bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transition-metal Complexes of Pyrrole Pigments. XV. Coordination of Pyridine Bases to the Axial Sites of Cobalt Corroles
Authors: Murakami Yukito , Yamada Sunao , Matsuda Yoshihisa , Sakata Kazunori 
Published: July 2006

Abstract
Cobalt(III) corroles exist predominantly as polymeric species in a concentration range above 5×10−3 M in chloroform at room temperature as confirmed by NMR measurements. The coordination behavior of pyridine bases at the axial sites of cobalt(III) corroles, in a concentration range where they are present exclusively in the monomeric species, has been investigated by measuring electronic spectra in acetone at 25.0±0.1 °C. Penta- and hexa-coordination processes were found to take place, and the stepwise formation constants were interpreted by means of the equations logKi=a·pKa+b and logKi⁄Ki0=ρσ. When the cobalt corrole was reduced at the nuclear cobalt from trivalent to bivalent state, only one pyridine molecule was coordinated at its axial sites, hexa-coordination being no longer possible as confirmed by ESR measurements. The axial ligation behavior of cobalt corroles is quite analogous in nature to that of cobalt corrinoid.
An Investigation on the Effect of Structural Variation on Thermal Decomposition of Rare Earth Chromates(V)
Authors: Roy Ajoy , Chaudhury M , Nag K 
Published: July 2006

Abstract
Non-isothermal decomposition kinetics of LaCrO4, PrCrO4, and NdCrO4 have been investigated. In each case, first order decomposition takes place. The energy of activation, Ea* has been evaluated by applying five different computational procedures based on the data of TG, DTA, and DTG. These values are fairly in good agreement with each other and the average activation energies per mole of the compounds are : LaCrO4: 240 kcal, PrCrO4: 180 kcal and NdCrO4: 170 kcal. The above trend in Ea* has been rationalized by taking into consideration the packing of atoms in rare earth chromates(V).
Gas Phase Photochemical Reactions of Nitrogen Dioxide. Effect of Oxygen on the Conversion of Benzene into Nitrobenzene
Authors: Watanabe Kazuo , Ishikawa Hiroshi , Ando Wataru 
Published: July 2006

Abstract
Gas phase photochemical nitration of benzene with nitrogen dioxide in the presence of oxygen was studied. Conversion of benzene into nitrobenzene was drastically accelerated by oxygen.
Metal-ion Complexation of Noncyclic Poly(oxyethylene) Derivatives. II. PMR Studies of the Complexation with Alkali and Alkaline-earth Metal Cations
Authors: Yanagida Shozo , Takahashi Kazutomo , Okahara Mitsuo 
Published: July 2006

Abstract
The complexation of homogeneous polyethylene glycols and their dimethyl ethers(glymes) with alkali and alkaline-earth metal cations was studied by PMR spectroscopy on the basis of a comparison with crown ethers. The ethylene proton signal of octaethylene glycol in methanol-d4 was split into three lines by the addition of a potassium, rubidium, caesium, strontium, or barium cation. The latter two cations also caused large downfield shifts of the signals, which are quite comparable with those of 15-crown-5 and 18-crown-6 caused by the same metal cations. As for heptaethylene glycol, a splitting was observed in the presence of a strontium ion or an alkali metal cation except for a lithium ion. A large downfield shift was also observed in the presence of a strontium or barium ion. As for hexaethylene glycol, the signal was split only by a sodium ion, and the optimal interaction with a calcium ion was confirmed on the basis of the downfield shift. In methanol-d4, lithium and magnesium ions did not cause any change in the PMR spectra of either the crown ethers or the glycols. The PMR downfield-shift method also disclosed the metal-ion complexation of the glycols in water. The terminal hydroxyl groups play an important role in the complexation.
Linear Response Polarizability Theory of the UV, ORD, and CD Bandshapes of Helical Biopolymers. Single- and Double-Stranded Polyadenylic Acids
Authors: Ito Hirotoshi , I’Haya Yasumasa J , Eri Toshiyuki 
Published: July 2006

Abstract
The UV, ORD, and CD spectral bandshapes of polyadenylic acid (poly A) have been investigated theoretically in order to challenge the problems of whether discrimination of the single- and double-stranded poly A’s is computationally possible and of what structure poly A holds in a neutral solution. A linear response polarizability theory is applied to the derivation of UV, ORD, and CD bandshape functions of a polymer composed of N identical monomers. Using the observed and/or assumed values for the spectral bandshape of the adenine monomer, the UV, ORD, and CD spectra of both single- and double-stranded poly A’s are calculated by changing geometrical parameters. The single-stranded poly A at neutral pH is assumed to have a regular helical structure which is regarded as a counterpart of the double helix form of the double-stranded poly A. This model leads to the chainlength (N) effect which in turn suggests that the structure of poly A in a neutral solution is very flexible and is such that it can be approximated as a random assembly of adenine dirners and/or trimers, when the theoretical spectra of both the single- and double-stranded poly A’s are compared.
ESR Study of Hot Ions in Solid Solutions of K2[(Zn,Cd,Hg)(CN)4]
Authors: Kozlowski Henryk , Isoya Jun-ichi , Fujiwara Shizuo 
Published: July 2006

Abstract
The ESR spectra of Cd(I) hot ions produced in solid solutions of K2[(Zn, Cd, Hg)(CN)4] indicate that there are paramagnetic species of hot-ion molecules characteristic of the single phase of K2[Zn(CN)4] and of the solid solution. The total contribution from the s and p orbitals to the spin density of the Cd(I) hot ions is constant, although the relative contributions from these two orbitals vary. It is shown that the mother lattice surrounding the hot ions determines the electronic structure and stability of the hot ions. These results suggest that the investigation of hot ions in a solid solution is useful for the study of microstructure of the solid solution.
Preparation and Isomerization of Three Isomers of l-Histidinatoiminodiacetatocobalt(III) Complex
Authors: Watabe Masatoshi , Zama Masayuki , Yoshikawa Sadao 
Published: July 2006

Abstract
Three isomers of l-histidinatoiminodiacetatocobalt(III) complex have been prepared and characterized on the basis of their absorption, circular dichroism and proton magnetic resonance spectra. These isomers isomerized mutually in water at 80 °C. The equilibrium mole fractions of these isomers in water were found for cisN, transN and fac to be 0.91, 0.04, and 0.05, respectively.
Kinetics and Mechanisms of the Reduction of Cobalt(III) Complexes by the Chromium(II) Complex Ligating N-(2-Hydroxyethyl)ethylenediamine-N,N′,N′-triacetate
Authors: Ogino Hiroshi , Shimura Makoto , Tanaka Nobuyuki 
Published: July 2006

Abstract
The reduction of the cobalt(III) complexes, CoX(NH3)5(3–m)+ (Xm−=Cl−, Br−, NCS−, and H2O) and Co(en)33+, by Cr(II)–HEDTRA was studied by the stopped-flow method, where en and HEDTRA denote ethylenediamine and N-(2-hydroxyethyl)ethylenediamine-N,N′,N′-triacetatic acid respectively. From the kinetic behavior and the spectral properties of the immediate chromium(III) products, it is concluded that the Cr(II)–HEDTRA reductions of CoX(NH3)52+ (X−=Cl−, Br−, and NCS−) are of an inner-sphere type. The effect of the HEDTRA coordinated to chromium(II) on the rates of the electron-transfer reactions is discussed.
The Intrachain Aminolysis of a Terminal p-Nitrophenyl Ester Group by a Terminal 4-Pyridyl Group Attached to Both Ends of a Poly(oxyethylene) Chain
Authors: Sisido Masahiko , Yoshikawa Eiichi , Imanishi Yukio , Higashimura Toshinobu 
Published: July 2006

Abstract
The intrachain aminolysis by a terminal 4-pyridyl group of a p-nitrophenyl ester group at the other terminal of a poly(oxyethylene) chain was investigated. The rate constants of the intrachain reaction were determined as a function of the degree of polymerization, n, of the poly(oxyethylene) chain over the range of 5–33 at 15, 25, and 35 °C. The rate constant was at its maximum at n=7 and decreased with an increase in the chain length. A comparison of the data with those obtained with polysarcosine chain showed that the intrachain reaction proceeded more effectively in the latter chain. Some thermodynamic considerations were made as to the cyclization process of a poly(oxyethylene) chain.
The Role of the Charge-transfer Complex in the Photocopolymerization of Oxygen with Styrene and α-Methylstyrene
Authors: Kodaira Toshiyuki , Hashimoto Kohzoh , Sakanaka Yoshihiko , Tanihata Sumio , Ikeda Katsuki 
Published: July 2006

Abstract
The effect of the wavelength of irradiated light on the photocopolymerizations of oxygen with styrene (1) and α-methylstyrene (2) was investigated in connection with the charge-transfer bands observed between these monomers and oxygen, with the latter as an electron acceptor. It appeared that the excitation of the charge-transfer bands is responsible for the copolymerizations and that the photoabsorptions due to 1 and 2 do not contribute to the reactions, although the excited singlet states of these compounds were quenched by oxygen according to a Stern-Volmer plot.
Studies on the Liquid Phase Oxidation of Nitroalkylbenzenes Catalyzed by Transition Metal and Bromide Ions
Authors: Hasegawa Ryoichi , Kamiya Yoshio 
Published: July 2006

Abstract
The liquid phase autoxidation of nitroalkylbenzenes catalyzed by transition metal and bromide ions in acetic acid was investigated at 55–85 °C. A remarkable synergistic effect was found on the mixtures of metal catalysts composed of cobalt and other transition metals, the maximum reaction rate being observed at the molar ratio of Co : Mn : Br=1 : 0.005–0.01 : 1–2. The rate of oxygen absorption of p- or m-nitroalkylbenzenes wasas affected by the partial pressure of oxygen, showing deviation from the first order dependency on the substrate concentration in contrast to the case of ordinary alkylbenzenes. The results can be explained by the retardation effect due to nitro compounds which might result from the reaction with alkyl radicals and the deactivation of metal catalysts. o-Nitroalkylbenzenes except nitroethylbenzene show a great resistivity against the oxidation. The retardation effect can be ascribed to the inhibiting effect due to inactive free radicals and also to the various reduced products resulting from the intramolecular reaction of nitro groups and active radicals. It was found that the autoxidation of p-nitrotoluene catalyzed by Co–Mn–Br catalyst proceeds very rapidly at temperatures as low as 85 °C, yeilding mostly p-nitrobenzoic acid along with a small amount of p-nitrobenzaldehyde.
Surface Tensions of Several Rare-earth Chlorides and Binary NaCl–YCl3 System in Molten State
Authors: Igarashi Kazuo , Mochinaga Junichi , Ueda Shiro 
Published: July 2006

Abstract
The surface tensions of YCl3, LaCl3, PrCl3, NdCl3, GdCl3, and DyCl3, and binary NaCl–YCl3 system in molten state were measured by a maximum bubble pressure method, and the results were represented by empirical formulas as functions of temperature. Surface enthalpies of rare-earth chlorides were calculated from the formulas.
The Separation of Iron(III), Cobalt(II), Nickel(II), Copper(II), Zinc(II), Mercury(II), Lead(II), Cadmium(II), and Palladium(II) as Their SDBM (3-Mercapto-1,3-diphenyl-2-propen-1-one) Complexes by Thin Layer Chromatography on Silica Gel
Authors: Honjo Takaharu , Honnami Hiromi , Kiba Toshiyasu 
Published: July 2006

Abstract
The separation of iron(III), cobalt(II), nickel(II), copper(II), zinc(II), mercury(II), lead(II), cadmium(II), and palladium(II) as their SDBM chelates has been achieved successfully on the thin layer of silica gel with such developing solvents as carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, and carbon disulfide.
An X-Ray Photoelectron Spectroscopic Study of Biuret Metal Complexes
Authors: Yoshida Tooru , Yamasaki Kiyoshi , Sawada Shigemasa 
Published: July 2006

Abstract
The mode of the co-ordination of biuret in biuret metal complexes has been examined by means of X-ray photoelectron spectroscopy. It has been found that the C(1s), O(1s), and N(1s) binding energies were clearly different among the bidentated, O-, and N-co-ordinated structures, and the monodentated O-co-ordinated one.
Electrosynthesis of Hetero-Hetero Atom Bonds. I. A Direct Preparation of Bis(dialkylthiocarbamoyl) Disulfides from Dialkylamines and Carbon Disulfide
Authors: Torii Sigeru , Tanaka Hideo , Misima Kiyosi 
Published: July 2006

Abstract
Bis(dialkylthiocarbamoyl) disulfides were synthesized directly from dialkylamines and carbon disulfide by electrolysis under constant voltage using an undivided cell. The electrochemical reaction was carried out effectively in a two-layer system of electrolysis solvents, e. g., water–chloroform, water–dichloromethane, water–1,2-dichloroethane, and water–carbon disulfide. Likewise, the electrolysis could be performed in a homogeneous solution using dimethylformamide and/or acetonitrile.
Beam Studies of the Ion-Molecule Reaction CO2++D2→DCO2++D
Authors: Tochihara Hiroshi , Murata Yoshitada 
Published: July 2006

Abstract
Reaction cross sections of the reaction CO2++D2→DCO2++D have been measured over the range of the collision energies E=0.4 to 4 eV in the center of mass system. The cross section was obtained from relative values of the reaction Ar++D2→DAr++D by using the mixed ion beam method. The observed cross sections are about half of the Langevin-Gioumousis-Stevenson cross sections and show approximately E−1⁄2 dependence.
The Structure of the Cyclodextrin Complex. VI. The Crystal Structure of α-CycIodextrin–m-Nitrophenol (1 : 2) Complex
Authors: Harata Kazuaki , Uedaira Hisashi , Tanaka Jiro 
Published: July 2006

Abstract
α-Cyclodextrin (α-CDx) forms a 1 : 2 crystalline complex with m-nitrophenol (m-NP). The crystal structure was determined by the X-ray method. The crystal is orthorhombic, and the space group is P21212 with Z=2. The cell dimensions are a=22.231(7), b=16.865(6), and c=8.152(1) Å. The structure was solved on the basis of the nearly isomorphous structure of the α-CDx-sodium benzenesulfonate complex by using 2246 reflections, and refined by the block-diagonal least-squares method to the final R-value of 0.10. The framework of the crystal is built up of a stack of α-CDx molecules with a head-to-tail arrangement along the two-fold axis, showing a channeltype structure. Two m-NP molecules are statistically disordered on the two-fold axis. One is located in the channel, while the other is sandwiched between the α-CDx molecules. In the channel, the nitro group of m-NP is inserted into the α-CDx ring from the secondary hydroxyl side, and the phenolic hydroxyl group is hydrogen-bonded to the primary hydroxyl group of the next α-CDx molecule. The enthalpy change was calculated for the complex formation in an aqueous solution. The calculated results are in qualitatively agreement with the observed values. The catalytic ability of α-CDx in the hydrolysis of substituted phenyl acetates was discussed on the basis of the structural data.
The Structure of the Cyclodextrin Complex. VII. The Crystal Structure of the α-Cyclodextrin–DMSO–Methanol(1 : 1 : 2) Dihydrate Complex A Simultaneous Inclusion of DMSO and Methanol
Authors: Harata Kazuaki 
Published: July 2006

Abstract
The crystal structure of the α-cyclodextrin(α-CDx)–DMSO–methanol (1 : 1 : 2) dihydrate complex was determined by the X-ray method. The crystal is monoclinic, and the space group is P21 with Z=2. The cell dimensions are a=9.505(1), b=14.150(1), c=19.738(2) Å, and β=102.88(1)°. The structure was solved by an inspection of a Patterson map and by a trial-and-error method, and was refined by the block-diagonal least-squares method to the final R-value of 0.083 for 3732 reflections. The α-CDx ring is nearly hexagonal, with diagonal distances of 8.40–8.53 Å between the glycosidic oxygen atoms. The α-CDx molecules are arranged to form molecular layers perpendicular to the ac plane. The DMSO molecule is located on the secondary hydroxyl side in the α-CDx cavity, forming two hydrogen bonds with the adjacent α-CDx molecules. One methanol molecule is found on the primary hydroxyl side in the cavity, while the other is located outside the cavity. Two water molecules are distributed in the space between α-CDx molecules.
The Crystal and Molecular Structures of Pyrrolidinium p-Chlorobenzoate and Pyrrolidinium p-Toluate
Authors: Kashino Setsuo , Kataoka Shin-ichi , Haisa Masao 
Published: July 2006

Abstract
The crystal structures of pyrrolidinium p-chlorobenzoate (PYC) and pyrrolidinium p-toluate (PYT) have been determined from visually estimated Cu Kα data. The crystals of PYC are orthorhombic, space group Pbca, a=9.53(1), b=27.28(3), c=9.39(2) Å, and Z=8. Those of PYT are monoclinic, space group P21/c, a=14.66(3), b=9.00(2), c=9.44(1) Å, β=101.3(4)° and Z=4. The structures of PYC and PYT were refined by the blockdiagonal least-squares method to R values of 0.073 and 0.089 for 855 and 1277 non-zero reflections, respectively. In both PYC and PYT, the pyrrolidinium and benzoate ions are linked together by two kinds of N–H…O hydrogen bonds to form a ribbon along the twofold screw axis. The shorter hydrogen bond [N…O 2.697(7) Å for PYC, 2.674(5) Å for PYT] lies nearly perpendicular to the twofold screw axis, and the longer bond [N…O 2.730(7) Å for PYC, 2.738(5) Å for PYT] makes an angle of about 20° with the axis. The O…N…O angle is near to the regular tetrahedral angle [105.4(2)° for PYC, 107.1(2)° for PYT]. The crystals of PYG are isomorphous with those of piperidinium p-chlorobenzoate, piperidinium p-bromobenzoate, piperidinium p-toluate and pyrrolidinium p-bromobenzoate, but PYT crystallizes in a subgroup of the space group of the others because of the cooperative effects of the bulkiness of the methyl group and the ring size of the base moiety. The pyrrolidine rings in PYC and PYT take an approximate CS symmetry.
Reactions between PbO and TiO2 under Hydrothermal Conditions
Authors: Kaneko Shoji , Imoto Fumio 
Published: July 2006

Abstract
The phase relation of products obtained by the reaction between PbO and TiO2 under hydrothermal conditions up to 500 °C and 500 kg/cm2 for 5h has been investigated. The yield and crystallographic properties of purified PbTiO3 depend upon the PbO/TiO2 mole ratio (Pb/Ti ratio) in raw mixtures as well as the reaction temperature. Both PbTiO3 and PbTi3O7 are synthesized at a remarkably low temperature under hydrothermal conditions, as compared with the ignition process in air. Pure and well-crystallized PbTiO3 is obtained by heat-treating above 400 °C at Pb/Ti ratios greater than 1.0 and by dissolving excess PbO with acetic acid. PbTi3O7 coexists occasionally with PbTiO3 to some extent at Pb/Ti ratios less than 1.0, but appears as a single phase in the temperature range 100–450 °C at the Pb/Ti ratio 0.33. The unit cell volume of PbTiO3 prepared at lower temperature is considerably large, suggesting a loosely-packed structure. The compound is always of tetragonal form containing no metastable cubic form.
Aromaticity-Based Theory of Pericyclic Reactions
Authors: Aihara Jun-ichi 
Published: July 2006

Abstract
The resonance energies of conjugated compounds in the electronically excited state were calculated on the basis of the aromaticity theory previously reported by us. The allowednesses of pericyclic reactions were predicted by means of these resonance energies. The predictions based on the resonance energy difference (RED) between the pericyclic transition state and the reactant(s) are in general agreement with the experiment.
The Reaction of N-AIkylisoxazolium Salts with Hydroxylamine
Authors: Kashima Choji , Arai Kimio , Imada Satoshi , Tsuda Yoshihiko 
Published: July 2006

Abstract
The alternating transposition of C-3 and C-5 substituents on 3,5-disubstituted isoxazoles was found by refluxing a mixture of hydroxylamine hydrochloride, potassium carbonate, and 3,5-disubstituted 2-methylisoxazolium salts, derived from the corresponding isoxazoles. Under the same conditions, 3,5-disubstituted 2-t-butyl- or 2-benzhydrylisoxazolium salts gave the corresponding isoxazoles without alternation of the substituents.
An Anion Radical Precursor in the Nucleophilic Substitution of p-Dinitrobenzene
Authors: Abe Takehiro , Ikegami Yusaku 
Published: July 2006

Abstract
Appearance of p-dinitrobenzene anion radical has been demonstrated by visible and ESR spectroscopy in the replacement of the one nitro group of p-dinitrobenzene by hydroxide ion in aqueous dimethyl sulfoxide. The formation of the anion radical seems to be due to the direct electron transfer from hydroxide ion to p-dinitrobenzene. The results of kinetic studies suggest that the anion radical is a precursor in the substitution reaction.
Gel Filtration Study of the Effect of Urea on the Dissolution State of Sodium Dodecyl Sulfate
Authors: Sasaki Tsunetaka , Amano Hiroshi , Suzuki Hitoshi 
Published: July 2006

Abstract
Using gel columns of Sephadex G 50 Fine and CPG gel, gel filtration studies were made of the sodium dodecyl sulfate (SDS)–urea system. The results demonstrated that both the CMC and the elution volume of SDS were increased by the addition of urea. The increase of the elution volume indicates the decrease in micellar size, and this coupled with the increase of CMC indicates the increased difficulty of micelle formation by the addition of urea. The direct interaction between SDS and urea was also examined by the gel filtration method and such interaction was confirmed to be absent both below and above the CMC of SDS. Furthermore, the micellar weight of SDS was estimated by the gel filtration method and values of 23000 and 11000 were obtained for SDS solutions containing 0 and 3 mol dm−1 urea, respectively.
The Preparation of Phosphonic Acids Having Labile Functional Groups
Authors: Morita Tsuyoshi , Okamoto Yoshiki , Sakurai Hiroshi 
Published: July 2006

Abstract
Phosphonic acids having labile functional groups have been prepared quantitatively by the hydrolysis of bis(trimethylsilyl) phosphonates, were prepared by the reaction under mild conditions of the corresponding dialkyl phosphonates with bromotrimethylsilane.
Electroorganic Chemistry. XXVI. Electrooxidation of Enamines, Haloolefins, and Enol Ethers
Authors: Shono Tatsuya , Matsumura Yoshihiro , Hamaguchi Hiroshi , Imanishi Tamotsu , Yoshida Kaoru 
Published: July 2006

Abstract
Electrooxidation of enamines in methanol afforded two types of methoxylated enamines. Similar treatment of enol ethers gave trimethoxylated compounds. The products formed by the electrolysis of haloolefins in acetic acid were α-acetoxy haloolefins and α-acetoxy ketones.
Carrier Effect on the Nature of V4+ and Active Oxygen Species in Vapor-phase Oxidation of Butadiene over Supported Divanadium Pentaoxide Catalysts
Authors: Akimoto Masamichi , Usami Masahiro , Echigoya Etsuro 
Published: July 2006

Abstract
The reactivity of V4+ with gaseous oxygen formed on various kinds of supported V2O5 catalysts has been investigated by ESR. The results are discussed as carrier effect in relation to the selectivity for maleic anhydride formation during the course of the vapor-phase oxidation of butadiene. V4+ formed on Al2O3 (V/Al≤10/90 atom ratio) and MgO (V/Mg≤30/70) showed a hyperfine ESR structure and was hardly oxidized whereas V4+ formed on SiO2 (V/Si≥5/95) had the singlet ESR signal and was easily oxidized. Formation of these two kinds of V4+ was observed on V2O5–Al2O3 (V/Al≥20/80). They were similarly observed in the case of V2O5-TiO2, but some portion of V4+ having the hyperfine structure was also oxidized. The selectivity was high over the catalysts forming the reactive V4+ as compared with those forming the unreactive one. The reactive V4+ was shown by X-ray diffraction to be preferentially formed in crystalline V2O5. Study of the reduction and reoxidation of unsupported crystalline V2O5 by means of IR and the effect of addition of alkali metal oxide on the catalytic activity of the supported V2O5 were discussed. The important role of double bond type lattice oxygen V=O in maleic anhydride formation was proposed.