bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Synthesis of the Chloro and Dichloro Derivatives of 2,10-Dihydroxydicyclohepta[b,d]furan-3,9-diones
Authors: Kusaba Tomoyuki , Mori Akira , Takeshita Hitoshi 
Published: July 2006

Abstract
4,8-Dichloro- and 5,7-dichloro-2,10-dihydroxydicyclohepta[b,d]furan-3,9-diones were synthesized. Although the latter could be obtained by condensation of 4-chloro-p-tropoquinone and its hydroquinone, the former required the hydrolysis of condensate of 3-chloro-p-tropoquinone and 7-chloro-5-hydroxy-2-methoxytropone. This mixed condensation led to several unsymmetrically substituted derivatives in improved yields.
High Resolution 29Si Nuclear Magnetic Resonance Study on Gallosilicates with Zeolitic Structures
Authors: Hayashi Shigenobu , Suzuki Kunio , Shin Shigemitsu , Hayamizu Kikuko , Yamamoto Osamu 
Published: July 2006

Abstract
High resolution 29Si nuclear magnetic resonance spectra have been measured using magic angle sample spinning technique for several gallosilicates and aluminosilicates with zeolitic structures. The number of gallium atoms coordinating to the SiO4 tetrahedron was determined by the technique in the same manner as established for aluminium in aluminosilicates. The resonance lines were observed to shift to lower field by the substitution of silicon atoms with gallium as well as aluminium. The magnitudes of lower-field shifts were larger for the substitution by gallium than aluminium. The chemical shift ranges of 29Si nuclei are discussed for gallosilicates with the values for aluminosilicates compared.
Photochemical Electron-transfer Reaction between Aromatic Olefins and Metal Ions. Dependence of the Reaction Course on the Structure of the Olefins
Authors: Kojima Masanobu , Sakuragi Hirochika , Tokumaru Katsumi 
Published: July 2006

Abstract
To investigate the photochemical electron transfer from aromatic olefins to copper(II) or iron(III) ions, a series of substituted styrenes (1) was irradiated in the presence of copper(II) or iron(III) salts in methanol, which gave dimethoxylated monomers (2) and one or more of three types of dimethoxylated dimers [α,α- (3), α,β- (4), and β,β,-dimers (5)]. The formation of these products are reasonably attributed to the participation of the cation radicals of the olefins generated by electron transfer from the excited olefins to the metal ions. Substituents on the substrates are found to govern the reaction products.
Magnetic Properties of Conjugated Systems. Bond Orders and Imaginary Bond-Bond Polarizabilities of “Acyclic” Bonds
Authors: Mizoguchi Noriyuki 
Published: July 2006

Abstract
Within the London-McWeeny formalism of the π-electron magnetic properties, the contribution of each bond in a conjugated system to the London susceptibility is studied. By using the relations between the bond orders Prs and the imaginary bond-bond polarizabilities \barπ(rs)(tu) proved in a previous paper, it is shown that two equations, Prs+βπ(rs)(rs)=0 and π(rs)(vw)=0, hold for the “acyclic” bond r-s in a conjugated system. The equations show that no bonds in acyclic conjugated systems or in acyclic fragments of cyclic systems make any contributions to the London susceptibilities (or to the ring currents) of the systems. On the basis of these equations, the expression for the London susceptibility is simplified. Moreover, we will discuss the relationships between the above equations and some consequences of McWeeny’s unitary transformation.
Calorimetric Studies of the Interaction between the Lecithin and Copolymers of l-Lysine and l-Leucine
Authors: Nakagaki Masayuki , Okamura Emiko 
Published: July 2006

Abstract
The interaction between the dimyristoyl phosphatidylcholine (DMPC) bilayers and aqueous copolymers of l-lysine and l-leucine was investigated by means of differential scanning calorimetry. None of the copolymers had any effects on the transition temperature of DMPC, irrespective of the lysine/leucine ratio, although the pretransition peak disappeared. The transition enthalpy did not appreciably change upon the addition of copolymers if the leucine fraction was small (&lt;0.25), but it remarkably decreased upon the addition of a copolymer with a large leucine content (&gt;0.3). The latter case suggests the penetration of copolymers into the hydrophobic region (hydrocarbon-chain region) of DMPC as a result of the hydrophobic effect of leucine residues. On the contrary, copolymers of a small leucine content can penetrate at most into the polar region of DMPC because of the electric charge derived from lysine residues, indicating the effect of the copolymer composition on the penetrability of a copolymer into lipid layers.
The Electrical Properties of Calcium Sulfide Doped with Lanthanum Sulfide and Zirconium Sulfide
Authors: Adachi Gin-ya , Imanaka Nobuhito , Sato Mineo , Shiokawa Jiro 
Published: July 2006

Abstract
Calcium sulfides doped with tri- and tetravalent metal sulfides were prepared. Their electromotive forces (EMF) were measured on a galvanic cell(Fe+FeS| Solid Electrolyte| Cu+Cu2S) where the solid electrolyte was a material in a CaS–Ln2S3–MS2 system. The cell, using calcium sulfide doped with La2S3 and ZrS2, exhibited an EMF value as high as the one calculated for thermodynamical equilibrium. The CaS–La2S3–ZrS2 solid electrolyte showed, predominantly, an ionic conduction in the sulfur pressure range from 10−4 to 102 Pa with an activation energy of approximately 56.7 kJ·mol−1, which was lower than for CaS and CaS–La2S3.
Fluorescence Emissions of Cycloalkanes and Mono-olefin by Controlled Electron Impact
Authors: Kawazumi Hirofumi , Uchida Tsuneaki , Ogawa Teiichiro 
Published: July 2006

Abstract
Emission spectra of cyclohexane, methylcyclohexane, trans-decalin and tetramethylethylene were measured under the controlled electron-impact (5–100 eV) excitation. A broad band was observed in the ultraviolet region in addition to lines and bands from such fragments as H, CH, and C2. This broad band was assigned to the fluorescence emission from the excited parent molecule, since its peak and lineshape resemble the fluorescence measured for liquid and since the threshold energy agrees with the absorption onset. The emission cross sections for these emissions were determined at an electron energy of 50 eV.
Studies of the Complexes of Np(V) with Inorganic Ligands by Solvent Extraction with Thenoyltrifluoroacetone and 1,10-Phenanthroline. I. Carbonato Complexes
Authors: Inoue Yasushi , Tochiyama Osamu 
Published: July 2006

Abstract
The complex formation of Np(V) in a carbonate medium has been studied in 1 mol dm−3 NaClO4 at pH 6.5–8.3 and 25 °C using the solvent-extraction method with thenoyltrifluoroacetone (TTA) and 1,10-phenanthroline. The formation constants of the complexes of Np(V) with CO32− were log(β1/mol−1 dm3)=4.14±0.01 and log(β2/mol−2dm6)=6.78±0.01, with no indication of the formation of HCO3− complexes. Based on these constants, the distribution of chemical species of neptunium are discussed under various conditions encountered in natural water.
Über den Effekt der Schwingungsmühle auf Thermische Zersetzung von Ammoniumhydrogenamidophosphat
Authors: Shimasaki Choichiro , Ookawa Shigenobu , Ishizaka Ryuichi 
Published: July 2006

Abstract
Das von einer Schwingungsmühle gemahlte Ammoniumhydrogenamidophosphat (NH4HPO3NH2) hat es herausgestellt, daß nach einer Stunde Laufzeit die erste endotherme Spitze in DSC Kurven in zwei Teile geteilt wird. Die Absorption infolge NH und Zwitterions in IR Spektren wird vom EinfuB der Schwingungsmühle verändert. Das Ergebnis unterstützt eine Transformation von NH4HPO3NH2 nach einer Zwischenphase, die durch die starke Wasserstoffbindung zwischen NH und POH gebildet worden hat.
Orbital Phase Design of Acyclic Electron Localizing and Delocalizing π-Conjugated Poly ions and Related Systems
Authors: Inagaki Satoshi , Iwase Koji , Kawata Hirofumi 
Published: July 2006

Abstract
Acyclic localization-delocalization of electrons in π-conjugated hydrocarbon polyions was predicted in terms of the continuity-discontinuity of the phase of the component orbitals. Many pairs of electron-localizing and -delocalizing conjugated polyions were designed as the model systems of which the relative stabilities have not been explored so far.
Thermodynamic Analysis of the Potentiometric Titrations of Polypeptides Accompanying the Coil–Beta Conversion
Authors: Maeda Hiroshi 
Published: July 2006

Abstract
The stability of uncharged β-structure of polypeptides from potentiometric titrations is examined based on thermodynamic considerations with special references to the aggregation and/or precipitation of polypeptides and the irreversible nature of the titration. It is concluded that most of the reported data on various kinds of polypeptides approximately represent the stability of the β-structure. Diverse stabilities exhibited by reported data can be partly ascribed to different extents of the stacking of the pleated sheets.
ESR Spectra of Six-coordinate Cobalt(III) Tetraphenylporphyrin Cation Radicals Generated by Electrochemical Oxidation II. Axial Ligand and Solvent Effects
Authors: Ichimori Kohji , Ohya-Nishiguchi Hiroaki , Hirota Noboru , Yamamoto Kiyoko 
Published: July 2006

Abstract
The ESR spectra of the π-cation radical generated electrochemically from 5,10,15,20-tetraphenylporphyr-inatocobalt(II), [CoII(tpp)], have been observed in the presence of various anions and in solvents such as halo-genated hydrocarbons, nitriles, ethers, ethanol, and organic acids. From the analyses of these spectra, the TT-cation radical has been found to coordinate axially the anion or the solvent according to the order of its coordinating ability; BF4−, ClO4−, PF6−, NO3−&lt;nitriles&lt;halogen anions&lt;ethanol&lt;CF3COO−, AcO−, SCN−, CN−. The singly-occupied molecular orbital has been assigned to be always a2uπ orbital regardless of the axial ligands. The spin densities on N and Co much increase due to the axial ligation. It has been further confirmed that the spin polarization mechanism mainly contributes to the appearance of the spin density on Co. These axial-ligand effects are quantitatively explained by a model calculation of the CNDO/2 MO method.
Reactions of the [PtC2L2] Complexes (L=Sulfide or Tertiary Phosphine) with β-Diketonate Anions
Authors: Sasakura Fumiyo , Isobe Kiyoshi , Kawaguchi Shinichi 
Published: July 2006

Abstract
cis- and trans-[PtCl2(Et2S)2] as well as [PtCl2(EtSCH2CH2SEt)] reacted with thallium(I) β-diketonates, Tl(β-dik), to give complexes containing a central-carbon-bonded β-dik ligand. The reaction of cis-[PtCl2(PEt3)2] with Tl(acac) (acac=acetylacetonato) did not give an acetylacetonato complex, but resulted in [Pt(CO3)(PEt3)2], while trans-[PtCl2(PEt3)2] yielded [PtCl(acac)(PEt3)]. [Pt(PPh3)2(H2O)2](ClO4)2 derived from cis-[PtCl2(PPh3)2] reacted with K(acac) and K(tfac) (tfac=trifluoroacetylacetonato) to afford [Pt(acac)(PPh3)2]ClO4 and [Pt(tfac)(PPh3)2]ClO4, respectively. Bases such as Et3N, K(acac), and K(tfac) removed a proton from the latter complex to give [Pt(tfac(2–)-C,O)(PPh3)2] containing a C,O-chelated tfac dianion.
Chemistry of 1,2-Thiaphosphole 2-Sulfides I. Cycloaddition Reactions of 1,2-Thiaphosphole 2-Sulfides with Some Dienophiles
Authors: Tanaka Hideyuki , Kametani Shunichi , Saito Takao , Motoki Shinichi 
Published: July 2006

Abstract
2,9-Dithia-1-phosphabicyclo[4.3.0]nona-3,7-diene 1-sulfides have been prepared by the reaction of α,β unsaturated ketones with P4S10 in the presence of NEt3. 1,2-Thiaphosphole 2-sulfides generated by the thermolysis of the phosphabicyclo compounds underwent cycloaddition reactions with acrylonitrile, styrene, butyl vinyl ether and norbornene to give the [4+2]cycloadducts, respectively.
A Potent Pyridoxal Model Capable of Promoting Transamination and β-Elimination of Amino Acids
Authors: Kondo Hiroki , Kikuchi Jun-ichi , Uchida Shinji , Kitamikado Tatsuya , Koyanagi Eiji , Sunamoto Junzo 
Published: July 2006

Abstract
N-Dodecyipyridoxal chloride (1a) has been synthesized as a potent pyridoxal 5′-phosphate model. The equilibrium constant for Schiff base formation of 1a with phenylalanine (21000 M−1) in 3 mM hexadecyltrimethylammonium chloride (CTACl) micelle is over a thousand times larger than that for the N-methyl counterpart (1b). The Schiff base of 1a and phenylalanine exists over a broad pH range of 5–11 in two ionic forms, HSB and SB−, that differ in the protonation state at the azomethine group. These Schiff bases undergo transamination at 30 °C in the absence of a metal ion at considerably different rates; 1.33×10−3 and 1.5×10−5 s−1 for HSB and SB−1, respectively. Likewise, the former species exhibited 11 times higher reactivity in the β-elimination of O-phosphonoserine catalyzed by 1a in 3 mM CTACl at 40 °C. These results indicate unambiguously the importance of a positive charge on the azomethine nitrogen as well as the one residing on the pyridine nitrogen in vitamin B6 catalysis. The kinetic α-deuterium isotope effect of 5.1 in the transamiantion of phenylalanine with 1a at pH 7.7 and 30 °C revealed that α-hydrogen abstraction takes place in the transition state.
NAD(P)+–NAD(P)H Models. 53. Proximity Effect of Intramolecular Heteroatom on Reaction Rate
Authors: Ohno Atsuyoshi , Goto Takehiko , Kobayashi Hisami , Oka Shinzaburo 
Published: July 2006

Abstract
NAD(P)H-model compounds that have a sulfur or oxygen substituent in the molecule have been synthesized and kinetics for the reduction of both substituted and unsubstituted α,α,α-trifluoroacetophenones with these model compounds are studied. Reduction with the heteroatom-containing model compounds proceeds at a slower rate than the reduction with a model without any heteroatom substituents. Furthermore, the dependency of the kinetic isotope effect on the electron-deficiency of the substrate differs. Kinetic parameters reveal that the retardation caused by the heteroatom is due to the loss of entropy in the initial electron-transfer process. The enthalpic term favors the reduction with the heteroatom-containing model.
The BBGKY Equation in the Interaction Site Model for Polyatomic Molecular Fluids
Authors: Lee Lloyd Lieh-shen 
Published: July 2006

Abstract
We extend the atom-atom interaction site model to a fluid of polyatomic molecules in an external field by deriving the first Born-Bogoliubov-Green-Kirkwood-Yvon(BBGKY) hierarchy for a nonuniform system. It is shown that the intramolecular structure contributes to the density gradient as well as the intermolecular correlations. By invoking the mechanical equilibrium conditions for microscopic forces we also obtain new expression for the gradient of the pressure tensor in inhomogeneous fluids. The BBGKY equation provides a consistency check on any theories of the interaction site variety. An examination of the so-called RISM theory of uniform fluids shows that the latter is inconsistent with respect to the BBGKY condition.
Studies on Mixed-Ligand Complexes of Cadmium with 2,2′-Bipyridyl and Some Dicarboxylic Acids in Dioxane Medium
Authors: Kumari Rajani , Chandel Chandra Pal Singh , Gupta Chand Mai 
Published: July 2006

Abstract
The mixed-ligand complexes of cadmium with 2,2′-bipyridyl and dicarboxylic acids (tartaric, succinic, maleic, malonic, and malic) were studied polarographically in the 50% dioxane medium. The stability constants of simple systems were calculated by Deford and Hume method, and the values of stability constants of mixed-ligand complexes have been determined by the method of Schaap and McMasters. The overall stability constants have been evaluated with the help of Leden’s graphical extrapolation method and the values of β11, β12 and β21 are (5.24, 5.80, and 8.19) for Cd-bpy-tartarate system (5.62, 6.15, and 8.34) for Cd-bpy-succinate system (5.48, 6.10, and 8.32) for Cd-bpy-maleate system (5.57, 6.15, and 8.37) for Cd-bpy-malonate system, and (5.57, 6.15, and 8.34) for Cd-bpy-malate system.
The Phosphorescence Spectra of 9,10-Anthraquinone β- and β,β′-Sulfonates in an Aqueous Solution at 77 K
Authors: Kuboyama Akira , Matsuzaki Sanae Y 
Published: July 2006

Abstract
The nπ* phosphorescence spectra, and their excitation spectra and lifetimes of 9,10-anthraquinone-2-sulfonate, and -2,6- and -2,7-disulfonates in water–ethylene glycol 1:1 mixture at 77 K have been obtained. These phosphorescence spectra shift to the red with increases in the concentration of the solutions, and show an excitation-wavelength dependence. From the results obtained it is concluded that in the glassy solutions at 77 K an association of these quinones occurs, and that the phosphorescence state of the associates corresponds to the nπ* triplet excimer state, similar to that of the p-quinone aggregates in polycrystalline solutions at 77 K, previously studied.
X-Ray Photoelectron Spectroscopy of Sodium-doped Polyacetylene
Authors: Ikemoto Isao , Ichihara Toshihide , Egawa Chikashi , Kikuchi Koichi , Kuroda Haruo , Furukawa Yukio , Harada Issei , Shirakawa Hideki 
Published: July 2006

Abstract
The change of the C ls peak shape in an X-ray photoelectron spectrum was studied for sodium-doped polyacetylene. The C ls peak due to negatively-charged carbon atoms was found to appear on the low-binding-energy side of a peak due to neutral carbon atoms. An electron, which is transferred to a polyacetylene chain from the sodium atom, has been determined to reside over several carbon atoms.
Application of Laser Flash Photolysis to Determine Association Constants between Zn–TPPS3 and Viologens
Authors: Okura Ichiro , Aono Shigetoshi , Hoshino Mikio , Yamaha Akira 
Published: July 2006

Abstract
The association behavior between zinc 5,10,15,20-tetraphenylporphyrintrisulfonate (Zn–TPPS3) and viologens was investigated from the T-T absorption band of the triplet Zn–TPPS3 by laser-flash photolysis. The association constants of Zn–TPPS3 with methylviologen and propylviologen-3,3′-sulfonate (PVS) were 1.7×104 and 7.3×102 mol−1. dm3, respectively.
Triphenylmethyl-substituted Arylthioaminyl Radicals, An ESR Study of N-(Arylthio)triphenylmethylaminyls
Authors: Miura Yozo , Isogai Mamoru , Kinoshita Masayoshi 
Published: July 2006

Abstract
The title radicals have been studied by ESR spectroscopy. The radicals are fairly long-lived in solution and satellite lines due to the 33S atom at natural abundance could be observed in their ESR spectra.
The Electrochemical Behavior of BR2-linked Bis(glyoximato)nickel(II) Complexes in a Nonaqueous Solvent
Authors: Aihara Makoto , Nishi Yumiko , Omatsu Hiroko , Nonaka Yasuomi 
Published: July 2006

Abstract
Nickel(II) complexes with dioximers replaced by BF2 and B(C2H5)2 groups for bridging by the hydrogen atom were investigated by electrochemical methods. The nickel(II) complexes exhibited two distinct one-electron reduction waves in N,N-dimethylformamide. It was found that the electron-withdrawing effect of the replaced group is exerted on the electronic states of the nickel(II) complexes.
Stability Constants of Complex Formations between Divalent Metal Ions and Cyclic Dipeptides: Cyclo(glycyl–l-histidyl) and Cyclo(l-methionyl–l-histidyl)
Authors: Kojima Yoshitane , Ishio Noriaki , Yamashita Tetsushi 
Published: July 2006

Abstract
The values(logK1i and logK2 of the complex formations between divalent metal ions and two cyclic dipeptides of this title were determined by Bjerrum’s method. It is apparent from 1H NMR data that metal ions link exclusively to the nitrogen atom of the imidazolyl group of cyclo(l-methionyl-l-histidyl).
Synthesis of β-Alkylimino α-Cyano Dithiocarboxylic Acids, 3-Alkyl-1,3-thiazine-2,6-dithiones, and Related Compounds
Authors: Yamamoto Tatsuo , Hirasawa Shigeo , Muraoka Motomu 
Published: July 2006

Abstract
The title compounds 2 and 5 were synthesized by the reaction of β-alkylimino nitriles with carbon disulfide.
Sintered Iron (III) Oxide Photoanode Doped with Molybdenum
Authors: Oishi Shigero , Tajime Keiko , Hosaka Akeri 
Published: July 2006

Abstract
Sintered iron(III) oxide electrodes which contained about 0.01 atomic% of molybdenum showed considerable improvement in generating anodic photocurrent, particularly, in a cathodic potential region. 0.01 Atomic% doping level was found to be attained by sintering at 1200 °C for 12h using 0.2 atomic% of MoO2 or 1.0 atomic% of MOO3.
Synthesis of Lariat Ferrocenocrown Ethers and Their Alkali Metal Complexes
Authors: Akabori Sadatoshi , Habata Yoichi , Sato Masaru 
Published: July 2006

Abstract
Lariat ferrocenocrown ethers were synthesized by the reaction of disodium salt of 1,1′-dihydroxyferrocene with N-substituted bis(2-chloroethyl)amines and/or by the reaction of bis(2-chloroethoxy)ferrocene with disodium salts of N-substituted bis(2-hydroxyethyl)amines. Crystalline 1:1 complexes of N-(2-methoxyethyl)-4-aza-1,7-dioxa[7]ferrocenophane with LiClO4 and NaClO4 were also isolated.
Kinetic and Mechanism of the Electrochemical Reduction of Fluoranthene in N,N-Dimethylformamide
Authors: Abdel-Hamid Refat 
Published: July 2006

Abstract
Detailed mechanism of electrochemical reduction of fluoranthene has been studied by cyclic voltam-metric method in N,N-dimethylformamide solution using 0.1 mol dm−3 tetraethylammonium perchlorate as a supporting electrolyte. It was found that fluoranthene undergoes a reversible diffusion-controlled one electron-transfer wave followed by an irreversible one-electron one. The reaction in the presence of proton donor such as phenol was also studied. The results reveal that the kinetics of the reaction is first-order in anion radical, zero-order in fluoranthene and first-order with respect to phenol. The overall reaction is of the ECEh type. It is concluded that the mechanism of the electrochemical reduction of fluoranthene consists of (a) heterogeneous electron transfer to form an anion radical, (b) proton transfer reaction, (c) homogeneous electron transfer in which the neutral radical formed in (b) is reduced to the carbanion and finally (d) the rapid protonation of the carbanion.
The Fast and Selective Reduction of Organic Halides by Lithium Hydrotri-s-butylborate
Authors: Kim Sunggak , Yi Kyu Yang 
Published: July 2006

Abstract
Lithium hydrotri-s-butylborate is shown to be a powerful reducing agent in its reducing abilitie: toward organic halides and discriminates structurally different organic halides due to the bulkiness of the reagent Essentially complete utilization of the hydride of the reagent for the reduction of organic halides is also of synthetic significance.
Synthesis and Characterization of Hydrazone and Azine Derivatives of Bis(cyclopentadienyl)titanium(IV)
Authors: Khera Brij , Sharma Anand Kumar , Kaushik Narender Kumar 
Published: July 2006

Abstract
Pentacoordinated hydrazone and azine derivatives of bis(cyclopentadienyl)titanium(IV) of the type [(OC6H4CR : NNHR′)TiCl(Cp)2] and [(OC6H4CR″ : NN : CR″C6H4O)Ti(Cp)2], where R=H or CH3, R′=H, C6H5 or C6H3(NO2)2 and R″=H or CH3, have been prepared. The products were characterized by chemical analyses, electrical conductance, IR, 1H NMR, and electronic spectral studies.
Absorption Spectra of Tetrahedral Co(III) and Co(II) Complexes in Heteropolytungstates
Authors: Kojima Kazuo , Matsuda Jiro 
Published: July 2006

Abstract
The absorption spectra of Co(III) and Co(II) in the single crystals of the Keggin-structure compounds, K5[CoIIIW12O40]·nH2O and K6[CoIIW12O40]·mH2O, have been measured at 77 K. The spectra of these complexes in aqueous solutions have also been observed. All the spectra have been interpreted using crystal-field theory by assuming that a Co(III) or Co(II) ion is in Td symmetry. The parameters, Dq, B, and C⁄B can be evaluated as 780 cm−1, 630 cm−1, and 4.7 respectively for the Co(III) complex, and 460 cm−1, 650 cm−1, and 4.5 respectively for the Co(II) complex.