetate
Authors: Ogawa Kazuo , Hirai Ikuo , Shimasaki Choichiro , Yoshimura Toshiaki , Ono Shin , Rengakuji Seichi , Nakamura Yuuko , Yamazaki Isao 
Published: June 2005

Abstract
To develop a simple method to determine the degree of substitution (dS) for starch ester, we prepared starch acetate with various dS values (0—3) and examined the mode of starch-iodine complex formation for the starch acetate by monitoring the ultraviolet-visible (UV-vis) spectra and their Fourier-transform infrared (FT-IR) spectral changes. The effect of acetylation on the formation of the starch-iodine complex was investigated by monitoring the decrease in absorbance at 680 nm (blue value). The blue value decreased by increasing the standard dS value determined by NMR for starch acetate, but two different correlations between the blue values and the dS values were observed for the low- and highly-substituted starch acetate. The FT-IR spectra for starch acetate particles were measured using a diffuse reflection method. The peak areas and absorbances of the bands assigned to the acetyl group showed a poor correlation with standard dS values from the NMR. On the other hand, the FT-IR peaks assigned to sodium acetate produced by saponification of the starch acetate could be detected using the ATR (attenuated total reflection) method; they showed a good correlation with the standard dS values from the NMR. From these results, it was concluded that the ATR method should be available for the dS determination of starch acetate.
Reversible Oxygen-Releasing from the Composite of Picketfence-Porphyrinatocobalt and Carbon in Response to a 1.5 V-Application
Authors: Nishide Hiroyuki , Suzuki Yoko , Tsuchida Eishun 
Published: June 2005

Abstract
5,10,15,20-Tetrakis(α-o-pivalamidophenyl)porphyrinatocobalt(II) (CoP) complexed with N-tritylimidazole in the solid state quickly and reversibly absorbed oxygen from air (14 cm3 O2/g), which was ascribed to a Co/dioxygen 1/1 adduct formation. The adduct formation was an exothermic reaction, and the absorbed oxygen was released above 65 °C. A disk (e.g., diameter 2 cm × 2 mm) was prepared with powders of the oxygen-absorbing, but electrically insulating, CoP complex and of electrically conductive carbon. The application of 1.5 V to the disk induced a temperature elevation in the disk, which momentarily released the absorbed oxygen. The oxygen-releasing and -absorbing cycle could be repeated more than 100 times, with a 5-min switching on-off interval under ambient conditions.
Construction of Defect-Diminished Fatty Acid Langmuir–Blodgett Film and Its Optical Waveguide Properties
Authors: Yanagida Masami , Takahara Atsushi , Kajiyama Tisato 
Published: June 2005

Abstract
A Langmuir–Blodgett (LB) film for a optical planar waveguide with a low optical propagation loss could be constructed from highly organized fatty acid monolayers prepared by a cooling multi-step creep method. The cooling multi-step creep method is the novel preparation technique to form a defect-diminished monolayer on the water surfaces on the basis of both the structural relaxation induced by area-creep and the control of thermal molecular motions in the monolayer. The fatty acid monolayer prepared by the cooling multi-step creep method was morphologically homogeneous and mechanically stable, even at a high surface pressure where the monolayer prepared by a conventional continuous compression method easily collapsed. The crystallographical and structural regularities of the monolayer and the LB film prepared by the cooling multi-step creep method were remarkably improved, compared with those of the monolayer and the LB film prepared by the conventional continuous compression method. The LB film waveguides prepared by the cooling multi-step creep method were morphologically homogeneous and structurally regular and could propagate incident light with a low optical propagation loss.