bluuebunny/crossref_metadata_2025_split huggingface dataset:
State of Polarization of Light Scattered by Colored Spheroids
Authors: Sano Yoh , Nakagaki Masayuki 
Published: July 2006

Abstract
Using the light-scattering theory of Rayleigh–Gans for spheroids, theoretical expressions were derived for the polarization state of light scattered by randomly oriented small and colored spheroidal particles in the case of linearly polarized incident light with an angle of inclination of ψ to the scattering plane. The azimuth angle ζ of the ellipse of the scattered light did not depend on the axial ratio p and the relative complex refractive index m (=m0−ik0), but was a function of only the scattering angle θ and ψ; also, the ellipticity of the ellipse of the scattered light was always equal to 0 and the scattered light was partially linearly polarized for linearly polarized incident light. The degree of polarization of the scattered light for spheroidal particles, P, defined as the ratio of the polarized component to the intensity of the scattered light, depended strongly on p, m0, k0, and θ together with the angle ψ. This P was found to be smaller than 1. In the case of spherical particles, P was always equal to 1 at any θ; this means that the scattered light was perfectly polarized. It has been concluded that a determination of P as a function of ψ and θ gives good information regarding the shape and the optical constants (m0 and k0) of the colored spheroidal particles.
Studies of Spin-Labeled Sodium Dodecyl Sulfate. II. Effect of Sodium Chloride on ESR Line Width
Authors: Yamaguchi Takeo , Yamauchi Akira , Kimoto Eiji , Kimizuka Hideo 
Published: July 2006

Abstract
The ESR spectra of spin-labeled sodium dodecyl sulfate were examined by changing the concentration, temperature, and ionic strength. The broadening of ESR lines due to a monomer surfactant could be explained in terms of an electron-spin exchange and a monomer-micelle exchange. The spin-exchange rate increased with increasing temperature and decreased with increasing ionic strength, i.e., the spin-exchange frequency was closely related to the viscosity of the medium. On the basis of an analysis of the line width above the critical micelle concentration, it was found that the aggregation number of the micelle of this compound and the monomer-micelle exchange frequency were dependent on the ionic strength.
On the Relationship Between the Chemical Structure and the Carcinogenicity of Polycyclic and Chlorinated Monocyclic Aromatic Compounds as Studied by Means of 13C NMR
Authors: Sakamoto Yohko , Watanabe Shosuke 
Published: July 2006

Abstract
The relationship between chemical structure and carcinogenicity was investigated in thirty-eight polycyclic aromatic compounds and forty-four chlorinated aromatic hydrocarbons by means of 13C NMR. As an “index” serving as a measure of the electronic structure of aromatic compounds, which is closely related to the carcinogenicity, the averaged 13C NMR chemical shift over all the aromatic carbons in the molecule was used. In polycyclic aromatic compounds, the averaged chemical shifts of the carcinogenic compounds are within the range from 127.11 to 127.87 ppm, but those of the noncarcinogenic compounds are not within this range. In chlorinated monocyclic aromatic compounds, the carcinogenic compounds was within the range from 127.76 to 132.64 ppm. Thus, we proposed that the “index” is very useful for the discernment of the carcinogenicity of polycyclic and chlorinated monocyclic aromatic compounds.
Trachit Change of the ZrSiO4 Single Crystal During Crystal Growth Studied by the Na2O·3V2O5 Flux Method
Authors: Ushio Masumi , Sumiyoshi Yoshihiro 
Published: July 2006

Abstract
The appearance and disappearance of the crystal faces of the ZrSiO4 single crystal during crystal growth under the conditions of a growth temperature of 900 °C and a Δt value (temperature difference) of 1 °C have been studied by means of the Na2O·3V2O5 flux method. A spherical seed prepared from a natural zircon single crystal was used. The c{001}, a{100}, and m{110} appeared at the earliest stage, and next appeared r{115}, u{015}, p{111}, e{011}, and q{021} after 20 h of growth time. However, the u-face, r-face, and q-face disappeared after 400 h, and the c-face and a-face began to disappear after 500 h. The final morphology after 1400 h was a firstorder prism and a pyramid consisting of only the m-face and the p-face. It was found that the m-face and the p-face were dominant on a flux-grown ZrSiO4 single crystal, and that this tendency was unchangeable after 2500 h.
Studies on Dissolved Metalloenzymes in Lake Water. II. Seasonal Variations in Phosphatase Activity in Lake Kasumigaura
Authors: Kobayashi Kensei , Hashimoto Shinya , Iwase Koichi , Otsuki Akira , Fujiwara Kitao , Fuwa Keiichiro , Haraguchi Hiroki 
Published: July 2006

Abstract
Alkaline phosphatase activity in Lake Kasumigaura was determined periodically and characterized by highperformance liquid chromatography and isoelectric focusing electrophoresis. There are two peaks in dissolved alkaline phosphatase activity; the bigger one in summer and the smaller one in winter. Molecular weight of ca. 89000 and isoelectric points 5–6 were found for most phosphatases in samples collected during the summer. A considerable part of the winter alkaline phosphatases, however, have much higher molecular weights, and major isoelectric points for these were ca. 4. These alkaline phosphatases were metalloenzymes activated by zinc. The observations above suggest that there are seasonal changes in the dominant microbial species producing dissolved alkaline phosphatase; i.e., blue-green algae, a procaryote, in summer and diatoms and flagellates, eucaryotes, in winter. The peak of alkaline phosphatase activity in lake water was predictive of a following increase in algal species therein.
Metallation of Aliphatic Carbon Atoms. IV. Syntheses and Characterization of the Cyclopalladated Complexes of 2-t-Butylbenzothiazole
Authors: Hiraki Katsuma , Fuchita Yoshio , Nakashima Motoharu , Hiraki Hirofumi 
Published: July 2006

Abstract
2-t-Butylbenzothiazole reacts with palladium(II) acetate in acetic acid to produce the cyclopalladated dimer [{Pd(CH2CMe2–C7H4NS)(μ-MeCO2)}2] (2) (C7H4NS=2-benzothiazolyl). Complex 2 shows temperature-dependent 1H NMR spectra, which have been interpreted on the basis of the inversion motion of the acetato bridges. Metatheses of 2 with lithium chloride and sodium iodide result in the formation of the chloro- and iodo-bridged analogues, [{Pd(CH2CMe2–C7H4NS)(μ-Cl)}2] (3) and [{Pd(CH2CMe2–C7H4NS)(μ-I)}2] (4), respectively, each of which is found to be composed of cis and trans isomers. The 1H NMR spectra of 3 and 4 depend on temperature and are ascribed to rapid exchange between the two isomers. Equimolar amounts of 3 and 4 afford a μ-chloro-μ-iodo binuclear complex, [(C7H4NS–CMe2CH2)Pd(μ-Cl)(μ-I)Pd(CH2CMe2–C7H4NS)]. The reaction of 3 with thallium(I) acetylacetonate [Tl(acac)] produces a mononuclear cyclopalladated complex [Pd(CH2CMe2–C7H4NS)(acac)]. Complexes 2 and 3 react with CO in methanol to give MeO2CCH2CMe2–C7H4NS, the formation of which comfirms also the cyclopalladated structure of 2-t-butylbenzothiazole in 2 and 3.
121Sb Mössbauer and 1H and 13C NMR Spectroscopic Studies of a Series of Organoantimony(V) Compounds, R3SbX2
Authors: Yanaga Makoto , Miura Taichi , Endo Kazutoyo , Nakahara Hiromichi , Takeda Masuo 
Published: July 2006

Abstract
The 121Sb Mössbauer spectroscopic and the 1H and 13C NMR nuclear magnetic resonance studies have been performed for a series of organoantimony(V) compounds: R3SbX2 (R=CH3, C6H5, p-CH3C6H4; X=F, Cl, Br, I). For the trimethylantimony dihalides, the isomer shifts and quadrupole coupling constants of the 121Sb Mössbauer spectra indicated that the withdrawal of the bonding electrons from the antimony atom along Sb–X increased, as the electronegativity of the halogen increased. The chemical shifts of the 1H and 13C NMR spectra showed that the electron population around the methyl group increased with increasing electronegativity of halogen. For phenyl and p-tolyl derivatives, both 121Sb Mössbauer and 13C NMR data showed a trend similar to the methyl compounds. The results suggest that the electron cloud around the antimony atom spreads, with an increase in the electronegativity of the halogen, not only toward the halogen atoms but also toward the plane perpendicular to the bonding direction with the halogen atoms.
The Reaction of cyclo-Triphosphate with Ethanolamines
Authors: Tsuhako Mitsutomo , Sueyoshi Chiyoko , Miyajima Tohru , Ohashi Shigeru , Nariai Hiroyuki , Motooka Itaru 
Published: July 2006

Abstract
The reaction of cyclo-triphosphate(P3m) with mono-(MEA), di-(DEA), or triethanolamine(TEA) in an aqueous solution was investigated under various conditions (mixing ratio of MEA, DEA, or TEA to P3m, pH, temperature, and reaction time). 1) In the pH region of 7–12, P3m reacted with MEA or DEA to yield tri-, di-, and monophosphate derivatives of MEA or DEA. The phosphoric acid ester of MEA or DEA was not formed at all. 2) The reactivities of MEA and DEA to P3m were in the order of MEA&gt;DEA, and TEA did not react with P3m. 3) The reactivity of P3m with MEA or DEA decreased with the decrease in the pH, and no reaction took place under acidic conditions. 4) The maximum yields of triphosphate derivatives of MEA, N-(2-hydroxyethyl)triphosphoramidate(P3-(N)MEA) and of DEA, N-bis(2-hydroxyethyl)triphosphoramidate (P3-(N)DEA), were about 75 and 60% respectively at a molar ratio of 1 : 1, at pH 12, and at room temperature. 5) P3-(N)MEA and P3-(N)DEA easily recyclized to the raw material, P3m, under acidic conditions. 6) The mechanism of the reaction between P3m and MEA or DEA was investigated.
Ring-Opening Reactions of Thiophene Derivatives by the Use of the Birch Reduction
Authors: Kumamoto Takanobu , Hosoya Kumiko , Kanzaki Satoshi , Masuko Kazuhiro , Watanabe Mikio , Shirai Kozo 
Published: July 2006

Abstract
It was found that the Birch reduction of 2-(2-thienyl)alkanoic acid and subsequent alkylation with benzyl bromide resulted in the formation of 2-alkyl-3-benzylthio-3-hexenoic acid selectively. Further, the Birch reduction of a 2,3-dialkylthiophene and subsequent alkylation with benzyl bromide gave a tetrasubstituted olefin which was formed by a selective C–S bond fission between the 1 and 5 positions of the thiophene nuclei. In contrast to these results, the Birch reduction of 3-thiophenecarboxylic acid derivatives and subsequent benzylation gave 2-alkyl-4-benzylthio-3-butenoic acid which was formed by a C–S bond fission between the 1 and 2 positions of the thiophene nuclei.
The Total Synthesis of (±)-Pisiferin
Authors: Matsumoto Takashi , Imai Sachihiko , Yoshinari Takashi , Matsuno Shigeo 
Published: July 2006

Abstract
The conversion of racemic α-cyclocitral into 3-(3-isopropyl-4-methoxyphenethyl)-4,4-dimethyl-2-methylenecyclohexanone (2) was carried out in five steps via 3-(3-isopropyl-4-methoxyphenethyl)-2,4,4-trimethyl-1-cyclohexene. An intramolecular cyclization of 2 with polyphosphoric acid produced the corresponding two tricyclic ketones possessing cis- and trans-A/B ring junctions. Each of these ketones was further converted into 12-mesyloxy-9(10→20)-abeo-abieta-1(10),8,11,13-tetraene in four steps. The mesylate was reduced with lithium aluminium hydride to give (±)-pisiferin.
Spacer-Assisted Catalytic Action of Imidazole-Appended γ-Cyclodextrin
Authors: Ueno Akihiko , Moriwaki Fumio , Osa Tetsuo , Ikeda Tsukasa , Toda Fujio , Hattori Kenjiro 
Published: July 2006

Abstract
Catalytic activity of γ-cyclodextrin bearing an imidazole moiety (1) was compared with that of the corresponding β-cyclodextrin derivative (2) in the hydrolysis of p-nitrophenyl acetate. The catalysts 1 and 2 hydrolyzed the ester 80 and 172 times, respectively, as fast in the complexes as the buffer without any catalyst. The binding of 1 for the ester was 40% weaker than that of 2. When sodium 1-naphthaleneacetate was present in the catalytic systems, the hydrolysis rate was enhanced for 1, but depressed for 2. This rate enhancement of 1 suggests that sodium 1-naphthaleneacetate acts as a spacer which facilitates 1 to bind the substrate by narrowing the large γ-cyclodextrin cavity. The time dependency of p-nitrophenol formation under the conditions of large excess of p-nitrophenyl acetate to 1 or 2 exhibited that the inhibitory effect of the product was remarkable for 2, but negligible for 1.
Mechanism of Carboxylic Acid-Catalyzed Reduction of Substituted Nitrosobenzenes by 1-Benzyl-3,5-bis(1-pyrrolidinylcarbonyl)-1,4-dihydropyridine in Acetonitrile
Authors: Awano Hiroshi , Tagaki Waichiro 
Published: July 2006

Abstract
Mechanism of carboxylic acid-catalyzed reduction of substituted nitrosobenzenes by 1-benzyl-3,5-bis(1-pyrrolidinylcarbonyl)-1,4-dihydropyridine has been studied in acetonitrile at 25 °C. The major product was hydroxylamine when the dihydropyridine was used in excess over nitrosobenzene, while that was azoxybenzene in the reverse case. The observed second-order rate constant k2R are dependent on acid concentration in a first-order manner with the acid-catalyzed third-order rate constant kHR. The Hammett relationship for kHR for substituted nitrosobenzenes gave a ρ=−0.93. The Brönsted plot of log kHR vs. pKa of acids gave a straight line with a slope of −0.34. The deuterium isotope effect for the catalysis by dichloroacetic acid was found to be kHR⁄kDR=2.80. These results indicate that a general acid catalysis by carboxylic acids plays an important role in the reduction of nitrosobenzene by dihydropyridine in acetonitrile.
Conformational Study of Acyclic Alcohols by NMR Spectroscopic Analysis, Molecular Force Field and Ab Initio Calculations
Authors: Abe Kazuhisa , Ito Kohichi , Suezawa Hiroko , Hirota Minoru , Nishio Motohiro 
Published: July 2006

Abstract
Conformations of a series of acyclic alcohols (CH3CH(R)CH(OH)CH3, CH3CH(R)CH(OH)CH(R′)CH3, and CH3CH(R)CH(OH)But) were studied (1) by measuring vicinal H–H coupling constants (3JH–H), (2) by lanthanoid-induced shift (LIS) analysis, (3) by molecular mechanics calculations (MM2), and (4) by ab initio (STO-3G, 4-31G geometry optimization) calculations. In the case of conformationally flexible alcohol as exemplified by 2-butanol and 3-pentanol, population of conformers determined by the LIS method do not agree with those determined by the 3JH–H, MM2, and ab initio methods. The discrepancy comes from the fact that the LIS measurement gives the most stable conformation of the alcohol in the LSR-alcohol complex and not of the free alcohol. In some flexible molecules, the most stable conformer in the complex can be different from that of the free molecule. In general, the conformational equilibrium is shifted by coordination of the shift reagent to the conformer whose alkyl chain stretches opposite to the direction of the coordination site of the shift reagent.
Synthetic Studies on Glycocinnamoylspermidine. II. Synthesis of 4-O-(2-Azido-2-deoxy-d-xylopyranosyl)-2-azido-2-deoxy-d-xylopyranose Derivatives
Authors: Araki Koichi , Kawa Manabu , Saito Yoshihiro , Hashimoto Hironobu , Yoshimura Juji 
Published: July 2006

Abstract
Synthetic intermediates for the aminopentose disaccharide moiety of glycocinnamoylspermidine were synthesized from d-xylose.
Fusogenic Behavior of Single-Walled Vesicles Composed of Synthetic Peptide Lipids
Authors: Murakami Yukito , Kikuchi Jun-ichi , Takaki Toshihiko 
Published: July 2006

Abstract
Fusogenic behavior of the single-walled vesicles formed with mixed or individual synthetic peptide lipids, N+C5Ala2Cn and (SO3−)C5Ala2Cn (n=14,16), was investigated in the presence of various water-soluble polymers or a nonbilayer-forming lipid by means of electron microscopy, differential scanning calorimetry, and turbidity measurements. The following ionic polymers having opposite charges to the net surface charges of the vesicles immediately induced fusion via vesicle aggregation; heparin, chondroitin sulfate C, chondroitin, and potassium salt of poly(vinyl sulfate) for the cationic vesicles, and polybrene for the anionic ones. On the other hand, ionic polymers having electrostatic charges identical with the vesicular surface charges and nonionic ones, such as amylose, poly(vinyl alcohol), polyethylene glycol 20000, and polyethylene glycol 6000, induced neither fusion nor aggregation. A nonbilayer-forming lipid, QC5Ala2C14, incorporated into the N+C5Ala2Cn vesicles induced fusion at kinetic rates much slower than those triggered by the ionic polymers. The observations were discussed with attention to the dehydration effect and the participation of nonbilayer structures in the fusion process.
Synthesis and Complexing Ability of New Type of Macrobicyclic Compounds
Authors: Nakatsuji Yohji , Kikui Takashi , Ikeda Isao , Okahara Mitsuo 
Published: July 2006

Abstract
New types of macrobicyclic compounds were synthesized from monoaza crown ethers bearing two hydroxyl groups and their complexing abilities regarding alkali metal cations were investigated.
Selective Linear Codimerization of Terminal Acetylenes and 1,3-Butadienes Catalyzed by (η4-1,5-Cyclooctadiene)(η6-1,3,5-cyclooctatriene)ruthenium(0)–Trialkylphosphine
Authors: Mitsudo Take-aki , Hori Yoji , Watanabe Yoshihisa 
Published: July 2006

Abstract
The reaction of terminal acetylenes with 1,3-butadienes catalyzed by (η4-1,5-cyclooctadiene)(η6-1,3,5-cyclooctatriene)ruthenium [Ru0(COD)(COT)]–PR3 (R=ethyl, butyl, octyl) in various solvents at 80 °C afforded linear codimers in good to excellent yield with high chemo-, regio-, and stereoselectivities. Reactions of deuterated acetylenes were also examined.
Synthesis and Antitumor Activity of N-Acetylmuramyl-l-alanyl-d-isoglutamine 6-Phosphate and Its Lipophilic Derivatives
Authors: Imoto Masahiro , Kageyama Shigeki , Kusumoto Shoichi , Kohno Morihiro , Matsumoto Kensuke , Hashimoto Shinjiro , Tohgo Akiko , Shiba Tetsuo 
Published: July 2006

Abstract
6-Phosphate of N-acetylmuramyl-l-alanyl-d-isoglutamine and its lipophilic derivatives, i.e., 6-(octadecyl hydrogenphosphate) and 6-(2-docosyltetracosyl hydrogenphosphate) were synthesized after the structural feature of mycobacterial cell walls for the purpose to modify and possibly to enhance the immunostimulating activity of the muramyl dipeptide which is the minimum requisite for the activity. As expected, the latter more lipophilic phosphate showed a high activity in a tumor regression test.
Dual-Mode Transport of Molecular Oxygen through the Membrane of the Poly(octyl methacrylate-co-4-vinylpyridine)(N,N′-disalicylideneethylenediaimine)cobalt(II) Complex
Authors: Nishide Hiroyuki , Ohyanagi Manshi , Kawakami Hiroyoshi , Tsuchida Eishun 
Published: July 2006

Abstract
Molecular oxygen transport through a polymeric membrane was enhanced in the membrane of poly(octyl methacrylate-co-4-vinylpyridine), complexed with (N,N′-disalicylideneethylenediamine)cobalt(II), which forms an oxygen adduct rapidly and reversibly. The cobalt complex in the membrane effectively acted as a fixed carrier on oxygen permeation. The oxygen-binding parameters determined spectroscopically were adequate to analyze the dual-mode transport model.
Kinetics and Mechanism of Acid-Catalyzed Oxidation of Substituted Toluenes by Pyridinium Fluorochromate
Authors: Bhattacharjee Bharati , Bhattacharjee Manabendra Nath , Bhattacharjee Mitra , Bhattacharjee Apurba Krishna 
Published: July 2006

Abstract
The kinetics of oxidation of substituted toluenes by pyridinium fluorochromate(VI) (PFC), C5H5N\overset+HCrO3F−, in aqueous acetic acid, in the presence of perchloric acid, have been studied. The main products are the corresponding aldehydes. While each of the oxidation is first order with respect to the oxidant, the rate is almost independent of the substrate concentration. The reactions depend on the first power of the concentration of acid. A kinetic isotope effect, kH⁄kD=5.4 at 30 °C, was observed. Electron-releasing groups were found to moderately facilitate the reaction, whereas the electron-withdrawing groups were found to have a retardation effect. Correlation with σ value yielded a ρ value of −2.0. The reaction does not induce polymerization of acrylonitrile. The effects of temperature and solvent compositions were studied and activation parameters evaluated. These and related data suggest that the initial reaction involves hydrogen abstraction forming an intermediate which subsequently produces the corresponding aldehyde.
Vibrational Spectrum of 2-Aminopyrazine
Authors: Kalkar Arun Kumar , Ars Comakshi C 
Published: July 2006

Abstract
Infrared and polarized laser Raman spectra in the solid phase and in the solution phase in different solvents have been obtained within the spectral region between 4000 and 200 cm−1 and analyzed for the purpose of vibrational assignments. The impact of intermolecular hydrogen bonding on amino group frequencies has been discussed in length. The fundamentals arising out of aromatic nucleus in particular various assignments are consistent with predicted spectral changes due to the presence of strong electron-activating amino group resulting in considerable perturbation of the vibrational levels of “parent” molecule pyrazine.
Interaction of Dithiophosphinates of Cobalt and Nickel with Pyridine-Type Donors
Authors: Mukherjee Rabindra Nath , Shankar Sanganabatla , Mascarenhas Denis Louis 
Published: July 2006

Abstract
The relative isotropic 1H NMR shifts of several pyridine-type base adducts of M(2,4-Me2dtpi)2 [where M=Co, Ni and 2,4-Me2dtpi=bis(2,4-dimethylphenyl)dithiophosphinate] were measured. The opposite signs of ring and methyl proton resonance shifts in α- and γ-picoline complexes of nickel indicate that both σ- and π-mechanisms are operative. In the cobalt cases all proton resonances are shifted down-field suggesting a negative dipolar contribution in addition to contact interaction. The magnetic and electronic spectral studies on these compounds are consistent with either MS4N or MS4N2 chromophores.
Kinetics of the Iron(II) Reduction of Glycinatobis(malonato)-, trans-Bis(malonato)bis(pyridine)-, Nitrilotriacetato(malonato)-, and Nitrilotriacetato(oxalato)cobaltates(III)
Authors: Viswanathan Ramakrishnan , Vijayaraghavan Venkatapuram Ramanujam 
Published: July 2006

Abstract
The kinetics of the iron(II) reduction of glycinatobis(malonato)-, trans-bis(malonato)bis(pyridine), nitrilotriacetato(malonato)-, and nitrilotriacetato(oxalato)cobaltates(III) have been studied in aqueous perchlorate medium at I=1.0 mol dm−3 (LiClO4) and 30 °C in the [H+] range 0.01–0.90 mol dm−3. The reductions are found to be second order. The reduction of [Co(gly)(mal)2]2− and [Co(py)2(mal)2]− is accelerated by H+, while the reduction of [Co(nta)(mal)]2− and [Co(nta)(ox)]2− is independent of [H+] in the range 0.1&lt;[H+]&lt;0.9 mol dm−3. The reduction of [Co(nta)(mal)]2− is, however, faster at [H+]&lt;0.1 mol dm−3. The activation parameters for the reduction of [Co(gly)(mal)2]2−, [Co(py)2(mal)2]−, [Co(nta)(mal)]2−, and [Co(nta)(ox)]2− are respectively as follows:
ΔH≠=49.8±4.8, 51.2±2.6, 41.1±3.2, and 41.4+3.6 kJ mol−1
ΔS≠=−98.3±8.3, −93.7±7.2, −119.2±9.7, and −114.6+9.6 J K−1 mol−1.
The proposed mechanism invokes [Co(L)(H2O)(mal)(malH)] (l-py2 or gly) formed in a H+-assisted step as the reactive species for the bis(malonato) complexes. [Co(nta)(mal)]2− is proposed to be present as [Co(nta)(malH)(H2O)]− while [Co(nta)(ox)]2− remains unaffected by H+.