bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ion-Pair Effect on the Rate of the Base Hydrolysis of the Pentaamminechlorocobalt(III) Complex
Authors: Iida Masayasu , Yamatera Hideo 
Published: July 2006

Abstract
The rate of the base hydrolysis of pentaamminechlorocobalt(III) ions was measured in the presence of multivalent anions at a constant ionic strength. The results were analyzed in view of the SN1 C.B. mechanism considering the formation of ion-pairs. The ion-pairing has the effect of suppressing the acid dissociation of the complex or the formation of its conjugate base, which acts as the intermediate of the reaction. This effect out-weighs the adverse effect of the probable acceleration of the rate-determining step of the base hydrolysis. The association constants obtained for [CoCl(NH3)5]2+·SO42− and [CoCl(NH3)5]2+·P3O93− were 40±5, and 82±5, respectively (I=0.1, 25°C).
The Sensitized Photooxygenation of 2-Vinylbenzofurans
Authors: Matsumoto Masakatsu , Dobashi Satoshi , Kondo Kiyosi 
Published: July 2006

Abstract
The sensitized photooxygenation of benzofuran, 2-methylbenzofuran, and six 2-vinylbenzofurans was investigated. Benzofuran and 2-methylbenzofuran were stable toward singlet oxygen. On the other hand, the vinylbenzofurans were easily photooxygenated to give the 1,4-endoperoxides. The 1,4-cycloaddition of singlet oxygen to the 2-benzofurans was confirmed to proceed with stereospecificity.
Photo-acylamination on Anthracene with Use of Acyl Azides
Authors: Ichimura Kunihiro 
Published: July 2006

Abstract
Irradiation of anthracene in the presence of acyl azide gives isocyanate and 9-acylaminoanthracene. The photolysis of aromatic hydrocarbon-acyl azide was followed by UV spectrophotometry and analyzed by the EDQ (quotients of extinction differences) diagram method.
The Aromatic Thiocyanation of 1-Alkoxynaphthalene by the Copper(II) Thiocyanate Method
Authors: Fujiki Kiyoko 
Published: July 2006

Abstract
A facile thiocyanation of 1-alkoxynaphthalene using copper(II) thiocyanate afforded 4-thiocyanato compound. The reaction proceeded at a moderate temperature (80–90 °C) even for 1-alkoxynaphthalene with higher alkyl groups (C6, C8, and C12).
Quantitative Analysis of Polybutadiene by Means of Pulse FT Carbon-13 NMR
Authors: Shibata Chizuko , Yamazaki Mitsuru , Takeuchi Tsugio 
Published: July 2006

Abstract
13C NMR was applied to the determination of the vinyl content in polybutadiene by means of the internal standard method. Under optimum experimental conditions, it was found that 13C NMR is applicable to the quantitative analysis of polymer by use of acetonitrile as an internal standard.
Conformational Study of Glutathione by NMR
Authors: Fujiwara Shizuo , Formicka-Kozlowska Grazyna , Kozlowski Henryk 
Published: July 2006

Abstract
Proton NMR spectra of glutathione have been analyzed over the whole pH region. The spectra of the glutamic acid residue are of the ABCDX type at pHs below 2.5, of the AA′BB′X types in the pH region 2.5–9, and of the ABCC′X type at pHs higher than 9. For the cysteine part, spectra of the ABC type have been observed at pHs higher than 8, which change to spectra of the A2B type at pHs lower than 7. On the basis of these results the conformation of the glutathione molecule in solution has been discussed in detail.
The Crystal and Molecular Structure of Dimethyl m-Phenylenediacrylate
Authors: Nakanishi Hachiro , Sasada Yoshio 
Published: July 2006

Abstract
Photooligomerizable crystals of dimethyl m-phenylenediacrylate are orthorhombic, Pmn21, with a=26.419(8), b=3.960(1), c=5.935(2) Å, and Z=2. The structure was solved by the direct method and refined by the block-diagonal least-squares calculation to the R value of 0.042 for 617 observed reflections. The molecule is nearly planar and V-shaped with a mirror symmetry. A parallel plane-to-plane stack is found along the short b-axis. The molecules in the stack overlap completely, in contrast with the half-molecule overlap in the photopolymerizable crystals of this kind. The length of the b-axis is just the shortest intermolecular distance between reactive double bonds, indicating that the double bonds related by the b-translation would react to form a cyclobutane ring with a mirror symmetry.
Nucleophilic Behavior of the Phenyl Radical in the Hydrogen Abstraction Reaction from Substituted Toluenes, A Contribution to the Study of the Phenyldiazenyl Radical
Authors: Suehiro Tadashi , Suzuki Akira , Tsuchida Yasuyoshi , Yamazaki Junji 
Published: July 2006

Abstract
Phenyl radicals derived from benzoyl peroxide (BPO) showed nucleophilic behavior, rho=+0.18 (metaseries) for the hydrogen abstraction reaction from substituted toluenes at 80 °C, and a kinetic deuterium isotope effect, kH⁄kD=3.73±0.2, was found for toluene. Comparison of these results with those for the phenyl radicals from phenylazotriphenylmethane (PAT) leads to the suggestion that the phenyldiazenyl radicals derived from PAT abstract hydrogen from toluene to yield benzene, which should amount to about 50% of the total benzene formed.
The Mechanism of NAD(P)H Reduction Reactions
Authors: Inagaki Satoshi , Hirabayashi Yoshio 
Published: July 2006

Abstract
The mechanism of reduction reactions by 1,4-dihydronicotinamides is investigated from the theoretical point of view of the electron configuration and orbital interactions for many systems. The following conclusions are drawn: (1) The reactions are situated near the one-electron-transfer region in the mechanistic spectra dependent on the donor-acceptor property of the reactants; (2) the hydride-equivalent transfers involved, whether concerted or not, proceed more or less in accordance with the nature of the sequential electron-proton-electron shift rather than via direct hydride-ion transfer; (3) the paradoxical frontier orbital interaction between the σ-LUMO of C4-H of 1,4-dihydronicotinamides and the LUMO of substrates is significantly involved in the transfer of the protonic entity. Pseudoexcitation is classified into Type I, where the normal HOMO-LUMO interaction remains important in addition to the LUMO-LUMO and HOMO-HOMO interactions, and Type II, where the HOMO-LUMO interaction contributes little. The NAD(P)H reduction reactions are predicted to belong to Type II.
The Hydrocracking of a Heavy Anthracene Oil over Molten Salt Catalysts
Authors: Nakatsuji Yohji , Fujioka Shigeyuki , Nomura Masakatsu , Kikkawa Sh\={o}ichi 
Published: July 2006

Abstract
The hydrocracking of a heavy anthracene oil over molten salt catalysts (zinc chloride or a binary mixture of zinc chloride and another metal chloride) at 400 °C for 3 h in a batch autoclave system was carried out, and the products were mainly identified by means of GC-MS. The effects of the hydrogen pressure (60 or 100 kg/cm2), the quantity of the catalyst, and the addition of metal chloride (potassium chloride or copper(I) chloride) to zinc chloride on the product distribution were examined and discussed. Based on the detailed product analysis, it was found that cata-condensed polycyclic aromatic compounds were hydrocracked more efficiently than peri-condensed polycyclic aromatic compounds. The CuCl/ZnCl2 molten salt displayed an excellent catalytic activity for the hydrocracking of the heavy anthracene oil.
The Photochemical Synthesis of 2-Chloro-3-(2-furyl)-1,4-naphthoquinones
Authors: Maruyama Kazuhiro , Otsuki Tetsuo 
Published: July 2006

Abstract
Upon the irradiation of a benzene solution of 2,3-dichloro-1,4-naphthoquinone, 1, and furan derivatives, 2, 2-chloro-3-(2-furyl)-1,4-naphthoquinones, 3, were obtained, accompanyed by a liberation of hydrogen chloride. The formation of a CT-complex between 1 and 2 was essential for the progress of the reaction. The 1H-CIDNP signals which were observed during irradiation suggest an intervention of a radical pair in the reaction.
Vibrational Spectra of Ethyleneurea and Its C,C′- and N,N′-Deuterated Derivatives
Authors: Saito Yutaka , Machida Katsunosuke 
Published: July 2006

Abstract
Infrared and Raman spectra of ethyleneurea and its C,C′- and N,N′-deuterated compounds have been measured. The fundamental frequencies have been assigned by referring to isotopic frequency shifts and Raman depolarization ratios. A normal coordinate analysis has been carried out for the infrared active vibrations of a planar C2V molecular model. A Urey-Bradley potential function supplemented by valence type constants for the outof-plane deformation and the torsional coordinates has been used. The calculated frequencies based on a refined set of force constants agree well with the observed.
Vibration Spectra and Rotational Isomerism of Chain Molecules. IV. Diethyl Sulfide, Ethyl Propyl Sulfide, and Butyl Methyl Sulfide
Authors: Ohta Masahiro , Ogawa Yoshiki , Matsuura Hiroatsu , Harada Issei , Shimanouchi Takehiko 
Published: July 2006

Abstract
The Raman and infrared spectra of diethyl sulfide, ethyl propyl sulfide and butyl methyl sulfide were measured for the gaseous, liquid, glassy and crystalline states. The normal vibration frequencies were calculated, a consistent set of force constants explaining the frequencies of basic aliphatic sulfides being assumed. The rotational isomerism was studied and the following conclusions were obtained. (1) Only the all-trans form exists in the crystalline state. (2) Many forms coexist in the liquid state and most of them persist in the glassy state even at the liquid nitrogen temperature. (3) In the liquid state, the gauche conformation about the S–C axis is more stable than the trans conformation, and the gauche conformation about the C–C axis directly adjoining the S–C axis is as stable as the trans conformation. These results confirm that the repulsive force between nonbonded hydrogen atoms is one of the important factors influencing the stability of molecualr conformations. The stable conformations of the sulfide molecules were correlated with those of polythioether chains.
The Backbone Rearrangement of 3β,4β-Epoxyfriedelane and the Synthesis of Dendropanoxide
Authors: Tori Motoo , Torii Takahiro , Tachibana Kazuo , Yamada Sachiko , Tsuyuki Takahiko , Takahashi Takeyoshi 
Published: July 2006

Abstract
Dendropanoxide (1) was synthesized by the reaction of 3β,4β-epoxyfriedelane (19) with boron trifluoride etherate in ether at −10 °C. In the rearrangement reaction, 4α-fluorofriedelan-3β-ol (20), D : B-friedo-olean-5(10)-en-3β-ol (21), β-amyrin (22), and D : B-friedo-olean-5-en-3β-ol (23) were also produced.
The Detemination of the Formation Constants of the Triiodide Ion in Water–Alcohol Mixed Solvents at Various Temperatures
Authors: Hayakawa Katumitu , Nakamura Sumio 
Published: July 2006

Abstract
The formation constants of the triiodide ion were determined in water-alcohol mixed solvents by a spectro-photometric method at various temperatures. The formation reaction of the triiodide ion from an iodide ion and an iodine molecule is accompanied by a negative enthalpy change and a positive entropy change at various alcohol contents: ΔH°/kJ mol−1, −15.4 (in water) to −14.3 (in methanol) in the water–methanol system, −15.4 (in water) to −21.4 (in ethanol) in the water–ethanol system; ΔSx°/J K−1 mol−1, 36 (in water) to 57 (in methanol) in the water–methanol system, and about 36 at various ethanol contents in the water-ethanol system. The enthalpy term is the dominant factor in the water–ethanol mixtures, whereas the entropy term is the dominant factor in the water–methanol mixtures. In order to explain the thermodynamic behavior, the changes in the solvation properties as well as the activity coefficients of solutes must be considered in both the mixture systems.
Infrared Studies on Water Adsorption Systems with the Use of HDO. I. Molecular Sieves 13X and 4A
Authors: Hino Masao 
Published: July 2006

Abstract
It was shown that the use of HDO molecules in IR studies on water adsorption system is advantageous for obtaining information as to whether 1) a band arises from the surface structural hydroxyl groups or from adsorbed water molecules, 2) a band arises from an overtone bending vibration, and 3) water molecules are adsorbed in a state of its two hydroxyl bonds being equivalent. The bands in the spectra of Molecular sieves–H2O systems were assigned as follows. I) 13X–H2O system. Bands at 3752, 3685, and 3647 cm−1 correspond to surface structural OH, bands at 3697, 3360, and 1650 cm−1 to asymmetrically adsorbed water molecules, band at 3230 cm−1 to overtone bending vibration of the same molecules. The band at 3590 cm−1 was found to arise from some other type of adsorbed water molecules. II) 4A–H2O system. Bands at 3500, 3400, and 1660 cm−1 correspond to symmetrically adsorbed water molecules, band at 3280 cm−1 to overtone bending vibration of the same molecules. Another type of adsorbed water was suggested to be present.
Vibration Spectra and Rotational Isomerism of Chain Molecules. V. 2,5-Dioxahexane, 2,5-Dithiahexane, and 2-Oxa-5-thiahexane
Authors: Ogawa Yoshiki , Ohta Masahiro , Sakakibara Masaaki , Matsuura Hiroatsu , Harada Issei , Shimanouchi Takehiko 
Published: July 2006

Abstract
The Raman and infrared spectra of 2,5-dioxahexane CH3OCH2CH2OCH3, 2,5-dithiahexane CH3SCH2CH2SCH3 and 2-oxa-5-thiahexane CH3OCH2CH2SCH3 were measured for the gaseous, liquid, glassy and crystalline states and were correlated with the normal-vibration calculations. The rotational isomerism was studied and the following conclusions were obtained. (1) The molecular form existing in the crystalline state is a non-extended form, in contrast with the cases of the unbranched ethers or sulfides containing one oxygen or sulfur atom which take the extended all-trans form. (2) Many forms coexist in the gaseous, liquid and glassy states. (3) The form existing in the crystalline state is the most stable in the liquid state. It was found that the repulsive force between non-bonded hydrogen atoms is one of the important factors influencing the conformational stabilities and for 2,5-dioxahexane the dipole-dipole interaction is another important factor. The stable conformations of these molecules were correlated with those of the polyether and polythioether chains. The stable isomers of 2-oxa-5-thiahexane could be explained on the basis of the knowledge of the conformational stabilities of the unbranched ethers and sulfides. The force constants of the ethers and sulfides were satisfactorily transferred to 2-oxa-5-thiahexane.
The Liquid-phase Oxidation of Aldehydes with Fe,Cu-Poly-phthalocyanine and Cobalt Tetra-p-tolylporphyrin
Authors: Ohkatsu Yasukazu , Sekiguchi Osamu , Osa Tetsuo 
Published: July 2006

Abstract
The effect of chemical species in a reaction system on the oxidation reaction of aldehydes was studied using Fe,Cu-polyphthalocyanine and cobalt tetra-p-tolylporphyrin as catalysts. Both catalysts activated the oxygen molecule on their central metals and then abstracted the hydrogen atom from aldehydes to initiate autoxidation. In this initiation step, every chemical species present in the reaction system, such as the solvent, the aldehyde, the oxygen molecule and the catalyst, is found to have an effect, one after another, either to accelerate or to retard the rate of initiation. The correlation of the nature of chemical species with such mutual interaction was discussed in detail.
Thermochemistry of Bis(tropolonato)copper(II)
Authors: Ribeiro da Silva Manuel A V , Irving Roger J 
Published: July 2006

Abstract
The standard enthalpy of formation of crystalline bis(tropolonato)copper(II) has been determined at 298.15 K by solution calorimetry: ΔHf°[Cu(trop)2] (c)=−102.47±0.42 kcal mol−1. Enthalpy changes at 298.15 K for the following hypothetical gaseous reactions have been subsequently derived:
2& Cu(g)+2 trop^.(g)=[Cu(trop)_2](c) & & ΔH=-150.4±14.1 kcal mol^-1
& Cu^2+(g)+2 trop^-(g)=[Cu(trop)_2](c) & & ΔH=-731.4±11.4 kcal mol^-1
The corresponding homolytic (E) and heterolytic(E′) copper(II)-oxygen bond energy parameters were calculated as
E_Cu–o=38±4 kcal mol^-1 and E’_Cu–o=183±3 kcal mol^-1
respectively.
Flux Growth of Rare-earth Niobates with Fergusonite Structure
Authors: Sugitani Yoshinori 
Published: July 2006

Abstract
Single crystals of rare-earth niobates RNbO4 (R denotes a rare-earth element) were grown from a melt of PbF2–PbO flux. They are monoclinic and isostructural with natural and synthetic fergusonites. These crystals, except those containing Pr, Nd, Sm, and Ho were found to emit luminescent colors under UV irradiation.
Improved Syntheses of 3′-Deoxybutirosin A and B
Authors: Watanabe Isamu , Tsuchiya Tsutomu , Umezawa Sumio 
Published: July 2006

Abstract
3′-Deoxybutirosin B and A (16, 17) were synthesized via condensation of 3,2′-bis-N-benzyloxycarbonyl-4′,6′-O-cyclohexylidene-3′-deoxyparomamine 1,6-carbamate (2) with tris-O-(p-nitrobenzoyl)-d-ribofuranosyl and -d-xylofuranosyl bromide, respectively, followed by 6′-O-tosylation of the decyclohexylidene derivative (8 and 9), cyclic 1,6-carbamate opening and amidation with (S)-4-benzyloxycarbonylamino-2-hydroxybutyric acid at the free C-1 amino group.
Pure Nuclear Quadrupole Resonance of Ionic Halides. I. 79Br-NQR Investigation of the Hydrogen Bonding, the 1H-2D Isotope Effect, and the “Order-Disorder” Transition in the Anilinium Bromides C6H5NH3⊕Br\ominus, C6H5ND3⊕Br\ominus, and C6D5NH3⊕Br\ominus
Authors: Pies Wolfgang , Weiss Alarich 
Published: July 2006

Abstract
The 79Br-NQR spectra of anilinium bromide, C6H5NH3⊕Br\ominus, of anilinium-d3 bromide, C6H5ND3⊕Br\ominus, and of aniliniunw-d5 bromide, C6D5NH3⊕Br\ominus, have been investigated in the temperature range 77≤T⁄K≤350. The three compounds show an order-disorder phase transition near room temperature. The respective transition temperatures have been determined as 296.9 K (C6H5NH3⊕Br\ominus), 291.5 K (C6H5ND3⊕Br\ominus), and 297.6 K (C6D5-NH3⊕Br\ominus). The large value of the 79Br-NQR frequency (v=17.780 MHz at 77 K for C6H5NH3⊕Br\ominus) and the large 1H–2D isotopic shift of this frequency (≈400 kHz at 77 K by deuteration of the NH3⊕-group) have been interpreted in terms of hydrogen bonding N-H…Br\ominus. The state of order in the high temperature modification is discussed in the light of the 79Br-NQR spectrum. The 79Br-NQR frequency of the Br\ominus ion in the low temperature modification is related to the change in the monoclinic angle β and to the temperature dependence of the order parameter s∝{(Tc–T)⁄Tc}1⁄3.
Application of a Coagulated Mixture Prepared from Finely Divided Cation and Anion Exchange Resins to the Enrichment of Copper (II)
Authors: Abe Masutaro , Ohzeki Kunio , Kambara Tomihito 
Published: July 2006

Abstract
Mutual coagulation takes place, when a suspension of finely divided cation exchanger is added to that of anion exchanger. The resulting mixed resin is bulky and easily separated from the solution by filtration. A rapid and selective collection of a trace amount of copper(II) ion was carried out by the combined use of mixed resin and 8-quinolinol-5-sulfonic acid (H2qs). The copper(II) collected on the mixed resin in the form of [Cu(qs)2]2− was brought into solution from the resin with ethylenediaminetetraacetate, converted into copper(II)–diethyldithiocarbamate, extracted into methyl isobutyl ketone, and determined by atomic absorption spectrometry. The method was satisfactorily applied to the determination of a trace amount of copper(II) in well water.
The Electronic Structure and Homolytic Dissociation of Dibenzoyl Peroxide
Authors: Kikuchi Osamu , Hiyama Akihisa , Yoshida Hiroshi , Suzuki Keizo 
Published: July 2006

Abstract
The conformations and electronic structures of dibenzoyl peroxide (BPO) and the benzoyloxyl radical (PhCOO) were elucidated by means of closed-shell and restricted open-shell SCF MINDO/3 calculations. The dihedral angle of BPO between the two PhCOO planes was predicted to be 115°, and the barrier to the trans form of BPO was estimated to be very small. The ground state of the PhCOO radical was predicted to be of the ∑-type. The non-planar conformation of PhCOO was more stable (2 kcal/mol) than the planar one. The variation in the radical-pair property of the lowest state of acetyl peroxide during the homolytic dissociation process was estimated by the analysis of the two-configuration wavefunctions. The substituent effect on the rate of the homolytic dissociation of BPO was discussed in terms of the electronic structures of substituted BPO.
Pyrolytic Sulfurization Gas Chromatography. II. Simple Determination of the Correction Factors Using Five Standard Compounds
Authors: Hara Tadashi , Fujinaga Kaoru , Tsuji Katsuya 
Published: July 2006

Abstract
An improvement has been made in the pyrolytic sulfurization gas chromatographic method, by which the atomic ratio between C, H, O, and N in a sample can be simultaneously determined. Analysis was carried out by use of the correction factors instead of calibration curves. Correction factors were obtained by use of five standard compounds, naphthalene, thiourea, cyanoguanidine, sucrose, and amidosulfuric acid. The method is simple, accurate, and applicable to various compounds.
Metal-Assisted Terpenoid Synthesis. V. The Catalytic Trimerization of Isoprene to trans-β-Farnesene and Its Synthetic Applications for Terpenoids
Authors: Akutagawa Susumu , Taketomi Takanao , Kumobayashi Hidenori , Takayama Kiyoshi , Someya Taichi , Otsuka Sei 
Published: July 2006

Abstract
Isoprene oligomerization was effected with a catalyst system Ni(OR)(η3-C3H5)PPh(NEt2)2 (R=n-C11H23, n-C15H31) to give a linear trimer fraction above 70% yield. The major component of the trimer fraction is (E)-7,11-dimethyl-3-methylene-1,6,10-dodecatriene (trans-β-farnesene) (1). The minor constituents of the fraction are (E)-2,6-dimethyl-10-methylene-1,6,11-dodecatriene. As slightly higher boiling point fractions, two cyclic trimers 1,5,9-trimethyl-1,5,9-cyclododecatriene and 1,5,10-trimethyl-1,5,9-cyclododecatriene were detected. Factors that influence the reaction path leading to 1 were discussed. Sesqui- and diterpenoids, including farnesyl acetate, farnesylacetone and isophytol were synthesised starting from 1. A regioselective tail to tail coupling of 1 was achieved with a palladium catalyst to give the dimer C30H48 which, upon catalytic hydrogenation, gave perhydrosqualene in 85% yield.
The Codimerization of Styrene and Butadiene with Three-Component Catalysts Consisting of Palladium Salt, Lewis Acid, and Tertiary Phosphine
Authors: Ito Takehiko , Takami Yasuo 
Published: July 2006

Abstract
The reaction of styrene and butadiene in the presence of a three-component catalyst consisting of a palladium salt, a Lewis acid, and a tertiary phosphine was investigated. As the three-component catalyst, combinations of such palladium(II) salts as (π-C3H5PdCl)2, (PdCl2·C6H5CH=CH2)2 and Pd(acac)2, such Lewis acids as BF3 and AlCl3, and such tertiary phosphines as Ph3P and Bu3P were adopted. From the reaction, 1-phenyl-1,4-hexadiene (a straight-chain codimer) was obtained as the main product, together with small amounts of branched-chain codimers. The ratio of the 1-phenyl-1,4-hexadiene to the branched-chain codimers was varied to some extent by changing the molar ratio of styrene to butadiene. With an increase in the molar ratio the ratio of 1-phenyl-1,4-hexadiene to the branched-chain codimers decreased. A reaction mechanism for the selective formation of 1-phenyl-1,4-hexadiene which involves the addition of butadiene, in preference to styrene, to a palladium hydride is proposed.