bluuebunny/crossref_metadata_2025_split huggingface dataset:
The J-Like Structures of Azobenzene-Containing Amphiphiles, C10AzoC5N+Br− and C8AzoC5N+Br−
Authors: Okuyama Kenji , Mizuguchi Chiyo , Xu Guiqing , Shimomura Masatsugu 
Published: July 2006

Abstract
Totally synthetic azobenzene-containing amphiphiles C10AzoC5N+Br− and C8AzoC5N+Br− (C31H50N3O3Br and C29H46N3O3Br respectively) were crystallized from their solutions by the solvent-evaporation method. Both crystals are triclinic, with the space group of P\bar1 and Z=2. The unit cell dimensions of the former crystal are a=3.233(5), b=0.854(2), c=0.608(1) nm, α=106.96(8), β=86.6(1), and γ=88.3(1)°. Those of the latter crystal are a=3.0098(6), b=0.8553(2), c=0.6084(1) nm, α=72.99(1), β=92.57(2), and γ=95.64(2)°. The crystal structure of C10AzoC5N+B− was solved by the direct method and refined by the block-diagonal least-squares method: R=0.082 for 2927 observed reflections (2θ&lt;120°, Cu Kα, λ=0.15418 nm). On the other hand, that of C8AzoC5N+Br− was refined by the full-matrix least-squares method: R=0.058 for 2993 reflections (2θ&lt;120°, Cu Kα). The molecular and crystal structures of these compounds are quite similar to those of the homologous compounds, C12AzoC5N+Br− and C6AzoC5N+Br−. That is, the CnAzoC5N+Br− molecules incline about 30° to the bilayer surface to pack in a tail-to-tail fashion. The azobenzene chromophore has a pronounced planarity which makes possible the parallel stacking of adjacent phenyl groups.
Entrained Responses of the Current Oscillation of Polymer Gels to Sinusoidal Stimulation
Authors: Osada Yoshihito , Umezawa Kayo , Yamauchi Aizo 
Published: July 2006

Abstract
The responses of the current oscillation of the water-swollen polymer gels generated by dc current to the sinusoidal stimulation were investigated. The current oscillation was semiquantitatively analyzed by fast Fourier transform and the phase diagram was made up from power spectra. It was found that the entrainment of oscillation occurred in the polymer gels when the frequency of sinusoidal stimulation was closed to that of parent current oscillation. It was also found that the stronger sinusoidal voltage caused the entrainment in wider frequency range.
Halogenation Using Quaternary Ammonium Polyhalides. XX. Bromination of Phenols with Polymer-Bound Benzyltrimethylammonium Tribromide
Authors: Kakinami Takaaki , Suenaga Hiroyuki , Yamaguchi Tadashi , Okamoto Tsuyoshi , Kajigaeshi Shoji 
Published: July 2006

Abstract
Bromo-substituted phenols were obtained quantitatively by passing a solution of phenols in dichloromethane–methanol through a column packed with styrene polymer-bound benzyltrimethylammonium tribromide.
A New Method for the Selective Synthesis of Biphenyl by Dehydrogenative Coupling of Benzene
Authors: Nakada Masahiro , Aimin Yu , Kawakami Shigenobu , Iwaki Shingo , Yamaguchi Tatsuaki 
Published: July 2006

Abstract
A method has been developed for the direct preparation of biphenyl by the thermal dehydrogenative coupling of benzene in the vapor phase on the surface of heater at 1000–1200 °C. Biphenyl was obtained at a high selectivity of more than 94% over the wide range of benzene conversion (3–77%).
Photodecomposition of Kraft Lignin Catalyzed by Titanium Dioxide
Authors: Kobayakawa Koichi , Sato Yuichi , Nakamura Shigeo , Fujishima Akira 
Published: July 2006

Abstract
The photocatalytic reaction of kraft lignin at titanium dioxide photocatalyst was investigated. Kraft lignin was completely decomposed into carbon dioxide and water through dehydrodimers of phenol derivatives constituting kraft lignin, methanol and organic acids such as oxalic and formic acids. Aromatic compounds such as vanillin could not be recovered due to their tendency to dehydrodimerization and the strong oxidizing power of the photo-generated holes by the action of which the dehydrodimers were completely decomposed into carbon dioxide and water. The production of methane, ethane, and ethylene was much smaller than that in the decomposition with hydroxyl radicals in homogeneous solution.
A Convenient Reductive Removal of Benzylic Hydroxyl and Trimethylsilyloxyl Groups with Me3SiCl–NaI–MeCN Reagent
Authors: Sakai Takashi , Miyata Kazuyoshi , Tsuboi Sadao , Takeda Akira , Utaka Masanori , Torii Sigeru 
Published: July 2006

Abstract
Secondary and tertiary hydroxyl groups at benzylic positions were reductively removed by treatment with 6 equivalents of Me3SiCl–NaI–MeCN reagent in hexane at room temperature. A benzylic trimethylsilyloxyl group was also eliminated by the addition of 2 equivalents of water to the reaction system. The reduction was applied to the syntheses of precursors of such anti-inflammatory agents as ibuprofen, butibufen, naproxen, and related compounds, as well as (±)-ar-turmerone, an odorous sesquiterpene.
Reactions of Alkylarenes, Benzyl Alcohols, Sulfides, and Phosphine with Manganese(III) Acetate–Chloride Ions
Authors: Futami Yasuo , Nishino Hiroshi , Kurosawa Kazu 
Published: July 2006

Abstract
The reactions of methoxytoluenes and methylnaphthalenes with a manganese(III) acetate–Cl− complex gave the corresponding aldehydes in 8 to 54% yields. In a similar reaction aromatic compounds having a methylene group were oxidized to the corresponding acetates and ketones. The primary and secondary benzyl alcohols gave aldehydes and ketones, respectively, in good yields. Sulfides and phosphine were oxidized to give oxides by the complex. The reaction of alkylarenes with lower ionization potentials can be explained in terms of an electron-transfer mechanism involving the manganese(III) acetate–Cl− complex.
The Easy Disruption of the β-Sheet Structure of Resin-Bound Human Proinsulin C-Peptide Fragments by Strong Electron-Donor Solvents
Authors: Narita Mitsuaki , Umeyama Hiroshi , Yoshida Toshihiko 
Published: July 2006

Abstract
The β-sheet structure disruption of cross-linked polystyrene resin-bound human proinsulin C-peptide fragments containing Pro residues at suitable intervals was investigated by a solvent titration method in CH2Cl2, mainly using TFE and HMPA as titrating solvents. The easy disruption of the β-sheet structure of resin-bound peptides in CH2Cl2 by TFE and HMPA strongly suggested that the concept of “the peptide segment separation by tertiary peptide bonds” was useful for estimating the β-sheet-structure-disrupted behavior and that the β-sheet structure of the protected peptides having high 〈Pc〉 values could easily be disrupted in a medium electron-acceptor solvent of CH2Cl2 by the addition of a strong electron-donor solvent of HMPA in spite of the electron donor-acceptor interaction between solvents. The present results indicate that effective solvents for solid-phase peptide synthesis by a fragment condensation procedure should be searched by taking the average helix, β-sheet, and coil conformation values, 〈Pα〉, 〈Pβ〉, and 〈Pc〉, of peptide segments into consideration.
Dielectric Relaxation and Intermolecular Association for Various Secondary and Tertiary Alcohols
Authors: Shinomiya Toshiomi 
Published: July 2006

Abstract
The dielectric constants and losses of 2-alkanol (n=4–8), 2-methyl-2-alkanol (n=3–7), six isomeric methylheptanols, and five isomeric nonanols have been measured at the frequencies from 1.35 to 4500 MHz at 15, 25, and 35 °C. The absorption has been resolved into two or three different Debye-like dispersion regions. The first, low-frequency, dispersion region could not be observed for more sterically hindered alcohols, such as several tertiary alcohols. For each alcohol, four concentrations of a linear hydrogen-bonded chain polymer (C1), a chain dimer and trimer (C2), a free monomer (C3), and a nonpolar cyclic polymer (CR) were evaluated by applying a modified Kirkwood–Fröhlich equation to each dispersion region. The equilibrium between C1 and C3 can be considered for more polar alcohols and that between CR and C3 for more sterically hindered alcohols. The mechanism of the relaxation process is discussed in terms of observations of the magnitude and relaxation time for the first region. The free energy of activation increases with increasing alkyl chain length, being about 20–23 for the first region, 16–18 for the second region, and 9–12 kJ mol−1 for the third region.
Gas-Phase Dehydrogenation of Alkylbenzenes on Rh/AlPO4 Catalysts
Authors: M. Bautista Felipa , M. Campelo Juan , García Angel , Luna Diego , M. Marinas José 
Published: July 2006

Abstract
The nonoxidative dehydrogenation of alkylbenzenes (ethylbenzene, propylbenzene, and isopropylbenzene) has been carried out at 693–853 K on rhodium catalysts at 1 wt% supported on two different types of AlPO4. In similar experimental conditions, the specific catalytic activity of the Rh/AlPO4 catalysts is higher than that obtained previously for Ni/AlPO4 (20 wt%) catalysts. Besides, a linear free energy relationship (LFER) was also obtained, manifesting itself through a “compensation effect” between the ΔH≠ and ΔS≠ activation parameters obtained from the Eyring equation (and between ln A and Ea, from the Arrhenius equation). Furthermore, no extensive metal-support interaction effect was obtained as in the case of Ni/AlPO4 catalysts in spite of exhibiting the same concerted mechanism previously described for the nonoxidative dehydrogenation of alkylbenzenes on supported nickel catalysts.
Temperature Change of Graphite Surface Due to Electrochemical Intercalation of ClO4− Ion
Authors: Maeda Yasuhisa 
Published: July 2006

Abstract
Anodic intercalation and cathodic deintercalation of ClO4− ions were shown to cause exothermic and endothermic changes, respectively, on a graphite surface. This suggests the occurrence of an increase in entropy for the deintercalation process and a decrease for the case of intercalation.
Regioselective Hydrogenation of Unsaturated Alcohol Using Platinum–Alumina Modified with Carboxylic Acid
Authors: Kuno Hideyuki , Takahashi Kyoko , Shibagaki Makoto , Matsushita Hajime 
Published: July 2006

Abstract
Platinum–alumina catalysts modified with carboxylic acid were prepared for the selective hydrogenation of unsaturated alcohols. These catalysts were stable in non-polar solvents. It has been demonstrated that the carbon–carbon double bond which is close to the hydroxyl group is preferentially hydrogenated in the case of several hexenols. This selectivity was applied to the regioselective hydrogenation of geraniol and citronellol was obtained in an 84.5% yield over one of the modified catalyst systems.
Synthesis and Characterization of the Pd(II) and Pt(II) Complexes of Trichalcogeno[n]ferrocenophanes (n=7 and 9). A Dative Fe–Pd or Fe–Pt Bond Formation
Authors: Sato Masaru , Asano Hirofumi , Suzuki Kaoru , Katada Motomi , Akabori Sadatoshi 
Published: July 2006

Abstract
1,7-Dithia-4-selena[7]- and 1,9-dithia-5-selena[9](1,1′)ferrocenophanes were prepared. These compounds, as well as 1,4,7-trithia[7]- and 1,5,9-trithia[9](1,1′)ferrocenophanes, were treated with (CH3CN)4Pd(BF4)2 or (CH3CN)4Pt(BF4)2 to give the corresponding 1/1 complexes in good yield. The spectral data of these complexes confirmed that there exsisted a dative Fe–Pd or Fe–Pt bond in these bimetallic complexes.
2,5-Diaryl-1,3,2-dioxaborinanes: A New Series of Liquid Crystals
Authors: Matsubara Hiroshi , Seto Koji , Tahara Tadasu , Takahashi Shigetoshi 
Published: July 2006

Abstract
2,5-Diaryl-1,3,2-dioxaborinane derivatives having various terminal groups were synthesized and found to form mesomorphic phases in a wide temperature range. They provide a new series of liquid-crystalline compounds containing a boron atom in the principal structure.
Model Compound Studies of Coal Liquefaction with Zinc–Butyl Iodide under Mild Conditions
Authors: Yoneyama Yoshiharu , Akaki Yu , Kato Tsutomu 
Published: July 2006

Abstract
A number of model compounds having representative coal structures were treated with zinc–butyl iodide under mild conditions. Gas chromatography and gas chromatography/mass spectrometry were used to identify the reaction products. Polynuclear aromatic compounds gave the butyl-substituted and butyl-addition products. In a reaction of anthracene, its aromatic backbone was cleaved. Alkoxynaphthalene and dibenzyl ether were butylated along with cleavage of ether linkage, while diphenyl ether gave only the butyl-substituted products without cleavage. Butylation and cleavage also took place in the reactions of diphenylmethane and bibenzyl. In the cases of substitution reaction, some butyl groups were rearranged to s-butyl. Because the formation of the most reaction products is interpreted by a similar mechanism to that of Friedel–Crafts alkylation and the formation of some butyl-addition products of polynuclear aromatic compounds is explained by assuming a radical reaction mechanism, it is suggested that both alkyl cation reaction and alkyl radical reaction occur competitively.
Formation of a Hydrogen Insertion Compound of Hydrated Molybdenum Oxide from Hydrogen Molybdenum Bronze
Authors: Eda Kazuo , Sotani Noriyuki 
Published: July 2006

Abstract
It was found that hydrogen molybdenum bronze, H0.3MoO3, turns into a hydrogen insertion compound of hydrated molybdenum oxide in a 1M HCl aqueous solution at 353 K. It was predictable that the compound has a composition of H0.15MoO3·0.88H2O and is identical with Mo8O15(OH)16 or a similar compound.
The Magnetic Properties of Copper(II) 3- and 4-Substituted Benzoate Adducts with Quinoline and 4-Methylquinoline
Authors: Emori Shuji , Matsunaga Satoru , Goto Miyako 
Published: July 2006

Abstract
Various copper(II) 3- and 4-substituted and 3,5-disubstituted benzoate adducts with quinoline and 4-methylquinoline have been prepared, and characterized by means of magnetic susceptibility and IR spectroscopy measurements. The variation of their magnetic moments is discussed in terms of the acidities of their parent acids and the resonance effects of 4-substituents.
Liquid-Crystalline Behavior and Configuration Change of Polyitaconates with Methoxyazobenzene as Mesogens
Authors: Shiraishi Kohei , Sugiyama Kazuo , Otsu Takayuki 
Published: July 2006

Abstract
Nematic polyitaconates having 4-methoxyazobenzene moieties as mesogen in the side chain were prepared. Thermal properties, polymer composition, and the photoinduced configuration change have been examined to suggest a possible use of the polymers for photosensitive liquid-crystalline materials.
Footprint Catalysis. III. Inducible Alteration of Substrate Specificities of Silica(Alumina) Gel Catalysts for 2,4-Dinitrophenolysis of Toluic Anhydrides by Footprint Imprinting
Authors: Morihara Kensaku , Tanaka Eiko , Takeuchi Yuko , Miyazaki Kazue , Yamamoto Nami , Sagawa Yoshimi , Kawamoto Eriko , Shimada Toyoshi 
Published: July 2006

Abstract
A tailor-made catalyst design was attempted for a required substrate specificity by the authors’ footprint imprinting method. Two silica(alumina) footprint catalysts were prepared by imprinting with N-benzoylbenzenesulfonamide (1) and N-(p-toluoyl)-p-toluenesulfonamide (2) from the same aluminum ion-doped silica gel. Their catalytic effects upon 2,4-dinitrophenolysis of benzoic anhydride, p-, m-, and o-toluic anhydrides were compared in order to find any difference in substrate specificities. The catalyst prepared by imprinting with 1 showed the largest specificity(kcat⁄Km) toward benzoic anhydride, whereas the catalyst prepared with 2 showed the largest specificity toward p-toluic anhydride. This finding evidently demonstrated that the substrate specificities of footprint catalytic sites are alterable, as required through selecting appropriate transition state analogs as template molecules for footprint marking.
Studies on Mixed Chelates. XVI. Mixed Copper(II) Chelates with 1,2-Dipiperidinoethane and β-Diketonates
Authors: Fukuda Yutaka , Cho Masako , Sone Kozo 
Published: July 2006

Abstract
1,2-Dipiperidinoethane (dipe) forms mixed chelates of the type [Cu(dike)(dipe)]ClO4 with Cu(ClO4)2 and various β-diketonate ions (dike); however, hexafluoroacetylacetonate (hfac) forms [Cu(hfac)2(dipe)] instead. The strong solvatochromism of the former, and the high solubility and volatility of the latter, were compared with those of similar chelates studied so far.
Enhancement of Catalytic Activity of Copper Ion-Exchanged Y Type Zeolites for the Decomposition of Nitrogen Monoxide
Authors: Iwamoto Masakazu , Yahiro Hidenori , Kutsuno Takashi , Bunyu Sukehiro , Kagawa Shuichi 
Published: July 2006

Abstract
Catalytic activity of Y zeolites containing copper ions (CuY) for decomposition of nitrogen monoxide was enhanced through additional exchange of other metal ions or evacuation treatment around 923–973 K. In the first case, Co3+ or Ni2+ ions increase the catalytic activity while Ca2+, Mn2+, Fe2+, and Zn2+ diminish the catalytic activity of CuY. In the second case, the catalytic activity of CuY evacuated at 973 K was twice that of CuY without the evacuation treatment, which is discussed in connection with the increment of Cu ions active for the decomposition.
Cis to Trans Photoisomerization of [CoCl2{(CH3)2PCH2CH2CH2P(CH3)2}2]+, [CoCl(H2O){(CH3)2PCH2CH2P(CH3)2}2]2+ and Related Complexes
Authors: Oguni Kazuma , Ohishi Tomoji , Kita Masakazu , Kashiwabara Kazuo , Fujita Junnosuke 
Published: July 2006

Abstract
Ligand field irradiation of cis-[CoCl2{(CH3)2PCH2CH2CH2P(CH3)2}2]+ in methanol and cis-[CoCl(H2O){(CH3)2PCH2CH2P(CH3)2}2]2+ in acetonitrile at 5 °C led to isomerization to the trans isomer with quantum yields of 0.010 and 0.070, respectively. The same cis to trans photoisomerization of [CoCl2(R2PCH2CH2PR2)2]+ (R=CH3, C4H9) occurred with much smaller quantum yields (ca. 1×10−4) and cis-[CoCl2{(C6H5)2PCHCHP(C6H5)2}2]+ was reduced to cobalt(II) species on irradiation.
The Triflic Acid-Catalysed Deacylation and Decarboxylation of Polymethylbenzenecarbonyl Derivatives under Mild Conditions
Authors: Keumi Takashi , Morita Toshio , Ozawa Yoshihiro , Kitajima Hidehiko 
Published: July 2006

Abstract
Sterically hindered acylarenes are deacylated to arenes in good yields on heating in boiling 1,2-dichloroethane containing a catalytic amount of triflic acid and water. Hindered arenecarboxylic acids undergo decarboxylation under the same conditions to give arenes in high yields.
Electrochemical Preparation and Characterization of the Radical Salts of (Phthalocyaninato)nickel, NiPc(SbF6)0.5, and NiPc(AsF6)0.5
Authors: Yakushi Kyuya , Yamakado Hideo , Yoshitake Michiko , Kosugi Nobuhiro , Kuroda Haruo , Sugano Tadashi , Kinoshita Minoru , Kawamoto Atsushi , Tanaka Jiro 
Published: July 2006

Abstract
The single crystals of NiPc(SbF6)0.5 and NiPc(AsF6)0.5 were prepared by means of an electrochemical method. The electrical, magnetic, optical, and structural properties of these crystals were examined. These crystals are isostructural to each other, and exhibit a metallic behavior at least above 200 K. The g-values of the ESR signals remarkably depend upon temperature. By the aid of the low temperature experiments of XANES and reflectance spectrum, the temperature dependence is explained by the model based on the interaction between the small amount of local spins on the Ni atoms and the conduction electrons on the ligand chain. In addition, a sample dependence was found on the ESR properties of the crystals of NiPc(AsF6)0.5. This is attributed to the sample dependence of the concentration of the local spins on Ni atoms. From these considerations, we concluded that the ligand part is mainly oxidized in these partially oxidized salts, in other words the conduction electrons are located on the ligand chain. The bandwidth of the conduction band was estimated to be about 1 eV.
Photochemical Reactions of the Oxoperoxovanadium(V) Complex in an Acidic Aqueous Solution
Authors: Shinohara Nobuyoshi , Nakamura Yayoi 
Published: July 2006

Abstract
The photochemical decomposition of oxoperoxovanadium(V), VO(O2)+, was studied in perchloric acid media. It was found that the irradiation of VO(O2)+ solutions with 313, 365, and 436 nm exciting light resulted in the photoreduction of the complex, and gave VO2+, with an evolution of oxygen. The overall reaction is: 4VO(O2)++4H+–→4VO2++3O2+2H2O. The photochemical reaction mechanism is also discussed.
Dielectric Dispersion and Intermolecular Association for 28 Pure Liquid Alcohols. The Position Dependence of Hydroxyl Group in the Hydrocarbon Chain
Authors: Shinomiya Toshiomi 
Published: July 2006

Abstract
The dielectric constants and losses of 28 linear alcohols, 1-alkanol (n=3–10), 2-alkanol (n=3–10), 3-alkanol (n=5–10), 4-alkanol (n=7–10), and 5-alkanol (n=9 and 10), have been measured at the frequencies from 1.35 to 4500 MHz at 15, 25, and 35 °C. The Kirkwood–Fröhlich equation was modified so that it could be applied to each dispersion region calculated. The concentration C1 of linear hydrogen-bonded chain polymers, which primary dispersion originates, was evaluated by means of this modified equation. The C1 decreases as the hydroxyl group approaches the center of a molecule, except for propanols and butanols, and also decreases with increasing temperature. For isomeric decanols, for example, the percentages of C1 (C1×100⁄C0) against alcohol gross stoichiometric concentration C0 at 15, 25, and 35 °C are about 71, 63, and 53% for 1-decanol, 52, 40, and 29% for 2-decanol, 22, 17, and 12% for 3-decanol, 11, 7, and 6% for 4-decanol, and 8, 6, and 5% for 5-decanol, respectively. The thermodynamic parameters, ΔF\eweq, ΔH\eweq, and ΔS\eweq, were obtained for dipole relaxation and viscous flow . The ΔFτ\eweq decreases, although the ΔHτ\eweq and ΔSτ\eweq increase, as the hydroxyl group approaches the center of a molecule. The ΔFη\eweq increases linealy with the molecular volume, irrespective of the position of the hydroxyl group.
Stabilities in Water and Transfer Activity Coefficients from Water to Nonaqueous Solvents of Benzo-18-crown-6–Metal Ion Complexes
Authors: Takeda Yasuyuki , Kohno Rie , Kudo Yoshihiro , Fukada Naoaki 
Published: July 2006

Abstract
Formation constants in water of 1:1 benzo-18-crown-6 (B18C6)–metal ion complexes and the B18C6 solubility in water were determined at 25 °C by conductometry or potentiometry with ion-selective electrodes and spectrophotometry, respectively. The selectivity sequences of B18C6 for metal ions in water are Pb2+&gt;Ba2+&gt;Sr2+&gt;Ag+&gt;K+&gt;Tl+&gt;Na+&gt;Rb+. In each case of alkali and alkaline earth metal ions, the more closely a metal ion fits into the B18C6 cavity, the more stable is the B18C6–metal ion complex. Although the solvation power of water for an alkali metal ion is not the largest of all solvents, the formation constant of a given B18C6–alkali metal ion complex in water is by far the smallest of all solvents. The transfer activity coefficients (γ) from water to nonaqueous solvents of the B18C6–metal ion complexes were then calculated from the formation constants of the B18C6 complexes, γ values of B18C6 (obtained from solubilities of B18C6), and γ values of the uncomplexed metal ions. The γ value of B18C6 is larger than those of B18C6–alkali metal ion complexes. This shows that when B18C6 forms a complex with an alkali metal ion, the B18C6 complex becomes more soluble in nonaqueous solvents than in water, compared with uncomplexed B18C6.