bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermochemical Treatment of Radiata Pine (Pinus radiata) Bark with Hydrogen Peroxide Solutions at Temperatures Higher than 100 °C
Authors: Inoue Seiichi , Ogi Tomoko , Yazaki Yoshi 
Published: December 2004

Abstract
Radiata pine bark was treated with 0—15% hydrogen peroxide (H2O2) solutions at temperatures higher than 100 °C, and fractionated into water soluble, insoluble, and gas fractions. The distribution of these fractions was calculated on the basis of weight and carbon content, and compared with the aim of finding the optimum conditions for efficiently obtaining water-soluble materials for producing wood adhesives. The yield of water-soluble materials was significantly dependent on the temperature and the concentration of H2O2 solution. The highest yields of water-soluble materials (47.4 and 47.9% on the basis of weight and carbon content, respectively) were obtained with 15% H2O2 solution at 120 °C. The yield increased with increasing temperature up to 120 °C and then decreased at higher temperatures. Under the latter conditions, gases such as CO2 and CO were generated. When the bark was treated with 15% H2O2 solution at 140 °C, an exothermic reaction took place and 47.4% of the carbon of the bark was converted into gases. At the same time, most of the H2O2 was decomposed. The water-soluble fraction mainly consisted of low molecular weight acidic components, which are degaradated and oxygenated products of lignin and polyflavanoids. This bark solubilization process consists of very complicated combinations of various reactions. Many organic compounds, other than acids, might be present in the water-soluble fraction. The water-insoluble material is the oxygenated cellulose compound.
Photoionization and Ion Pair Formation of N,N-Diethyl-p-phenylenediamine in Various Polar Solvents
Authors: Hirata Yoshinori , Kawashima Osamu 
Published: December 2004

Abstract
By using transient absorption and photoconductivity measurement techniques, we have investigated the photoionization process of N,N-diethyl-p-phenylenediamine in various polar solvents. Significant excitation wavelength and excitation intensity effects were observed in alcoholic solvents. The slowly rising component of the photoconductivity in hundreds of nanoseconds or longer time scale is ascribed to the dissociation of the monophotonically produced ion pairs. In addition, a photoconductivity signal that has almost the same duration as the excitation laser pulse and is due to the geminate pair formed via the two-photon ionization is clearly observed with the 248-nm excitation. On the other hand, the biphotonic process was negligible with the 351-nm excitation in ethanol and 1-propanol. The monophotonically formed long-lived ion pair did not contribute to the conductivity. The long lifetime of the ion pair indicates that not only the Coulombic interaction but also the exciplex-like specific interaction is important.
The Photovoltaic Mechanism of a Polythiophene/Perylene Pigment Two-Layer Solar Cell
Authors: Nakamura Jun-ichi , Suzuki Shinji , Takahashi Kohshin , Yokoe Chiho , Murata Kazuhiko 
Published: December 2004

Abstract
The energy conversion efficiency of a two-layer organic solar cell consisting of a perylene pigment (PV) and regioregular polythiophene polymer (P3DT) was 0.99% under illumination with simulated solar light (AM 1.5–100 mW cm−2). The photovoltaic mechanism is discussed on the basis of the ionization potential of the component materials. The photoinduced hole-transfer from PV to P3DT quickly occurred at the PV/P3DT interface because of the large free energy change of 1.2 eV, then the subsequent charge separation efficiently proceeded, resulting in a large short-circuit photocurrent of 6.5 mA cm−2. On the other hand, the open-circuit photovoltage was only 0.42 V because the LUMO level of PV is close to the HOMO level of P3DT. The difference between the LUMO and the HOMO can be attributed to the open-circuit photovoltage.
Electron-Transfer Kinetics of Nitroxide Radicals as an Electrode-Active Material
Authors: Suga Takeo , Pu Yong-Jin , Oyaizu Kenichi , Nishide Hiroyuki 
Published: December 2004

Abstract
The electron-transfer rate constants of nitroxide derivatives, 4-(N-t-butyl-N-oxylamino)-t-butylbenzene, 4-(N-t-butyl-N-oxylamino)methoxybenzene, and 2,2,6,6-tetramethylpiperidinyl-N-oxyl, were investigated by electrochemical methods, which demonstrated that these radicals can potentially be used as a high power-rate electrode-active material due to their fast electron-transfer process.
A New Synthetic Method for Dipeptides Containing α,β-Didehydroamino Acids Utilizing an α-Tosylglycine Residue
Authors: Shiraishi Yohsuke , Yamauchi Hiroshi , Takamura Takashi , Kinoshita Hideki 
Published: December 2004

Abstract
The reaction of peptides containing an N-Boc- or N-Z-α-tosylglycine residue at the N-terminus with a variety of excess nitro compounds under basic conditions to give the nitro compound-adducts in good yields, followed by the elimination of nitrous acid from the adducts to afford the corresponding dipeptide containing α,β-didehydroamino acids with (Z)-configuration predominantly. Treatment of the same starting materials with aldehydes in the presence of base and tributylphosphine also gave a dipeptide containing α,β-didehydroamino acids with high (Z)-selectivity in satisfactory yields. The present method can be successfully applied to the synthesis of a protected leucine enkephalin analog.
Synthesis and Stereochemistry of N-Phenyl-N-9-triptycylhydroxylamine Derivatives and Related Compounds
Authors: Agawa Chiharu , Otsuka Keiko , Minoura Mao , Mazaki Yasuhiro , Yamamoto Gaku 
Published: December 2004

Abstract
During the course of attempts at synthesis of N-phenyl-N-9-triptycylhydroxylamine (1), we found that the reaction of N-9-triptycylhydroxylamine (5) with benzenediazonium-2-carboxylate afforded 3-(2-carboxyphenyl)-1-(9-triptycyl)triazene 1-oxide (6), the structure of which was confirmed by X-ray crystallography. Oxidation of N-(9-triptycyl)aniline (4) with mCPBA gave phenyl 9-triptycyl nitroxide (7) and N-(9-triptycyl)-1,4-benzoquinonimine (8) in small yields. Reduction of 7 with phenylhydrazine gave 1, and O-ethylation of 1 gave O-ethyl-N-phenyl-N-9-triptycylhydroxylamine (2). Results of X-ray crystallography for compounds 2, 4, 7, and 8 and results of dynamic NMR studies for 1, 2, and 8 are presented. In compound 8, Tp–N rotation and C=N topomerization took place on the NMR timescale at high temperatures above 60 °C, and the energy barriers to both processes were obtained. In compounds 1 and 2, dynamic NMR behavior was observed at very low temperatures below ca. −50 °C, and the energy barriers to the respective processes could not be determined except for those related to “Ph-passing”.
A Water-Soluble Phospholipid Polymer as a New Biocompatible Synthetic DNA Carrier
Authors: Sakaki Shujiro , Tsuchida Mamoru , Iwasaki Yasuhiko , Ishihara Kazuhiko 
Published: December 2004

Abstract
The purpose of this work was the preparation of a water-soluble DNA complex with a biocompatible phospholipid polymer for delivering DNA into a target cell. The phospholipid polymer, poly[2-methacryloyloxyethyl phosphorylcholine (MPC)-co-2-aminoethyl methacrylate (AEMA)] (poly(MPC-co-AEMA)), was synthesized and the functions of poly(MPC-co-AEMA) as a DNA carrier were compared with those of a conventional cationic DNA carrier such as poly(l-lysine). We investigated the toxicity of these polymers and the water solubility, structures, and nuclease resistance of the associated DNA/polymer complexes. An evaluation of toxicity in a colony forming test using Chinese hamster fibroblast cells (V-79 cells) indicated that the toxicity of poly(MPC-co-AEMA) is about 40% of that of poly(l-lysine). In the case of a salmon sperm DNA/poly(l-lysine) complex, a water-insoluble precipitate formed. In contrast, the DNA/poly(MPC-co-AEMA) complex was completely water-soluble. Although the DNA/poly(l-lysine) complex did not provide a CD spectrum, the DNA/poly(MPC-co-AEMA) complex did. DNase I hardly degraded the DNA in the DNA/poly(MPC-co-AEMA) complex. To demonstrate the transient expression of β-galactosidase, a plasmid DNA/poly(MPC-co-AEMA) complex was incubated with V-79 cells with chloroquine treatment. Under a phase-contrast microscope after 5-bromo-4-chloro-3-indolyl-β-d-galactopyranoside (X-gal) staining, more stained cells due to the transient expression of β-galactosidase were observed in a sample with the poly(MPC-co-AEMA) complex than in a sample with the poly(l-lysine) complex. From these results came the following conclusions: poly(MPC-co-AEMA) is a useful water-soluble polymer that can form a complex with DNA, and DNA/poly(MPC-co-AEMA) has good potential for DNA delivery into cells.
Free Energy Perturbation Studies on Enantiomeric Discrimination of Pyridino-18-Crown-6 Ethers
Authors: Hwang Sungu , Lee One-Sun , Chung Doo Soo 
Published: December 2004

Abstract
We performed FEP and MD simulations on enantiomeric complexes of seven 18-crown-6 ether compounds and a chiral protonated amine to obtain the free energy differences, and to elucidate the mechanism responsible for enantioselectivity. The FEP calculation reproduced the experimental enantioselectivity quite well. We partitioned the binding free energy in solution into the binding free energy in the gas phase and the solvation energy, and discussed the results. In the MD simulations, the detailed motion of host–guest complexes was monitored.
Carrier Mobility of Discotic Lamellar Mesophases of 5,10,15,20-Tetrakis(4-n-pentadecylphenyl)porphyrin
Authors: Monobe Hirosato , Mima Shoji , Shimizu Yo 
Published: December 2004

Abstract
The carrier mobility of discotic lamellar mesophases was evaluated by Time-of-Flight (TOF) method for mesogenic 5,10,15,20-tetrakis(4-n-pentadecylphenyl)porphyrin and was found to be in the order of 10−4 cm2 V−1 s−1. In spite of the higher order of molecular orientation in the lamellar mesophases, it is comparable with that of hexagonal disordered columnar mesophase. This is the first report of charged carrier mobility of a discotic lamellar mesophase.
A Ruthenium(II)-Pyridylamine Complex Showing a Fluxional Intramolecular π–π Interaction
Authors: Kojima Takahiko , Hayashi Ken-ichi , Matsuda Yoshihisa 
Published: December 2004

Abstract
A novel ruthenium(II) complex having 2-naphthoylamide groups attached to TPA (tris(2-pyridylmethyl)amine) was synthesized and characterized; the 2-naphthoylamide arms exhibited fractional behavior of intramolecular π–π interaction.
Lithium Tetrakis(pentafluorophenyl)borate-Catalyzed Friedel–Crafts Benzylation Reactions
Authors: Mukaiyama Teruaki , Nakano Masakazu , Kikuchi Wataru , Matsuo Jun-ichi 
Published: December 2004

Abstract
Lithium tetrakis(pentafluorophenyl)borate [LiB(C6F5)4], a neutral salt, effectively catalyzed Friedel–Crafts benzylation reactions of aromatic compounds with benzyl chloride or mesylate and their substituted derivatives. The LiB(C6F5)4-catalyzed reactions proceeded more efficiently in the coexistence of magnesium oxide.
Molecular Networks Consisting of Dumbbell-cage Motif: Structure and Anion Exchangeability of [Ag(Py2S)2·BF4]n (Py2S = 4,4′-Dipyridyl Sulfide)
Authors: Jung Ok-Sang , Park Sung Ho , Lee Young-A , Lee Uk 
Published: December 2004

Abstract
The silver(I) network with Py2S has the face-to-face (π–&#960;) interactions to generate unusual dumbbell-cage motif. The BF4− counteranion within each cage has been reversibly exchanged with the similar anions in size.
Functional Flavin Receptors. Bis-melamine Derivatives Bearing a Guanidinium Ion Which Bind 6-Azaflavin and a Thymine-Linked Substrate through Hydrogen Bonds in Chloroform
Authors: Hayashi Tomohiro , Fujimoto Akihide , Kajiki Takeshi , Kondo Shin-ichi , Yano Yumihiko 
Published: December 2004

Abstract
Bis-melamine derivatives bearing a guanidinium ion bind 6-azaflavin via five hydrogen bonds and an NADH model having a thymine moiety via three H-bonds in CHCl3, resulting in the rate acceleration due to the proximity effect.
Photoimages Formed by Lyotropic Liquid Crystals
Authors: Ichimura Kunihiro , Momose Masayuki , Fujiwara Takenori 
Published: December 2004

Abstract
The orientation of lyotropic liquid crystals consisting of about 90 wt% water is controllable on thin films of a polymer with azobenzene side chains, which are exposed to linearly polarized light, to give rise to thermally stable birefringent photoimages.
Lipophilic Peptide as Novel Sensory Material for Chiral Amine Recognition
Authors: Mathew Beena , Kuboyama Toshiharu , Nakamura Shigeo , Takagi Makoto 
Published: December 2004

Abstract
Chiral recognition of chiral amines 4–10 by lipophilic peptide derivatives 1–3 was studied spectrophotometrically in chloroform. Peptide 3 as compared with 2 indicated greater binding affinity and enantiomer selectivity towards the (R)-isomer of 4 and 6. Also 3 showed strikingly high binding and diastereoselectivity towards 9 and 10.
Induced Codeposition of Al–Mg Alloys in Lewis Acidic AlCl3–EMIC Room Temperature Molten Salts
Authors: Morimitsu Masatsugu , Tanaka Nobutada , Matsunaga Morio 
Published: December 2004

Abstract
Voltammetric measurements and elemental analyses of electrodeposits have revealed the induced codeposition of Al–Mg alloys in acidic AlCl3–EMIC melts containing MgCl2.
Nanosphere of Ordered Silica MCM-41 Hydrothermally Synthesized with Low Surfactant Concentration
Authors: Cai Q , Cui F Z , Chen X H , Zhang Y , Luo Z S 
Published: December 2004

Abstract
Nanospherical MCM-41 silica has been hydrothermally synthesized for the first time in the sodium hydroxide medium with low surfactant concentration. The average size of the nanosphere is about 105 nm.
113Cd MAS NMR Study of Cadmium Halides and Their Salts
Authors: Sakida Shinichi , Kawamoto Yoji 
Published: December 2004

Abstract
113Cd magic-angle spinning (MAS) NMR spectra have been measured of twenty-three kinds of Cd2+-containing halide crystals with known structures to determine the isotropic chemical shifts δiso. The δiso values of halogen coordination polyhedra largely changed with the kind and the coordination number of halogen. The relationship between the δiso values and the halogen coordination environments around Cd2+ was revealed.
Chiral Recognition of α-Amino Esters on the Chiral Helical Surface of Zinc Bilinone
Authors: Yagi Shigeyuki , Sadachi Hidetoshi , Kashiwagi Yukiyasu , Takagishi Toru , Mizutani Tadashi , Kitagawa Susumu , Ogoshi Hisanobu 
Published: December 2004

Abstract
Chiral recognition of α-amino esters was examined using the homochiral helical dimer of the zinc complex of linear tetrapyrrole (zinc bilinone) as a host. 1H NMR and thermodynamic studies indicated that favorable (Phe–Ome and Leu–Ome) or unfavorable (Asp–(Ome)2) interactions of the side chain of α-amino esters with zinc bilinone lead to enantioselectivity.
Effect of pKa of Polymer Microcarriers on Growth of Mouse L Cell
Authors: Sakata Masayo , Kato Dai , Uchida Masahiro , Todokoro Masami , Mizokami Hiroshi , Furukawa Shinichi , Kunitake Masashi , Hirayama Chuichi 
Published: December 2004

Abstract
In order to obtain fundamental information about the electrostatic effect of microcarriers on fibroblastic cell growth, the aminated poly(γ-methyl l-glutamate) and the cross-linked poly(ε-lysine) beads were prepared. When the growth of mouse L cell on the various beads were determined by common cell culture methods, it strongly depends on the apparent pKa of the beads but not on their amino-group content. The polymer beads with neutral apparent pKa (7.4–7.6), just as in the physiological environment, were found to be excellent microcarriers, showing the highest growth of fibroblastic cells.
Nitrosyl Iron(II) Complex of meso-Tetrakis(α,α,α,α-o-pivalamidophenyl)porphyrin with a Covalently Linked 2-Methylimidazolylalkyl Group
Authors: Komatsu Teruyuki , Matsukawa Yasuko , Tsuchida Eishun 
Published: December 2004

Abstract
meso-Tetrakis(α,α,α,α-o-pivalamidophenyl)porphinatoiron(II) with an intramolecularly bound 2-methylimidazole forms a six-coordinate nitrosyl complex in toluene at 298 K, which is revealed by ESR and IR spectroscopy; the NO-binding affinity (P1/2) is 1.8 × 10−8 Torr and the association rate constant (kon) is 8.9 × 108 M−1s−1.
Easy Preparation and Prominent Gelation of New Gelator Based on l-Lysine
Authors: Hanabusa Kenji , Nakayama Hiroko , Kimura Mutsumi , Shirai Hirofusa 
Published: December 2004

Abstract
A new prominent gelator 1, Nε-lauroyl-Nα-stearylaminocarbonyl-l-lysine ethyl ester was effortlessly prepared by esterification of Nε-lauroyl-l-lysine and addition of n-octadecyl isocyanate in a total yield of 89%. Gelator 1 was capable of gelling up a wide variety of organic fluids. A comparison of the gelation ability of structurally related compounds clarified that not only the introduction of long-chain alkyl but also more importantly the ureylene segment connecting the α-amino group and the alkyl chain are required for effective gelation.
A Novel, Efficient, and Selective Cleavage of Acetals Using Bismuth(III) Chloride
Authors: Sabitha Gowravaram , Babu R Satheesh , Reddy E Veakata , Yadav J S 
Published: December 2004

Abstract
Treatment of acetals with bismuth(III) chloride in methanol provides a simple, convenient and chemoselective process for deprotection, and the parent aldehyde or ketone was obtained in high yield. The acetals have been cleaved selectively in the presence of silyl, benzyl and tetrahydropyranyl ethers.
A Novel Hydrogen-Bonded Duplex Made up of Water Molecules and Halide Ions in the Sandwich Inclusion Structures of (C10H8N3S)+·X·2H2O [X = Cl−, Br−]
Authors: Prabakaran Ponraj , Murugesan Somasundaram , Robert Jebamony Justin , Panneerselvam Pathus , Muthiah Packianathan Thomas , Bocelli Gabriele , Righi Lara 
Published: December 2004

Abstract
The X-ray crystal structures of thiabendazolium halide dihydrates (C10H8N3S)+·X·2H2O [X = Cl−, Br−] 1, 2 reveal a novel hydrogen-bonded duplex consisting of alternate edge-sharing (H2O·X)2 quadrilaterals and (2H2O·X)2 hexagons; notably these duplexes exist as host lattices and sandwich thiabendazole molecules into two different supramolecular architectures by similar N···X and N···O hydrogen bonds.
Stereochemistry of N-Ethyl-N-9-triptycylhydroxylamine and Its O-Alkyl Derivatives
Authors: Yamamoto Gaku , Nakajo Fusako , Endo Naoka , Mazaki Yasuhiro 
Published: December 2004

Abstract
Static and dynamic stereochemistry of the title compounds was studied by X-ray crystallography and variable-temperature NMR. Stereomutation in solution was quantitatively analyzed in terms of two rate processes in which the nitrogen substituents pass over one of the benzene rings of the triptycene skeleton.
Preparation of Silica-Coated Rhodium Nanoparticles Using Water-in-Oil Microemulsion
Authors: Kishida Masahiro , Tago Teruoki , Hatsuta Takatoshi , Wakabayashi Katsuhiko 
Published: December 2004

Abstract
Monodispersed silica-coated rhodium nanoparticles were synthesized by using the w/o microemulsion of polyoxyethylene (15) cetyl ether / cyclohexane / water system. By hydrolysis of tetraethyl orthosilicate in the presence of rhodium complex nanoparticles followed by thermal treatment, the silica-coated metallic rhodium nanoparticles were obtained in the microemulsion. In the composite nanoparticles, a metallic rhodium particle with a diameter of 4 nm was located nearly at the center of a spherical silica particle. The thickness of silica layer was 14 nm.
Dipolar Cycloaddition Reactions of Isatin Derived Azomethine Ylide with 3,4-Diphenylcyclobutene-1,2-dione: Synthesis of Novel Spiro[oxindole-3,2′-pyrrolidine] Derivatives
Authors: Nair Vijay , Sheela K C , Rath Nigam P 
Published: December 2004

Abstract
Azomethine ylide, generated by the decarboxylative condensation of sarcosine with isatins has been trapped by 3,4-diphenylcyclobutene-1,2-dione to afford novel spiro[oxindole-3,2′-pyrrolidine] derivatives.
Reaction between Conjugated Azoalkenes and Pyrazolinones: A Precious Entry to New Conjugated Azodiene and Asymmetric 4,4′-Bipyrazole Derivatives
Authors: Attanasi Orazio A , Filippone Paolino , Fiorucci Chiara , Mantellini Fabio 
Published: December 2004

Abstract
The first direct nucleophilic addition under mild reaction conditions of heterocyclic compounds to conjugated azoalkenes is reported. This reaction readily gives rise to new conjugated azodiene or asymmetric 4,4′-bipyrazole derivatives by means of two independent pathways.
The First Study on the Mobility of Surface-Adsorbed Molecules Using 1H NMR Spin–Lattice Relaxation Time
Authors: Mohri Taizo , Nakahara Yoshio , Zhang Wanbin , Nakatsuji Yohji , Muneishi Toshiko , Miyaji Yoko , Ikeda Isao 
Published: December 2004

Abstract
The function of alkanoic acid amine salt adsorbed onto the pigment surface was examined by means of 1H NMR spin–lattice relaxation time using a high-resolution magic angle spinning (MAS) 1H NMR probe called 1H Nano·nmrTM Probe. The adsorption mechanism of the salt to the pigment was discussed on the bases of the results.
Synthesis of Na2[Fe6(OCH2CH2OCH3)18 (μ6-O)]: Its Sol–Gel Application to Sr2FeMoO6
Authors: Chae Hee K , Hwang Chulsoon , Dong Yongkwan , Yun Hoseop , Jang Ho G 
Published: December 2004

Abstract
An air-stable iron cluster alkoxide complex Na2[Fe6(OCH2CH2OCH3)18(µ6-O)] was prepared from the reaction of iron(III) chloride and sodium 2-methoxyethoxide. The complex was used to prepare Sr2FeMoO6, which spin-coated film shows a very high positive magnetoresistance of 25% with a magnetic field of 0.8 T at 300 K.
Electrochemical aspects of radiolytically enhanced UO2dissolution
Authors: Grambow Bernd , Mennecart Thierry , Fattahi M. , Blondiaux G. 
Published: December 2004

SummaryExperiments were performed, irradiating UO2colloids of 3 nm diameter by a 5 MeV alpha beam of a cyclotron. Both the dissolution rate of these colloids and the production rate of hydrogen peroxide have been measured. The experimentally measured corrosion rate of these colloids is very similar to the corrosion rates measured for bulk UO2samples, indicating on the one hand that similar reaction mechanism prevail and on the other hand that the UO2colloids are well representative for bulk UO2. The results were compared with two current models for radiolytical dissolution of spent fuel. Additionally a new coupling between water radiolysis reactions and spent fuel dissolution has been established. The coupling is not anymore based on rate constants for direct reaction of oxidants with UO2, but on the electrochemical coupling of anodic dissolution reactions with cathodic reduction of molecular and radical radiolysis products. The model not only describes well the experimental data, it also allows to predict both the establishment of corrosion potentials and of fractional reaction orders with respect to oxidant concentrations. Model results can also be compared with experimental data (corrosion potential ...) using UO2as an electrode.
Effect of alpha radiolysis on doped UO2 dissolution under reducing conditions
Authors: Mennecart Thierry , Grambow Bernd , Fattahi M. , Andriambololona Z. 
Published: December 2004

Summary
The aim of the present work is to quantify the influence of alpha radioactivity of 225Ac doped UO2 on the dissolution rate under reducing conditions at pH 6. The doped or undoped material was prepared by precipitation and the size of particles was about 3 nm. The total alpha activity of the doped material was about 2000 MBq g-1 UO2, about 4 times higher than that of 15 years old spent fuel. The solution was kept under reducing conditions during the experiment by permanent electrochemical reduction under inert atmosphere. The results showed that the dissolution rate of doped material was a function of alpha activity and thus a function of the dose.