bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Absorption Spectra of Monolayers of Fluorescent Probes and the Orientations of Their Chromophores
Authors: Matsuki Kazunori , Fukutome Hideo 
Published: July 2006

Abstract
The UV absorption spectra of monolayers of 12-(9-anthrylcarbonyloxy)octadecanoic acid (12-AS), 2-(9-anthrylcarbonyloxy)hexadecanoic acid (2-AP), and 2-octadecylamino-6-naphthalenesulfonic acid (ONS) were measured at normal incidence and the polarized spectra at 45° incidence. New peaks which were absent in the spectra of their solutions were observed in the polarized spectra at 45° incidence. The orientation of their chromophores in the monolayers were investigated by means of the dichroic ratios obtained from their polarized spectra. These monolayers were found to consist of H-aggregates where chromophores are oriented nearly perpendicularly to the monolayer plane and molecules in a monomer-like state where the chromophores are rather randomly oriented. The molecular axes of 12-AS, 2-AP, and ONS were found to be oriented uniaxially against the normals of their monolayer planes in the ranges 0–7°, 0–21°, and 0–34°, respectively.
Isotope Effect on the Emission Cross Section and Translational Energy of Excited Hydrogen Atoms Produced in Electron-Hydrogen Chloride Collisions
Authors: Higo Morihide , Kamata Satsuo , Ogawa Teiichiro 
Published: July 2006

Abstract
The Balmer-α, β, γ lines of the excited hydrogen atoms (n=3, 4, 5) produced in e-HCl and DCl collisions have been measured in the energy range of 30–300 eV. The average translational energies of H* and D* are 4–5 eV at higher electron energies and 2–2.5 eV at lower electron energies; no appreciable isotope effect is found for the translational energy. The relative emission cross section of D* and H* shows an isotope effect and this effect is larger in the lower electron energy range; σD⁄σH’s are 0.74 for n=3, 0.71 for n=4 and 0.78 for n=5 at 30 eV. These results show that there are two groups of the excited hydrogen atoms and their relative cross sections vary with the electron energy. The existence of the isotope effect indicates a competing decay process in the repulsive excited states of HCl.
Synthetic Control by Internal Interaction. The Intramolecular Diels-Alder Reactions of Furan Derivatives and α, β-Unsaturated Amides
Authors: Takebayashi Toyonori , Iwasawa Nobuharu , Mukaiyama Teruaki 
Published: July 2006

Abstract
An efficient method for the acceleration of the intramolecular Diels-Alder reaction was established utilizing the internal interaction—the internal hydrogen bonding and the internal coordination of a magnesium salt. The intramolecular Diels-Alder reaction between nitrofuran derivatives and various acrylic acid derivatives give good yields of the cycloadducts when internal hydrogen bonding is present. When cyclic α,β-unsaturated amides are employed as dienophile, the corresponding cycloadducts are obtained in high yield utilizing internal coordination of a magnesium salt.
Studies of Bitter Peptides from Casein Hydrolyzate. II. Syntheses of Bitter Peptide Fragments and Analogs of BPIa (Arg–Gly–Pro–Pro–Phe–Ile–Val) from Casein Hydrolyzate
Authors: Otagiri Ken , Miyake Ichizo , Ishibashi Norio , Fukui Hiroshi , Kanehisa Hidenori , Okai Hideo 
Published: July 2006

Abstract
In order to investigate the relationship between bitterness and chemical structure of BPIa, eleven kinds of fragments and analogs of BPIa were synthesized. des–Gly2–BPIa and des-Pro4-BPIa exhibited extremely bitter taste. However, the pentapeptide (Arg–Gly–Pro–Pro–Phe) of BPIa possessed weak bitterness. The bitterness exhibition of BPIa probably derived from the spatial structure of its molecule.
Synthesis and Enzymatic Carboxylation of a Biotin-containing Peptide Representing the Coenzyme Binding Site of E. coli Acetyl–CoA Carboxylase
Authors: Kondo Hiroki , Uno Shingo , Moriuchi Fumio , Sunamoto Junzo , Ogushi Susumu , Tsuru Daisuke 
Published: July 2006

Abstract
A biotin-containing pentapeptide Boc–Glu–Ala–Met–Bct–Met (1) that corresponds to the coenzyme binding site of E. coli acetyl–CoA carboxylase has been prepared. Peptide 1 as well as free biotin served as a substrate for the carboxylation reaction catalyzed by the biotin carboxylase subunit dimer of E. coli acetyl–CoA carboxylase. The Michaelis constant, Km, and the maximum velocity, Vmax, for 1 were 18 mM and 2.8 μM min−1 (1 M=1 mol dm−3), respectively. The corresponding values for biotin were 214 mM and 28 μM min−1. Thus, the overall reactivity (Vmax⁄Km) of peptide 1 exceeded that of biotin by 20%.
ESR Studies of Unstable Six-coordinated Cobalt(II) Complexes Produced by γ-Radiolysis of Glassy Solutions at 77 K
Authors: Hoshino Mikio , Konishi Shiro , Nakajima Masao , Imamura Masashi 
Published: July 2006

Abstract
ESR spectra of γ-irradiated glassy solutions of cobalt(II) chelates of N,N′-bis(1-methyl-3-oxobutylidene)ethylenediamine (acacen) having two NH3 in the axial positions at 77 K show the formation of a metastable cobalt(II) complex in which two NH3 are forced to be confined in the axial positions.
Syntheses and Characterization of Lanthanoid(III) Propoxyacetate
Authors: Kondo Satoshi , Nagai Kiyofumi , Ouchi Akira 
Published: July 2006

Abstract
New lanthanoid(III) complexes with the formula of ML3·H2O, where M=La, Ce, Pr, Nd, Eu, Dy, or Er, and HL=propoxyacetic acid, have been synthesized; they are isostructural with each other. From the shift direction of the 1H-NMR peaks of L− in an aqueous solution upon adding Eu(III) or Pr(III) salt, the ligand is likely to be coordinated to the metal by both the ether and carboxyl oxygen atoms.
Preparation of Alkanesulfenamides by Selective Elimination of t-Butyl Group in S-Alkyl-S-t-butylsulfilimines
Authors: Yamamoto Tamotsu , Kakimoto Masa-aki , Maejima Takeshi , Okawara Makoto 
Published: July 2006

Abstract
N-Tosylalkanesulfenamides have been prepared via the reactions of alkyl halides with 2-methyl-2-pro-panethiolate followed by S-imination with chloramine T and the thermolysis. This method comprises the use of selective elimination of t-butyl group in S-alkyl-S-t-butylsulfilimines.
Fluorescence Spectrum and Its Intensity of Europium Tris(ethyl sulfate) Enneahydrate
Authors: Ohoka Tomoyuki , Kato Yoshifumi 
Published: July 2006

Abstract
The polarized fluorescence spectrum of the europium tris(ethyl sulfate) enneahydrate crystal was measured at 95 K by using excitation lines of an Ar+ laser. The multipole character of transitions and the energies and crystal quantum numbers for the crystal field components of the 7FJ(J=0, 1,···,6) and 5D0.1 terms were determined from the spectral analysis. It was ascertained that most of the transitions were due to forced electric dipole transitions but some of them due to magnetic dipole transitions, in which nine strong lines appeared as magnetic dipole radiations satisfying the selection rule for ion levels, while three weak lines were magnetic dipole radiations forbidden in ions. The relative intensities of both the forbidden electric dipole transitions and the magnetic dipole transitions were calculated by the crystal field wavefunctions obtained to reproduce the experimental data. From the comparison of the calculated intensities with the observed ones, the ratio of the populations of the 5D0 term to the 5D1 term in fluorescent process was estimated to be about 20, although the 5D0 term was 1750 cm−1 lower than the 5D1 term. The result suggested that the configuration mixing due to g-orbitals was significant to allow electric dipole transitions.
Excimer Fluorescence of 1,2-Di(9-anthryl)ethane, 1,3-Di(9-anthryl)propane, and 9,9′-Bianthryl at High Pressures
Authors: Hara Kimihiko , Katou Yoshikazu , Osugi Jiro 
Published: July 2006

Abstract
Fluorescence spectra of 1,2-di(9-anthryl)ethane (1), 1,3-di(9-anthryl)propane (2), and 9,9′-bianthryl (3) have been studied at high pressures up to 50 kbar both in crystalline state and in PMMA matrix. In the case of 1 and 2 in crystalline state, the excimer emissions appear reversibly at high pressures accompanied by the reversible red shifts. While in PMMA the fluorescence spectra assigned as locally excited state are observed, whose peak shifts are quite analogous to that of anthracene in the same matrix. As for 3, a new band also appears at high pressure which is similar to the intramolecular charge-transfer band. Possible interpretations of the pressure effects are discussed.
Kinetics of the Formation of the Intermediate Complex in the Aromatic Nucleophilic Substitution of Methyl 4-Methoxy-3,5-dinitrobenzoate with Piperidine in Dimethyl Sulfoxide
Authors: Hasegawa Yoshinori 
Published: July 2006

Abstract
The intermediate complex in the aromatic nucleophilic substitution of methyl 4-methoxy-3,5-dinitrobenzoate with piperidine in dimethyl sulfoxide was confirmed by visible absorption spectroscopy. Kinetics of the formation of the intermediate were studied by a stopped-flow spectrophotometer, and rate and equilibrium constants were determined. The observable intermediate (Z−) was the conjugate base of the initial zwitterionic complex (ZH). Proton transfer between ZH and Z− was rate limiting and the intermediate formation was base catalyzed.
Temperature Programmed Reduction of Copper–Silica Catalysts Prepared by Ion Exchange Method
Authors: Shimokawabe Masahide , Takezawa Nobutsune , Kobayashi Haruo 
Published: July 2006

Abstract
Temperature programmed reduction (TPR) has been used to study copper–silica catalysts which were prepared by ion exchange method and the effects of preparation of catalysts upon their reducibilities were elucidated. Three peaks appeared with maxima at 265–300 °C (α), 400 °C (β), and 650–800 °C (γ) over the catalysts calcined at 500 °C. Highly dispersed cupric oxide clusters were reduced to metallic copper, giving α peak. Isolated copper(II) ions which were strongly interacted with silica surface were reduced stepwise to metallic copper through copper(I) ion species, giving α and γ peaks. However, isolated copper(II) ions which were weakly interacted with the support gave α and β peaks. When the catalysts were precalcined above 800 °C, the fourth peak (α′) appeared at 330–350 °C and α, β, and γ peaks diminished. This was assigned to the reduction of bulk CuO which was crystallized from species described above. The reducibility of copper–silica catalyst was found to depend strongly upon the conditions of preparation.
Kinetics of the Precipitation of Human Fibrinogen by ZnCl2 and CuCl2
Authors: Kishi Takaaki , Maeda Hiroshi , Ikeda Shoichi 
Published: July 2006

Abstract
Kinetics of the precipitation of human fibrinogen by the addition of ZnCl2 was followed by the turbidity at 350 or 500 nm. Fast or slow precipitation occurred depending on whether the metal concentration (CM) was higher or lower than its critical value. In fast precipitations, the turbidity reached the stationary value within about 30 min. From the stationary values of the turbidity the critical concentration could be determined. A sigmoidal increase of the turbidity was often observed at low protein concentrations (CP); the lag time decreased with both CM and CP. At the final stage of the precipitation, the turbidity reached the stationary value exponentially; the characteristic time constant was almost independent of both CM and CP. These kinetic behaviors were consistent with the gelation model proposed to the present precipitation. When CuCl2 was used in place of ZnCl2, similar kinetic behaviors were obtained in many respects, suggesting the similar mechanism of precipitation for both ZnCl2 and CuCl2. Changes from slow to fast precipitation were observed when ionic strength was lowered.
Mono-complex Formation Kinetics of 2-Thenoyltrifluoroacetone with Nickel(II) and Copper(II) Ions in Aqueous Solution
Authors: Ando Isao , Yoshizumi Kiyomi , Ito Kazuhisa , Ujimoto Kikujiro , Kurihara Hirondo 
Published: July 2006

Abstract
The mono-complex formation of 2-thenoyltrifluoroacetone (HTTA) with nickel(II) and copper(II) ions was studied in aqueous solution at 25.0 °C and an ionic strength of 0.20 mol dm−3 by means of a stopped-flow method. The rate-[H+] profiles for the formation of these mono-complexes revealed that the rate-determining step of the complex formation interchanges depending upon hydrogen-ion concentration, as in the case of the Ni(II)–bpy complex. The rate constants of the mono-complex formation with TTA−, kf, and that with HTTA, kfh, were determined from the rate-[H+] profile in the region of the high hydrogen-ion concentration, where the pseudo-equilibrium of acid dissociation of the ligand was maintained during the complex formation; kf=(9.2±3.0)×102, kfh=(1.3±0.3)×10−1 mol−1 dm3 s−1 for the Ni(II)–TTA complex and kf=(2.0±1.2)×103, kfh=(5.0±0.9)×10−1 mol−1 dm3 s−1 for the Cu(II)–TTA complex. The deprotonation-rate constants of HTTA could be evaluated from the apparent rate constants of the complex formation in low hydrogen-ion concentration. The values thus obtained agreed well with that determined independently by a pH jump method.
Inversion of the Retention Volume Order of Enantiomers Caused by the Concentration of Eluent
Authors: Sakaguchi Ushio , Yamamoto Ippei , Izumoto Shinji , Yoneda Hayami 
Published: July 2006

Abstract
The retention volumes of enantiomers of several complex anions on the IEX 220 anion-exchange resin, when eluted by an aqueous solution of Δ-[Co(en)3]3+, Δ-[Co(sep)]3+, or Δ-[Co(l-chxn)3]3+, have been measured as a function of the eluent concentration, where en=ethylenediamine, sep=1,3,6,8,10,13,16,19-octaazabicyclo[6.6.6]eicosane, and l-chxn=(−)-trans-1,2-cyclohexanediamine. The order of retention volumes of enantiomers of some complex anions has been found to be inverted by the concentration of the eluents. The mechanism of the inversion has been discussed.
Synthetic Studies on Methyl α-Trioxacarcinoside B
Authors: Suami Tetsuo , Nakamura Katsumi , Hara Tamio 
Published: July 2006

Abstract
Trioxacarcinose B is a unique carbohydrate which has been discovered in antibiotic trioxacarcin A as a component. As a step of total synthesis of the antibiotic, methyl α-trioxacarcinoside B has been synthesized from methyl 2,3-anhydro-6-deoxy-α-l-allo-hexopyranoside by a 7 steps reaction in a yield of 4.3%. The product has been identified by comparison with the authentic sample which was prepared by methanolysis of the antibiotic.
Synthesis of Potential Antineoplastic Anthracenedione Derivatives. I. Sugar Derivatives
Authors: Nakamura Katsumi , Asai Tomoyuki , Hara Tamio , Minorikawa Naoki , Suami Tetsuo 
Published: July 2006

Abstract
Seven 1-O-glycosyl derivatives of 4-[2-(2-hydroxyethylamino)ethylamino]-9,10-anthracenedione have been prepared as potential antineoplastic agents.
The Identification of 3-Amino-9H-pyrido[3,4-b]indole Derivatives in l-Tryptophan Pyrolysates
Authors: Tada Masao , Saeki Hisaaki , Oikawa Atsushi 
Published: July 2006

Abstract
The compounds, 3-amino-9H-pyrido[3,4-b]indole and 3-amino-1-methyl-9H-pyrido[3,4-b]indole, which are effectors in induction of sister chromatid exchanges in human cells, were isolated from pyrolysis products of l-tryptophan and characterized by HPLC and UV techniques.
The Reaction of Benzonitrile Oxides with S,S-Dimethyl-N-(2,4,6-trihalophenyl)sulfimides. The Formation of Benzoxazole Derivatives
Authors: Shiraishi Shinsaku , Hayakawa Tohru , Shigemoto Tadashi 
Published: July 2006

Abstract
The reactions of nitrile oxides with S,S-dimethyl-N-(2,4,6-trihalophenyl)sulfimides gave unusual products, which structure was determined to be 2-aryl-4,6-dihalobenzoxazoles from their elementary analyses and spectral data. While the reactions with S,S-dimethyl-N-(2-bromophenyl)- or S,S-dimethyl-N-(2,4-dibromophenyl)sulfimide gave 1,2,4-benzoxadiazine derivatives. A plausible reaction mechanism for the unusual formation of benzoxazoles was proposed.
Kinetics of Ion-exchange on Sodium-, Calcium-, and Magnesium Saturated Kaolinites
Authors: Bansal Om Prakash 
Published: July 2006

Abstract
The kinetics of Na+, Ca2+, Mg2+, and Ni2+ ion-exchange reactions on kaolinite have been studied at four temperatures 16, 26, 36, and 46 °C. The mechanism of ion-exchange is a film diffusion as shown by interruption and φ tests. Kinetics parameters e.g. diffusion coefficients, half time of exchange, energies of activation have also been calculated and were used to predict the theoretical behaviour (mechanism) of Ni2+ exchange on the kaolinite surface.
Studies on Synthetic Inorganic Ion Exchangers. VI. Synthesis and Characterization of Iron(III) Molybdate as an Ion Exchanger
Authors: Thind Pritam Singh , Singh Harbans , Parveen (Miss) 
Published: July 2006

Abstract
Six preparations of iron(III) molybdate were obtained at various pH values under different conditions. They all possess cation exchange properties. The preparation, obtained by reaction of iron(III) nitrate with ammonium molybdate at pH 1 with 24 h refluxing, is the stablest and has an ion exchange capacity of 1.39 mequiv. g−1. The mole ratio of Fe: Mo is 1:3. Distribution coefficients for many metal ions were determined on this preparation. On the basis of pH titrations, chemical and thermal analyses, and infrared and Mössbauer spectra, a tentative structure of iron(III) molybdate is proposed.
The Crystal and Molecular Structure of 3,4-Dichloronitrobenzene
Authors: Kumakura Shigekazu , Kuroishi Yoshinobu 
Published: July 2006

Abstract
C6H3Cl2NO2, F. W.=192.0, tetragonal, I41/a, a=28.094(12), c=3.838(6) Å, V=3030 Å3, Z=16, Dx=1.68 Mg m−3, μ(Mo Kα)=0.8 mm−1. Refinement with 1093 diffractometer data gave a final R value of 0.07. The molecule is practically planar except for the nitro group, the plane of which is inclined at 8.8° to the benzene plane. The two C–Cl bond distances are approximately equal to each other. The intermolecular Cl(2)···O(2ii) contact of 3.095 Å is remarkably short.
The Reaction of Organoboranes with Lithium Salts of Trisylhydrazones of Cycloalkanones Followed by Treatment with Iodine
Authors: Baba Tsutomu , Avasthi Kamlakar , Suzuki Akira 
Published: July 2006

Abstract
The titled reaction proceeds smoothly under mild conditions to give corresponding 1-alkylcycloalkenes in excellent yields. The overall reaction provides a convenient synthetic procedure of cycloalkenes for cycloalkanones, with various alkyl substituents readily available by means of hydrobortation.
The Crystal and Molecular Structure of Daphnin Dihydrate: 7-(β-d-Glucopyranosyloxy)-8-hydroxycoumarin Dihydrate
Authors: Ueno Katsuhiko , Sato Mitsuhiko , Saito Norio 
Published: July 2006

Abstract
The title compound, C15H16O9·2H2O, crystallizes in orthorhombic space group P212121 with a=7.082(2), b=34.789(5), c=6.867(2) Å, and Z=4. The structure was solved by direct method and refined by least-squares to a final R of 0.038 based on 1841 observed reflections measured on a four-circle diffractometer. The coumarin ring is approximately planar and the torsion angle around the glucosidic C–O bond is 13.5°; this is much smaller than the corresponding value in 8-glucosyloxy-7-hydroxycoumarin, and causes considerable intramolecular repulsion around the glucosidic linkage. The valence angle of the oxygen atom linking the coumarin and glucose moieties is quite large, 118.5°. The glucopyranose portion is in a C1 chair conformation. Glucosidation at the 7-hydroxyl group brings about considerable decrease of the resonance system of the 7-hydroxylated coumarin moiety. Such an effect seems to play an important role in the transglucosidation of dihydroxycoumarin glucosides.
Kinetics of Valinomycin- and Tetranactin-mediated Cation Transport through Liposomal Membrane
Authors: Ueno Masaharu , Yasui Tomomi , Horikoshi Isamu 
Published: July 2006

Abstract
Kinetics of valinomycin- and tetranactin-mediated cation transport were studied. An equation was derived which describes the kinetics of ionophore induced cation leakage from liposomes. The theoretically predicted ion-selectivity of the ionophore-mediated cation transport agreed well with that given by experiments. This supports the assumptions used in the derivation and is consistent with the following characteristics of the ionophores: (1) Ionophore-mediated cation transport is carried out by stoichiometrically forming a ternary complex between ionophore, cation and lipophilic anion. (2) The ion-selectivity of the ionophore is determined primarily by the formation constant of the ionophore cation complex in water. (3) A relative value of the complex formation constant in water can be calculated from both the complex formation constant in methanol, which is estimated more easily than that in water, and the difference between desolvation energy of the cation in water and methanol.
Coenzyme Models. 34. Synthesis and Oxidation Ability of a Metal-coordinative Flavin
Authors: Shinkai Seiji , Ishikawa Yuichi , Manabe Osamu 
Published: July 2006

Abstract
A new metal-coordinative flavin(2,4,7-trimethylquino[8,7-g]pteridine-9,11(7H,10H)-dione: (1)) which has a phenanthroline-like skeleton within the molecular structure was synthesized. Being different from conventinal flavins, the new flavin showed a significant affinity toward metal ions and the absorption spectra were sensitively affected by added metal ions. The spectral patterns were classified into three types, which were assigned respectively to the different coordination structures. It was demonstrated through oxidation of dihydropyridine derivatives, phenylhydrazine, and l-ascorbic acid that complexed metal ions are able to “activate” 1 as oxidizing agent. The complexes with Zr4+ and Fe3+ even oxidized alcohols at ambient temperature. Unexpectedly, it was found that tetrahedral coordination metals such as Cd2+, Zn2+, and Co2+ frequently give the stable semiquinone radical of 1. The remarkable stabilization effect of these metals was attributed to a bent, butterflywing structure of the semiquinone radical. These findings suggest that the 1–metal complexes are useful not only as a model system of metalloflavoproteins but also as an in vitro oxidation catalyst.
Photoresponsive Crown Ethers. 9. Cylindrical and Phane Crown Ethers with Azobenzene Segments as a Light-switch Functional Group
Authors: Shinkai Seiji , Honda Yoshihiro , Minami Takahide , Ueda Kaori , Manabe Osamu , Tashiro Masashi 
Published: July 2006

Abstract
Cylindrical and phane crown ethers with azobenzene segments as a light-switch functional group were synthesized. Cylindrical ionophores in which two diazacrown ethers are linked by two photoresponsive azobenzene pillars change their binding ability for polymethylenediammonium salts in response to photoirradiation. Thus, the distance between the two crown rings can be photocontrolled. A phane-type ionophore in which 1,23-bis(p-aminophenoxy)-3,6,9,12,15,18,21-heptaoxatricosane is linked by a trans-4,4′-azobenzenedicarbonyl segment exhibits no affinity with all alkali metal cations but significantly binds Rb+ and Cs+ under UV-light irradiation. This is the example of the “all-or-nothing” control of the ion-binding ability and implies that a crown-like loop emerges only when the azobenzene segment is photoisomerized to the cis-configuration. These ionophores are categorized to novel photoresponsive crown ethers.
The Interaction of a Neutral Polymer with Small Ions in Solution. III. Ionic Association on a Poly(oxyethylene) Chain
Authors: Awano Hiroshi , Ono Katsumichi , Murakami Kenkichi 
Published: July 2006

Abstract
Conductivities of NaSCN and KSCN solutions have been measured in ethanol and nitromethane in the presence of poly(oxyethylene). For poly(oxyethylene)–KSCN solutions in ethanol and nitromethane, a distinct minimum appears in conductivity vs. polymer concentration curves. In addition, for a poly(oxyethylene)–NaSCN solution in nitromethane, the conductivity curve rises steeply after passing through the minimum. These anomalies cannot be explained by the cation binding to the polymer alone, and the ionic association on the polymer chain should be taken into account at the same time. In order to analyze the results, a theory based on the duplicate ion binding on a one-dimensional lattice has been developed. The theory not only predicts the appearance of the conductivity minima, but also makes it possible to estimate the ionic association constants.