bluuebunny/crossref_metadata_2025_split huggingface dataset:
Association of Inclusion Compounds of β-Cyclodextrin in Aqueous Solution
Authors: Hamai Sanyo 
Published: July 2006

Abstract
Inclusion compounds in the systems naphthalene–β-cyclodextrin (CDx) and 2-methoxynaphthalene (MN)–o-dicyanobenzene (DB)–β-cyclodextrin in aqueous solution were studied by means of absorption and fluorescence spectra. In the former system a naphthalene excimer fluorescence was observed. By the analyses of the concentration dependence of the absorption spectra and the excimer fluorescence intensities, the species responsible for the excimer fluorescence is identified as a 2:2 inclusion compound which is formed by association of two 1:1 naphthalene–CDx inclusion compounds, not a 2:1 inclusion compound in which two naphthalene molecules enter into the cavity of one CDx molecule. In the latter system, absorption and fluorescence spectra due to a charge transfer complex of MN with DB were observed. By analyses similar to the naphthalene case, the existence of a 1:1:2 association compound formed between a MN–CDx inclusion compound and a DB–CDx inclusion compound is confirmed. Fluorescence quenching by I− and IO3− was also studied for the inclusion compounds in both systems.
Electron Transfer in the Quenching of Triplet States of Zinc Phthalocyanine and Methylene Blue by the Use of Fe(III), Co(III), and Organic Oxidants
Authors: Ohno Takeshi , Kato Shunji , Lichtin Norman N 
Published: July 2006

Abstract
The mechanism of the quenching of the triplet state of zinc phthalocyanine (ZnPc) and Methylene Blue (MB+) by low-spin complexes of Fe(III) and Co(III) and aromatic oxidants was studied. The quenchers studied included FeIII(CN)63−, FeIII(CN)4(2,2-bipyridyl)−, FeIII(CN)2(2,2-bipyridyl)+, ferrocenium ion, CoIII(2,2′:6′-2″-terpyridyl)3+, CoIII(1,10-phenanthroline)3+, dimethylviologen, 1,4-benzoquinone, and 2,4,7-trinitro-9-fluorenone (TNF). The rate constants of the quenching of 3ZnPc varied from a diffusion-controlled one to 6×105 dm3 mol−1 s−1 in the mixed solvent of dimethylacetamide (DMA) and water (7:3 by volume). The metal complexes quenched 3MB+ and the triplet state of protonated MB+ with a rate constant of more than 2×106 dm3 mol−1 s−1 in an aqueous solution with 0.5 mol dm−3 of MgCl2. The fractions of electron transfer yielding ZnPc\underset.+ in the quenching process (F1) were high except for TNF and the iron(III) compounds. The F1 fractions were also obtained in the quenching of 3MB+ and the triplet state of the protonated MB+. The absence of radical production in the quenching by the doublet iron(III) compounds can be explained in terms of spin-allowed reverse electron transfer in the life of the geminate radical pair. Fractions of the reverse electron transfer between the half-reduced quencher and ZnPc\underset.+ or MB\underset.2+ were also measured; they are very close to those of 1–F1. The data reported in this study are consistent with the following mechanistic features. (1) Every quenching encounter produces a geminated radical pair. (2) The geminated pair is common to the quenching of the triplet excited state by oxidants and to the reverse electron transfer between the free radicals formed in the quenching. The molar extinction coefficient of ZnPc\underset.+ was determined to be 2.9×104 dm3 mol−1 cm−1 at 520 nm.
Estimation of Compressibility and Volume of Electrostriction Layer in Water–Methanol System and Its Application to the Partial Molar Volumes of LiCl, KCl, and CsCl in This System
Authors: Kawaizumi Fumio , Suzuki Hiroshi , Nomura Hiroyasu , Miyahara Yutaka 
Published: July 2006

Abstract
A theory of electrostriction based on the spherical symmetry of electric field around ion and the dielectric continuum of solvent has been applied to the mixed solvent of water–methanol. The isothermal compressibility, κT, and the volume decrease, ΔV of primary solvation layer have been calculated for univalent ions. Calculation procedure consists of two steps; 1) calculation of the variation of electric field strength and dielectric constant with the distance from ion, 2) calculation of the compressibility and the volume decrease of electrostriction layer. In step 2), the calculation method proposed by Desnoyers et al. (J. Chem. Phys., 43, 243 (1965)) was used. Parameters necessary for the calculation were estimated in an appropriate manner and the results of calculation are shown as plots of κT and ΔV, vs. the distance from the center of ion. Partial molar volumes of LiCl, KCl, and CsCl in water–methanol system have been measured and the disordered part of partial molar volume has been determined after taking account of the values of κT and ΔV of the primary solvation layer.
The Structure of Liquid Water by Neutron Scattering. II. Temperature Dependence of the Liquid Structure
Authors: Ohtomo Norio , Tokiwano Kazuo , Arakawa Kiyoshi 
Published: July 2006

Abstract
The structure factors for heavy water at 25, 50, 70, and 95 °C were determined in the range of Q, 1.4–20 Å−1, by means of the time-of-flight (TOF) neutron diffraction method using the electron linear accelerator (LINAC). An analysis of the neutron diffraction data was made by applying a new general theoretical procedure of analysis for the fluid system composed of molecular clusters with various sizes. Structure factors were calculated according to the general procedure for the pentamer-monomer mixture model as a mixture of regular tetrahedral pentamers and non-bonded monomers with a due assignment of pentamer fraction at each temperature. Excellent agreement was obtained between the calculated and observed structure factors at temperatures in 25–95 °C. Combined with the preceding result (N. Ohtomo, K. Tokiwano, and K. Arakawa, Bull. Chem. Soc. Jpn., 54, 1802 (1981)), it was concluded that the pentamer-monomer mixture model is the best one for water from room temperature to near the boiling point.
Tunnel Electrode I. Electron Transfer Process at Highly Doped SnO2 Electrode with Ce4+ in High Overvoltage Region
Authors: Kobayashi Kenkichiro , Aikawa Yoshihiro , Sukigara Mitsunori 
Published: July 2006

Abstract
Electron transfer theory at tunnel semiconductor electrode was derived from the double adiabatic perturbation theory. The cathodic current of Ce4+ with very positive redox potential was measured at highly doped SnO2 electrode. The rearrangement energy of 0.65 eV for Ce4+ was estimated from the relationship of transfer coefficient vs. electrode potential. Large electron transfer rate in the high overvoltage region can be explained in terms of the contribution of excited vibrational states in the first coordination sphere into electron transfer.
Temperature Effect on the Hydrophobic Hydration in Aqueous Solution of Nonpolar Molecule by Monte Carlo Calculation
Authors: Okazaki Susumu , Touhara Hidekazu , Nakanishi Koichiro , Watanabe Nobuatsu 
Published: July 2006

Abstract
Monte Carlo calculations have been carried out for pure water and aqueous solution of Lennard-Jones particle at infinite dilution between 273.15 K and 353.15 K in order to examine temperature effect on the hydrophobic hydration. It is found that internal energy of mixing ΔU due to the introduction of the solute into water becomes less negative monotonously with increasing temperature. It is in good correspondence with the tendency obtained from solubility measurement, and represents that heat capacity of mixing ΔCV is positive. Furthermore the dissolution proceeds no longer exothermically at 353.15 K, where water behaves as a normal solvent. Several structural and energetical distribution functions have been calculated for the deep understanding of these observations.
Simple Approximate Approaches for the Determination of Circular Dichroism Spectra in Multiple Scattering Systems
Authors: Taniguchi Yutaka , Shimura Yoichi 
Published: July 2006

Abstract
A convenient method for the determination of CD spectra in multiple scattering systems is demonstrated. The formula of approximation, which gives the molar CD in terms of the values observable with commercial spectrometers by using a plate of opal glass, is presented based on some assumptions. The resulting solid-state CD spectrum of Λ-[Co(en)3]Br3·H2O is reported and compared with the solution CD spectrum.
Kinetics and Mechanism of the Oxidation of (Substituted Phenylthio)acetic Acids by Chloramine T
Authors: Srinivasan Chockalingam , Pitchumani Kasi 
Published: July 2006

Abstract
The kinetics of oxidation of (phenylthio)acetic acid and several (para-substituted phenylthio)acetic acids by chloramine T has been studied in alkaline medium (pH 10.06). A first-order dependence in chloramine T and (phenylthio)acetic acid and a near inverse first-order dependence in hydroxide ion has been observed. The oxidation rate considerably decreases with increase of pH. The reaction exhibits positive salt effect and added p-toluenesulfonamide increases the rate. The oxidation process has been shown to proceed via two paths, the major path involving N-chloro-p-toluenesulfonamide as the main oxidizing species and the other involving hypochlorite ion. Studies with (para-substituted phenylthio)acetic acids show an excellent correlation of the rate constants with σ constants. The reaction exhibits a reaction constant ρ of −2.46 at 308 K (r=0.998, s=0.05, confidence limit on ρ±0.15). The activation parameters and isokinetic temperature have been determined.
Diarsenic Trioxide for Substituting Bridging Oxygen for Chlorine in Phosphorus Chlorides
Authors: Watanabe Makoto , Van Wazer John R 
Published: July 2006

Abstract
A preferential exchange of chlorines and bridging oxygens between phosphorus(III and V) chlorides and diarsenic trioxide was studied by adding diarsenic trioxide into phosphorus chlorides and then heating the mixtures at 50–60 °C with vigorous stirring under dried nitrogen (phosphorus(III) chlorides) or dried air (phosphorus(V) chlorides). 31P NMR study showed that the exchange of chlorines and oxygens occurred between diarsenic trioxide and phosphorus trichloride, phosphoryl chloride, diethylphosphinic chloride, tetramethyl-phosphorodiamidic chloride, or diethylphosphinothioic chloride and that P–O–P bonds were formed in the products.
Reactions of Alkanoyl Fluorides with F-Isopropyl and F-1-Chloroethyl Anions
Authors: Ishikawa Nobuo , Iwamoto Kazuhiko , Ishiwata Tatsumi , Kitazume Tomoya 
Published: July 2006

Abstract
Reactions between alkanoyl chlorides and F-propene or F-chloroethene with fluoride ion were investigated. While alkyl (F-isopropyl) ketones and 1-(F-isopropyl)alkenol esters were formed in the former case, 1-(F-1-chloroethyl)alkenol esters were exclusively obtained in the latter case. Reaction mechanisms are discussed.
Alcoholysis Equilibria of Triethylalkoxysilanes Catalyzed by Iodine or Iodine Monobromide
Authors: Ito Katsuko , Ibaraki Takeshi 
Published: July 2006

Abstract
The equilibrium constants K of alcoholysis of triethylalkoxysilanes were determined at 20 °C and 40 °C. Iodine monobromide was used to promote the reactions associated with the tertiary alkoxyl groups, while the other reactions proceeded in the presence of iodine. The K values of the reaction systems with ethoxyl or propoxyl—primary, secondary, and tertiary alkoxyl pairs were 1 or above, about 0.5, and about 0.05, respectively. These values reflect the extent of the binding abilities of the alkoxyl groups to silicon, which is in the expected order of primary&gt;secondary&gt;tertiary alkoxyl groups. A mechanism is postulated for the reaction which involves participation by the iodine or iodine monobromide.
Deoxygenation of Tertiary Amine Oxides with Carbon Bisulfide
Authors: Yoshimura Toshiaki , Asada Kaoru , Oae Shigeru 
Published: July 2006

Abstract
Reduction of various tertiary amine oxides with carbon disulfide was examined and kinetic experiments were carried out. Trialkylamine oxides and N,N-dialkylarylamine N-oxides were readily reduced by CS2 to give the corresponding tertiary amines in good yields, while heteroaromatic amine N-oxides such as picoline N-oxide were not affected. The oxygen atom in the N-oxide was found to be transferred to CO2 upon mass spectral analysis of the gas evolved. The kinetic experiments were carried out following the UV spectra of N,N-dimethylaniline N-oxide in CH3CN containing much excess of CS2 and the rate was found to be of 2nd order in the N-oxide and CS2. Activation parameters (ΔH\eweq=55.7 kJ mol−1, ΔS\eweq=−78.2 J K−1 mol−1 at 20 °C are characteristic of a normal bimolecular reaction. The logarithms of the rate constants for para-substituted N,N-dimethylaniline N-oxides are nicely correlated with Hammett σ values and a small negative ρ value (ρ=−0.2) was obtained. The rate of reaction was faster in polar aprotic solvents than in nonpolar or protic solvents. These observations seem to suggest that the reaction proceeds via an initial nucleophilic attack of the N-oxide oxygen at carbon disulfide followed by the rate-determining N–O bond fission to give the tertiary amine.
Catalytic Efficiency of Functionalized Vesicles in the Transamination of Pyridoxal-5′-phosphate with a Hydrophobic Amino Acid
Authors: Murakami Yukito , Nakano Akio , Akiyoshi Kazunari 
Published: July 2006

Abstract
The transamination reaction of pyridoxal-5′-phosphate (PLP) with N-dodecyl-l-alaninamide (AlaC12) was investigated in an aqueous phosphate–borate buffer at pH 7.0, μ 0.10 (KCl), and 30.0±0.1 °C in the presence of single-walled vesicles of N,N-ditetradecyl-Nα-(6-trimethylamnioniohexanoyl)-l-histidinamide bromide(N+C5His2C14). The electrostatic and hydrophobic interactions between the vesicles and the reactants resulted in incorporation of PLP and AlaC12 into polar and hydrophobic domains of the vesicles, respectively, in the Schiff-base formation process. The isomerization of the aldimine Schiff-base to the corresponding ketimine Schiff-base was confirmed to be the rate-determining step in the transamination process. The reaction site in the vesicular system was found to be equivalent in polarity to dioxane–water (7:3 v/v). However, the overall reaction rate in the vesicles was enhanced 230-fold relative to that in dioxane–water (7:3 v/v). A hydrophobic and suitably polar microenvironment constructed at the reaction site is responsible for such a marked rate-enhancement. In addition, each vesicle of N+C5His2C14 provided functional (imidazolyl) groups in its hydrogen-belt domain to catalyze the intramolecular pro to tropic shift to yield the ketimine Schiff-base. The microenvironmental effects of molecular assemblies of N,N-ditetradecyl-Nα-(6-trimethylammoniohexanoyl)-l-alaninamide bromide and CTAB on the overall transamination were also discussed.
The Effect of Ultraviolet Radiation on the Wattability of Silicone Polymers
Authors: Esumi Kunio , Meguro Kenjiro , Schwartz Anthony M , Zettlemoyer Albert C 
Published: July 2006

Abstract
The effect of UV radiation in air on the wettability of silicone polymers was studied by measuring the contact angles. From the contact-angle data, the surface energies were also calculated. As the irradiation progressed, the surface energy of the polar component increased, while the surface energy of the dispersive component remained constant, for all the samples. This increase in surface energy is attributable to a surface photooxidation of the silicone polymers. Especially, poly(diphenylsiloxane) showed a remarkable increase in the surface energy of the polar component after the irradiation.
Preparation and Properties of Octahedral Nickel(II) Complexes with and Schiff Bases Derived from Substituted Salicylaldehydes and Bis(2-aminoethyl) Sulfide
Authors: Hori Kiichi , Takahashi Kazuko 
Published: July 2006

Abstract
The octahedral complexes listed in the title have been prepared. The magnetic and spectral properties of these complexes indicate that the non- and 5-substituted complexes have a structure bridged by the phenolic oxygen of the Schiff bases and the 3-substituted complexes probably are mononuclear.
An Ultrasonic Nebulizer for Microliter Samples in Inductively Coupled Plasma Emission Spectrometry
Authors: Kawaguchi Hiroshi , Tanaka Tomokazu , Mizuike Atsushi 
Published: July 2006

Abstract
A batch type ultrasonic nebulizer is constructed for 300-μl samples to produce an aerosol for more than 60 s. Desolvation facilities are not used. The internal standard method is employed to compensate for the instability of nebulization.
Oxidizing Action of Complex of N,N-Dimethylbenzylamine Oxide with SbCl5
Authors: Yamamoto Jiro , Tanioka Yukio , Umezu Masahiro 
Published: July 2006

Abstract
A 1:1 complex of N,N-dimethylbenzylamine oxide–SbCl5 (1) was prepared in carbon tetrachloride quantitatively. Complex 1 was found to be a better reagent for oxidation of benzoin, furoin, benzyl alchols and pinacols than the complexes pyridine N-oxide–SbCl5 and trimethylamine oxide–SbCl5. The reaction path in oxidation of benzhydrol with 1 is described.
Solvent Effect on Photooxidation of Triphenylphosphine Selenide Sensitized by Polymer-supported Rose Bengal
Authors: Tamagaki Seizo , Akatsuka Ryuji 
Published: July 2006

Abstract
Solvent effect on the photooxygenation of triphenylphosphine selenide was examined by using cross-linked polystyrene- or silica gel-anchored Rose Bengal as sensitizers. Different types of solvent dependency of the product yields were observed in each case.
Friedel-Crafts Reactions of Benzene with 1-Phenylpropanols. Effects of CuCl2, Cu2Cl2, and Decalin
Authors: Ichikawa Katsuhiko , Chano Keizo , Inoue Masashi , Sugita Toshio 
Published: July 2006

Abstract
Highly regioselective formation of 1,1-diphenylpropane was observed when copper(I) or (II) chlorides was added to the aluminium chloride-catalyzed reaction of benzene with 1-phenyl-1-propanol. In the reaction with 1-phenyl-2-propanol, the addition of copper salts increased the formation of 1,1-diphenylpropane. The addition of decalin diminished the alkylation reaction to give a reduction product.
X-Ray Crystallographic Analysis of 3α,5-Epoxy-6β-3β-methyl-A-homo-4-oxa-5α-cholestane, a Major Product of Photo- and Thermally-induced Radical Rearrangements of Hypoiodites of 3α-and 3β-methyl-5-cholesten-3-ols
Authors: Furusaki Akio , Katayama Chuji , Suginome Hiroshi 
Published: July 2006

Abstract
The major product of photo- and thermally-induced radical rearrangements of hypoiodites of 3α-and 3β-methyl-5-cholesten-3-ols in the presence of iodine with mercury(II) or silver(II) oxide has been established as 3α,5-epoxy-6β-iodo-3β-methyl-A-homo-4-oxa-5α-cholestane by means of X-ray crystal structure analysis.
A One Step Transformation of the Sodium Salt of α-aci-Nitrotoluene into 3,4,5-Triphenylisoxazole
Authors: Fukunaga Kimitoshi , Okamoto Akihiko , Furumoto Keiji , Kimura Makoto 
Published: July 2006

Abstract
3,4,5-Triphenylisoxazole was produced by the reaction of the sodium salt of α-aci-nitrotoluene with the 1-cyano-1-methylethyl radical. The reaction was found to proceed via one electron transfer from α-aci-nitrotoluene anion to a 1-cyano-1-methylethyl radical.
Interaction between Hydrophilic Proteins and Nonionic Detergents Studied by Surface Tension Measurements
Authors: Nishikido Nagamune , Takahara Tomoyuki , Kobayashi Hideki , Tanaka Mitsuru 
Published: July 2006

Abstract
The surface tensions of the systems of hexa(oxyethylene) dodecyl ether (C12E6) vs. lysozyme (Lyz) or bovine serum albumin (BSA) were measured for constructing the binding isotherms, since the surface tension method is more convenient for the systems of nonionic detergents and proteins than is equilibrium dialysis. The obtained binding isotherms depend on the protein concentration; this effect is much more remarkable for Lyz–C12E6 systems than for BSA–C12E6 ones. The binding isotherms of BSA–C12E6 systems obey the Scatchard equation, and the maximum number and estimated free energy for C12E6 binding to BSA are comparable to those for the system of Triton X-100 and BSA determined by equilibrium dialysis. The agreement suggests that the surface tension method is sound and has advantages over equilibrium dialysis for the estimation of the number of detergent molecules bound to protein. In the systems of Lyz–C12E6, the binding isotherms follow the Freundlich-type equation rather than the Scatchard equation. The remarkable protein concentration dependence of the binding isotherms and this result suggest the occurrence of protein aggregation.
Further Comments on the Line-broadening of the Chlorine 35 NMR Spectra and the Local Structure around a Chloride Ion in Aqueous Solutions of Non-electrolytes
Authors: Yudasaka Masako , Sugawara Tadahi , Iwamura Hiizu , Fujiyama Tsunetake 
Published: July 2006

Abstract
The remarkable line-broadenings of the 35Cl NMR spectra observed for the KCl in aqueous solutions of non-electrolytes were explained well by considering the formation of water-cages which surround the non-electrolytes. This result, in turn, suggests that the line-width measurement is a useful method for determining local structures formed in solutions.
The Structure of Dichloro(4-hydroxy-l-proline)cadmium(II)
Authors: Yukawa Yasuhiko , Inomata Yoshie , Takeuchi Toshio , Shimoi Mamoru , Ouchi Akira 
Published: July 2006

Abstract
An X-ray diffraction study of the title complex has been carried out. The crystal is monoclinic, with the space group P21; Z=2; a=8.196(4), b=7.275(3), c=7.740(4) Å, β=103.73(4)° Full-matrix least-squares refinements have led to the final R value of 0.030. The structure consists of one-dimensional polymers bridged by chlorine atoms and a carboxyl group. Four chlorine atoms coordinate to a cadmium atom and form a square plane. The planes extend in the direction of the b axis like an infinite folding screen, sharing opposite edges. From the trough positions in the zigzag structure, the carboxyl oxygen atoms of 4-hydroxy-l-proline coordinate forkedly to two cadmium atoms. The ligand is a zwitter ion in the complex.
Synergistic Effect of Nitrogen Neutral Bases in the Solvent Extraction of Zinc(II) and Cadmium(II) Diphenylcarbazonates
Authors: Yamada Etsu , Nakayama Eiichiro , Kuwamoto Tooru , Fujinaga Taitiro 
Published: July 2006

Abstract
The extraction behavior of zinc and cadmium with diphenylcarbazone(DPC) into benzene and chloroform were studied in both the absence and presence of neutral bases(S). In the case of chloroform, all of the neutral bases gave rise to adduct complexes with the formula of M(DPC)2S. On the other hand, in the case of benzene, the adduct complexes can be represented as M(DPC)2S for all neutral bases except for 1,10-phenanthroline(phen), in which the adduct complexes can be expressed as M(DPC)2(phen)2. The stability of the adduct complexes is related not only to the basicity of the bases, but also to the steric effect attributable to substitution. Furthermore, the adduct-formation constant increase in the following order against the normalized values of basicity: pyridine bases&lt;2,2′-bipyridyl&lt;1,10-phenanthroline derivatives. This order agrees with the increasing order of the coordinated ability as ligands. The basicity of the bases has a larger effect on the adduct-formation constants for Cd than on those for Zn. This may be attributed to the fact that Zn chelates have greater stability than the Cd chelates, as a result, the “residual Lewis acidity” of Zn is smaller than that of Cd, and therefore zinc chelates form less stable adducts.