bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetic Studies of Thermal Decomposition Reactions of Amminechromium(III) Complexes in Solid State
Authors: Nagase Kenzo , Tanaka Nobuyuki 
Published: July 2006

Abstract
Kinetics of the thermal decomposition reactions of [Cr(NH3)6]X3 (X=Br, I and NCS) and [Cr(NCS)(NH3)5](NCS)2 in solid state were studied by the manometric method. The rate constants, activation energies and activation entropies of the substitution reactions of outer-sphere anions for coordinated ammonia molecules were presented, and possible reaction mechanisms were discussed.
Studies of Organosulfur Compounds. IX. The Preparation of Organometal IVb Esters of Aromatic Thio Acid
Authors: Kato Shinzi , Akada Wataru , Mizuta Masateru , Ishii Yoshio 
Published: July 2006

Abstract
It was found that the reactions of potassium salts of aromatic thio acid with chlorotrimethylsilane gave the corresponding thionoacyloxysilanes [ArC(S)OSi(CH3)3]. On the other hand, the reactions with chlorotrimethylgermanes or -stannane gave the corresponding thiol esters [ArC(O)SM(CH3)3, M: Ge, or Sn] containing the sulfur-metal (IVb) linkage in almost quantitative yields.
Kinetic Studies of the Nickel Phthalate Complex Formation in Solution by the Pressure-jump Method
Authors: Harada Shoji , Tanabe Hideyuki , Yasunaga Tatsuya 
Published: July 2006

Abstract
The rate constants of the complex formation and the dissociation of the nickel phthalate (o-phthalate) complex have been determined by the pressure-jump method. The thermodynamic parameters of the reaction were obtained from studies at various temperatures between 10 and 30°C. Upon a comparison of the data on the nickel complexes of the succinate, adipate, maleate, and phthalate, no systematic relationship between the nature of the ligands and the kinetic values has been found; this can be ascribed to the monodentated form of these complexes. The rate-determining step is the loss of the water molecule from the inner-coordination sphere of the nickel ion when the monodentated complex is formed.
The Chemical Structure of Glass of the NaPO3–Sb2O4 System
Authors: Watanabe Makoto 
Published: July 2006

Abstract
Glassy substances of the NaPO3–Sb2O4 system with P/Sb ratios in the range from 5.0 to 300 were prepared by heating a mixture of NaPO3 glass and Sb2O4 at 1000 °C and by then rapidly quenching the melt of the mixture. From the results of the colorimetric determination and the average degree of polymerization of the condensed phosphates, it has been found that the chain length of the phosphates increases with an increase in the P/Sb ratio. When the glass was treated with water, antimony trioxide was deposited. By using these results, a theoretical treatment for the average degree of polymerization of condensed phosphates has been made and it has been concluded that there are P–O–Sb linkages in the glass of the NaPO3–Sb2O4 system.
Electrochemical Fluorination of Diols and Heterocyclic Compounds
Authors: Abe Takashi , Nagase Shunji , Baba Hajime 
Published: July 2006

Abstract
Electrochemical fluorination of diols (HO–CH2–CH2–)2X (X=CH2, O, S, NH, NCH3, NC2H5) afforded the corresponding perfluoro-heterocyclic compounds together with the cleaved products as a result of cyclization. Perfluoro-p-dioxane, a new compound having boiling point at 22.5–23.0 °C, was obtained from diethylene glycol. Electrochemical fluorination of heterocyclic compounds such as tetrahydropyran, p-dioxane, p-thioxane and morpholine was carried out and the results were compared with those obtained with diols.
Intramolecular Interaction between the Phenol and the Indole Chromophores
Authors: Tamaki Takashi 
Published: July 2006

Abstract
The singlet-energy transfer from the phenol to the indole chromophores occurs intramolecularly, with a high efficiency, in the compounds containing these chromophores joined by the methylene and the amide groups. The total emission spectra of the compounds consisted only of those from the indole chromophore, neither the fluorescence nor the phosphorescence of the phenol chromophore contributing to them, and the excitation spectra of the fluorescence were similar to the absorption spectra. The quantitative analysis of the fluorescence-polarization spectra suggested that the 1Lb transition of the indole chromophore was excited in the energy transfer. The intramolecular interactions between these chromophores in the ground and excited states are discussed.
The Reaction Mechanism of 2-Dimethoxymethyl-3-methoxypropiononitrile with Acetamidine. III. The Reaction with Benzamidine
Authors: Nishino Takenori , Kiyokawa Masumi , Miichi Yoshiyuki , Tokuyama Kanji 
Published: July 2006

Abstract
In order to elucidate the effect of basicities of amidines on their reactions with 2-dimethoxymethyl-3-methoxypropiononitrile (1), the reaction of 1 with benzamidine was studied. Products are similar to those from the reaction of 1 with acetamidine. The minor pathway in the reaction with acetamidine (Route B in Chart 1) was the major one in the reaction with benzamidine. This remarkable difference could be explained in terms of the electronic effect of 2-substituents of the intermediates (4a and 4b) in both reactions and of basicities of acetamidine and benzamidine.
Anodic Ring Opening Reaction of 2-Methoxy-1-cyclopentene-1-carboxylic Acids
Authors: Torii Sigeru , Tanaka Hideo , Fukuoka Tokio , Hirai Shukuo 
Published: July 2006

Abstract
Electrolysis of 2-methoxy-1-cyclopentene-1-carboxylic acids 2 and 12a gave α,β- or β,γ-ring opening products 4, 5a, 7a, and 15. Electrolysis of 2 without separation of anode and cathode compartments gave 6a in a notable yield. 6a is expected to be formed by the reduction of a key intermediate 8, which can be rationalized by leading to 4 and 5. The results from the anodic oxidation of 12 suggest that the C=C double bond function of 12 was initially oxidized giving 14 followed by discharge of the carboxylate anion to afford 15. A possible mechanism for the anodic reaction of 2 and 12 has been discussed.
Synthetic Studies of Carbohydrate Derivatives with Photochemical Reactions. IX. The Photochemical Addition of 1,3-Dioxolane to Several Enoses
Authors: Matsuura Kazuo , Nishiyama Kazunari , Yamada Koh , Araki Younosuke , Ishido Yoshiharu 
Published: July 2006

Abstract
The photochemical addition reactions of 1,3-dioxolane to enoses with an endocyclic or exocyclic double bond, such as 3,4,6-tri-O-acetyl-d-glucal, 2,3,4,6-tetra-O-acetyl-2-hydroxy-d-glucal, methyl 4,6-di-O-acetyl-2,3-dideoxy-α-d-erythro-hex-2-enopyranoside, and methyl 5-deoxy-2,3-O-isopropylidene-β-d-erythro-pent-4-enofuranoside, were studied. It was found that the addition of 1,3-dioxolane to the enoses proceeds with great ease, thus affording the corresponding l,3-dioxolan-2-yl derivatives in excellent yields, and with a considerable regiospeciflcity and stereoselectivity. The reactions of tetrahydrofuran with the enoses were also studied.
Compounds Related to Acridine. X. The Reaction of 9-Ethynylacridine with Active Methylene Compounds
Authors: Tsuge Otohiko , Torii Akiyoshi 
Published: July 2006

Abstract
In the presence of aqueous sodium hydroxide, 9-ethynylacridine (I) reacts with malononitrile and with ethyl cyanoacetate to yield the corresponding 1,1-disubstituted 3-(9-acridanylidene)propenes III. A similar reaction of I with diethyl malonate affords a 2:1 adduct VI and a 1:2 adduct VII. On the other hand, I reacts with acetylacetone to give 3-acetyl-5-(9-acridanylidene)-1-(9-acridinyl)pent-1,3-diene (IX). In this context, the reaction of 9-chloroacridine (XI) with active methylene compounds has been reinvestigated; XI reacts with malononitrile and with ethyl cyanoacetate to afford products XII with an acridane structure, while with diethyl malonate XI gives 9-di(ethoxycarbonyl)methylacridine (XIII), as has been reported previously.
Studies on Nitrile Salts. I. Dimerization of Nitriles Having α-Hydrogen in the Presence of Hydrogen Chloride
Authors: Yanagida Shozo , Fujita Tetsuo , Ohoka Masataka , Katagiri Ichiro , Komori Saburo 
Published: July 2006

Abstract
The compositions and structures of several stable nitrile-HCl salts previously reported were reinvestigated. Most of them have been found to have the composition of 2RC≡N·2HCl and have been identified as N-(α-chloroalkenyl)alkylamidine hydrochlorides (3) by mass and NMR spectra analyses. However, the 2:3 adduct from chloroacetonitrile was confirmed to be N-(α,α,β-trichloroethyl)chloroacetamidine hydrochloride. The scope and limitations of the dimerization reaction of nitriles having α-hydrogen with HCl were studied. Most nitriles having α-hydrogen react with HCl to give N-(α-chloroalkenyl)alkylamidine hydrochlorides (3). Their hydrolysis to diacylamines (4) was also investigated.
An MO-simulation of Elementary Reactions in Hydrocarbon Oxidation. I. A Bimolecular Coupling Reaction of the Methyl Radical and Molecular Oxygen
Authors: Ohkubo Katsutoshi , Kitagawa Futoshi 
Published: July 2006

Abstract
An MO-simulation of the geometrical change in the bimolecular methane oxidation, CH3+O2→CH3O2, was performed using the CNDO/2 approximation. The geometry of CH3O2 was predicted to take rOO=1.19 Å and ∠COO=111° with fixed distances of rCO=1.44 Å and rCH=1.09 Å. The coupling reaction proceeds smoothly, without any appreciable activation energy, with the geometric transformation of the momentarily-living CH3--O2, with rCO=2.36∼1.44 Å, rOO=1.132∼1.19 Å, and ∠COO=90∼111°. The magnitude of the electron migration between CH3 and O2 throughout the reaction was estimated.
Hydrates of Organic Compounds. I. Solid-Liquid Phase Equilibria in the Water+1,4-Dioxane System and Some Properties of 1,4-Dioxane Hydrate
Authors: Nakayama Haruo , Tahara Masao 
Published: July 2006

Abstract
The solid-liquid phase diagram for the water +1,4-dioxane system has been determined by the ordinary cooling curve method and with the aid of a differential scanning calorimeter (DSC). The diagram shows the existence of a hydrate which is stable in rather narrow ranges of temperature (−15.8∼−13.5 °C) and of composition (37.0∼46.5 wt% dioxane). From the phase relations and an analysis of the calorimetric data, the composition and the heat of formation (from the liquid states of both components) of the hydrate have been estimated to be C4H8O2·mH2O with m=36∼39 and ΔH1=−51.3 (for m=36)∼−55.6 (for m=39) kcal/mol respectively. This hydrate seems to be the same as that recently reported by Rosso et al., though the compositions and the temperature ranges are very different.
Acidic properties of Binary Metal Oxides
Authors: Shibata Katsue , Kiyoura Tadamitsu , Kitagawa Jun , Sumiyoshi Takashi , Tanabe Kozo 
Published: July 2006

Abstract
Eighteen binary metal oxides consisting of TiO2–MmOn, ZnO–MmOn and Al2O3–MmOn (MmOn: metal oxide) were prepared by the usual co-precipitation method, their acid amounts and strengths being determined by n-butylamine titration using various acid-base indicators. The acid strengths of fourteen of the tested binary oxides of molar ratio 1 : 1 were found to be remarkably higher than those of the component single oxides. High acid strengths were as follows: H0≤−8.2 for TiO2–SiO2, H0≤−5.6 for TiO2–Al2O3 and Al2O3–ZrO2 and H0≤−3 for TiO2–CdO, TiO2–SnO2 and ZnO–SiO2. The acid amounts of sixteen binary oxides were larger than those of the component oxides. The effect of the composition of binary oxides on acidity was examined for TiO2–Al2O3, ZnO–Al2O3 and Al2O3–ZrO2. The acidity maxima appearing for TiO2–Al2O3 and ZnO–Al2O3 were found to be of molar ratio\simeq9:1 and for Al2O3–ZrO2\simeq3:2. A fairly good correlation has been demonstrated between the observed highest acid strengths and the average electronegativities of metal ions of binary oxides.
Solvent Effect under High Pressure. Participation of Solvent in the Activated Complex in the Menschutkin Reaction
Authors: Tamura Katsuhiro , Ogo Yoshiaki , Imoto Tatsuya 
Published: July 2006

Abstract
Rates of the reaction between 3,5-lutidine with ethyl iodide have been measured at 50 °C over the pressure range 1–1,940 kg/cm2 in benzene-nitrobenzene mixtures. The solvation number and average pressure within the solvation-shell of activated complex have been estimated from the rates and the compression of solvent. The solvation number was almost independent of solvent composition, but not the average pressure within the solvation-shell. Estimation of the structural term of the activation volume Δ1V\eweq in the reaction has been discussed. The logarithms of the rate constants showed a linear relation with the ET-values under atmospheric pressure.
The Photoelectron Spectra of Alcohols, Mercaptans and Amines
Authors: Ogata Hitoshi , Onizuka Hatsuki , Nihei Yoshimasa , Kamada Hitoshi 
Published: July 2006

Abstract
The HeI photoelectron spectra of aliphatic amines, alcohols and mercaptans were measured. These spectra, especially those of methylsubstituted compounds, were interpreted in terms of the orbital energies and corresponding eigenvectors calculated by the CNDO/2 and the INDO type self-consistent field molecular orbital techniques. Modification of CNDO/2 was also performed and the results are briefly discussed.
Intermediates and Mechanism of Photo-Oxygenation Reaction of Triethylamine
Authors: Tsubomura Hiroshi , Yagishita Teruo , Toi Hiroo 
Published: July 2006

Abstract
The electronic absorption spectrum caused by the charge transfer interaction between oxygen and triethylamine was studied quantitatively. It is concluded that there is no particular stabilization between them due to the charge transfer interactions. The intermediate radicals produced by the excitation of triethylamine–O2 in the region of the charge transfer band were studied by the ESR method at various temperatures from 77 to 300 K. The chemical analysis of the irradiation products of the same system was also carried out. The radicals observed are methyl, ethyl, and possibly, (C2H5)2N\dotCHCH3, \dotOOH and (C2H5)2NO·. The products identified are acetaldehyde and diethylamine. Based on these results, the various reactions taking place in the overall photochemical process were speculated.
Electron-donating Strengths of Some Ketimines Intermolecular Charge Transfer Studies
Authors: Abu-Eittah R , Hamed M M 
Published: July 2006

Abstract
The electron-donating strengths of some ketimines have been investigated via the formation of charge transfer complexes with iodine as electron-acceptor. Two types of ketimines were chosen as electron-donors, namely, the =N– unsubstituted as well as the =N– substituted ketimines. With the first type of donors the “n” charge transfer complex was obtained whereas with the second type the “π” charge transfer complexes were obtained. The equilibrium constants were computed for the different types of complexes. An attempt is made to estimate the ionization potentials of the donors from the position of the charge transfer band characteristic of the specific complex.
Intramolecular Rotations in 1,2-Dialkoxyethanes in the Liquid State
Authors: Das Arati , Ghatak Alpana , Hasan Abul , Roy S B 
Published: July 2006

Abstract
Dielectric measurements have been made in 1,2-dimetboxy- and 1,2-diethoxyethane in the liquid state in 1.62, 3.17, and 3.49 cm microwave region. Both the molecules are found to relax mostly by methoxy/ethoxy group rotations.
Polarographic Study of the Substitution Reactions between Nickel(II) Ions and Copper(II) Chelates of Triethylenetetraminehexaacetic Acid
Authors: Haque Md Shamsul , Kopanica Miloslav 
Published: July 2006

Abstract
The mechanism of substitution reaction between nickel ion and Cu–TTHA chelate was studied by polarographic technique. During the study of the substitution reaction the existence of mixed binuclear chelate CuXNi2− was verified and the value of the stability constant was calculated on the basis of polarographic data. Formation of the mixed binuclear chelate was further verified by the amperometric tit ration of the equimolar mixture of both metal ions with TTHA. Finally the existence of mixed binuclear chelate CuXNi2− was verified by potentiometric titration method. When nickel is present in large excess the replacement of Cu2+ ions from Cu2X2− occurred directly without formation of intermediate mixed binuclear chelate. The stability constant of Cu2X2− was calculated from equilibrium study.
A UV Study of the Magnesium Haematoporphyrin Complex
Authors: Anand V D , Carper W R 
Published: July 2006

Abstract
The interaction between magnesium and haematoporphyrin has been studied spectrophotometricaly as a function of concentration, pH and temperature and the existence of a strong 1 : 1 complex has been established. The Benesi-Hildebrand equation was used to determine Kc’s at various wavelengths and temperatures, at pH’s of 7.4, 8.2, and 9.0. The enthalpy of complex formation is seen to change from +9.78 kcal/mol to −9.50 kcal/mol as the pH changes from 8.2 to 9.0. This change may be a reflection of the change in the various ligands which coordinate to the magnesium ion in addition to the porphyrin ring.
Some Reversible and Irreversible Electrode Processes at DME. A Study on Uranyl and Zinc Complexes of l-Hydroxyproline in Aqueous and Aqueous-Methanolic Solutions
Authors: Rawat P C , Gupta C M 
Published: July 2006

Abstract
Complexes of zinc and uranyl ions with l-hydroxyproline (LHP) have been investigated by polarographic method of analysis at 25±1 and 35±1 °C. At pH 4.5, formation of uranyl-LHP complex was observed with metal to ligand ratio of 1: 1 in aqueous and aqueous-methanolic solutions. The stability constant for the complex species is logKc=1.50, 1.30, 1.61, 1.87 in aqueous (25 °C), aqueous (35 °C), aqueous-methanolic (10% v/v) and aqueous-methanolic (50% v/v) media respectively. Between pH 3.0–12.0, zinc–LHP complex has been observed to be reduced irreversibly at DME. Detailed investigations have been reported on the system at 25±1 °C and 35±1 °C at pH 10.0 in varying concentrations of the ligand. Kinetic parameters—the formal rate constant Kf,h° and transfer coefficient α have been calculated.
Liquid-Liquid Extraction of Zinc with Thiothenoyltrifluoroacetone Direct Photometric Determination in the Organic Phase
Authors: Solanke K R , Khopkar S M 
Published: July 2006

Abstract
The thioderivative of 2-thenoyltrifluoroacetone [1,1,1-trifluoro-4-(2-thienyl)-4-mercaptobut-3-en-2-one (STTA)] is used for the simultaneous extraction and direct photometric determination of zinc. About 68 μg of zinc was quantitatively extracted at pH 7–7.5 with 10 ml of 0.001 M STTA in carbon tetrachloride as yellow green colored complex. It was measured spectrophotometrically at 450 nm. The system conformed to Beer’s law over the concentration range of 0.4 to 30 μg of zinc per ml. The color of the complex was stable for more than 96 hr. Zinc was extracted quantitatively and was determined in the presence of large excess of (1 : 300) ions which are associated with it. The method was made selective by using sequestering agents like ascorbic, oxalic, citric acids or alkali cyanide to form unextractable negatively charged complexes. The selective extraction with mesityl oxide was used to eliminate the interferences due to iron and chromium. The procedure was found to be applicable for the analysis of zinc in gun metal and brass. The proposed method is comparable with the standard methods for the extraction of zinc.
The Thermal Properties of Gallium-bearing Allophane
Authors: Kasai Mitsuhiro , Kudo Yoshiyuki , Hamada Shuichi 
Published: July 2006

Abstract
The DTA patterns of synthesized coprecipitated gels, SiO2–Al2O3–Ga2O3–H2O system, resembled that of allophane, and the exothermic peak temperature in the DTA was lowered continuously from 980 to 810 °C with an increase in the gallium content, while that on mixed gels scarcely lowered. The apparent activation energy for this exothermic reaction on the coprecipitated gels decreased with an increase in the gallium content, while that on the mixed gels hardly changed. The crystallization process during the heat treatment of the gels depended on the content and on the coexistence state of the gallium. A unit cell volume of a mullite crystallized at 1200 °C in the coprecipitated gels was enlarged by forming a solid solution with the gallium ion, in contrast to the small change in that formed in the mixed gels. Further, the exothermic peak in the DTA was considered to originate not only from the formation of the mullite, but also from that of the silico-alumina spinel in the gallium-bearing gels; the exothermic reaction products seem to depend on the composition or the coexistence state of gallium in the gels.
An MO-theoretical Interpretation of the Reductive Cleavage of Organic Halides by Pentacyanocobaltate(II)
Authors: Ohkubo Katsutoshi , Kanaeda Hirokazu , Tsuchihashi Kohji 
Published: July 2006

Abstract
The mechanism of the reductive cleavage of organic halides (RX) by pentacyanocobaltate(II) Co(CN)53− was investigated by means of the extended Hückel MO theory. First, the molecular structure of Co(CN)53− was considered to be the square-pyramidal C4V configuration, without H2O as its sixth ligand. Secondly, the order of the observed rate constants for the Co(CN)53−+RX→Co(CN)5X3−+R. reaction was found to be in satisfactory accordance with that of the calculated binding energies of the R-X bond. Thirdly, the reductive cleavage of RX by Co(CN)53− proceeds by the aid of the predominant electron-migration from the highest-occupied, lone-pair halogen-orbital to the singly-occupied dz2 Co-orbital and from the highest-occupied dxz (or dyz) Co-orbital to the lowest-unoccupied, antibonding pσ* orbital of the R–X bond. Finally, the mode of the interaction between Co(CN)53− and RX was precisely discussed in terms of the homolytic cleavage of the R–X bond.
The Solubility of Sulfur in Na2O–SiO2 Melts under Various Oxygen Partial Pressures at 1100 °C, 1250 °C, and 1300 °C
Authors: Nagashima Shigeru , Katsura Takashi 
Published: July 2006

Abstract
The solubility of sulfur in Na2O–SiO2 melts with the Na2O/SiO2 molar ratios of 1/3, 1/2, and 1/1 was investigated by varying the oxygen partial pressure at 1100, 1250, and 1300 °C. The results at 1100 °C are complicated, for the equilibrium state within the gas phase is not established. From the experiments at 1250 and 1300 °C, the following conclusions are reached: (1) When the temperature and the Na2O/SiO2 ratio in the melt are constant, the solubility of sulfur increases with an increase of the total amount of sulfur in the gas phase. (2) When the temperature, the Na2O/SiO2 ratio, and the total amount of sulfur in the gas phase are constant, the solubility of sulfur shows its minimum at a specific oxygen partial pressure; at higher oxygen partial pressures, the sulfur dissolves in the melts mostly as sulfate, while at lower oxygen partial pressures, the sulfur dissolves mostly as sulfide. (3) When the temperature and the total amount of sulfur in the gas phase are constant, the solubility rises greatly with an increase in the Na2O/SiO2 ratio in the melt. (4) When the Na2O/SiO2 ratio in the melt and the total amount of sulfur in the gas phase are constant, the minimum point of the solubility shifts in the direction of higher oxygen partial pressures as the temperature increases. This corresponds to the shifts of the equilibrated gas composition as the temperature increases.
Molecular Complexes of Arenetricarbonylchromium
Authors: Kobayashi Hiroshi , Kobayashi Mitaka , Kaizu Youkoh 
Published: July 2006

Abstract
Arenetricarbonylchromium forms a charge-transfer molecular complex with electron acceptors such as 1,3,5-trinitrobenzene and tetracyanoethylene but not with electron donors such as N,N,N′,N′-tetramethyl-p-phenylenediamine. The ionization potentials of arenetricarbonylchromium complexes were determined from the charge-transfer transition energies in the molecular complexes. The molecular complexes are formed by a charge-transfer interaction of electron acceptor toward the π-coordinating benzene ring of arenetricarbonylchromium in the case of 1,3,5-trinitrobenzene, and by a charge-transfer toward the central chromium in the case of tetracyanoethylene.