bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Crystal and Molecular Structure of the Tricyclic Methyldisilanylenesiloxane, ((CH3)6Si4O3)2
Authors: Higuchi Taiichi , Shimada Akira 
Published: July 2006

Abstract
Tricyclic methyldisilanylenesiloxane, ((CH3)6Si4O3)2, crystallizes in the triclinic space group P\bar1 with the unit-cell dimensions a=7.71, b=10.17, c=10.17 Å, α=106.7°, β=109.6° and γ=78.1° (Dx=1.165 g·cm−3 with Z=1 and Dm=1.12g·cm−3). The phase problem was mainly solved by the Patterson function. The final atomic parameters were obtained by the least-squares refinement. The molecule consists of two seven-membered rings and one six-membered ring in the chair conformation with a center of symmetry, and the skeletons of those rings consist of Si–Si and Si–O bonds. The seven-membered ring is nearly planar, except for one oxygen atom. The six-membered ring has a chair form. The dihedral angle between these rings is about 109°. The whole molecule, approximately, has a non-crystallographic mirror plane perpendicular to the line connecting the mid-points of two Si–Si bonds in the six-membered ring. The lengths of the Si–Si bonds are 2.36 Å and 2.38 Å with e. s. d. 0.01 Å. The mean lengths of the Si–O bonds and the Si–C bonds are 1.65 Å and 1.91 Å respectively. The Si–O–Si bond angles are 148° for the seven-membered ring, and 133° for the six-membered ring. Most of the closest contacts between the molecules are either of the CH3···CH3 type or of the CH3···O type.
The Crystal and Molecular Structure of 2-Bromomethyl-2,3-dihydrofuro[2,3-b]tropone
Authors: Shimanouchi Hirotaka , Ashida Tamaichi , Sasada Yoshio , Kakudo Masao , Murata Ichiro , Kitahara Yoshio 
Published: July 2006

Abstract
Crystals of 2-bromomethyl-2,3-dihydrofuro[2, 3-b]tropone, C10H9O2Br, are monoclinic, with four molecules in a unit cell of the dimensions: a=8.34, b=10.23, c=11.26 Å, and β=96.9°, and with the space group of P21⁄c. The intensities were recorded on multiple-film equi-inclination Weissenberg photographs and measured visually against a standard scale. The structure was solved by the heavy atom method. The positional and thermal parameters were refined by the least-squares method. The final R factor for (hkl) reflections is 0.095. An apparent bond alternation in the conjugated seven-membered ring is observed. The longest and the shortest bond lengths in the ring are 1.48 and 1.36 Å respectively. The C–O bond length in the carbonyl group is 1.23 Å, suggesting a considerable contribution of ionic resonance forms. The IR absorption band at 1612 cm−1 could be assigned to the stretching frequency of the carbonyl group. The seven carbon atoms in the tropone ring are coplanar, but the oxygen atom in the carbonyl group lies significantly out of the seven-membered ring plane. This may be interpreted as a result of short intermolecular contact. The other intermolecular distances are equal to or larger than the sum of the van der Waals radii.
Studies on Pentakisantipyrine Copper(II) Perchlorate
Authors: Gopalakrishnan J , Ravi A , Patel C C 
Published: July 2006

Abstract
Five coordinated antipyrine (A) complex of copper(II) perchlorate, [CuA5](ClO4)2 has been prepared. Both the electric conductivity and the cryoscopic determination of molecular weight in nitrobenzene solution show that the complex dissociates into three ions. Differential thermal analysis gives one peak at about 285°C owing to the explosion of the complex. Infrared spectrum reveals the presence of both strongly and weakly coordinated antipyrine molecules in the complex. The complex in 1,2-dichloroethane absorbs at 16130 (ε=51) cm 15630 (ε=53) and 14500 (ε=56) cm1. These d-d transitions with comparatively high intensities suggest C4v symmetry for the complex ion [CuA5]2+. A square pyramidal structure with four antipyrine molecules in the square plane at normal Cu-O bond distance and one antipyrine occupying the axial position with an elongated Cu-O bond, is assigned to the complex ion.
The Photoinduced Isomerization of cis-Dichlorobis(ethylenediamine)cobalt(III) Chloride in Methanol
Authors: Kawaguchi Shinichi , Fujioka Hiroaki 
Published: July 2006

Abstract
The isomerization of cis-dichlorobis(ethylenediamine)cobalt(III) chloride to its trans form is induced at 0°C in methanol by ultraviolet irradiation. The visible light in the wavelength region of the ligand field bands is not effective, but the ultraviolet light corresponding to the charge transfer band is essential. The effects of the dissolved oxygen, the initial concentration of the reactant, and the intensity of the incident light were examined, and the reaction was found to proceed further even after the cessation of irradiation. A chain mechanism is proposed which includes the Co(II) species, the photoreduction product of the Co(III) complex, as a chain carrier. The isomerization reaction was also conducted at 0°C in the dark in the presence of cobalt(II) chloride and ethylenediamine; the most effective catalyst was assumed to be a five-coordinated Co(II) species, CoClen2+ . The induction period which was observed in the photoreaction was explained as being due to the deactivation of the reactive Co(II) species throguh oxidation with the dissolved oxygen.
Association Involving Optically Active Ions. I. Association Constants of Tris(ethylenediamine)cobalt(III) and Tartrate Ions
Authors: Ogino Kazuko , Saito Umihiko 
Published: July 2006

Abstract
The enantiomer differentiation of an optically active metal complex through the presence of another kind of optically active ion in the solution is considered to be due to association. A mathematical treatment has been made of the equilibria which exist in solutions containing either or both antipodes of an optically active ion and optically active counter ions which do not racemize rapidly. The results have been applied to a system of [Co en3]3+ (en=ethylenediamine) and d-tartrate ions. The increase in the optical absorbancy of [Co en3]3+ in the charge transfer absorption region is not the same for d-, l- and dl-[Co en3]3+. The association constants of d-[Co en3]3+·d-tartrate2− and l-[Co en3]3+·d-tartrate2 were found, by an analysis of the increase in the optical absorbancy, to be 26 and 21 respectively at μ=0.1 at 25°C.
The Kinetics of Substitution Reactions Involving Metal Complexes. IX. Reactions between Copper(II) and Propylenediaminetetraacetatoplumbate(II) and between Lead(II) and Propylenediaminetetraacetatozincate(II)
Authors: Ogino Hiroshi , Tanaka Nobuyuki 
Published: July 2006

Abstract
Kinetic studies of the reactions between copper(II) and propylenediaminetetraacetatoplumbate(II) and between lead(II) and propylenediaminetetraacetatozincate(II) have been carried out. It was revealed from these studies that the reactions proceed through four simultaneous reaction paths, of which two involve electrophilic substitution reactions and the others, the complex-forming reactions between entering metal ions and ligands dissociated from complexes. The rate constants were compared with those of the corresponding reactions involving metalethylenediaminetetraacetate and the effects of ligands on the reaction rates were discussed.
The Chemiluminescence of Luminol and Acetyl-luminol
Authors: Omote Yoshimori , Miyake Takeo , Ohmori Seiya , Sugiyama Noboru 
Published: July 2006

Abstract
Several acetyl derivatives of luminol were synthesized and their chemiluminescence were studied in water or in DMF-water. The role of the amino group in the chemiluminescence was revealed by comparing the chemiluminescence of luminol (I) with that of N-acetyl-luminol (II). Also, it was found that, in the case of the chemiluminescence of I or II in water, the emitting species did not seem to be the corresponding substituted phthalate ion, while in the case of the chemiluminescence in DMF-water, the 3-aminophthalate or 3-acetylaminophthalate ion could be presumed to be the emitting species.
The Hydrodimerization of Acrylonitrile
Authors: Misono Akira , Uchida Yasuzo , Tamai Katsumi , Hidai Masanobu 
Published: July 2006

Abstract
During the course of our studies of the dimerization of such vinyl monomers as acrylonitrile or acrolein with various Ziegler-type catalysts or metal carbonyls, it has been found that acrylonitrile is converted at an elevated temperature in an iron or cobalt carbonyl-alkali-water system, an iron or cobalt carbonyl-sodium borohydride or -lithium aluminum hydride system, or a cobalt carbonyl - H2 system to hydrodimers of acrylonitrile composed of adiponitrile and 2-methylglutaronitrile as well as propionitrile. Some iron carbonyl hydrides, which are presumably formed as intermediates in these reactions, were therefore prepared and subjected to reaction with acrylonitrile, 3-chloropropionitrile, or ethyl acrylate. On the basis of these experimental results, a reaction mechanism containing a cyanoethyl complex as an intermediate was proposed for the formation of hydrodimers of acryionitrile.
Studies on the Chemical Constitution of Agar-agar. XXIII. Isolation of d-Xylose, 6-O-Methyl-d-galactose, 4-O-Methyl-l-galactose and O-Methylpentose
Authors: Araki Choji , Arai Kiyoshi , Hirase Susumu 
Published: July 2006

Abstract
Commercial agar was subjected to complete hydrolysis with dilute sulfuric acid, and the products were carefully investigated. Besides d- and l-galactose, which have been known to exist, there were isolated small amounts of d-xylose, 6-O-methyl-d-galactose, 4-O-methyl-l-galactose, and O-methylpentose, all the sugars except the last one being obtained in crystalline forms. Among these products, 4-O-methyl-l-galactose is a new compound, so its structure has been fully investigated. As commercial agar is made from Gelidium amansii, occasionally mixed with several other species of seaweeds, the experiments were repeated for the agar prepared from G. amansii only. The same products as those from commercial agar were isolated except the O-methylpentose.
The S. W. Polarographic Determination of Disulfide, Mercaptan and Free Sulfur in Petroleum Naphtha
Authors: Kashiki Masayuki , Ishida Kazuyoshi 
Published: July 2006

Abstract
The application of square-wave polarography to the determination of small amounts of disulfide, mercaptan and free sulfur in a mixed solution of methanol, glacial acetic acid, and sodium acetate was studied. Disulfide, mercaptan, and free sulfur in concentrations below 10 ppm were easily determined in these mixed solvents. The derivative wave heights were proportional to the concentrations predicted by the theory of s. w. polarography. The effects of changes in solvent and in supporting electrolyte concentration, dissolved oxygen, and temperature were discussed. It was determined that concentrations of 2 vol% glacial acetic acid and 1.4 m sodium acetate were necessary to obtain a constant peak height. The temperature coefficients of disulfide, mercaptan and free sulfur were about 4.5 (first wave), 0.7 and 4.5% per degree respectively in the neighborhood of 25°C. The effect of the dissolved oxygen was removed by passing nitrogen through for 5 min.
Thermal Rearrangement of Mixed Dithiocarbamic-Imidic Anhydrides
Authors: Miyazaki Koshin 
Published: July 2006

Abstract
The various mixed dithiocarbamic-imidic anhydrides with the formula R2N–C(=S)–S–C-(=N–Ph)–Ph (I) rearranged to thiobenzoyl-thioureas with the formula R2N–C(=S)–N(–Ph)–C(=S)–Ph (II) when kept at an elevated temperature in an inert solvent. This rearrangement was found to be reversible, and it followed first-order kinetics. The value of the forward rate constant (k1) in o-dichlorobenzene at 100°C increased in the order: R=CH3&gt;C2H5&gt;n-C3H7&gt;n-C4H9, and a good correlation between log k1 and σ* for R was obtained. The rearrangement following mixture of (CH3)2N–C(=S)–S–C(=N–Ph)–Ph and (C2H5)2N–C(=S)–S–C(=N–C6H5Cl-p)–Ph gave no crossed products. A probable reaction mechanism was proposed.
Reaction of Aluminum Haloalkoxide with Diazomethane
Authors: Saegusa Takeo , Tomita Shimpei , Ueshima Takashi 
Published: July 2006

Abstract
In the reaction of diazomethane with four aluminum haloalkoxides, Al(OCH2CF3)3 (I), Al(OCH2CCl3)3 (II), Al(OCH2CBr3)3 (III), and Al[OCH(CH2Cl)2]3 (IV), a methylene insertion into the aluminum-alkoxyl linkage was observed along with the polymethylene formation. By the methylene insertion, an organoaluminum compound with a haloalkoxymethyl-aluminum linkage is formed. Among aluminum alkoxides, these four haloalkoxides are distinguished by this methylene insertion. The usual aluminum alkoxides of unsubstituted alcohols do not undergo a methylene insertion reaction, but only the polymethylene formation. The difference in the reactivity towards diazomethane between the four haloalkoxides and usual alkoxides has been explained by the difference in acid strength.
Reduction Product and Leuco-form of Flavanthrone
Authors: Aoki Junji 
Published: July 2006

Abstract
By reducing flavanthrone (II), 8,16-diazapyranthrene (V) (denoted as flavanthrene) was obtained. On the other hand, leucoflavanthrone dibenzoate was also prepared. Since these two substanses give nearly identical absorption spectra, the leucobenzoate is considered to have the VI formula (5,13-dibenzoyloxy-8,16-diazapyranthrene) and to belong to the same conjugated system as flavanthrene. Consequently, it may be considered that the leuco-form of flavanthrone corresponds to the IV formula (5,13-dihydroxy-8,16-diazapyranthrene) in which two carbonyl groups are reduced, but not the III formula (8-hydro-13-hydroxy-5-oxo-8,16-diazapyranthrene) previously presented. In addition, the leucobenzoate can also be synthesized by boiling the quinone with zinc dust and benzoyl chloride in o-dichlorobenzene containing pyridine. This method, devised by the author, is easy to perform and gives a good yield.
Diphenyl Sulphoxide Complexes of Lanthanide and Yttrium Perchlorates
Authors: Ramalingam S K , Soundararajan S 
Published: July 2006

Abstract
Diphenyl sulphoxide complexes of nine lanthanide perchlorates of the general composition [Ln(DPSO)6](ClO4)3 where Ln=La, Ce, Pr, Nd, Sm, Gd, Ho and Yb and Y have been synthesised and characterized. Infrared studies indicate coordination through the oxygen atom of the ligand and the retention of the Td symmetry of the perchlorate group. The molar conductance and cryoscopic studies suggest a coordination number of six for the metal ions. Cryo-scopic studies in DMSO indicate that DMSO is a better donor than DPSO. DTA and UV data are also presented.
Hydrogen Formation in the Radiolysis of Liquid Olefins. The Role of Hot Hydrogen Atoms and Superexcited States
Authors: Hatano Yoshihiko , Shida Shoji , Sato Shin 
Published: July 2006

Abstract
The γ-radiolysis of liquid olefins was undertaken to obtain reliable evidence for a possible role of hot hydrogen atoms and superexcited states in radiation chemistry. The contribution of thermal hydrogen atoms may reasonably be excluded in this system. The effect of various electron or positive-ion scavengers on hydrogen formation in the radiolyses of liquid propylene and ethylene has been examined. The hydrogen formation is not appreciably affected by these additives, which indicates ionic species may not play an important role in the hydrogen formation. The liquidphase radiolyses of C3H6-C3D6 and C2H4-C2D4 mixtures have also been investigated and compared with those previously reported of C4H8-l - C4D8-l and trans-C4H8 - 2-trans-C4D8-2 mixtures. The data indicate that the hydrogen from the olefins except ethylene may be formed for the most part by bimolecular processes. A large part of the hydrogen from liquid ethylene may be interpreted in terms of the molecular detachment of a hydrogen molecule, while from the other olefins it may be interpreted in terms of the hydrogen-atom abstraction reaction of hot hydrogen atoms formed by direct excitation which must at least partially involve superexcitation. To attempt quantitative substantiation of the above viewpoint a simple calculation has been made based on the so-called optical approximation. Calculated yields of the hydrogen formation are apparently in good agreement with observed ones.
Formation Constants of Maleatochromium(III) Complexes and Some Properties Thereof in the Solid State
Authors: Tomita Takeshi , Kyuno Eishin , Tsuchiya Ryokichi 
Published: July 2006

Abstract
The formation constants of the chromium(III) complexes with maleic acid have been determined by the pH method to be logk1=5.4±0.1, logk2=3.0±0.1, and logk3=1.9±0.2 at an ionic strength of μ=0.1 and at 25°C. We also attempted to prepare the solid of the chromium(III) complex with maleic acid. Though it was an amorphous solid to X-ray diffraction measurement, its composition was presumed to be [Cr(mal)(OH)(H2O)3]. After it had been dried in a desiccator for a few days, when it was exposed to moist air we observed the curious phenomenon that the solid was made jumping due to the absorption of water vapor.
Kinetics of Isotopic Exchange between 8-Quinolinol-14C and Tris-8-quinolinolato Complexes of Tervalent Typical Elements
Authors: Saito Kazuo , Takahashi Michihiko , Miyakawa Yukio , Masuda Kazuyo 
Published: July 2006

Abstract
Rate of isotopic exchange between 8-quinolinol-14C and the 8-quinolinolato (oxinato) complexes of aluminum, gallium and indium has been studied in chloroform. Pure yellow complexes are precipitated by adding petroleum ether to the reaction mixture. The exchange rate decreased in the sequence In&gt;Al&gt;Ga, and a detailed kinetic study can be substantiated only with the gallium complex below 0°C. The rate is proportional to the concentration of the complex, but is independent of that of free 8-quinolinol (quinolH) and the Arrhenius activation energy is 18 kcal per mole. The reaction is accelerated by acid and presumably by water. It appears as if one of the ligands is present as unidentate under the given condition and the break of the remaining bond would be the rate determining step. Any reagent that can retard the recombination of the free end of unidentate ligand would catalyse the exchange reaction.
Kinetics and Mechanisms of Thermal Decomposition Reactions of Cobalt(III) Complexes. Hexammine-, Halogenoammine- and Oxalatoamminecobalt(III) Complexes
Authors: Tanaka Nobuyuki , Nagase Kenzo , Nagakura Saburo 
Published: July 2006

Abstract
Kinetics of the thermal decomposition reactions of hexammme-,halogenoammine- and oxalatoamminecobalt(III) complexes in solid state has been studied by following the change in the cobalt (III) contents with time. It was found that the decomposition of these complexes was initiated by the change of the valence state of cobalt(III) to cobalt(II), and that these electrontransfer reactions were kinetically of a first order. The first-order rate constants, the activation energies and the frequency factors of these electron-transfer reactions were obtained. The values of the activation energies were found to increase in parallel with the increase in the difference between t2g and eg orbitals of the cobalt(III) complexes investigated. (The notations, t2g and eg, are used in the expression of an Oh-symmetry approximation for halogenoammine- and oxalatoamminecobalt(III) complexes.)
Activity Measurements in Orthosilicate and Metasilicate Solid Solutions. I. Mg2SiO4-Fe2SiO4 and MgSiO3-FeSiO3 at 1204°C
Authors: Kitayama Kenzo , Katsura Takashi 
Published: July 2006

Abstract
The activity-composition relations in ortho-, and metasilicate solid solutions in the FeO-MgO-SiO2 system are determined at 1204°C on the basis of the measurement of equilibrium oxygen partial pressures. Both the olivine and the pyroxene solid solutions show significant deviations from ideality. Using the present data, the standard free energy change of formation of ferrosilite (hypothetical compound, FeSiO3) is calculated to be −41.7±0.2 kcal/mol on the basis of the equilibrium between metallic iron and silica, and to be −1.6±0.2 kcal/mol on the wüstite (“FeO”) and silica.
Polymerization Catalyst of the Triethylaluminum-Chloral Hydrate System. I. Triethylaluminum-Chloral Hydrate Reaction and Catalyst Activity in Cationic Polymerization
Authors: Saegusa Takeo , Fujii Hiroyasu , Ueshima Takashi , Tanaka Katsumi 
Published: July 2006

Abstract
In reaction of AlEt3 with chloral hydrate has been investigated. The reaction system was examined by means of infrared and NMR spectra and by the vapor-phase chromatographic analysis of the acidolysis product of this system. The gas evolved during the reaction was also analyzed. The AlEt3-chloral hydrate system was proved to contain the linkages of &gt;AlOCH2CCl3, &gt;AlOCH(CCl3)OAl&lt;, &gt;AlOCH(Et)CCl3, &gt;AlOAl&lt;, &gt;Al–Et and &gt;Al–Cl. This system showed a very high catalytic activity for the cationic polymerization of i-butyl vinyl ether. Tetrahydrofuran, 3,3-bis(chloromethyl)oxacyclobutane, α-methylstyrene, and styrene were also polymerized by this catalytic system. The acid strength of the AlEt3-chloral [hydrate system was examined by two methods, the Hammett indicator method and shift of the infrared carbonyl band of xanthone caused by coordination to Lewis acid. It has been shown that the acid strength of this system is as strong as AlEt3–H2O (1:0.8) and Et2AlCl. The relation between the strong acid character of the AlEt3-chloral hydrate system and its structure was discussed.
Preparation and Properties of Aluminum and Zinc Haloalcoholates
Authors: Ueshima Takashi , Tomita Shimpei , Saegusa Takeo 
Published: July 2006

Abstract
Seven haloalcoholates of aluminum and zinc were prepared by the reactions of haloalcohols with metal alky Is in ethyl ether, and their properties were examined. The following differences have been observed between these haloalcoholates and the usual alcoholates, those with no halogen in the alkyl groups. (1) The metal haloalcoholates are unstable to heat and decompose at 90–220°C. Except for Al(OCH2CF3)3, they are neither distilled nor sublimed even in vacuo. The usual aluminum alcoholates, such as ethoxide and isopropoxide, are easily distilled under reduced pressures. (2) The haloalcoholates are stronger Lewis acids than the usual alcoholates. The acid strength of some aluminum haloalcoholates is even higher than triethylaluminum. The strong acid nature of the aluminum haloalcoholate can be ascribed to the electron-withdrawing effect of halogen. (3) As expected from their strong acid strength, the haloalcoholates induce the cationic polymerizations of vinyl monomers and cyclic ethers, such as styrene, α-methylstyrene, isobutyl vinyl ether, 3,3-bis-(chloromethyl)oxacyclobutane, and tetrahydrofuran. The usual metal alcoholates are weaker acids and do not cause the polymerizations of these monomers. In the ethylene oxide polymerization, both the haloalcoholates and the usual alcoholates showed catalytic activity. However, these two types of alcoholates differ from each other in the catalysis mechanism. For the polymerization of ethylene oxide by the haloalcoholate catalyst, a cationic polymerization mechanism was assumed on the basis of the formation of dioxane as a by-product. The polymerization by the usual alcoholate catalysts is assumed to be of a coordinate anionic mechanism.