bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of 2-Azido-2-deoxypentose Derivatives
Authors: Hashimoto Hironobu , Araki Koichi , Saito Yoshihiro , Kawa Manabu , Yoshimura Juji 
Published: July 2006

Abstract
2-Azido-2-deoxypentose derivatives having d-xylo and l-arabino configurations were prepared via azidonitration of 1,5-anhydro-2-deoxypent-1-enitols, that is, xylal and arabinal derivatives, respectively. The l-ribo isomer was prepared by substitution of 2-trifluoromethylsulfonyloxy and 2-(1-imidazolylsulfonyloxy) group with azide. The d-xylo isomer was converted into the corresponding d-ribo and d-lyxo isomers.
Reaction of Olefins with Malonic Acid Derivatives in the Presence of Manganese(III) Acetate
Authors: Fujimoto Noriyuki , Nishino Hiroshi , Kurosawa Kazu 
Published: July 2006

Abstract
The reaction of methylmalonic acid with mono- and disubstituted olefins in the presence of manganese(III) acetate yielded 2-carboxy-2-methyl-4-butanolides in moderate to good yields. The reactions of bromomalonic acid and chloromalonic acid with a variety of olefins gave 2-halo-4-butanolides and/or 2-buten-4-olides. The reaction of ethyl hydrogen malonate with olefins in the presence of manganese(III) acetate yielded 2-ethoxycarbonyl-2-buten-4-olides, 2-ethoxycarbonyl-2-ethenyl-4-butanolide, 2,7-dioxaspiro[4.4]nonane-1,6-diones, 2-ethoxycarbonyl-4-butanolide, and ethyl 3-butenoate. These reactions can be accounted for in terms of a free-radical mechanism involving substituted dicarboxymethyl radicals.
Photochemical Addition of Benzyltriethylgermane and Dibenzyldiethylgermane to Olefins
Authors: Kobayashi Masanori , Yoshida Masato , Kobayashi Michio 
Published: July 2006

Abstract
A novel photochemical addition of a germyl radical to the olefinic double bond was discovered when benzyltriethylgermane or dibenzyldiethylgermane was irradiated with a medium-pressure mercury lamp in the presence of olefins.
The Preparation of Polythia[n](1,1′)ruthenocenophanes. Their Platinum Group Metals Complexes and Their X-Ray Crystal Structures
Authors: Akabori Sadatoshi , Sato Sadao , Tokuda Takehiko , Habata Yoichi , Kawazoe Kayoko , Tamura Chihiro , Sato Masaru 
Published: July 2006

Abstract
Polythia[n](1,1′)ruthenocenophanes were prepared by reaction of 1,1′-bis(2-chloroethylthio)ruthenocene with disodium alkanedithiolates in tetrahydrofuran/ethanol. The ruthenocenophanes efficiently formed 1 : 1 complexes with platinum and palladium dichlorides. X-Ray crystallography of complexes of the 1,4,7,10-tetrathia[n](1,1′)ruthenocenophane with PtCl2 and PdCl2 revealed that the Pt (or Pd) atom bonded selectively to the two sulfur atoms at the 4,7-positions among the four sulfur atoms in the bridge of the ligand with a slightly distorted cis square-planar configuration. The conformation of the organic moiety in the 1 : 1 complex is greatly changed from that of the metal-free ligand. Also, the 1 : 1 palladium complex is isomorphous with the 1 : 1 platinum complex.
Reactions of Schiff Bases with Superoxide Ion in Acetonitrile
Authors: Shibata Katsuyoshi , Saito Yoshiyuki , Urano Katsuyoshi , Matsui Masaki 
Published: July 2006

Abstract
The reactions of Schiff bases such as N-benzylideneanilines with superoxide ion in acetonitrile under mild conditions gave the cyanomethyl adducts, 3-arylamino-3-arylpropionitriles, as the main products in relatively good yields. In the case of N-(4-nitrobenzylidene)aniline, the adduct was further oxidized to β-anilino-4-nitrocinnamonitrile. No oxidative products such as amides were obtained except in the reactions of N-(4-chloro- and 4-nitrobenzylidene)aniline.
Equilibrium and Kinetic Studies of the Dimerization of Acridine Orange and Its 10-Alkyl Derivatives
Authors: Murakami Kiyofumi , Mizuguchi Katsumi , Kubota Yukio , Fujisaki Yasuo 
Published: July 2006

Abstract
The thermodynamics and kinetics of the dimerization of Acridine Orange (AO, 3,6-bis(dimethylamino)acridinium chloride) and its 10-alkyl derivatives in 0.1 M NaCl solution have been studied by spectrophotometry and temperature-jump method. Dimerization constants, which were determined spectrophotometrically, become large with an increase in the length of the introduced alkyl chain; this behavior is the same as that in water and a dilute HCl solution. The association and dissociation rate constants determined from the temperature-jump measurements also depend on the length of the alkyl chain. Especially, the rate constants for methyl–AO are unexpectedly small. Both the effect of added salt on the thermodynamic parameters and the kinetic results are discussed in view of the structure of hydration water surrounding dye molecules. 1H NMR data for AO and methyl–AO suggest that the planes of two component molecules in a dimer are parallel to each other. This result is consistent with the spectrophotometric and kinetic data.
Exciplexes in Perfluorohydrocarbon. Charge-Transfer Interaction between Exciplexes and Perfluorohexane
Authors: Kano Koji , Yanagimoto Masaru , Hashimoto Shizunobu 
Published: July 2006

Abstract
The rate constants for photochemical processes of pyrene in perfluorohexane (PFH) and hexane containing N,N-dimethylaniline (DMA) have been determined by analyzing the rise and decay curves of the pyrene–DMA exciplex to study the interaction between electronically polar exciplex and an extremely nonpolar solvent, PFH. In PFH, the dissociation of the exciplex to the original pyrene in the excited singlet state and DMA was decelerated and the radiationless deactivation of the exciplex to the ground states was accelerated. In the case of the naphthalene–triethylamine exciplex system, the radiationless deactivation of the exciplex was also much faster in PFH than in hexane. These results suggest charge-transfer interactions between the polar exciplexes and PFH. The negative charges of the exciplexes may transfer to the strongly electronegative fluorine atom(s) of PFH. The deceleration of the back reaction and the acceleration of the radiationless deactivation seem to lead the efficient fluorescence quenching of pyrene and naphthalene by amines in PFH.
Magnetic Properties of Dimeric Copper(II) 2,2-Dimethylpropanoate Complexes
Authors: Muto Yoneichiro , Hirashima Nobuchika , Tokii Tadashi , Kato Michinobu , Suzuki Ikuo 
Published: July 2006

Abstract
Dimeric copper(II) 2,2-dimethylpropanoate complexes, [Cu(Me3CCOO)2·L]2, where L is pyridine, acridine, quinaldine, 2-picoline, 4-picoline, and 2,6-lutidine, have been prepared. Magnetic data show that the singlet–triplet separation (−2J) ranges from 319 to 397 cm−1. Strong antiferromagnetic interaction observed for the acridine adduct (−2J=397 cm−1) is discussed on the basis of weak Cu–N(acridine) bond. The magnetic behavior of the non-adduct compound [Cu(Me3CCOO)2]2 (−2J=403 cm−1) is explained with respect to its non-polymeric structure.
Reactions of Alkyl Isothiocyanates with Dianions of Cyclic Thioureas
Authors: Matsumura Noboru , Tomura Masaaki , Mando Ritsuo , Tsuchiya Yuko , Yoneda Shigeo 
Published: July 2006

Abstract
The reactions of methyl (or ethyl) isothiocyanate with dianions (4, 5, and 6), which are readily derived from available cyclic thioureas (1, 2, and 3) with butyllithium, gave ring fused 1,3-disubstituted 1,3,5-triazine-2,4(1H,3H)-dithiones (7) and/or thiocarbamoyl derivative (8) as major products.
Cobalt(III)-Peroxo Complexes Containing 1,2-Bis(dimethylphosphino)ethane (dmpe) or 1,3-Bis(dimethylphosphino)propane (dmpp). Molecular Structures of [Co(O2)(dmpe)2]B(C6H5)4 and [Co(O2)(dmpp)2]BF4·H2O
Authors: Ohishi Tomoji , Kashiwabara Kazuo , Fujita Junnosuke , Ohba Shigeru , Ishii Toshio , Saito Yoshihiko 
Published: July 2006

Abstract
Monomeric (yellow) and dimeric (red) cobalt(III)–dioxygen complexes containing 1,2-bis(dimethylphosphino)ethane (dmpe) have been prepared from [Co(dmpe)2]+ and [Co(dmpe)2]2+, respectively, by air oxidation. The 1,3-bis(dimethylphosphino)propane (dmpp) complex afforded only the monomeric dioxygen complex by either preparative method. The crystal structures of [Co(O2)(dmpe)2]B(C6H5)4 (1) and [Co(O2)(dmpp)2]BF4·H2O (2) have been determined by X-ray analysis. Crystal data for 1; monoclinic, P21⁄a, a=18.011(12), b=18.761(10), c=11.455(6) Å, β=107.78(4)°, V=3686(4) Å3, Z=4, and R=0.064. Crystal data for 2; orthorhombic, Pbcn, a=14.540(5), b=13.123(4), c=13.138(2) Å, V=2507(1) Å3, Z=4, and R=0.076. The complex ions in both 1 and 2 have a trigonal-bipyramidal coordination geometry when the O2 group bonded to the Co atom in the side-on form at a coordination site of the trigonal plane is assumed to be a unidentate ligand. Bond lengths. Co–O (1.858(7)–1.881(4) Å) and O–O (1.414(12) and 1.425(6) Å), and O–O stretching frequencies (877 and 862 cm−1) indicate that both 1 and 2 are the peroxo complexes. The monomeric dioxygen complexes react immediately with SO2 and with concd HCl to afford [Co(SO4)(dmpe or dmpp)2]+ and cis-[CoCl2(dmpe or dmpp)2]+, respectively. The red dimeric trans-[(dmso)(dmpe)2Co(μ-O2)Co(dmpe)2(dmso)](BF4)4 (dmso=dimethyl sulfoxide) complex was isolated and characterized.
Convenient Synthesis of 3-Aminocoumarin Derivatives by the Condensation of 1,4-Diacetyl- or 3-Substituent-2,5-piperazinediones with Various Salicylaldehyde Derivatives
Authors: Shin Chung-gi , Nakajima Yoshiharu , Haga Toshiya , Sato Yoshiaki 
Published: July 2006

Abstract
The condensation of 1,4-diacetyl- or 3-substituted 2,5-piperazinediones (PDO) with various salicylaldehyde derivatives in the presence of a base, such as potassium t-butoxide or triethylamine, was found to give two extremely different kinds of products: 1-acetyl-3-arylmethylene-PDO and 3-(acylamino)coumarin derivatives. The former, which has a (Z)-geometric structure, was readily converted to the latter by irradiation. Furthermore, the conversion mechanism and the structural confirmation are discussed.
Paramagnetic Cobalt(III) Complexes with Organic Ligands. IX. The Preparation and Properties of Paramagnetic Tetraammine(5-nitrosalicylideneaminato)cobalt(III) Complexes
Authors: Yamamoto Yoshihisa , Toyota Eiko 
Published: July 2006

Abstract
The title paramagnetic cobalt(III) complexes, (Remark: Graphics omitted.),(X3: Cl2·NO3, (NO3)3), both green color, have been isolated and characterized by analytical, spectroscopic and magnetic methods. The effective magnetic moments are 1.7 BM, suggesting an unpaired spin. The 1H NMR spectra indicate that the unpaired spin on the complexes is localized over the π-orbitals of the chelated ligand. In the XPS, the high binding energy area at 286–289 eV of the C ls peak of both the complexe is larger than that for the corresponding diamagnetic cobalt(III) complex. The cobalt 2p peaks do not have satellites in the same manner as the usual diamagnetic cobalt(III) complexes. It can be concluded that an unpaired spin on complexes is not located on the cobalt atom, but is located over the π-orbitals of the chelated ligand of complexes.
1H NMR Studies on the Reorientational Motions of Cations in Four Solid Phases of Methylammonium Iodide and the Self-Diffusion of Ions in Its Highest-Temperature Solid Phase
Authors: Ishida Hiroyuki , Ikeda Ryuichi , Nakamura Daiyu 
Published: July 2006

Abstract
Four solid phases of CH3NH3I named as α′, β′, δ, and ε were studied by the temperature dependence of 1H spin-lattice relaxation time T1 and 1H spin–spin relaxation time T2 (for ε) at several NMR frequencies, and of 1H NMR second moment. Phase transitions were studied by means of differential thermal analysis and 1H T1. The X-ray powder patterns of the highest-temperature ε phase taken at ca. 440 K revealed that the crystal forms a CsCl-type cubic lattice. The measurements of differential scanning calorimetry gave unusually small entropy of melting indicating that the cations of the ε phase are in a state having the most part of their motional freedom. From 1H NMR T1 experiments, it was found that the transformation of the room-temperature α′ phase to the low-temperature stable β′ phase needed longer time than three months at Dry Ice temperature for samples carefully purified and dried for a long time under vacuum whereas it was completed within two weeks for roughly dried samples. The NMR results indicated that the cations are bound tightly in the β′ phase whereas they are fairly free to reorient in the low-temperature substable δ phase. In the α′ phase, the cations perform C3 reorientations very rapidly about their C–N bond axis. The cations of the ε phase undergo overall rotation as well as self-diffusion which was confirmed by electrical conductivity measurements. The mechanism of the self-diffusion of the cations is discussed.
Glycinoeclepins, Natural Hatching Stimuli for the Soybean Cyst Nematode, Heterodera Glycines. II. Structural Elucidation
Authors: Masamune Tadashi , Fukuzawa Akio , Furusaki Akio , Ikura Mitsuhiko , Matsue Hideki , Kaneko Tatsuya , Abiko Atsushi , Sakamoto Noriyasu , Tanimoto Norihiko , Murai Akio 
Published: July 2006

Abstract
The structures of three new compounds, glycinoeclepins A, B, and C, isolated from the hatch-stimulating extracts of kidney beans for the soybean cyst nematode, have been determined. The structures were resolved by using spectroscopic methods, especially by the difference NOE techniques, and confirmed by the X-ray diffraction analysis. These structures are characterized by (1) migration of two methyl groups in the C and D rings, (2) oxidative cleavage of the B ring with loss of one carbon atom and (3) presence of the 7-oxabicyclo[2.2.1]heptane system in the A ring, compared with those of cycloartanes, and are regarded as pentanor- (GEA) or nortriterpenes (GEB and GEC).
Quinoxaline Derivatives. XII. The Reactions of Quinoxaline 1,4-Dioxides with Acetic Anhydride
Authors: Ahmed Yusuf , Qureshi M Ikram , Habib M Saleem , Farooqi M Amir 
Published: July 2006

Abstract
Quinoxaline 1,4-dioxide (XIIIa) with acetic anhydride gave 1-acetoxy-2(1H)-quinoxalinone (XIVa) which was prone to facile hydrolysis to yield 1-hydroxy-2(1H)-quinoxalinone (XVa). Both XIVa and XVa were isolated from the reaction mixture. On prolonged heating with acetic anhydride, XIIIa, XIVa, and XVa were converted slowly to the same end product, 2,3(1H,4H)-quinoxalinedione (XXa). 6-Ethoxy- (XIIIb), 6-methoxy- (XIIIc), and 6-methylquinoxaline 1,4-dioxide (XIIId) behaved similarly, except that the attack of the reagent took place exclusively on N-oxide para to the electron-donating substituents, and none of the other expected isomeric compounds XVIIb–d were isolated. Whereas 6-chloroquinoxaline 1,4-dioxide (XIIIe) bearing an electron-attracting chloro substituent on the benzene ring gave exclusively the other isomers XVIIe, XVIIIe, and XXe. A mechanism for this novel rearrangement is proposed and discussed.
Coordination-Site Exchange of Azaheterocyclic Ligands in Five-Coordinate Palladium(II) Complexes. Bis(4,7-dimethyl-1,10-phenanthroline)(triphenylphosphine)palladium(II) Tetrafluoroborate and the 4,7-Diphenyl Derivative
Authors: Yamazaki Shinsaku 
Published: July 2006

Abstract
Variable-Temperature 1H NMR suggests that the fluxional motion of a potentially five-coordinate complex [Pd(PPh3)(4,7-R2-phen)2][BF4]2 (R=Me, Ph) is frozen at lower temperatures, where the complex is in a rigid configuration (an unusual trigonal bipyramid). The fluxional motion is explained by two synchronous rearrangement systems, and an activation parameter, ΔG*, for the site exchange is given.
The Crystal and Molecular Structure of Bis(dibenzylamine)bis(thiocyanato)cadmium(II), Cd(SCN)2{(C6H5CH2)2NH}2
Authors: Taniguchi Masahiro , Ouchi Akira 
Published: July 2006

Abstract
The crystal and molecular structure of the title complex was determined by means of a single-crystal X-ray diffraction technique. A crystal of CdC30H30N4S2, F.W.=623.13, is triclinic, with a space group P\bar1, a=11.284(2), b=11.404(2), c=5.974(1) Å, α=93.31(2), β=98.37(1), γ=71.84(1)°, U=722.6(2) Å3, Z=1, Dm=1.42(3) Dx=1.43 Mg m−3, and μ(Mo Kα)=9.17 cm−1. The cadmium(II) atom is hexa-coordinated, being ligated with two thiocyanato(SCN)sulfur atoms as well as two SCN and two dibenzylamine nitrogen atoms, where the respective pairs of the same kinds of atoms are all in a trans-configuration. All cadmium(II) atoms are lined along the c-axis and the side-by-side metal atoms are doubly bridged by SCN ions.
Molecular-Weight Dependence of the Polymer Adsorption at Solid-Liquid Interfaces as Studied by ESR Spectroscopy
Authors: Sakai Harutoshi , Imamura Yoshio 
Published: July 2006

Abstract
The conformation of poly(methyl methacrylate) adsorbed from dilute solution on nonporous silica was investigated by ESR method using three-component spectrum analysis. The fraction of the polymer segments in train, short loop, and long loop or tail, as well as the rotational correlation time for the segments were examined with regard to molecular weight (M=103–3×106), the degree of adsorption, and the particle size of silica. In CCl4, the saturation adsorption, As, increased from 6 to 16×10−8 g cm−2, the fraction of polymer segments in train, p, decreased from 0.9 to 0.4, and the segment mobility reduced with the increase in molecular weight, respectively. Remarkable changes in As and p were found in a range of molecular weight of 5×104. In benzene, the values of As and p were less dependent on molecular weight than the cases of adsorption in CCl4. Marked effects of intrachain interactions on the conformation were revealed for the adsorption of coiled polymers with high molecular weight from CCl4 solution at low degrees of adsorption, where the loop formation was observed for polymers of M&gt;104. The intrachain force was attributed to overlapping among the segments. The difference in the adsorption behavior between the cases in CCl4 and benzene was interpreted by the difference in the degree of deformation of polymer molecules upon adsorption.
Extraction and Transport of Ions in a Liquid Membrane Containing Crown Ether
Authors: Sakim Maria , Hayashita Takashi , Yamabe Takeo , Igawa Manabu 
Published: July 2006

Abstract
The ion-transport mechanism through a liquid membrane containing dibenzo-18-crown-6 as a carrier was investigated by measuring the salt flux, the distribution coefficient to the membrane phase, and the membrane potential. The salt flux increased to a great extent with the activity of the source phase solution, but the effect of the activity on the distribution coefficient varied with the membrane solvent. The mobility ratio of cations to anions increased with an increase in the hydrophobicity of the membrane solvent. Although the selectivity of the cation transport is controlled mainly by the size of the crown ring, the hydrophobicity of the cation also influenced the salt flux and the flux of a slightly hydrated large cation, such as cesium ion, was high. The hydration degree of anions influenced the salt flux considerably since the stability constants of the crown ether complexes accompanied by a hydrophobic anions were very high. The salt flux correlated well with the lyotropic number of anions.
Action of Serine Carboxypeptidases on Endopeptidase Substrates, N-Acyldipeptideamides
Authors: Kunugi Shigeru , Tanabe Kazuo , Yamashita Kouji , Fukuda Mitsuhiro 
Published: July 2006

Abstract
Action patterns of two serine carboxypeptidases, one from yeast (Y) and the other from wheat bran (W), on N-[3-(2-furyl)acryloyl]-(Fua-) dipeptideamide substrates were examined by HPLC and amino acid analysis. In the reaction of the wheat enzyme the substrates were hydrolyzed to Fua-amino acid and no sufficient amount of Fua-dipeptides were detected on HPLC in the product mixtures. Very few or no free amino acids were observed by amino acid analysis. This indicates that the wheat enzyme exhibited carboxamidopeptidase activity on these substrates. On the contrary, carboxypeptidase Y gave Fua-amino acids and Fua-dipeptides as products, depending on the structure of the substrates. Accordingly, liberations of free amino acids were detected in some cases. This result shows that the yeast enzyme acts on some of the substrates in a two step manner: First by amidase and second by a carboxypeptidase activity. Based on these results the substrate binding mechanisms of these enzymes are discussed.
Partition Parameters for Three Redox Forms of Viologen in a Nonionic Micellar Solution
Authors: Hoshino Katsuyoshi , Sasaki Hiroaki , Suga Kosaku , Saji Tetsuo 
Published: July 2006

Abstract
The partition parameters of 1,1′-dimethyl-4,4′-bipyridinium (1), 1-decyl-1′-methyl-4,4′-bipyridinium (2), and 1-dodecyl-1′-methyl-4,4′-bipyridinium (3) between the micellar and water phases were determined by electrochemical methods. It was shown that 10, 2\underset.+, 20, and 32+ are almost completely solubilized in the micellar phase and that 12+, 1\underset.+ and 22+ are partitioned into two phases.
Determination of the Intrinsic Reaction Coordinate in the 2H+O(1D) System Near the Equilibrium H2O
Authors: Cho Seikichi 
Published: July 2006

Abstract
A normal coordinate analysis was applied to the 2H+O(1D) three atomic system, using the Schinke–Lester analytic expression for the adiabatic potential energy. Defining the reaction coordinates as the “infinitely slow motion trajectories,” the reaction coordinate of the heavy oxygen atom was calculated easily, while that of the light hydrogen atom was obtained with some difficulty. Several repeated corrections were needed to converge the reaction coordinates to the “intrinsic” reaction coordinate. The intrinsic reaction coordinate of a hydogen atom to the uphill side of H2O was found to be very difficult to follow. This fact might help to explain the low frequency factor of the decomposition reaction of H2O.
Asymmetric Hydrogenation Catalyzed by Bis(disubstituted glyoximato)cobalt(II)(L)-Chiral Cocatalyst System. Effect of Structural Variation of Ligands and Hydrogen Pressure
Authors: Ohgo Yoshiaki , Tashiro Yasuhisa , Takeuchi Seiji 
Published: July 2006

Abstract
The reaction rate was extremely enhanced by increasing the basicity of the axial ligand of [Co(dmgH)2(L)] and by increasing the hydrogen pressure without decreasing the enantioselectivity. Substituting one and two methyl groups of the dimethylglyoxime ligand in [Co(dmgH)2(L)] with a phenyl group enhanced and retarded the reaction rate, respectively. The chirality at the cobalt did not affect the enantioselectivity.
Insertion of Ketene and Diphenylketene to the Pnictogen-Heteroatom Bonds
Authors: Ando Fumio , Kohmura Yoshihiko , Koketsu Jugo 
Published: July 2006

Abstract
Ketene and diphenylketene insert across the heteroatom-metal bond of amino-, alkoxy-, and alkylthiopnictogens, R3−nMXn, to give the corresponding α-metallated acetamides, esters, and thioesters, R3−nM(CH2COX)n and R3−nM(CPh2COX)n (M=As, Sb, Bi; X=NR2, OR, SR; n=1,3), respectively.
The Oxidation of PbSO4 to PbO2 in Sulfuric Acid Solution
Authors: Takehara Zen-ichiro , Kanamura Kiyoshi 
Published: July 2006

Abstract
The interface between PbO2 and PbSO4 was considered to be the reaction site of the oxidation of PbSO4 to PbO2. The area of this site depended on the changing crystal size of PbSO4 with the discharge conditions. The oxidation rate of PbSO4 to PbO2 increased with a decrease in the crystal size of PbSO4 since the reaction site area per unit volume increased with a decrease in the crystal size of PbSO4. The oxidation of PbSO4 to PbO2 depended on the discharge current, the sulfuric acid concentration and the rest time after a discharge.