bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anomalous Light Scattering by Poly(2-vinylpyridine) in Methanol
Authors: Sakamoto Noriyuki , Yoshida Masafumi , Arichi Shizuo 
Published: July 2006

Abstract
The light scattering of a poly(2-vinylpyridine) solution was measured under various conditions. In solvents such as methanol, ethanol, 2-propanol, 2-butanone, and pyridine, anomalous Zimm plots with an upward inflection at lower angles were observed. This anomaly was especially striking in methanol, in which the dissymmetry coefficient was frequently less than unity. Systematic investigations carried out with methanol as a solvent revealed that; (1) the anomaly does not depend appreciably on the concentration or tacticity of the polymer, the temperature, or the wavelength of the incident light; (2) the anomaly diminishes with an increase in the molecular weight of the polymer; (3) the anomaly disappears upon the addition of dry ammonia of 10−2 mol/1 or more in methanol, and (4) similar perturbed Zimm plots are realized by the addition of a trace amount of hydrochloric acid or sulfuric acid in a methanol solution of a higher-molecular-weight fraction which showed a normal Zimm plot in pure methanol. The anomaly can not be explained in terms of the effects of the optical anisotropy of the polymer segment, but the external interference arising from the non-random arrangement of the polymer in solution may contribute to it.
The Crystal Structure of dl-1,2,3,4,5,6-Hexahydro-6,11,12,12-tetramethyl-2,6-methano-3,11-propano-3-benzazocine Hydrochloride Monohydrate
Authors: Kimura Michio , Nakajima Takesi , Inaba Shigeho , Yamamoto Hisao 
Published: July 2006

Abstract
The structure of the title crystal (C19H27N·HCl·H2O) has been determined by X-ray diffraction method. The racemate crystallizes in monoclinic, space group P21/c with a=14.30, b=15.74, c=7.79Å, β=98°58′ and Z=4. The reflection intensities were measured visually from equi-inclination integrating Weissenberg photographs taken with CuKx radiation. The structure was solved by the direct method of phase determination. The final R factor was 0.113. The molecules are linked in endless chains along c-axis by N+···Cl− and Cl−···H2O···Cl− hydrogen bonds. Two piperidine rings in the molecule have the chair conformation. This product which shows analgesic activity has a new molecular structure having a four-ring system, part of which is a benzomorphan nucleus.
Studies of Ruthenium Complexes. VII. Photochemical Reactions of cis-Dihalogenotetraammineruthenium(III) Complexes in Aqueous Solutions
Authors: Ohyoshi Akira , Takebayashi Noriyuki , Hiroshima Yutaka , Yoshikuni Kenichiro , Tsuji Kazuhiko 
Published: July 2006

Abstract
Studies have been made of the photochemistry of cis-dihalogenotetraammineruthenium(III) in aqueous solutions. For the cis-dichlorocomplex, no photochemical reaction has been observed by the irradiation of the visible light region. For cis-dibromo- and cis-diiodo-complexes, a simple aquation of halide ligand seems to occur in a solution with a pH lower than 2.5. The typical values of the quantum yields for the cis-[RuX2(NH3)4] ++H2O\xrightarrowhν cis-[RuX(OH2)(NH3)4]2+X− reaction were 0.27×10−2 (382 nm light) and 0.82×10−2(408 nm light) for dibromo- and dichloro-complexes respectively. The quantum yield was dependent on the wavelength of light, but was independent of the concentrations of halide and hydrogen ions. The quantum yield seems to depend on the oxidizability of the ligand or on probability of the deactivation process in the primary excited state. In accounting for the low quantum yield, it seems most probable that the photoexcited complex species is converted to the ground state by non-radiative transitions.
Electron Transfer Reaction between Thallium(I) and Thallium(III) in the Presence of Cerium(IV) in Aqueous Solution
Authors: Wada Goro , Tamaki Kyoko 
Published: July 2006

Abstract
The kinetics of the electron transfer reaction between Tl(I) and Tl(III) was investigated in the presence of Ce(IV) by use of a radioactive tracer 204Tl. The apparent rate constant of the reaction, kapp, was dependent upon [H+] and [Co(IV)] (&lt;0.6×103 M) and can be expressed by
k_app=k_A+\frack_B[H^+]+\left(k_C+\frack_D[H^+]\ight)[Ce(IV)].
k app is gradually saturated to a limiting value according to [H+] at higher [Ce(IV)]. The observed values are kA=4.70 M−1 h−1, kB=2.13 h−1, kC=1.30×103 M−2 h−1 and kD=2.61×103 M−1 h−1 at 50 °C. Since Ce(IV) is a one-electron-oxidant, Tl(I) is oxidized by one-electron transfer to produce Tl(II) as an intermediate. However, in the absence of one-electron-oxidant or -reductant, two electrons are transferred from Tl(I) to Tl(III) not through double steps of one-electron transfer but predominantly through a single step of two-electron transfer.
Kinetics of Multidentate Ligand Substitution Reactions. XVI. Substitution Reactions of l,2-Cyclohexanediamine-N,N,N′,N′-tetraacetic Acid (CyDTA) with the Zinc(II)–Ethylenediaminemonoacetate (EDMA) and -Ethylenediamine-N,N′-diacetate (EDDA) Complexes and That of Ethylenediamine-N,N,N′,N′-tetraacetic Acid (EDTA) with the Nickel(II)–EDDA Complex
Authors: Kodama Mutsuo 
Published: July 2006

Abstract
The kinetics of the substitution reactions of CyDTA with zinc(II)–EDMA and –EDDA complexes and that of EDTA with the nickel(II)-EDDA complex were studied systematically by using the polarographic technique. All the substitution reactions were found to be first-order with respect to the CyDTA or EDTA anion and also first-order with respect to the 1 : 1-ratio EDMA or EDDA complex. From a comparison of the observed rate constants with those estimated on the basis of the proposed reaction intermediates, the detailed reaction mechanisms were discussed. The rates of the reactions of zinc(II)–EDMA complex and nickel(II)–EDDA complex could be understood in terms of the ethylenediamine reaction mechanism, but that of the reaction of the zinc(II)–EDDA complex with the CyDTA anion could not. This discrepancy may be ascribed by the steric hindrance of the CyDTA anion to the formation of an ethylenediamine reaction intermediate in the reaction of the zinc(II)–EDDA complex.
Cobalt-59 Nuclear Magnetic Resonance Study of Cobalt(III) Complexes. Empirical Rules for the Cobalt-59 Chemical Shifts and Line Widths of [CoIII(en)x(NH3)6−2x−yLy]-type Complexes
Authors: Yajima Fumikazu , Koike Yasuo , Yamasaki Akira , Fujiwara Shizuo 
Published: July 2006

Abstract
The cobalt-59 chemical shifts and line widths for about seventy cobalt(III) complexes of the [CoIII(en)x(NH3)6−2x−yLy] (L= Cl, Br, NO2, N3, OH, H2O, CO3, and C2O4) type have been measured. The cobalt-59 chemical shifts of this type of complex are approximately represented by a simple relation:
δ(ppm)=360x+\oversety\underseti=1∑δ_i(L) (x=0, 1, and 2),
where δi(L) is the i-th ligand shift parameter which represents the contribution of the i-th ligand, l, to the total chemical shift. Three empirical rules can be derived from experimental observations: I. The chemical shift of a trans-isomer is higher than that of the corresponding cis-isomer. II. The line width of the trans-CoA4B2 isomer is larger than that of the cis-CoA4B2 isomer. III. The line width of a meridional isomer is larger than that of the corresponding facial isomer. Illustrative examples are presented where cobalt-59 NMR is used to identify cobalt (III) complexes and to study the kinetics and equilibrium in solution.
Crystal Structure of Bis(iminodiacetamide)copper(II) Perchlorate
Authors: Sekizaki Masao 
Published: July 2006

Abstract
Bis(iminodiacetamide)copper(II) perchlorate was newly synthesized, and the crystal structure was determined from three-dimensional X-ray data collected on a diffractometer. The structure was refined by blockdiagonal least-squares methods to give R=0.08 for the 950 observed reflections. The crystals are monoclinic with the space group of P21/c. There are two formula units per unit cell with a=6.183, b=17.617, c=8.900 Å, and β=110.2°. The complex is centrosymmetric, in which the two ligand molecules coordinate to the central copper atom through two imino nitrogen atoms and two of the four amide oxygen atoms in trans positions, exhibiting a square-planar coordination. The other two amide oxygen atoms are weakly bonded to the copper atom above and below this square-plane, thus completing an s-facial distorted (elongated) octahedral coordination. The complex cations are held together through hydrogen bonds to form infinite chains along the a axis. These chains are connected with one another by perchlorate ions through hydrogen bonds, thus forming three-dimensional networks.
The Reaction of N-Chlorocarbamoylethyl Starch with Amines in an Aqueous Alkaline Medium; Reactions of An Isocyanate Group
Authors: Higuchi Mitsuo , Takeshita Kenji , Senju Ryoichi 
Published: July 2006

Abstract
The reactions of N-chlorocarbamoylethyl starch with simple monoamines were investigated in order to elucidate the mechanism of the reaction of an isocyanate group with amines in an aqueous alkaline medium. It was confirmed that the N-chloroamide group reacts with amines through the formation of an isocyanate group. The reactions of the isocyanate with amines in the presence of sodium hydroxide obeyed the following equation: (rate of isocyanate–amine reaction)/(rate of isocyanate–OH− reaction)=ku[amine]/ka[OH−] showing no catalytic effects of reactants or products. The reactivities of most of the primary amino groups attached to primary carbon with the isocyanate are comparable to that of the hydroxide ion. The relative rates of the reactions of amines with the isocyanate are not always correlated to their basicities, even when differences in steric hindrance are not great. Both the enthalpy and entropy of activation for the isocyanate–amine reactions are smaller than those for the isocyanate–OH− reaction.
A Mechanistic Study of the Acetolyses of 3-Chloropropene Sulfide and 2-Chloroethyl Methyl Sulfide
Authors: Tabushi Iwao , Tamaru Yoshinao , Yoshida Zen-ichi 
Published: July 2006

Abstract
Forming a marked contrast to hydrolysis, the first-order rate constant in the acetolyses of 3-chloropropene sulfide (I) and 2-chloroethyl methyl sulfide (II) has been observed to be seriously decreased; this may be ascribed to the return to the starting material of the sulfonium intermediate (III′ or IV) by the chloride ion liberated in the course of the reaction. The reaction has substantially obeyed first-order kinetics, giving exclusively and quantitatively skeletally-rearranged 3-acetoxy-thietane (the first-order rate constant; k1=2.1×10−5 s−1, at 55.0 °C) and 2-acetoxyethyl methyl sulfide (k1=4.8×10−4 s−1, at 55.0 °C) from I and II respectively.
A Polarographic Study of Aryl-substituted Tetra-aza- and Hexa-aza-pentalenes in Dimethylformamide
Authors: Matsumoto Akira , Lee Joung Hee , Yoshida Masayuki , Simamura Osamu 
Published: July 2006

Abstract
The polarographic reduction potentials of aryl-substituted 1,2,4,5-tetra-aza- and 1,2,3,4,5,6-hexa-aza-pen-talenes were shown to be approximately governed by the numbers of nitrogen atoms and aryl-substituents. Such effect of nitrogen atoms was discussed in terms of the orbital energies of parent azapentalenes obtained by HMO calculations.
Preparations and Properties of 5-Phenyl-5H[1,2,3]-triazolo[4,5-c][1,2,5]-oxadiazole, -thiadiazole, and -selenadiazole
Authors: Matsumoto Akira , Yoshida Masayuki , Simamura Osamu 
Published: July 2006

Abstract
The title compounds have been synthesized, and their chemical reactivities and spectroscopic properties are discussed in comparison with those of 2,5-diphenyl-v-triazolo[4,5-d]-v-triazole.
Reactions of Iodocarbenoid of Zinc. II. The Iodocyclopropanation of Olefins with Diethylzinc and Iodoform
Authors: Miyano Sotaro , Hashimoto Harukichi 
Published: July 2006

Abstract
The iodocyclopropanation of olefins by the iodocarbenoid of zinc generated from diethylzinc and iodoform was investigated. When the reaction was carried out in a neat olefin, cyclohexene, 1-hexene, cis-2-butene, isobutene, and styrene gave the corresponding iodocyclopropanes in yields of 70, 34, 63, 55, and 44% respectively, showing that the CHI3–Et2Zn system is a convenient route for iodocyclopropanes. The reaction with cyclohexene was investigated in some detail. syn-7-Iodonorcarane easily gave 3-ethylcycloheptene upon treatment with diethyl zinc in the presence of zinc iodide.
Synthetic Study of Colchicine
Authors: Kato Michiharu , Kido Fusao , Wu Ming-Der , Yoshikoshi Akira 
Published: July 2006

Abstract
An efficient route based upon solvolytic fragmentation of a cyclopentadiene-dichloroketene adduct 4c has been investigated for the synthesis of trimethoxyphenylpropyltropolone 2b, a synthetic intermediate of colchicine 1a. Attempted synthesis of the corresponding unsaturated tropolones 8a and 10 is also discussed.
Synthesis of Sesquirosefuran
Authors: Kumazawa Satoru , Nishihara Koichi , Kato Tadahiro , Kitahara Yoshio , Komae Hisashi , Hayashi Nanao 
Published: July 2006

Abstract
Sesquirosefuran (I) was synthesized by the coupling of geranyl bromide with 2,2′-bis(3-methylfuryl)-mercury in 29% yield.
The Direct-current Conductivity of Silica Gel
Authors: Muroya Masa-aki , Kondo Seiichi 
Published: July 2006

Abstract
The study of the effect of heat-treatment on the direct-current conductivity of silica gel showed that the conductivity changed in response to the dehydration of the adsorbed water and of various kind of silanols. The temperatures of dehydration by this experiment seems to coincide with other experiments such as IR spectroscopy.
The ESR Spectra of Michler’s Ketone Anion Radicals
Authors: Fujita Hideo , Kako Saburo , Yamauchi Jun , Ohya-Nishiguchi Hiroaki , Deguchi Yasuo 
Published: July 2006

Abstract
The ESR spectra of Michler’s ketone anion radicals reduced by alkali metal in solution consist of five groups of lines at +20 °C, but change into three groups of lines at −50 °C. The assigned hyperfine splitting constants are AHo=3.22, AHm=0.43, AN=0.72, AHCH3=0.29 gauss at +20 °C.
Solvolytic Reactions in Dipolar Aprotic Solvents. Reaction Rates of the Tertiary Aralkyl System
Authors: Uchida Takane , Marui Sumie , Miyagi Yo , Maruyama Kazuhiro 
Published: July 2006

Abstract
Solvolytic reaction rates of 2-aryl-2-chloropropanes in dipolar aprotic solvents were determined in order to obtain activation parameters, ρ-values, and β-deuterium effect. The results are compared with those in protic solvents.
Determination of Enantiomeric Purity of 1-Phenylalkanols Using a Chiral NMR Shift Reagent
Authors: Yamamoto Keiji , Hayashi Tamio , Kumada Makoto 
Published: July 2006

Abstract
Addition of tris[3-(trifluoromethylhydroxymethylene)-d-camphorato]europium(III) to solutions of partly active (S)-1-phenylalkanols caused large enantiomeric shift differences (ΔΔδ) in their 1H NMR spectra, which permitted a direct determination of enantiomeric compositions of these alkanols.
Calculation of the Carbon-13 NMR Chemical Shifts of Linear and Branched Paraffins and Saturated Cyclic Hydrocarbons
Authors: Takaishi Kitsuma , Ando Isao , Kondo Masahiro , Chûjô Riichirô , Nishioka Atsuo 
Published: July 2006

Abstract
The carbon-13 NMR chemical shifts of linear and branched paraffins have been calculated by means of Pople’s theory, particularly using the averaged excitation energy method. The calculation was carried out based on the CNDO/2 molecular orbital method. The values calculated by means of the averaged excitation energy method deviate extremely from the experimental ones; therefore, the energies most suitable for giving good agreement are investigated and determined for linear and branched paraffins. The suitable energies are expressed by an empirical formula, correlated to the molecular structure. The results obtained may be briefly expressed by;
& ΔE= 11.30×1.015^a×0.958^b×1.010^c×S
& S=1.011^d×1.009^e×1.029^f×1.009^g×1.030^h×1.031^i
(see Results and Discussion for the notations used).
This empirical averaged excitation energy expression is applied to cyclic hydrocarbons, such as cyclohexane, methylcyclohexane, and dimethylcyclohexane. Further, the γ-effect is estimated on the basis of these results.
A New Pyrochlore System, Pb(Tix·Sn1–x)O3, and Its Transition to a Perovskite System
Authors: Shirasaki Shin-ichi , Yamamura Hiroshi , Muramatsu Kunitaka , Takahashi K\={o}ichiro 
Published: July 2006

Abstract
A series of pyrochlore compounds of Pb(Tix·Sn1–x)O3, was aqueously prepared. They were characterized in terms of inhomogeneously distributed Ti and Sn ions in the equivalent lattice positions. In the composition range where the value x was between 0.00 and 0.45, monophasic pyrochlore was crystallized. In the composition range of x\gtrsim0.45, however, the pyrochlore phase more or less coexisted with a noncrystalline substance whose composition was supposed to be Pb/(Ti+Sn) mole ratio &lt;1.0. The process of thermal transition from the pyrochlore-type Pb(Ti0.4·Sn0.6)O3 to the perovskite-type system was traced by two lines of measurements of the pyrochlore, i.e., the lattice constant and the degree of fluctuation of interplanar spacings, and by measurements of the tetragonal lattice strain of the resultant perovskite. The results showed that the transition occurred preferentially at Ti-rich microregions in the matrix lattice, in which a measurable fluctuation of the Sn: Ti ratio was detected.
A Study of the Thermal Degradation of Several Halogen-containing Polymers by Torsional Braid Analysis
Authors: Furusho Noboru , Komatsu Tsuyoshi , Nakagawa Tsurutaro 
Published: July 2006

Abstract
The thermal degradation of several halogen-containing polymers in air was studied by means of the TBA(Torsional Braid Analysis) method and IR spectroscopy. The samples were poly(vinyl chloride)(PVC), vinylidene chloride-vinyl chloride copolymer(PVdC-VC), poly(vinyl fluoride)(PVF), poly(vinylidene fluoride)(PVdF), poly(vinyl bromide)(PVB), and poly (vinylidene bromide)(PVdB). The dynamic mechanical properties of these polymers are complicated at higher temperatures because of the thermal degradation, by, for example, dehydrohalogenation. The relative shear modulus (Gr) increases and then decreases through a maximum, accompanied by changes in the logarithmic decrement. The temperatures at which the changes in Gr occur become higher in the order of PVdB&lt;PVB&lt;PVdC-VC&lt;PVC&lt;PVdF&lt;PVF. This order agrees with that of the bond energy in carbon-halogen bonds. The apparent activation energies of these reactions were obtained from the changes in Gr and from the relative absorbance ratio of the carbon-carbon double bond with time, respectively. In general, the values estimated by these two procedures agreed well in each case.
Studies on Reactions of the N-Phosphonium Salts of Pyridines. V. The Preparation of Carboxylic Amides and Esters by Means of the One-electron-transfer Oxidation of Phosphorous Acid and Its Esters in the Presence of Tertiary Amines
Authors: Yamazaki Noboru , Higashi Fukuji 
Published: July 2006

Abstract
The oxidation of phosphorous acid and its esters with an equimolar amount of mercurous chloride and half an equimolar amount of mercuric chloride was carried out in tertiary amines. On the treatment of the oxidation mixture with carboxylic acids, amines, and alcohols, followed by aminolysis, alcoholysis, or acidolysis, the corresponding carboxylic amides and esters were obtained in good yields, together with a nearly quantitative yield of metallic mercury. The yield was affected by the tertiary amines, the alkyl groups in the dialkyl phosphites, and the steric effect of the carboxylic acids. The reaction was proposed to proceed through the activation of carboxylic acids, amines, and alcohols via the N-phosphonium salts prepared by the oxidation. The electron-transfer processes involved in the oxidation were discussed on the basis of the yield of the amides obtained. These procedures were successfully extended to the preparation of peptides and active esters of amino acids, using diphenyl phosphite in pyridine.
Synthesis of Succin-as-eins
Authors: Gopal R , Gupta P C , Garg S P 
Published: July 2006

Abstract
A new series of compounds, succin-as-eins(SAE)–methyl phenol SAE, methyl resorcinol SAE, methyl catechol SAE, methyl quinol SAE, methyl phloroglucinol SAE, methyl pyrogallol SAE and methyl orcinol SAE have been prepared by condensing 2-acetyl propionic acid with appropriate phenols. The structure of methyl resorcinol SAE, based on chemical reactions and spectral data is discussed. The λmax values for few of the dyes are comparable with their analogous succineins and phthaleins.
Tritium Fractionation in the Crystallization of Aluminum Alums from Their Aqueous Solutions
Authors: Tanaka Haruhiko , Ando Hiroko , Negita Hisao 
Published: July 2006

Abstract
The tritium fractionation in the crystallization of NH4Al(SO4)2·12H2O from a solution was found to be larger than those in NaAl(SO4)2·12H2O and KAl(SO4)2·12H2O. This fact was discussed in terms of the proton exchange between NH4+ and H2O.
The Standard Free Energy of the Formation of LaFeO3 at 1204°C
Authors: Kimizuka Noboru , Katsura Takashi 
Published: July 2006

Abstract
The standard free energy of the formation of LaFeO3 was detemined to be −68700±200 cal·mol−1 at 1204°C by the following reaction: 1/2 La2O3(s)+Fe(s)+3/4 O2(g) = LaFeO3(s), based on precise phase equilibria in the Fe–Fe2O3–La2O3 system.
Dissociation Constants of 2-Aminotroponcs
Authors: Imafuku Kimiaki , Takata Yasuyoshi , Matsumura Hisashi 
Published: July 2006

Abstract
The dissociation constants of 2-aminotropones were measured in 50% aqueous methanol at 20°C and shown to be correlated by the Hammett equation with ρ=3.40. The difference between 4- and 6-substituents is discussed.
Decomposition of 1,4-Dimethoxybenzene Radical Cations in CH3NO2–AlCl3 System
Authors: Nishinaga Akira , Hayashi Hidetoshi , Matsuura Teruo 
Published: July 2006

Abstract
The decomposition of 1,4-dimethoxybenzene cation (2a) and 1,4-dimethoxy-2,5-dimethylbenzene cation (2b) gave 2,2′,5,5′-tetramethoxydiphenyl and 2,5-dimethyl-p-benzoquinone indicating that the reaction pathway depends on substituent at nucleus of the radical cations 2.
Carbon-13 Nuclear Magnetic Resonance Spectra of α-Ribonucleosides
Authors: Sugiyama Hiroshi , Yamaoka Naotaka , Shimizu Bunji , Ishido Yoshiharu , Seto Shuichi 
Published: July 2006

Abstract
The C-13 NMR spectra of four α- and two β-ribonucleosides have been measured and all carbon signals have been assigned.
The Heck Reaction of 2-Vinylpyridine
Authors: Kasahara Akira , Izumi Taeko , Takeda Toru , Imamura Hayao 
Published: July 2006

Abstract
In the presence of lithium chloropalladite, 2-vinylpyridine reacted with phenylmercuric chloride to give di-μ-chloro-bis[2-phenyl-2-(α-pyridyl)ethyl]dipalladium (II). Similar complexes were obtained from p-toy-, p-anisyl-, or m-nitrophenylmercuric chloride. The σ-bonded structures of these complexes have been confirmed by a study of their absorption and of the NMR spectra.
The Molar Volume and Entropy of Adsorbed Methane on Porasil
Authors: Hori Yoshio , Kobayashi Riki 
Published: July 2006

Abstract
With the use of high-precision gas-chromatography, the multilayer adsorption of methane on fused silica beads was precisely measured between 145.0 K and 213.6 K. The molar volume and the partial molar entropy of the adsorbed methane were determined as a function of the temperature. The molar volume in the monolayer region depends much less on the temperature than that of the bulk liquid. However, the molar volume of multilayer adsorbed methane shows a dependence on the temperature similar to that of bulk liquid, which is at a lower temperature. The volume of the monolayer is practically constant under the present experimental conditions. The apparent thickness of the adsorbed monolayer was interpreted in terms of a simple collision model. The partial molar entropy of the adsorbed phase is much lower than that of the saturated bulk liquid. The lower dependence of the molar volume on the temperature and the lower entropy suggest that the freedom of motion of the adsorbed molecules is restricted as compared with those in bulk liquid.