bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reversing-Pulse Electric Birefringence of Poly(γ-methyl l-glutamate) in Hexafluoro-2-propanol
Authors: Ueda Kazuyoshi 
Published: July 2006

Abstract
Reversing-pulse electric birefringence (RPEB) signals of poly(γ-methyl l-glutamate) (PMLG) were measured, for the first time, in hexafluoro-2-propanol at 25 °C and at 535 nm. Quantitative analyses were carried out on the steady-state birefringence and the field-free decay time (&lt;τ&gt;EB) in the wide field strength region and also on the rise, reverse, and decay portions in the low field strength region by taking into account the continuous molecular length distribution of a fractionated PMLG sample. The weight-average length (lw), permanent dipole moment (μw), polarizability anisotropy (Δαw), and the degree of polydispersity (lw/ln) were evaluated by two procedures: one from the analysis of the reverse-transient portion and the other from the field-free decay portion of RPEB signals. These two sets of the parameters should be identical with each other, if the electrooptical and hydrodynamic properties of PMLG do not change during the field-on and field-off processes. However, the length of the PMLG helix is shorter by about 18% in the presence of an electric field than that in the absence of the field. In order to explain this discrepancy, a new concept of reversible conformational transition under the external electric field is introduced.
The Two-phase Oxidation of Some Aromatic Compounds with Cerium Ammonium Nitrate in the Presence of Surfactants
Authors: Skr\.{z}ewski Jacek , Cichacz Ewa 
Published: July 2006

Abstract
The two-phase oxidations of 3,6-dimethoxydurene and xylenes in cyclohexane solutions with the aqueous solution of cerium ammonium nitrate were carried out in the presence of cationic, nonionic, and anionic surfactants. Both cationic (ammonium salt) and nonionic (Dipodand) surfactants inhibited the reaction. The anionic surfactant (sodium dodecyl sulfate, SDS) catalyzed these oxidations. From the product distribution it was concluded that the catalytic action of SDS is due to the binding of aromatic compounds and the Ce(IV) ions to the surface of the SDS micelles. The micellar oxidant has the high oxidation potential which should allow to oxidize the comparatively nonreactive substrates.
Molybdenum Peroxo Complex. Structure and Thermal Behavior
Authors: Segawa Koichi , Ooga Katsumi , Kurusu Yasuhiko 
Published: July 2006

Abstract
The molybdenum peroxide (Mo-y) prepared by oxidation of molybdenum metal with hydrogen peroxide has been studied to determine its structure and thermal behavior. Temperature programmed decomposition has been used to study the thermal stability of Mo-y. Two distinct peaks, I and II, of decomposition processes are discernible in Mo-y. Peak I corresponds to the elimination of water of crystallization and peak II to the decomposition of a peroxide ion of Mo-y. IR and UV examinations support the results of the thermal analysis. The IR band at 931 cm−1 and the UV band at 381 nm show the same thermal behavior. Both bands are attributable to the peroxide ion of Mo-y. Spectroscopic studies show that Mo-y has the tetrahedral coordination derived from the single molybdenum complex, which has double bond oxygens attached to Mo atom and has a symmetric type of peroxide ion with one water of crystallization.
Preparation of Ni- or Pt-Containing Cyclic Esters by Oxidative Addition of Cyclic Carboxylic Anhydrides and Their Properties
Authors: Sano Kenji , Yamamoto Takakazu , Yamamoto Akio 
Published: July 2006

Abstract
Metal containing cyclic ester complexes, (Remark: Graphics omitted.)(L=1,2-bis(diphenylphosphino)ethane (dpe) or 2,2′-bipyridine (bpy); R1, R2=H or CH3) and (Remark: Graphics omitted.) (L=tricyclohexylphosphine (PCy3) or dpe; n=1 or 2), have been prepared by oxidative addition of cyclic carboxylic anhydrides to zero-valent metal complexes. These complexes have been characterized by elemental analysis and spectroscopies (IR as well as 1H-, 13C{1H}-, and 31P{1H}-NMR) and chemical reactivities. Rate of the oxidative addition of succinic anhydride to Ni(bpy)(cod) (cod=1,5-cyclooctadiene) is expressed by a second order rate equation, R=k[Ni(bpy)(cod)][succinic anhydride], and temperature dependence of k gives the activation energy of 68 kJ mol−1. The reaction of methylsuccinic anhydride with Ni(cod)2 in the presence of tertiary phosphine or bpy affords two isomers, (Remark: Graphics omitted.) and (Remark: Graphics omitted.), corresponding to two modes of C–O bond cleavage in methylsuccinic anhydride promoted by Ni; dependence of the ratio between the two isomers on the kind of ligand added and reaction conditions has been examined.
The Crystal Structure of 4-Cyanoimino-3-methoxymethylperhydro-1,3,5-oxadiazine
Authors: Ebisuno Toichi , Takimoto Michiaki , Shiba Ryuichi 
Published: July 2006

Abstract
The structure of 4-cyanoimino-3-methoxymethylperhydro-1,3,5-oxadiazine in the crystalline state was determined by X-ray crystal analysis. The crystal is triclinic, space group P\={l}, a=10.307(3), b=8.166(2), c=5.082(1) Å, α=97.34(2), β=91.98(2), γ=107.13(2)°, Z=2. The final R value was 0.061 for 1651 reflections.
Preparation and Characterization of [S-(2-Aminoethyl)-l-homocysteinato]cobalt(III) Complexes with Bidentate Ligands
Authors: Suzuki Masutaro , Arisato Osamu , Okamoto Ken-ichi , Einaga Hisahiko , Hidaka Jinsai 
Published: July 2006

Abstract
Three kinds of cobalt(III) complexes with S-(2-aminoethyl)-l-homocysteinate (l-aehc) and a bidentate ligand (glycinate, oxalate, and ethylenediamine) were prepared and chromatographically separated into the quasi-enantiomeric isomers: ΔL-trans(O)·mer(N)-R(S), ΔL-cis(O)·mer(N)-R(S), ΛL-cis(O)·mer(N)-S(S), and ΛL-cis(O)·fac(N)-S(S) for the glycinato complex, ΔL-trans(N)-R(S) and ΛL-cis(N)-S(S) for the oxalato one, and ΔL-R(S) and ΛL-S(S) for the ethylenediamine one. These isomers were characterized from their electronic absorption, CD, and 13C NMR spectra. The conformations of the six-membered N–S chelate ring in the l-aehc, of the chair for ΔL-R(S) and of the chair or skew-boat for ΛL-S(S), were suggested on the basis of the 13C NMR spectra. The CD spectra of the isomers are discussed in relation to their geometrical and absolute configurations.
Formose Reactions. XXI. A Selective Formation of Dihydroxyacetone in the Formose Reaction in N,N-Dimethylformamide
Authors: Shigemasa Yoshihiro , Sasaki Yoshihiro , Ueda Nasuo , Nakashima Ruka 
Published: July 2006

Abstract
Dihydroxyacetone (DHA) was obtained in good yield from the selective formose reaction which was conducted with 2-(dimethylamino)ethanol and vitamin B1 in N,N-dimethylformamide (DMF). The major products were isolated from the formose and identified as dihydroxyacetone and 2-(1,2-dihydroxyethyl)-5-(2-hydroxyethyl)-4-methylthiazole by spectral data. Vitamin B1 suppressed the vaporization of formaldehyde from the reaction solution. Irrespective of the 2-(dimethylamino)ethanol concentration (above 0.1 M (1M=1 mol dm−3)), the maximum yield of DHA was 80–90 glc% at 1.0 M formaldehyde concentration, when the formaldehyde consumption was above 90%. Above 3.0 M formaldehyde concentration, selective formation of DHA (above 80 glc%) was obtained at the early stage of the reaction. The scheme for the formation of DHA in the formose reaction in the presence of vitamin B1 was also proposed.
Selective Condensation of [3-(Alkylthio)allyl]titanium Reagent with Carbonyl Compounds
Authors: Furuta Kyoji , Ikeda Yoshihiko , Meguriya Noriyuki , Ikeda Nobuo , Yamamoto Hisashi 
Published: July 2006

Abstract
[3-(Ethylthio)allyl]titanium reagent generated easily from allyl ethyl sulfides condensed with aldehydes to give erythro-β-hydroxy sulfides in highly regio- and stereoselective manner. In contrast, crotyl ethyl sulfide reacted with aldehydes affording δ-hydroxy vinyl sulfide exclusively. The substitution pattern of the starting sulfide can have a pronounced effect on the selectivity in this condensation reaction. erythro-β-Hydroxy sulfide obtained was transformed stereoselectively to the trans-vinyloxirane or 1,3-alkadiene.
Ab Initio Self-consistent Field MO Calculations of Ethanethiol and Ethanol
Authors: Ohsaku Masaru , Ichiishi Takehiro , Imamura Akira , Hayashi Michiro 
Published: July 2006

Abstract
Ab initio self-consistent field MO calculations were performed on EtSH and EtOH, and the optimized geometries were obtained by the use of the STO-3G and STO-3G* basis sets. It was found that ab initio MO calculations reproduced the observed geometries of these molecules sufficiently well. The variation in the observed bond angle, α(CCX) (X=S and O), from the trans to the gauche rotamers, which was observed by means of microwave spectroscopy, was very reasonably reproduced from the results of these calculations. The total energy calculated gives a reasonable explanation of the stability between the rotational isomers.
1H NMR and Differential Scanning Calorimetry Studies on Molecular Motions and Phase Transitions in Butylammonium Bromide
Authors: Fukada Shin-ichi , Ikeda Ryuichi , Nakamura Daiyu 
Published: July 2006

Abstract
The temperature dependences of the 1H NMR spin-lattice relaxation time and of the second moment of 1H NMR absorptions in the temperature ranges of 90–400 K and 77–456 K, respectively, were studied for butylammonium bromide and its N-deuterated analog. There are three known crystalline phases in butylammonium bromide as a result of two phase transitions which are confirmed by the present differential thermal analysis (DTA) experiments. The transition temperatures determined in this study are 200 and 249 K for butylammonium bromide. In the low temperature phase of this salt, CH3 groups perform the C3 reorientation with a relatively low activation energy of 11.0 kJ mol−1. The asymmetric T1 curves observed suggest the existence of some kind of disorder in the crystal structure of this phase. In the intermediate phase, the C3 reorientation of NH3+ groups and the 180 ° flip motion of butylammonium chains are activated with the activation energies of 23 and 14 kJ mol−1, respectively. The present NMR results for the high temperature phase indicate the occurrence of the conformational melting of the cation chains. The mechanism of the phase transitions is discussed.
Cadmium(II)-, Magnesium(II)-, and Zinc(II)-bearing Ferrites Formed from γ-FeOOH at Various Reaction pH’s
Authors: Ito Kazuo , Tamaura Yutaka , Katsura Takashi 
Published: July 2006

Abstract
The reaction of γ-FeOOH with the metal (Cd(II), Mg(II), or Zn(II)) and Fe(II) ions in solution gave the metal ion-bearing ferrites without oxidation. The ferrites obtained were the stoichiometric Mg(II)- and Zn(II)-bearing ferrites [Mg0.27Fe2.73O4.00 (pH 10.6), Zn0.38Fe2.61O4.00 (pH 10.5)] at pH 7.5–11.4, and the nonstoichiometric Cd(II)-bearing ferrites [Cd0.19Fe2.68O4.00 (pH 10.2)] at pH 7.5–10.5 (25 °C). The Cd(II)- and Mg(II)-ion content in the ferrites increases with an increase in the reaction pH, but the Zn(II)-ion content is almost constant at pH 7.5–10.5. This pH dependence of the metal-ion content in the ferrites agrees with that of the fractional adsorption of these metals on γ-FeOOH. This suggests that only the adsorbed metal ions are incorporated into the ferrites. The pH dependence of these metal-ion contents in the air-oxidation reaction is also similar to that in the transformation reaction from γ-FeOOH. This transformation reaction seems to be one process in the air-oxidation reaction.
Ylide-Metal Complexes. IX. The Preparation and Properties of Metal (Be, Mg, Zn, Cd, Hg, Al, In, Sn, and Pb) Complexes with Methylenetriphenylarsorane
Authors: Yamamoto Yoshihisa 
Published: July 2006

Abstract
The reactions of methylenetriphenylarsorane, (C6H5)3As=CH2 (L), with ZnCl2 or HgCl2 in the mole ratio 2:1 yield new monomeric compounds of bis(methylenetriphenylarsorane)metal dichloride, [(C6H5)3AsCH2–M–CH2As(C6H5)3]Cl2. The reactions of L with BeCl2 or MgCl2 in the mole ratio 2:2 yield dimeric trigonal compounds of di-μ-chloro-bis[(methylenetriphenylarsorane)metal] dichloride, (Remark: Graphics omitted.). The reactions of L with AlCl3 or InCl3 in the mole ratio 4:2 yield dimeric tetrahedral compounds of di-μ-chloro-bis[bis(methylenetriphenylarsorane)metal] tetrachloride, (Remark: Graphics omitted.). The reactions of L with (C6H5)3MCl (M: Sn and Pb) in the mole ratio 1:1 yield new monomeric compounds of (methylenetriphenylarsorane)triphenyl-metal chloride, [(C6H5)3AsCH2–M(C6H5)3]Cl. They are thermally stable complexes and their properties are compared with those of the methylenetriphenylphosphorane metal compounds.
Solvent Effects on Dimerization of Copper(II) Decanoate in Ketone Solvents
Authors: Yamada Hiromichi , Takahashi Kaoru , Fujii Yukio , Mizuta Masateru 
Published: July 2006

Abstract
The extraction of copper(II) with decanoic acid in some ketone solvents was carried out at 25 °C and at 0.1 mol/dm3 (NaClO4) aqueous ionic strength. Organic solvents used are 2-pentanone, 3-pentanone, 2-hexanone, 4-methyl-2-pentanone, 5-methyl-2-hexanone, and 2-octanone. For all solvents, the extracted species are CuA2, CuA2HA, Cu2A4, and Cu2A4(HA)2 (HA: decanoic acid). The dimerization and adduct formation of copper(II) decanoates in each organic phase can be formulated as:
CuA2+HA\oversetKad,monomer\ightleftharpoonsCuA2HA,
Cu2A4+2HA\oversetβad,dimer\ightleftharpoonsCu2A4(HA)2,
2CuA2\oversetKdim–1\ightleftharpoonsCu2A4,
2CuA2HA\oversetKdim–2\ightleftharpoonsCu2A4(HA)2.
The solvent effects on the dimerization of copper(II) decanoate can be interpreted in terms of the regular solution theory. It was proved that the number of solvent molecules liberated in the formation of the dimeric copper(II) decanoate in ketones was less than that in alcohols.
The Synthesis and Thermal Decomposition of Calcium Phosphoramidate
Authors: Watanabe Makoto , Morii Yoshio , Sato Shoji 
Published: July 2006

Abstract
Calcium phosphoramidate monohydrate was made by adding an aqueous calcium chloride solution to an aqueous potassium hydrogenphosphoramidate solution at pH 9.0–9.5 below 5 °C. The product was stable at room temperature, but it was decomposed by heating. When the product was heated at 150 °C in air, the phosphoramidate decomposed to produce anhydrous calcium phosphoramide and also ortho- and diphosphates. The elimination of ammonia from amino groups to form a P–N(H)–P linkage was not observed at this temperature. The phosphoramidate decomposed in air to form ortho-, imidodi-, di-, and a small amount of higher polyphosphates at a temperature higher than 150 °C. Imidodiphosphate was decomposed to diphosphate by moisture in air. β-Calcium diphosphate was formed by heating the phosphoramidate at a temperature higher than 750 °C in air. When the phosphoramidate was heated in dried N2, it showed the same thermal reaction as that in air below 250 °C, while the amount of imidodiphosphate in the thermal product was larger than that in air at a temperature higher than 400 °C.
The Syntheses, Properties, and Crystal and Molecular Structures of Bis(benzamide)tris(O,O′-diisopropyl dithiophosphato)neodymium(III), [Nd{(C3H7O)2PS2}3(C6H5CONH2)2], and Its Isomorphous Complexes of La, Ce, Pr, Sm, Eu, and Gd
Authors: Nakamura Reiko , Nagai Kiyofumi , Shimoi Mamoru , Ouchi Akira 
Published: July 2006

Abstract
The new complexes indicated in the title have been synthesized, and the crystal and molecular structure of the neodymium(III) complex has been determined by the X-ray diffraction method. The crystal is monoclinic, with the space group C2/c, Z=16, a=28.887(4), b=28.913(5), c=24.814(5)Å, β=106.72(1)°. The final R value for 7761 reflections is 0.066. The central neodymium(III) atom of the complex is octa-coordinated and is in a dodecahedron geometry; three O,O′-diisopropyl dithiophosphato ligands, chelating by both of the sulfur atoms, span the two m edges of a trapezium as well as one a edge of the other trapezium, and two oxygen atoms of both the benzamide ligate at both tips of the base edge of the latter trapezium. The solid and the acetonitrile solution of the europium(III) complex are orange in color, and they show a charge-transfer band in their near-ultraviolet absorption spectra.
Theory of Time-resolved Photon Absorption by Molecules after Radiationless Transition. Application to Benzene after S2\ightsquigarrowS0
Authors: Fujimura Yuichi , Arai Minoru , Nakashima Nobuaki , Yoshihara Keitaro 
Published: July 2006

Abstract
Expressions for the intensity of the time-resolved absorption (TRA) by molecules after radiationless transition have been derived. It is assumed that a non-equilibrium vibronic distribution is realized after the radiationless transition and relaxes to the equilibrium one. Two types of non-equilibrium distributions, Poisson distribution and canonical distribution with temperature higher than that of the heat bath are taken into account. The theory developed is applied to the TRA spectra (S3←S0) of benzene after the internal conversion S2\ightsquigarrowS0 (N. Nakashima and K. Yoshihara, J. Chem. Phys. 79, 2727, (1983)). It is shown that the expression for the intensity in the Sulzer-Wieland model is involved in the expression derived using the canonical distribution.
Studies of the Interaction of Isocyanides with Transition-metal Complexes. XXVI. The Preparation of Octakis(aryl isocyanide)dirhodium
Authors: Yamamoto Yasuhiro , Yamazaki Hiroshi 
Published: July 2006

Abstract
The treatment of a mixture of [Rh(cod)Cl]2 and aryl isocyanide with sodium amalgam afforded octakis(aryl isocyanide)dirhodium. A structure with two bridging and six terminal isocyanide ligands was deduced from the IR spectrum in comparison with that of the known cobalt analog. The temperature-dependent 1H NMR spectrum of this complex suggested harder intramolecular and easier intermolecular ligand exchanges than those of the corresponding cobalt analog.
400 MHz Proton Nuclear Magnetic Resonance Study of Magydardienediol, a Diterpene from Magydaris panacifolia
Authors: Nagano Hajime , Tori Motoo , Shiota Michio , de Pascual Teresa Joaquín 
Published: July 2006

Abstract
A detailed analysis of the 400 MHz 1H-NMR spectrum of magydardienediol (1), a diterpene isolated from Magydaris panacifolia (Vahl) Lange, has been performed by use of a combination of proton homonuclear spin decoupling, COSY, NOE difference, and NOESY techniques. This 1H-NMR spectral analysis, in conjunction with the mass spectral analysis of some derivatives of 1, revealed that the structure of 1 should be revised to t-6-hydroxymethyl-1,t-3-dimethyl-t-2-(3-methyl-2-butenyl)-3-(4-methyl-3-pentenyl)-γ-1-cyclohexanol.
A Rapid Pulse Nebulization Technique for Flame Atomic Fluorescence Spectrometry
Authors: Ekanem Edet Joseph 
Published: July 2006

Abstract
A simple and rapid pulse nebulization technique in which 200 μl sample volume is injected and aspirated into a flame-nebulizer is described for the determination of cadmium by line source atomic fluorescence spectrometry (AFS) and for magnesium and other elements by continuum source AFS. The volume of blood and serum samples required for replicate analysis is reduced below 1 ml; nebulizer clogging by heavy sample matrices is reduced; small volumes of rare samples can be analysed in the same batch as bulky samples using this technique. The technique is also applicable to flame AES which can also be performed with the instrumentation used in this work.
The Self-condensation of Methyl Iodide. The Intermediacy of Methylium Ions in C–C Bond Formation
Authors: Ono Yoshio , Kogai Masahiko 
Published: July 2006

Abstract
Hydrocarbons are formed by the reaction of methyl iodide vapor with solid-silver dodecatungstophosphate. The self-condensation is plausibly initiated by the attack of the methylium ion on the C–H bond of methyl iodide. It is suggested that the methylium ion is a key intermediate also in the conversion of methanol into hydrocarbons.
Theoretical Interpretation of the Mössbauer Parameter in [1]Ferrocenophanes
Authors: Ikuta Shigeru , Motoyama Izumi , Sano Hirotoshi 
Published: July 2006

Abstract
The smaller quadrupole splitting values in [1]ferrocenophanes than that in ferrocene were accounted for by assuming a lesser quantity of the nuclear part in the electric-field gradient at the iron nucleus; smaller quadrupole splitting could not be explained by the electron distribution among Fe 3d orbitals.
Solvent Effects on the n→π* Absorption Intensities of Acetone and Cyclopentanone
Authors: Shibuya Tai-ichi 
Published: July 2006

Abstract
The recently proposed theory [J. Chem. Phys. 78, 5175 (1983)] for the solvent effect on the absorption intensity has been successfully applied to the n→π* bands of acetone and cyclopentanone in various organic solvents observed by Nakashima, et al. [Bull. Chem. Soc. Jpn. 55, 415 (1982)].
Fermi Resonance Effects on the ν1 Raman Bands of Liquid CH2Br2 and CH3Br
Authors: Fujita Kazuyoshi , Fukuda Takuya , Fukushi Kohji , Kimura Masao 
Published: July 2006

Abstract
Applying Fermi-resonance-band-shape functions to the isotropic Raman band profiles of liquid CH2Br2 and CH3Br in the ν1 region, the peak frequencies, band-widths, and coupling constants of the ν1 and combination vibrations have been determined.
On the Crystal-Structure Change of Manganese Dioxide (CMD) during the Acid Digestion in MnSO4-H2SO4 System
Authors: Ohzuku Tsutomu , Hirai Taketsugu 
Published: July 2006

Abstract
The wet method to convert chemically prepared manganese dioxides (MnO2s) into β-MnO2 was reported. Chemically prepared MnO2S, such as I. C. Sample Nos. 5, 8, 11, and 12, were converted into β-MnO2 by using a proton-assisted rearrangement reaction in a boiling dil. H2SO4 solution containing Mn2+ ion at 100±10°C.
A Convenient Method for the Preparation of Conjugated Olefins from Allylic Acetates and Aldehydes. Synthesis of Pellitorine
Authors: Tsukahara Yuhko , Kinoshita Hideki , Inomata Katsuhiko , Kotake Hiroshi 
Published: July 2006

Abstract
A variety of allylic acetates were treated with sodium bromide and triphenylphosphine in the presence of 5 mol% of [Pd(PPh3)4] to give the phosphonium salts, which were converted to the ylids in situ and allowed to react with various aldehydes to afford the corresponding conjugated olefins in good yields. Furthermore, this procedure was applied to the synthesis of an insecticidal substance, Pellitorine.
Second-order Rate Constants for the Decomposition of Methyl Iodide in Different Rare Gases
Authors: Saito Ko , Tahara Hiroyuki , Murakami Ichiro 
Published: July 2006

Abstract
The thermal gas-phase decompostion of methyl iodide was studied in He and Kr over the temperature range of 1025–1520 K and the total-density range of (0.96–2.3)×10−5 mol cm−3. The results showed that, at high temperatures, these inert gases act as “weak colliders.” From the low-pressure limit rate constants, the relative values of the collision efficiency, βc(M), were evaluted as;
βc(He):βc(Ar):βc(Kr)=1.7:1.0:0.46
by connecting them with the previously reported data for an Ar mixture.
Dynamic NMR as a Nondestructive Method for the Determination of Rates of Dissociation. VIII. Proton Affinities of Anions Derived from Strong Acids in Chloroform
Authors: Oki Michinori , Ohira Manabu 
Published: July 2006

Abstract
Dynamic NMR study of topomerization by dissociation of N,N-dibenzylanilinium salt was applied to the determination of proton affinities of anions derived from strong acids in chloroform-d. The total line shape analysis of the benzylic proton signals gave the following order of proton affinity:
Cl−&gt;p-CH3C6H4SO3−&gt;CH3SO3−&gt;Br−.