bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaporation Rate Measurement of Water and Liquid 1-Alkanols across Air–Liquid Interface Using Thermogravimetry
Authors: Rusdi Muhammad , Moroi Yoshikiyo 
Published: May 2003

Abstract
Evaporation rate measurements of water across air/water interface were made by using a thermogravimetry technique. A sample liquid was held in a partially filled, open-topped pan in a furnace tube, through which dry air was flowing. The effect of the flow rate of the dry air on the evaporation rate was very large at lower flow rates, while it became smaller at higher flow rates. The evaporation rate of water over the temperature range 298.2–333.2 K was studied in order to obtain the activation energy for the evaporation. The energy was found to decrease with increasing temperature. A newly developed equation was used to analyze the evaporation rate. Purified liquid 1-alkanols (carbon number = 4, 6, 8, 10, and 12) were employed as test substances in order to estimate the effects of terminal –CH2OH group and of residual CH2 groups on the activation energy. The contribution of –CH2OH group to the activation energy was found to slightly decrease with increasing temperature, while the contribution of residual CH2 group increased with increasing chain length; the temperature-dependence remained almost the same irrespective of the alkyl chain.
Detection of Ascorbic Acid in an Ethanol–Water Mixed Solution on a Conductive Diamond Electrode
Authors: Komatsu Masaharu , Fujishima Akira 
Published: May 2003

Abstract
Conductive boron-doped diamond thin-film electrodes have been shown to be highly suitable as electrochemical detectors in flow injection analysis (FIA) due to the lack of electrode deactivation due to fouling and the ability to withstand highly positive electrochemical potentials. In the present work, a diamond electrode was applied to the detection of ascorbic acid (AA) in an alcohol–water mixed solution. During FIA of AA in an ethanol (EtOH)–water solution including 0.1 M NaClO4, the interference from EtOH oxidation that would have been observed with a Pt electrode was avoided, and the amperometric response for AA was observed with the use of a conductive diamond as the electrode material. Moreover, The detection limit for AA that could be observed was lower than that for a glassy carbon electrode, because diamond exhibits a lower background current, smaller background noise, and smaller injection noise. These findings suggest that the diamond electrode may be applied in the detection of other redox-active impurities and added substances in alcohol or alcohol–water solutions, such as chlorophyll, nicotinamide, caffeine, riboflavin, and dl-α-tocopherol.
Hydration Structure of Alanine Molecule in Concentrated Aqueous Solutions
Authors: Kameda Yasuo , Sugawara Kentaro , Usuki Takeshi , Uemura Osamu 
Published: May 2003

Abstract
Time-of-Flight (TOF) neutron diffraction measurements have been carried out on aqueous 3 mol% d,l-alanine solutions. The isotopic substitution technique has been applied to both nitrogen and methyl-hydrogen atoms within the alanine molecule in order to obtain information concerning the hydration structure around the amino- and the methyl groups within the alanine molecule in the aqueous solution. There exist, on the average, 2.4(1) water molecules that are hydrogen bonded to the amino group with an intermolecular distance of rNO = 2.88(2) Å. The tilt angle between the N–D···O axis and the molecular plane of the D2O molecule has been determined to be 60.4(5)°. The first hydration shell of the methyl group involves ca. two water molecules per one alanine molecule. The nearest neighbor HM(methyl)–OW(water) and HM(methyl)–HW(water) distances have been determined to be 2.58(1) and 2.99(2) Å, respectively.
Electronic and Magnetic Properties of Organic Conductors (DMET)2MBr4 (M = Fe, Ga)
Authors: Enomoto Kengo , Yamaura Jun-Ichi , Miyazaki Akira , Enoki Toshiaki 
Published: May 2003

Abstract
(DMET)2MBr4 (M = Fe, Ga) are isostructural organic conductors whose crystal structure consists of an alternate stacking of quasi one-dimensional chain-based donor layers and anion square lattices. The resistivity, ESR, magnetic susceptibility, magnetization, and magnetoresistance of these salts were investigated in order to clarify the correlation between the electronic structure and the magnetism. The electronic structures of both salts are metallic down to TMI ∼40 K, below which a Mott insulating state is stabilized, accompanied by an SDW transition at TSDW ∼25 K. The FeBr4 salt with Fe3+ (S = 5/2) localized spins undergoes an antiferromagnetic transition at TN = 3.7 K. In the FeBr4 salt, the magnetization curves, which show field-direction-dependent anomalies in addition to a spin-flop transition, are demonstrated to have a participation of donor π-electron spins in the magnetization processes. The field dependence of the magnetoresistances below TN tracks faithfully that of the magnetization, where the donor π-electrons and Fe3+ d-electrons are responsible for the former and the latter, respectively. This clearly demonstrates the presence of the π–d interaction that plays an important role in the interplay between electron transport and magnetism.
Photophysical and Photochemical Processes of Poly(methylphenylsilane) Functionalized with Pendant p-Nitroazobenzene Groups
Authors: Zhao Changli , Horiuchi Hiroaki , Okutsu Tetsuo , Tobita Seiji , Takigami Shoji , Hiratsuka Hiroshi 
Published: May 2003

Abstract
The synthesis of poly(methylphenylsilane) functionalized with pendant p-nitroazobenzene groups (PMPS-azo) has been carried out, and their photophysical and photochemical processes have been studied. The fluorescence quantum yields of PMPS-azo decrease with an increase of the amounts of the pendant p-nitroazobenzene groups. The picosecond fluorescence decay kinetics of PMPS-azo was interpreted in terms of not only the energy transfer, but also the electron transfer from the Si–Si main chain to the pendant p-nitroazobenzene group. The evidence for intramolecular electron transfer was provided by the formation of the radical anion of the pendant trans-p-nitroazobenzene group upon steady-state photolysis of PMPS-azo at 77 K.
Appearance of Phosphate-Selectivity by Hydrolytic Trimerization of Simple Dialkyltin(IV) Compounds Used as Carrier
Authors: Yuchi Akio , Kani Shinpei , Suzuki Takashi , Hattori Hiroyuki 
Published: May 2003

Abstract
The complexation equilibria of dimethyltin(IV) and trimethyltin(IV) ions with several anions in aqueous solutions were potentiometrically studied as a model of the interaction of lipophilic dialkyltin(IV) and trialkyltin(IV) compounds, the carriers of ion-selective electrodes, with anions in the membrane phase. Phosphate and arsenate reacted with dimethyltin(IV) ion to yield partially hydrolyzed trimeric species, [(SnMe2)3(OH)2(HPO4)2] and [(SnMe2)3(OH)2(HAsO4)2]. Such oligomerization, which ensures the interaction of phosphates or arsenate with two Sn centers, is also possible for lipophilic dialkyltin(IV) compounds. Moreover, shielding these anions from the solvent by lipophilic alkyl groups projected from Sn atoms may enhance the distribution of the carrier-anion associates into the membrane phase. These cooperate to give lipophilic dialkyltin(IV) compounds with high selectivities to these ions. The presence of such electroactive species in the membrane phase was discussed with reference to the previous studies.
Synthesis and Photochemical Properties of Novel Ruthenium(II)-Nickel(II) and Ruthenium(II)-Copper(II) Dinuclear Complexes
Authors: Onozawa-Komatsuzaki Nobuko , Katoh Ryuzi , Himeda Yuichiro , Sugihara Hideki , Arakawa Hironori , Kasuga Kazuyuki 
Published: May 2003

Abstract
Novel Ru(II)-Ni(II) and Ru(II)-Cu(II) dinuclear complexes have been synthesized and characterized. In these complexes, the ruthenium(II) polypyridyl group and the Ni(II)- or Cu(II)-Schiff base units are fused together by a bridging ligand, 5,6-di(salicylidenamino)-1,10-phenanthroline. X-ray crystallography on the Ru(II)-Ni(II) dinuclear complex shows that the Ni(II)-Schiff base unit is distorted against the plane of the phenanthroline ring due to the effect of a steric repulsion between the phenanthroline ring and the Ni(II)-Schiff base unit. The properties of the excited states of the dinuclear complexes are discussed by comparing them with that of the Ru(II)-Zn(II) analogue as a reference compound. These complexes show the emission from the excited state, which is assigned to MLCT0 (the excited state due to the transition from Ru(II) to the bridging ligand). For the Ru(II)-Cu(II) complex, the lifetime of the emission is found to be 80 ns, which is identical to that of the Ru(II)-Zn(II) analogue, suggesting that no quenching process exists. On the contrary, for the Ru(II)-Ni(II) complex, the emission decays very rapid. The energy transfer to the Ni(II)-Schiff base unit deactivates the MLCT0 excited state.
Preconcentration of Catecholamines into Liposomes with Imposed pH Gradients
Authors: Ishida Akihiko , Ikemoto Manabu , Ishida Yoshiki , Kamidate Tamio 
Published: May 2003

Abstract
The preconcentrations of epinephrine (EP) and norepinephrine (NE) into phosphatidylcholine liposomes with imposed pH gradient across the membrane were investigated by adding the catecholamine (CA) to the external medium of liposomes. To determine the CAs entrapped into liposomes, a simple method was also developed, based on the adsorption of CAs onto alumina and chemiluminescence detection. The uptake of the CAs into the liposomes was examined over a wide ΔpH range of 0–5 units (internal pH 5.0). The maximum uptakes of EP and NE were 70% and 88%, respectively, around an external pH of 9 (ΔpH 4), where zwitterionic species of EP and NE are dominant. The final concentrations of EP and NE in internal volumes were 34- and 43-fold greater than the initial concentrations of EP and NE, respectively. The uptake of the CAs was studied by using a mathematical model, which indicates that the uptake is contributed by the molar fraction of the zwitterion species in the external volume as well as the pH gradient. The uptake of EP was found to suffer from a steric hindrance due to a methyl group substituted for the hydrogen of the amino group. This study proves the capability of the liposomes for accumulation media of CAs.
Synthesis and Crystal Structure of N-Heterocyclic Carbene Complexes of Bis(η5-cyclopentadienyl)molybdenum
Authors: Yamaguchi Yoshitaka , Oda Ryoji , Sado Katsunori , Kobayashi Kimiko , Minato Makoto , Ito Takashi 
Published: May 2003

Abstract
The one-pot reaction of [Mo(η5-C5H5)2(H)(OTs)] (1) with 1,3-diisopropylimidazolium chloride (IiPr·HCl, 2a) in the presence of two equivalents of KOtBu in THF gave a bis(η5-cyclopentadienyl)molybdenum derivative bearing the 1,3-diisopropylimidazol-2-ylidene ligand, [Mo(η5-C5H5)2(IiPr)] (3a). 1,3-Dimethyl- and 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene coordinated molybdenocene complexes (3b, 3c) were prepared in a similar fashion (Method A). The treatment of [Mo(η5-C5H5)2(H)Li]4 (6-Mo) with the corresponding imidazolium salt in THF under photo-conditions also gave carbene complexes 3a–3c (Method B). X-ray crystal structure analyses of 3a and 3b revealed that the N-heterocyclic carbene ligand is bonded to a bent molybdenocene skeleton. The Mo–C(carbene) bond distances are 2.219(7) Å for 3a and 2.212(6) Å for 3b. The five-membered carbene ligand in both complexes is located on the bisecting plane between two cyclopentadienyl rings.
Kinetics and Mechanism for the Metalation Reaction of 5,10,15,20-Tetrakis(pentafluorophenyl)porphyrin with Diaquabis(1,1,1,5,5,5-hexafluoropentane-2,4-dionato)nickel(II) in Supercritical Carbon Dioxide
Authors: Liu Shijun , Inada Yasuhiro , Funahashi Shigenobu 
Published: May 2003

Abstract
The nickel(II) ion incorporation reaction into 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin (H2tpfpp) to form the [Ni(tpfpp)] complex has been kinetically investigated using diaquabis(1,1,1,5,5,5-hexafluoropentane-2,4-dionato)nickel(II), [Ni(hfac)2(H2O)2], in supercritical carbon dioxide (scCO2) medium in a spectrophotometric cell at various temperatures and pressures. The metalation reaction is first order with respect to porphyrin under the conditions where [Ni(hfac)2(H2O)2] is in a large excess relative to H2tpfpp. The saturation dependence was observed for the conditional first-order rate constants as a function of the mole fraction (xNi) of the excess [Ni(hfac)2(H2O)2]. Such dependence suggests that the metalation reaction consists of a fast pre-equilibrium of the formation of the outer-sphere association between [Ni(hfac)2(H2O)2] and H2tpfpp and a first-order rate-determining nickel(II) ion incorporation into the porphyrin core. The conditional first-order rate constants kobs are well expressed by kobs = KkxNi/(1 + KxNi), where K is the equilibrium constant for the formation of the outer-sphere association and k is the first-order rate constant for the nickel(II) ion incorporation. The thermodynamic and kinetic parameters are obtained as follows: ΔH° = 14.4 ± 1.3 kJ mol−1 at 20.5 MPa, ΔS° = 133 ± 4 J mol−1 K−1 at 20.5 MPa and ΔV° = 15 ± 1 cm3 mol−1 at 333.3 K for the pre-equilibrium; ΔH≠ = 110 ± 5 kJ mol−1 at 20.5 MPa, ΔS≠ = 22 ± 16 J mol−1 K−1 at 20.5 MPa, and ΔV≠ = 81 ± 8 cm3 mol−1 at 333.3 K for the rate-determining step. The positive change in enthalpy and volume and significant positive change in entropy strongly indicate that the outer-sphere association is derived from the desolvation of reactants in scCO2.
η3-Coordination of Hexadentate N,N,N′,N′-Tetrakis(2-pyridylmethyl)ethylenediamine (tpen) to a Mononuclear fac-ReVIIO3 Center. The Isolation of a New Class of Metal-containing Ligands
Authors: Mitani Ayako , Abe Masaaki , Tsuge Kiyoshi , Sasaki Yoichi 
Published: May 2003

Abstract
Reaction of ReVOCl3(PPh3)2 with an equimolar amount of tpen affords fac-[ReVIIO3(η3-tpenH)](ClO4)2 (1), in which the tpen ligand coordinates to the fac-ReVIIO3 center in a η3-mode, and the dangling bis(2-pyridylmethyl)amine arm in 1 is subsequently used to produce a heterobimetallic complex fac-, fac-[ReVIIO3(μ-η3:η3-tpen)ReI(CO)3](ClO4)2.
Synthetic Dioxygen-carrying Hemoprotein. Human Serum Albumin Including Iron(II) Complex of Protoporphyrin IX with an Axially Coordinated Histidylglycyl-propionate
Authors: Nakagawa Akito , Komatsu Teruyuki , Ohmichi Naomi , Tsuchida Eishun 
Published: May 2003

Abstract
Human serum albumin incorporating the iron(II) complex of protoporphyrin IX having an axially coordinated histidylglycyl-propionate formed a dioxygen-adduct complex in aqueous media (pH 7.3). The O2-binding affinity (P1/2) was 0.1 Torr at 25 °C.
Preparation and Photochemical Properties of Polyisocyanides with Regularly Arranged Porphyrin Pendants
Authors: Takei Fumie , Nakamura Sugiko , Onitsuka Kiyotaka , Ishida Akito , Tojo Sachiko , Majima Tetsuro , Takahashi Shigetoshi 
Published: May 2003

Abstract
A novel triblock polyisocyanide having free-base- and zinc-porphyrins as pendants was prepared by living polymerization with a Pt-Pd μ-ethynediyl complex as an initiator, and irradiated at 420 or 556 nm in a THF solution to cause intramolecular energy transfer from the zinc-porphyrin to the free-base-porphyrin.
Unsymmetrical n-Channel Semiconducting Naphthalenetetracarboxylic Diimides Assembled via Hydrogen Bonds
Authors: Katz Howard E , Otsuki Joe , Yamazaki Katsutoshi , Suka Atsushi , Takido Toshio , Lovinger Andrew J , Raghavachari Krishnan 
Published: May 2003

Abstract
Organic field-effect transistors have been fabricated from novel naphthalenetetracarboxylic diimides with unsymmetrical substitution. Two of these show distinct electron mobility, providing the first evidence that hydrogen bonding can be a means of producing a semiconducting morphology from organic compounds.
The SPV NO2 Gas Sensor Fabricated by Mesoporous Tin Oxide Film
Authors: Yuliarto Brian , Zhou Haoshen , Yamada Takeo , Honma Itaru , Asai Keisuke 
Published: May 2003

Abstract
A highly sensitive NO2 gas sensor was successfully fabricated by mesoporous tin oxide film based on surface photo voltage (SPV). The sensor measured the changes of the average value of AC photocurrent and has detection level as low as 1 ppm of NO2 gas.
Design and Synthesis of Two Cytotoxic Analogs of the Novel Pyrrolo[1′,2′:1,2][1,4]diazepin [7,6-b]indol-5(6H)-one Nucleus
Authors: Tsotinis Andrew , Vlachou Margarita , Kiakos Konstantinos , Hartley John A , Thurston David E 
Published: May 2003

Abstract
The design and synthesis of the two cytotoxic derivatives 15 and 16 of the novel pyrrolo[1′,2′:1,2][1,4]diazepin[7,6-b]indol-5(6H)-one nucleus is described. Readily available methyl 2-indolecarboxylates 5 and 6 are nitrosated with NaNO2 in AcOH to give the analogs 7 and 8, which are then oxidized with KMnO4 in aq. NaOH to provide the 3-NO2 acids 9 and 10. These, in turn, are subjected to amidation with (2S)-pyrrolidine-2-carboxaldehyde diethyl thioacetal in the presence of EDCI and HOBt and then to a 7-exo-trig cyclization reaction to give the target molecules 15 and 16. The new analogs were evaluated in the human leukemic K562 cell line and were shown to have micromolar potency.
Copper(II) Triflate-mediated Addition Reaction of α-Oxygenated Alkylstannanes to Imines for the Synthesis of vicinal-Amino Alcohol Derivatives
Authors: Kagoshima Hirotaka , Shimada Kohei 
Published: May 2003

Abstract
In the presence of copper(II) triflate, a novel addition reaction of α-oxygenated alkylstannanes to various kinds of imines proceeded smoothly to give the corresponding vicinal-amino alcohol derivatives in good yield.
Electrochemical Synthesis and Properties of Poly[1,4-bis(N-pyrrolylalkoxy)benzene]s with a Three-dimensional Crosslinked Structure
Authors: Ono Katsuhiko , Yamada Satsuki , Ohkita Masakazu , Saito Katsuhiro , Tanaka Shoji , Hanaichi Takamasa 
Published: May 2003

Abstract
The title polymers, which were composed of π-conjugated pyrroles and dialkoxybenzene crosslinkers, were prepared by electrochemical polymerization to afford uniform thin films. These films were characterized by cyclic voltammetry (CV), scanning electron microscope (SEM), and redox stability.
Facile Synthesis of Novel, Surface-active, Comb-like Polymeric Surfactants with Polyurethane Backbone
Authors: Takachi Kiyohiro , Ohkuwa Yuichi , Taniguchi Tatsuo , Kawaguchi Seigou , Nagai Katsutoshi 
Published: May 2003

Abstract
Novel, comb-like polymeric surfactants with polyurethane (PUSs) as the backbone, and dodecyl and polyethylene glycol (PEG) groups as the side chains were synthesized. The surface-active properties of the resulting PUSs in terms of surface tension reduction of water were found to be higher than those of polyacrylates (PASs) with the corresponding side chains.
Influence of Organic Vapors on the Self-assembly of Gold Nanoparticles at Solution-gas Interfaces
Authors: Wang Suhua , Sato Seiichi , Kimura Keisaku 
Published: May 2003

Abstract
The self-assembly of gold nanoparticles at gas/suspension interface was strongly affected by the presence of organic vapor in the gas phase. Nonpolar organic molecules in the gas phase induced spherical assembly of gold nanoparticles, while polar organic molecules favored the formation of irregular aggregates at the gas/suspension interfaces.
Facile Synthesis of 3β-Cholesterol H-Phosphonates
Authors: Xiao Qiang , Sun Jing , Ju Yong , Zhao Yufen , Cui Yuxin 
Published: May 2003

Abstract
A series of H-phosphonates of 3β-cholesterol, which are convenient precursors of various 3β-cholesterol phosphates, were synthesized in one pot by a tandem transesterification of diphenyl phosphite (DPP) with 3β-cholesterol and hydroxyl compounds.
Synthesis, Structure, and Properties of a Dibenzo-ortho-terphenoquinone. The First o-Terphenoquinone Derivative
Authors: Kurata Hiroyuki , Takehara Yuko , Kawase Takeshi , Oda Masaji 
Published: May 2003

Abstract
A dibenzo-ortho-terphenoquinone derivative, the first o-terquinone derivative, is largely deviated from coplanarity, is in a slight equilibrium with its diradical form, displays an easy rotation of the exocyclic double bonds, and shows photoresponsive switching property traceable by ESR spectroscopy.
Synthesis of Zeolite MCM-22 Using N,N,N,N′,N′,N′-Hexamethyl-1,5-pentanediaminium and Alkali Metal Cations as Structure-directing Agents
Authors: Lee Song-Ho , Shin Chae-Ho , Hong Suk Bong 
Published: May 2003

Abstract
A novel synthesis route to the high-silica zeolite MCM-22, which includes the combined use of a flexible, linear diquaternary ion N,N,N,N′,N′,N′-hexamethyl-1,5-pentanediaminium and Na+ or K+, is described. Unlike the previously known organic structure-directing agents leading to the crystallization of MCM-22 and related materials, the organic additive used here was found to locate inside both the 12-ring supercages and the sinusoidal 10-ring channels of MWW topology.
Synthesis of ZnO Nanobelts by Carbothermal Reduction and Their Photoluminescence Properties
Authors: Kong Xianghua , Sun Xiaoming , Li Yadong 
Published: May 2003

Abstract
Semiconducting ZnO nanobelts have been fabricated by carbothermal reduction process using ZnO powders mixed with graphite as starting materials at a temperature of 900 °C. SEM, TEM images and SAED show that the nanobelts are pure, thin, uniform, and single-crystalline. One strong green-light emission peak at 500 nm was observed.
Amination of Arenes with N,N-Dimethyl-2-imidazolidinone O-Methoxyacetyloxime
Authors: Baldovini Nicolas , Kitamura Mitsuru , Narasaka Koichi 
Published: May 2003

Abstract
Treatment of nucleophilic arenes with N,N-dimethyl-2-imidazolidinone O-methoxyacetyloxime and SnCl4 produced the corresponding N-arylimines, which were converted to anilines by hydrolysis with CsOH and to N-methylanilines by LiAlH4 reduction.
Synthesis of Rhodamine 6G/Cationic Surfactant/Clay Hybrid Materials and Its Luminescent Characterization
Authors: Sasai Ryo , Iyi Nobuo , Fujita Taketoshi , Takagi Katsuhiko , Itoh Hideaki 
Published: May 2003

Abstract
In order to develop the solid-state laser oscillator based on laser dye compound, the intercalation of rhodamine 6G (R6G) together with cetyltrimethylammonium cations (CTA+) into montmorillonite (Mont) interlayer space was investigated. It was found that the solid material with the light-emitting ability was prepared by cointercalating R6G and CTA+ molecules into Mont interlayer space at lower molar ratio of R6G to CTA+ molecules.
Cyclopropyl-containing Photoacid Generators for Chemically Amplified Resists
Authors: Kim Jin-Baek , Jang Ji-Hyun , Kim Hyun-Woo , Woo Sang-Gyun 
Published: May 2003

Abstract
Several cyclopropyl-containing photoacid generators (PAGs) were synthesized in order to reduce absorbance at 193 nm and induce the photobleaching effect. From the GC–mass experiment, cleavage of S–C(cyclopropyl) which is more preferential than that of S–C(phenyl) results in photobleaching effect. The resist containing cyclopropyldiphenylsulfonium triflate gave better resolution than the resist containing the conventional PAG, triphenylsulfonium triflate.