bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transition-metal Complexes of Pyrrole Pigments. IX. Divalent and Trivalent Iron Chelates of Dipyrromethenes
Authors: Murakami Yukito , Matsuda Yoshihisa , Sakata Kazunori , Harada Kenji 
Published: July 2006

Abstract
The iron chelates of polymethyl-substituted dipyrromethenes were prepared. The ferrous ion was found to form complexes having a ligand to metal ratio of 2 : 1 with 5,5′-substituted dipyrromethenes, 3,3′,5,5′-tetramethyl- and 3,3′,4,4′,5,5′-hexamethyl-dipyrromethene. On the other hand, the ferric ion gave a complex having a 3 : 1 molar ratio of ligand to metal with a 5,5′-unsubstituted ligand, 3,3′,4-trimethyldipyrromethene. The complexes were studied by means of visible and IR spectroscopy as well as by magnetic susceptibility measurements. The iron(II) chelates were confirmed to be of high spin type with distorted tetrahedral structure (D2), while the iron(III) chelate demonstrated a low spin character with hexacoordination. The strong ligand-field bands of the latter complex was ascribed to the trigonally distorted octahedral coordination (D3) along with a high covalent nature of metal-ligand bonds.
Peptides. V. Some Carbonates of Ethyl 2-Hydroximino-2-cyanoacetate and Related Compounds as Esterification Reagents for Peptide Synthesis
Authors: Itoh Masumi 
Published: July 2006

Abstract
Some carbonates (III) of ethyl 2-hydroximino-2-cyanoacetate (Ia) and 2-hydroximino-2-cyanoacetamide (Ib) were prepared and utilized as simple esterification reagents for acylamino acids.
Hydroxyl Stretching Frequencies and Conformations of 4-Chromanol, 4-Thiochromanol, and 4-Thiochromanol 1,1-Dioxide
Authors: Hanaya Kaoru , Onodera Shinji , Awano Sachio , Kudo Hideaki 
Published: July 2006

Abstract
Conformations of ten epimeric alcohols have been examined by the measurements of the OH stretching absorptions. The preference of the OH quasi-axial conformations was shown.
The Magnetic Properties of Manganese(II) Phthalocyanine. II
Authors: Miyoshi Hirokazu 
Published: July 2006

Abstract
The magnetic susceptibilities of manganese(II) phthalocyanine (PcMn) have been measured in the paramagnetic region between 13.8 and 280 K. The deviation from the Curie-Weiss law was found at a moderately high temperature (about 70 K), and the Weiss constant was obtained as 23 K. Comparing the ratio of Tc to θ (0.37) with that of the 2- or 3-dimensional lattice, the data were analysed on the basis of the ferro-magnetic linearchain model. The magnitude of the intra-chain interaction (J) was deduced as 5.64k by comparison with Fisher’s classical form of the theory of the ferromagnetic Heisenberg chain. We have also measured the magnetic susceptibilities of cobalt(II) phthalocyanine (PcCo) and of copper(II) phthalocyanine (PcCu), which are isomorphous with manganese(II) phthalocyanine, from 1.8 to 77 K. In PcCo, a broad maximum has been observed, and the data were analysed in terms of the theory of the antiferromagnetic Ising-chain model. On the other hand, PcCu obeyed the Curie law down to 1.8 K. A qualitative explanation of the exchange interactions in PcMn, PcCo, and PcCu was presented on the basis of their electronic states.
Isomerization of 2-Pinene Catalyzed by Solid Acids
Authors: Ohnishi Ryuichiro , Tanabe Kozo , Morikawa Shinsuke , Nishizaki Tadao 
Published: July 2006

Abstract
The isomerization of 2-pinene (I) and 2(10)-pinene (II) in the liquid phase has been studied at 50 °C over solid acid catalysts such as silica–alumina, aluminum phosphate, nickel sulfate and zinc sulfide which have different acid strengths. The primary reaction products were camphene (III), 1,7,7-trimethyl-tricyclo[2.2.1.02,6]heptane (IV) and p-mentha-1,8-diene (VI). The catalytic activities increased with increasing acid strength and acid amount of the catalysts. The selectivities for the formation of III+IV and VI from I were about 90 and 10% respectively over NiSO4, but about 10 and 70% respectively over SiO2–Al2O3 and AlPO4. Those for the formation of I, III+IV and VI from II also depended on the acid strength. In the isomerization of VI, p-mentha-1,4(8)-diene (VII) was formed predominantly over NiSO4 and p-cymene (IX) over SiO2–Al2O3. From these results together with those of the isomerizations of III and IV, a reaction mechanism is proposed which consists of two parallel reactions proceeding via a common intermediate between I and II: one which gives monocyclic terpenes and the other bi- and tricyclic terpenes.
Studies on Preparation of High Purity Sulfur. IV. Effect of the Distillation with Adsorbent and Silver on the Removal of the Impurities in Sulfur
Authors: Suzuki Hiroshi , Higashi Kunishige , Miyake Yoshizo 
Published: July 2006

Abstract
The distillation was shown to be effective in removing arsenic, selenium, tellurium, carbon, and common elements in sulfur. However, there was the disadvantage that trace amounts of common elements were not reduced further by the repetition of the distillation. This could be carried out by the zone refining.
Direct Syntheses of Methyl 2-Deoxy-2-alkoxycarbonylamino-d-glucopyranoside from 2-Amino-2-deoxy-d-glucose
Authors: Otani Sinichi 
Published: July 2006

Abstract
Methyl 2-deoxy-2-methoxycarbonylamino-and methyl 2-deoxy-2-ethoxycarbonylamino-d-glucopyranosides were synthesized by the reaction of 2-amino-2-deoxy-d-glucose with alkyl chlorocarbonate and sodium carbonate in methanol by a one-step process.
The Gas Chromatographic Determination of Selenium in Plant Material with 4-Nitro-o-phenylenediamine
Authors: Shimoishi Yasuaki 
Published: July 2006

Abstract
Selenium(IV) reacts with 4-nitro-o-phenylenediamine to form 5-nitropiaselenol, which is detected by means of a gas chromatograph equipped with an electron-capture detector. By this highly sensitive method, the determination of very small amounts of selenium in plant materials has been investigated. Fuming nitric acid digests the plant sample completely, and the selenium is converted to the quadrivalent state. No loss of selenium can be found by this treatment. A method is proposed for the determination of selenium in plant materials at levels as low as 0.005 μg/g in dried material.
Solvent Extraction Equilibria of Acids. VII. The Co-extraction of Water with Strong Mineral Acids by Trioctylphosphine Oxide
Authors: Niitsu Masaru , Iritani Nobuhiko , Sekine Tatsuya 
Published: July 2006

Abstract
The extraction of water from a 1 mol dm−3 sodium perchlorate solution with trioctylphosphine oxide (TOPO) in four organic solvents and the co-extraction of water with hydrochloric, hydrobromic, hydroiodic, perchloric, nitric, and thiocyanic acids from 1 mol dm−3 of the acid solution by TOPO in hexane have been studied at 25 °C. The extraction constants of water in the absence of any of the acids, K′H2O=[TOPO·H2O]org[TOPO]org−1, were determined to be 100.40, 100.00, 10−0.12, and 10−0.36 in benzene, hexane, carbon tetrachloride, and chloroform respectively. A discrepancy from the 1: 1 molar ratio of TOPO and water in the extract was observed in the higher-TOPO-concentration region in the hexane system. The co-extraction of water with the acids disolvated by TOPO was greater in the order of HCl\simeqHBr&gt;HI&gt;HClO4, and it was much poorer with the monosolvated acids, nitric and thiocyanic acid. The equilibria for these co-extractions of water with the acids are complicated.
Molecular Weight Distribution and Kinetics of Low-temperature Propene Polymerization with Soluble Vanadium-based Ziegler Catalysts
Authors: Doi Yoshiharu , Takada Morio , Keii Tominaga 
Published: July 2006

Abstract
A kinetic study has been carried out on the low-temperature polymerization of propene with the soluble catalyst system, VCl4 and alkylaluminium (AlEt2Cl, AlEt2Br, or AlEt3). The rate coefficients of the elementary reactions were evaluated at −78 °C. The molecular weight distribution function was derived on the basis of the polymerization mechanism. The theoretical distribution curves and experimental distribution curves obtained by use of a gel permeation chromatography agree, supporting the mechanism proposed for the coordination polymerization.
Acidic Property and Oxidation Activity of MoO3-V2O5-P2O5 Ternary Oxides
Authors: Ai Mamoru 
Published: July 2006

Abstract
The relationship between the acid-base properties and the oxidation activity of a series of ternary oxide catalysts, MoO3–V2O5–P2O5, with different V/Mo composition and a constant phosphorus content, P/(Mo+V)=0.1, was investigated. The acidity was determined by means of the NH3 adsorption and by studying the catalytic activity for acid-catalyzed reactions, such as dehydration of isopropyl alcohol and isomerization of 1-butene, in the presence of an excess of air. A new acidic site is generated by the combination of two binary oxides, i.e., MoO3–P2O5 and V2O5–P2O5, and a broad maximum in the acidity occurs at V/(Mo+V)=0.4–0.9. The basic property is so small that no satisfactory data can be obtained from the adsorption of acidic molecules such as CO2, SO2, and acetic acid. The catalysts, regardless of composition, are inactive for reactions which are accelerated by basic sites, such as oxidative dehydrogenation of isopropyl alcohol to acetone, oxidative decomposition of formic acid to CO2, and oxidation of methanol to CO2. The oxidation activities for butadiene and methanol can be tied to the acidity of the catalysts.
Molecular Dynamics of Polystyrene Model Molecules; Reorientational Correlation Times of Phenyl Groups of 2,4-Diphenylpentane
Authors: Koda Shinbu , Nomura Hiroyasu , Miyahara Yutaka 
Published: July 2006

Abstract
The reorientational correlation times of phenyl groups in 2,4-diphenylpentane in solution were measured as a function of the temperature by means of Raman line-shape analysis. The reorientational correlation times of both isomers increase as the temperature increases, that is, the reorientational motion of phenyl groups in molecules gradually become active. In the low-temperature region, the reorientational correlation times of the meso 2,4-diphenylpentane are longer than those of the racemic one. This fact that the molecular motion of phenyl groups of the racemic isomer rotates more easily than that of the meso one is in agreement with the results obtained from ultrasonic study by Monnerie et al. On the other hand, in the higher-temperature region, the reorientational correlation times of the meso isomer are shorter than those of the racemic one. In addition, the potential barriers for the reorientational motion of phenyl groups are found to be (3.3±0.3) kcal/mol for the meso isomer and (2.0±0.3) kcal/mol for the racemic isomer.
Studies of the Separation Mechanism in Ion-exchange Chromatography. I. Inversion of the Elution Order of cis and trans Isomers of Metal Complexes
Authors: Yoneda Hayami , Yamazaki Shigeo 
Published: July 2006

Abstract
The inversion of the elution order in ion-exchange chromatography was found for cis and trans isomers of [Co(X)2(en)2]+ (X=N3−, NO2−, and NCS−) by the addition of dioxane to NH4Cl or (NH4)2SO4 aqueous solution as eluent, and the separation mechanism was discussed.
EPR Studies of the Cobalt(II)–(N2S2)-Schiff Base Complex with Lewis Bases and CO
Authors: Sakurada Matsujiro , Sasaki Yoshihiro , Matsui Masakazu , Shigematsu Tunenobu 
Published: July 2006

Abstract
The EPR and optical spectra of N,N′-bis-3-thioxo-1-methylbutylidene)ethylenediaminatocobalt(II) in the presence of Lewis bases and CO were measured. The cobalt(II) complex formed five-coordinate adducts with Lewis bases and CO, which had a rhombic symmetry with a (dx2−y2, dxz, dyz)6(dz2)1 ground configuration.
The Carbonylation of α-Haloacetophenones and Benzyl Halides by Disodium Tetracarbonylferrate
Authors: Watanabe Yoshihisa , Taniguchi Kenichi , Suga Masataka , Mitsudo Take-aki , Takegami Yoshinobu 
Published: July 2006

Abstract
α-Haloacetophenones and benzyl chlorides can be converted into derivatives of β-keto acid and phenylacetic acid respectively by two succesive reactions, with Na2-Fe(CO)4 and then with nitrobenzenes or iodine-ethanol as the oxidizing reagents.
Preparation of 1,3-Bis(4-aminobutyl)-1,3-dimethyl-1,3-diphenyldisiloxane and Siloxane-containing Polyamides
Authors: Takiguchi Toshio , Amagai Kazuo , Kawabata Hisashi 
Published: July 2006

Abstract
1,3-Bis(4-aminobutyl)-1,3-dimethyl-1,3-diphenyldisiloxane has been readily obtained by the reduction of 1,3-bis(3-cyanopropyl)-1,3-dimethyl-1,3-diphenyldisiloxane, the hydrolysate of chloro(3-cyanopropyl)methylphenylsilane. The diamine reacted with abietic acid forming an equimolar crystalline adduct which gave a siloxane-containing polyamide by the conventional salt fusion technique.
A Convenient Method of Preparing p-Toluenesulfonates of Ethyl Esters of Amino Acids Using Ethyl p-Toluenesulfonate
Authors: Ueda Kazuo 
Published: July 2006

Abstract
The treatment of amino acids with ethyl p-toluenesulfonate affords the p-toluenesulfonates of the ethyl esters in good yields. Tryptophan ethyl-ester p-toluenesulfonate was also prepared in an 81% yield.
14N Nuclear Quadrupole Relaxation in Sulfuric Diamide and Methanesulfonamide
Authors: Negita Hisao , Kubo Tsuneo , Maekawa Michio , Ueda Akinobu , Okuda Tsutomu 
Published: July 2006

Abstract
The 14N nuclear quadrupole resonances (NQR) in sulfuric diamide (sulfamide), H2NSO2NH2, and methanesulfonamide, CH3SO2NH2, were studied by the pulse method. The resonance frequency and the spin-lattice relaxation time (T1) were measured in the temperature range from liquid nitrogen temperature to room temperature. In the case of sulfuric diamide, T1 decreases monotonously as the temperature rises, and is dominated by the thermal torsional motion below 140 K. On the other hand, T1 is attributed to the reorientation of the amino group in the temperature range from 200 to 240 K, whereas it is due to the reorientation of the molecule above 240 K; the activation energies in these orientations are 43.5 and 61.5 kJ·mol−1 respectively. In the case of methanesulfonamide, the minimum of T1 is found near 130 K. This is caused by the rotation of the methyl group. The activation energy for this motion is calculated to be 9.6 kJ·mol−1. The dominant relaxation mechanism is attributed to the reorientation of the amino group from 200 to 240 K and to the reorientation of the molecule above 240 K. The activation energies for these motions are 19.2 and 40.6 kJ. mol−1 respectively.
Ultrasonic Absorption in Dodecane Solution of Aerosol OT
Authors: Yamashita Teruyo , Yano Hiroshige , Yasunaga Tatsuya 
Published: July 2006

Abstract
The ultrasonic absorptions of Aerosol OT in dodecane solution were measured in the frequency range 5–95 MHz at various temperatures. An excess absorption caused by single relaxation was observed above the second critical micelle concentration. This is attributed to the conformational change in structure of two kinds of Aerosol OT micelles, since the maximum excess absorption per wave length depends on the concentration and temperature. The thermodynamic and kinetic parameters were determined in relation to the reaction.
Intramolecular Charge-transfer Absorption Spectra of Tetracyanotetrathiafulvalene
Authors: Yoneda Shigeo , Kawase Tokuzo , Yoshida Zen-ichi 
Published: July 2006

Abstract
The electronic spectrum and structure of tetracyanotetrathiafulvalene have been investigated by the ASMO-SCF-CI method, in which the 3d orbitals of sulfur atoms are taken into account. The calculated results showed that the absorption band at the longest wavelength can be interpreted in terms of intramolecular charge-transfer.
The Determination of the Chemical Diffusion Coefficients for AgBr and α-Agl by Means of an Improved d.c. Polarization Cell
Authors: Mizusaki Junichiro , Fueki Kazuo , Mukaibo Takashi 
Published: July 2006

Abstract
In order to determine the chemical diffusion coefficients for AgBr and α-AgI, a new experimental technique was developed. A Pt probe was inserted into the middle of the AgX (X=Br or I) pellet in an improved d.c. polarization cell of the Ag/AgX/carbon type, and the applied potential difference between the Ag and carbon electrodes was changed abruptly. The accompanying change in E(L⁄2), the EMF between the Ag electrode and the Pt prcbe, was followed, and the cherrical diffusion coefficient, \ ildeD, was determined by the analysis of the change in E(L⁄2) with the time. In the temperature range from 325 to 400 °C, \ ildeD for AgBr with excess silver was found to be
\ ildeD=7.10×102exp\left(−\frac1.96×104 cal molRT\ight)cm2s−1. (i)
In the temperature range of 330 to 500 °C, \ ildeD for a-AgI was
\ ildeD=4.95×10−1exp\left(−\frac7.71×103 cal mol−1RT\ight)cm2s−1. (ii)
Using these chemical diffusion coefficients and the electronic conductivity data, the nonstoichiomctry, and apparent mobility of electronic carriers of AgBr and α-AgI were determined.
Adsorptive Mechanism on Activated Carbon in the Liquid Phase. I. Free Energy Change for Adsorption of Organic Compounds from Aqueous Solution on Activated Carbon
Authors: Abe Ikuo , Hayashi Katsumi , Kitagawa Mutsuo , Urahata Toshihiro 
Published: July 2006

Abstract
The adsorption isotherms, from aqueous solution onto activated carbon, have been determined for the 22 aliphatic monofunctional compounds; alcohols, carboxylic acids, ketones, ethers, esters, and aldehydes. The free energy change for the adsorption process has been calculated from the adsorption equilibrium constant at infinite dilution; a linear relationship exists between the free energy change and the number of carbon atoms in the solute. The free energy of adsorption has been divided into two contributions: the hydrocarbon and the functional group contribution. The free energy change for the adsorption process has been compared with the free energy change for the precipitation process from solution into the pure liquid solute. The free energy contribution per individual methylene group to the adsorption process shows an approximate agreement with that for the precipitation process indicating that the adsorption process of the hydrocarbon portion of the solute is analogous to the precipitation process. The free energy contribution of the functional group to the adsorption process is smaller than that for the precipitation process indicating that the functional group portion of the solute is not appreciably dehydrated in the adsorption phase.
The Study of Carrier Effects on the ESR of Vanadium Ions Formed in Supported Catalysts, as Assisted by Spectrum Calculation
Authors: Ueda Hisashi 
Published: July 2006

Abstract
In order to study the carrier effects on the supported catalysts of vanadium, the ESR spectra of vanadium ions supported on γ-Al2O3, SiO2, ZrO2, TiO2, MgO, or CaO and reduced in H2 at 500 °C were studied. When γ-Al2O3, SiO2, ZrO2, or TiO2 were used as the carriers, the main spectral component could be assigned to the V4+ ion. The results of data analysis, assisted by spectrum calculation, showed that, on catalyst which had a high activity in the reduction of NOx by NH3, the V4+ ion had a highly populated dxy orbital, while on catalyst of low activity, V4+ had a dxy with a low spin density. If the carrier was MgO, the V ion was reduced to V2+. If the carrier was CaO, no ESR signals due to V ions were observed. It has been suggested that an inhomogeneous and axially symmetric crystal-field model may interpret the intensity ratios among the hyperfine lines of the V4+ ESR absorption rather than a non-axial symmetry model of the V4+ unpaired electron.
Effect of Methyl Substitution on the Electron Spin Resonance Spectra of Yang’s Biradical
Authors: Mukai Kazuo 
Published: July 2006

Abstract
Mono- and dimethyl derivatives (II) and (III) of Yang’s biradical (I) were prepared, and the methyl-substitution effects on the molecular symmetry and spin-density distribution of Yang’s biradical have been studied. Resolved hyperfine structures were observed in the ESR spectra of liquid solutions of the biradicals (II) and (III), giving the hyperfine splitting values theoretically expected for their triplet states. In a fluid solution, the biradical molecules retain a three-fold symmetry, as has been reported for Yang’s biradical, and the expected methyl-substitution effect is too small to induce any asymmetric, unpaired spin distribution. The g- and D-tensor values of the (II) and (III) biradicals were determined from analyses of the asymmetric ESR spectra of frozen solutions containing the biradicals. The results suggest that these biradicals must also lack a three-fold symmetry in a frozen solution, as has been observed for Yang’s biradical. Essentially the same g- and D-tensor values as those of Yang’s biradical are observed for the monomethyl derivative (II). On the other hand, the dimethyl derivative (III) shows quite different g- and D-tensor values.
The Combined Field Emission-Spin Trapping Method for Studying Reactions of Electrons in Organic Solutions
Authors: Noda Shoji , Ohta Yasunari , Yoshida Hiroshi 
Published: July 2006

Abstract
The reactions of electrons injected by field emission into solutions have been investigated. Free radicals generated by the dissociative electron attachment to chlorinated solutes in benzene solutions were detected by the spin trapping-ESR method, using pentamethylnitrosobenzene as a spin trapping agent. Nondissociative electron attachment to styrene caused by the field emission was also evidenced by detecting the α-methylbenzyl radical generated secondarily from the styrene radical anion. The electrons field-emitted into the solutions are captured almost quantitatively by the electron scavenging solutes. The field emission method has been found to be useful for generating authentically free radicals and for studying the anionic reaction induced by electrons without interference of countercations and of any reaction intermediates from solvent molecules. As an example of the chemical utilization of the field emission technique, the ESR parameters of the spin adducts of several hydrocarbon radicals have been collected by this technique.
ESR Study of Molecular Oxygen Anion Radicals Produced on Cation-exchanged X-Type Zeolites by γ-Irradiation
Authors: Kanzaki Natsuko , Yasumori Iwao 
Published: July 2006

Abstract
Molecular Oxygen anion radicals (O2−) were produced on X-zeolites by γ-irradiation in the presence of O2. Their properties were systematically investigated by means of ESR spectroscopy. Two kinds of O2− species with different gz values were formed on monovalent cation-exchanged (LiX, KX, RbX, CsX) zeolites and MgX, while three and single O2− species were observed on divalent cation-exchanged (CaX, SrX, BaX) and trivalent cation-exchanged (LaX) zeolites, respectively. These O2− radicals showed different reactivities with N2O or 1-butene, and their gz values were classified into four groups. By considering the results from the gz values and the effect of introduced high pressure O2 on the O2− spectra, the adsorption sites for the radicals on zeolites were determined.
Antiferromagnetic Spin-exchange Interaction in Mixed-spin Trinuclear Cobalt(II) Complexes with Quadridentate Schiff Bases
Authors: Kasempimolporn Visit , Okawa Hisashi , Kida Sigeo 
Published: July 2006

Abstract
Trinuclear cobalt(II) complexes, [Co(R1R2-L)]2CoX2 (R1 R2=H, Me; L=en, ch, ph; X=Cl−, Br−), have been synthesized, where H2(R1,R2-L) denotes the Schiff bases obtained by condensing a 5(R1), α(R2)-substituted salicylaldehyde with a diamine (H2N-L-NH2) in a 2:1 mole ratio. From IR spectra and cryomagnetic properties, it was concluded that these complexes are in mixed-spin state of a Co(II)(s=l/2)-Co(II)(s=3/2)–Co(II)(s=l/2) system, strong antiferromagnetic spin-exchange interaction operating between low-spin and high-spin cobalt(II) ion via dπ(low-spin Co)-pπ(O)-dπ(high-spin Co) super pathway.