bluuebunny/crossref_metadata_2025_split huggingface dataset:
Telomerization of Isoprene with Dialkylamine Catalyzed by Palladium Complexes
Authors: Hidai Masanobu , Mizuta Haruyoshi , Hirai Kiyomiki , Uchida Yasuzo 
Published: July 2006

Abstract
Telomerization of isoprene with diethylamine in the presence of catalytic amounts of palladium chloride and triphenylphosphine under carbon dioxide and/or using methanol as solvent gave three kinds of 2:1 adducts in good yields, one of which was found to be an adduct of new type.
Restricted Rotation Involving the Tetrahedral Carbon. XXXI. Barriers to Rotation in 2,3-Dichloro-9-(1-cyano or 1-methoxycarbonyl-1-methylethy)triptycenes
Authors: Otsuka Soichi , Yamamoto Gaku , Mitsuhashi Tsutomu , Oki Michinori 
Published: July 2006

Abstract
The title compounds were prepared to see the effects of substituents in 1-position on the barriers to rotation about the C9–Csubst bond. The barrier was found to be higher for the cyano compound than those for the corresponding compounds carrying a substituent in 1-position, whereas the methoxycarbonyl compound gave almost the same barrier irrespective of the substituent.
Heterogeneous Catalysis in the Liquid-phase Oxidation of Olefins. IV. The Activity of a Supported Vanadium or Chromium Oxide Catalyst in the Decomposition of t-Butyl Hydroperoxide
Authors: Takehira Katsuomi , Hayakawa Takashi , Ishikawa Toshio 
Published: July 2006

Abstract
The liquid-phase decomposition of t-butyl hydroperoxide (t-BuOOH) has been carried out in benzene under an N2 atmosphere using a vanadium or chromium oxide, supported on γ-Al2O3 or SiO2 as the catalyst, for the purposeof clarifying the reaction mechanism of the cyclohexene oxidation. The decomposition of t-BuOOH on the supported oxide catalyst was a first-order reaction; the main products were t-butyl alcohol, di-t-butyl peroxide, and acetone, suggesting that t-BuOOH is decomposed homolytically on the catalyst by the Haber-Weiss mechanism. The effect of the vanadium–chromium binary system formation was small, but the interaction between metal oxides and the supports appeared to be important in the t-BuOOH decomposition. Tetrahedrally co-ordinated vanadium species were formed on SiO2 and showed the highest activity, followed by the chromium co-ordinated tetrahedrally on SiO2 or on γ-Al2O3, while an octahedrally co-ordinated vanadium or chromium showed low activity. Such order of the activity was in good agreement with that obtained in the liquid-phase oxidation of cyclohexene. We observed a relatively good correlation between the catalytic activity and the acidity of the supported binary metal oxides. The V2O5–SiO2 system showed an especially large acidity; here t-butyl alcohol was dehydrated into di-t-butyl ether and 2-methyl propene.
The Crystal Structure of the A′-form of Tridecanoic Acid
Authors: Goto Midori , Asada Eiichi 
Published: July 2006

Abstract
The A′-form of tridecanoic acid is triclinic, with the space group P\bar1 and with a=4.273(1), b=4.972(1), c=37.69(1) Å, α=90.36(2), β=109.44(2), and γ=112.43(2)°. The structure was determined by the Patterson method. Refinement by block-diagonal least-squares methods gave a final R factor of 0.071.
The Thermal Desorption of Surface Hydroxyls on Tin(IV) Oxide
Authors: Morishige Kunimistu , Kittaka Shigeharu , Morimoto Tetsuo 
Published: July 2006

Abstract
The structure of the adsorbed layer of water on SnO2 was investigated by means of thermal desorption, water physisorption, and electron diffraction, using four kinds of SnO2 samples which differ in method of preparation. Two distinct peaks appear around 513 and 573 K in the thermal-desorption spectra. The peak around 513 K is due to the condensation dehydration of hydroxyls on the (100) plane of SnO2, on which the two-dimensional condensation of water occurs. The peak around 573 K is associated with that on the (101) plane, on which the physisorption of water is strong and the two-dimensional condensation of water does not occur. The portion of the (100) plane occupied by water molecules is relatively small, and the 1 : 4 ratio (H2O : OH) holds also on the surfaces on which the two-dimensional condensation of water does not occur. In conclusion, the fully hydroxylated surfaces of SnO2 are hydrophobic in the sense that they sparsely adsorb water molecules.
Film Dichroism. V. Linear Dichroism Study of Acridine Dyes in Films with Emphasis on the Electronic Transitions Involved in the Long-wavelength Band of the Absorption Spectrum
Authors: Matsuoka Yukio , Yamaoka Kiwamu 
Published: July 2006

Abstract
The long-wavelength bands of the absorption spectra of 10-methylacridinium (MeAcr), Acridine Orange (AO), and Acridine Yellow (AY) in the poly(vinyl alcohol) film were investigated by the linear dichroism method. The parallel- and perpendicular-dichroic spectra of each dye were resolved into the long-axis and short-axis polarized absorption components. From these component bands the isotropic spectrum was reconstituted and the reduced dichroism spectrum was simulated by computer with a new technique which utilizes a general expression for the reduced dichroism of planar molecules with the multiple band structure. A weak absorption band (or bands) hidden in a strong one could be revealed by reproducing the observed isotropic and linear-dichroic spectra. The vibrational sub-bands of MeAcr were shown to have the average intervals of ca. 1.5×103 cm−1 for the short-axis polarized 1La band and of ca. 0.7×103 cm−1 for the long-axis polarized 1Lb band. In the visible region of the isotropic spectrum, the weak 1La band of AO was clearly shown to consist of the fine structure with a regular energy separation, although it is overlapped with the intense 1Lb band which is also composed of a vibrational structure. The same spectral feature was observed for AY. The dichroic results are discussed under considerations of (1) the overlap of the mutually orthogonal transition moments, whose angles were determined relative to the long axis of the C2v-symmetric dye molecule, (2) the angle between the orientation axis and the long axis of the molecular plane, and (3) the average degree of orientation of dye molecules in the film.
Thickness Measurement of Surface Layer by the Angular Dependent X-Ray Photoelectron Spectroscopy
Authors: Yamada Masamichi , Kuroda Haruo 
Published: July 2006

Abstract
A sample-holding device to study the photoelectron take-off angle dependence of XPS spectrum is described. The take-off angle dependence was studied on a silicon surface covered with an oxide layer and a contamination carbon layer, and the (thickness)/(electron attenuation length) ratio of each layer was determined from the analysis of the angular dependence of the Si2p, O1s, and C1s peak intensities.
Fluorescence Quenching Process of Anthracene by Maleic Anhydride
Authors: Yesaka Hiroshi , Kobayashi Takayoshi , Suzuki Kaoru , Nagakura Saburo 
Published: July 2006

Abstract
The time dependence of fluorescence intensity after picosecond laser excitation and the steady-state fluorescence intensity were measured in order to study the mechanism of fluorescence quenching of anthracene by maleic anhydride in 1,4-dioxane. The nonlinear relationship between the reciprocal of steady-state fluorescence intensity and quencher concentration was observed for this system and interpreted in terms of the transient effect in the quenching process. The kinetic study by picosecond laser photolysis supports this interpretation. The reaction radius (R) and the sum of diffusion constants of both reactants (D) at various temperatures were determined by applying the diffusion model of Andre et al. The observed values are R=7.2 Å, D=1.46×10−5 cm2 s−1 (22 °C), 1.87×10−5 cm2 s−1 (50 °C), 2.42×10−5 cm2 s−1 (75°C). Studies of the main path in the quenching process by nanosecond laser photolysis suggest the existence of an extra path in the quenching process which overwhelms the fluorescent exciplex formation, the photoionization, the triplet anthracene formation, and the adduct formation.
Photodissociation Spectroscopy and Photoreactions in t-Butylbenzene Cation and Its Daughter Cations
Authors: Takenoshita Yoshiya , Dunbar Robert C 
Published: July 2006

Abstract
Photodissociation spectra were observed for t-butylbenzene cation (m/e 134) and its daughter ion (m/e 119). Photoproduction spectra of the ions at m/e 119 and m/e 91 were observed in the visible region. It was shown that the photodissociation of m/e 134 yields m/e 119 almost 100% at wavelengths above 450 nm. Below 450 nm m/e 91 and m/e 57 appear as light-produced species. From pressure dependence and double resonance results, it was concluded that m/e 91 is a direct photoproduct from m/e 119, and that m/e 57 is produced in an ion-molecule reaction of m/e 91 with neutral t-butylbenzene. The photodissociation spectrum of m/e 119 is very similar to that of m/e 105 obtained by protonation of styrene, and it is reasonable to assume that m/e 119 has the protonated methylstyrene structure.
Photo-induced Alkoxybromination of Olefins by N,N′-Dibromo-2,5-piperazinedione
Authors: Sera Akira , Yamada Hiroshi , Itoh Kuniaki 
Published: July 2006

Abstract
Irradiation of N,N′-dibronio-2,5-piperazinedione in dichloromethane in the presence of an alcohol induced alkoxybromination of cyclohexene to give trans-1-bromo-2-alkoxycyclohexane in a good yield. The reaction was thought to proceed through an ionic mechanism.
Electrochemical and Spectroscopic Studies of α,β,γ,δ-Tetrakis[1-(2-hydroxyethyl)pyridinium-4-yl]porphine and Its Metal Complexes
Authors: Kobayashi Nagao , Fujihira Masamichi , Osa Tetsuo , Kuwana Theodore 
Published: July 2006

Abstract
The preparation and properties of a water soluble porphyrin having functional groups, α,β,γ,δ-tetrakis[1-(2-hydroxyethyl)pyridinium-4-yl]porphine, are described. This porphyrin is water soluble from below pH 0 to above pH 14. Acid-base titration revealed the diprotonated diacid-monocation equilibrium (pK4=1.0) and the monocation-free base equilibrium (pK3=1.9) in the acidic range and the free base-monoanion equilibrium (pK2=13.0±0.2) in the basic region. The zinc, iron, and cobalt derivatives of the porphyrin were also synthesized and purified. Catalytic properties of the iron and cobalt complexes for reduction of molecular oxygen in water are reported in terms of cyclic voltammetry. The electrochemical reduction utilizing these complexes was interpreted to proceed via electrochemical catalytic regeneration mechanism as had been observed for tetrakis(1-methylpyridinium-4-yl)orphinatoiron(III). The apparent rate constants for electron transfer from the iron and cobalt porphyrins to oxygen were estimated to be 3–4×107 and 1×107 dm3 mol−1 s−1, respectively.
The Crystal and Molecular Structure of γ-Metasantonin
Authors: Ueda Hideo , Katayama Chuji , Tanaka Jiro 
Published: July 2006

Abstract
The crystal and molecular structure of γ-metasantonin has been determined by the X-ray method. The crystal is orthorhombic, P212121, with lattice parameters a=10.371(1), b=7.904(1), c=15.975(1) Å. The molecule has two independent α,β-unsaturated ketone chromophores which take a chiral configuration. The chromophores show good planarity. A/B ring fusion is cis.
Synthesis and Photoreaction of D-Nor-5α-androstan-16-one Acetylhydrazone in the Presence of Oxygen
Authors: Suginome Hiroshi , Uchida Tsutomu , Kizuka Kazuhiko , Masamune Tadashi 
Published: July 2006

Abstract
D-Nor-5α-androstan-16-one was prepared via seven steps from 16-diazo-3β-hydroxyandrost-5-en-17-one. The major products of the photolysis of its acetylhydrazone in dioxane containing oxygen were the parent ketone and 17-oxa-5α-androstan-16-one, accompanied by low yields of three isomeric lactams: 17-aza-5α-androstan-16-one, 16-aza-5α-androstan-17-one, and 17-aza-5α,13α-androstan-16-one. These three are the same lactams formed in the photo-Beckmann rearrangement of the corresponding oxime, D-nor-5α-androstan-16-one oxime. Their formation from the acetylhydrazone may have some mechanistic significance with regard to the path of the formation of lactams in the photolysis of 5α-androstan-17-one acetylhydrazone in the presence of oxygen reported previously. The mass spectrometric fragmentations of fifteen D-nor-5α-androstanes with functional groups at their C-16 positions are described.
The Thermal Decomposition of N,O-Diacyl-N-t-butylhydroxylamines
Authors: Uchida Yuzuru , Hashimoto Yukinobu , Kozuka Seizi 
Published: July 2006

Abstract
Several N,O-diacyl-N-t-butylhydroxylamines and O-acyl-N-t-butylhydroxylamines were prepared, and their thermal decompositions were studied. The thermal decompositions of N,O-diacyl-N-t-butylhydroxylamines in tetralin gave substituted N-t-butylbenzamides, carboxylic acids, 1,1′-bitetralyl, and 1,2-dihydronaphthalene as the major products, together with small amounts of carbon dioxide, t-butylamine, and benzanilides. In the thermal decompositions of O-acyl-N-t-butylhydroxylamines, the products were t-butylamine, carboxylic acids, substituted N-t-butylbenzamides, 1,1′-bitetralyl, and 1,2-dihydronaphthalene.
Enolate Anions. III. Substituent Effects of Sodium Diethyl Alkylmalonates in DMSO
Authors: Kiyooka Syun-ichi , Kodani Tsukasa , Suzuki Kojiro 
Published: July 2006

Abstract
The conformations of sodium enolate anions, derived from diethyl malonate and diethyl alkylmalonates (alkyl=methyl, ethyl, propyl, isopropyl, butyl, isobutyl, and s-butyl), have been determined to be Z,Z-type by the analysis of their 1H-NMR spectra in DMSO. In the case of diethyl t-butylmalonate, such a Z,Z type contributes to the lesser extent to the conformations of the sodium enolate anion because of repulsion between the t-butyl substituent and the two ethoxyl groups, which exist in three types (Z,Z, Z,E, E,E) of conformation, as is evident in the 1H-NMR spectra. The IR spectra of sodium diethyl malonate in DMSO showed two characteristic absorption bands at 1679 and 1556 cm−1. The IR isotope shifts upon the use of the enolates of diethyl malonate-2-13C and diethyl malonate-1,3-13C2 suggested that these two bands are attributable to the C··O and C··C··C bonds. All sodium diethyl alkylmalonates except for the t-butyl derivative have two characteristic IR bands in the region of 1500–1700 cm−1, the bands on the high-frequency side of which have nearly equal wave numbers, while those on the low-frequency side have a good correlation with the substituent constant, σ*.
Studies on Biologically Active Pteridines. IV. Synthesis of Several Biopterin Derivatives as an Antigen in Radioimmunoassay for Biopterin
Authors: Sugimoto Takashi , Matsuura Sadao , Nagatsu Toshiharu 
Published: July 2006

Abstract
The synthesis of biopterin, d(and l)-erythro-neopterins, and their derivatives having a substituent at the 2-amino group via the 2-methylthio analogues is described. The 2-(methylthio)pteridines were synthesized by condensation of 4,5-diamino-6-hydroxy-2-(methylthio)pyrimidine with 5-deoxy-l-arabinose and d(and l)-arabinose phenylhydrazones, followed by oxidation with K3[Fe(CN)6] and O2 in the presence of KI in an acidic solution, respectively. Aminolysis of these thioethers with ammonia and other amines in the presence of acetic acid gave the title compounds.
Stereochemical Studies on the Nucleophilic Substitution in the Reaction of Allylic Phosphates with Organoaluminum Reagents
Authors: Itoh Akira , Ozawa Shuji , Oshima Koichiro , Sasaki Shizuka , Yamamoto Hajime , Hiyama Tamejiro , Nozaki Hitosi 
Published: July 2006

Abstract
The reaction of cis- or trans-5-isopropenyl-2-methyl-2-cyclohexenyl diethyl phosphate (1) with Me2AlX (X=OPh, SPh, NHPh) in hexane results in substitution of the –O–PO(OEt)2 group with X under predominant inversion. In contrast, treatment of cis- or trans-1 with trialkylaluminum produces predominantly the allyl-nonallyl couplingproducts of the same (thermodynamically more stable) configuration. Similar alkylation of endo- and exo-2-acetoxynorcarane gave endo-2-methylnorcarane, exclusively.
Concentration and Spectrophotometric Determination of Molybdenum with Thiocyanate and Rhodamine 6G
Authors: Prasada Rao T , Ramakrishna T V 
Published: July 2006

Abstract
A method is described for the determination of molybdenum based on reaction with potassium thiocyanate and Rhodamine 6G in 0.55–0.8 mol dm−3 hydrochloric acid medium. The method is sensitive (ε=2.63×105 l mol−1 cm−1) and obeys Beer’s law over the range 0.04–0.24 ppm of molybdenum. Selectivity can be considerably improved by collecting molybdenum on iron (III) hydroxide. In conjunction with the collection procedure, the method is useful to determine as low as 5 ppb of molybdenum present in 100 cm3 of aqueous samples.
A Further Evidence of the Vibronic Coupling through b3g Vibrational Modes in the Fluorescence Spectrum of Anthracene
Authors: Terada Tomoyuki , Koyanagi Motohiko , Kanda Yoshiya 
Published: July 2006

Abstract
Angular dependence of the fluorescence polarization spectra of anthracene was investigated in polyethylene films using a sample rotation technique. An important role of a nontotally symmetric vibration, the b3g ring vibration at 1655 cm−1, was further confirmed by a combination of this technique and the modulation polarization technique developed previously.
Infrared Studies of the Oxidation of 2-Propanol on ZnO
Authors: Miyata Hisashi , Hata Kazuo , Nakajima Takashi , Kubokawa Yutaka 
Published: July 2006

Abstract
The oxidation of 2-propanol and acetone on ZnO has been studied by IR spectroscopy. Surface isopropoxide was oxidized to acetate and formate ions via enolate complex of acetone. Formation of α-diketone-like species was proposed for oxidation with dinitrogen oxide.
Naphthalene-sensitized Photolysis of Dibenzoyl Peroxide
Authors: Kitamura Akihide , Sakuragi Hirochika , Yoshida Masayuki , Tokumaru Katsumi 
Published: July 2006

Abstract
Naphthyl benzoates and phenylnaphthalenes were produced, on naphthalene-sensitized photolysis of dibenzoyl peroxide, in different distribution of their isomers from its thermolysis in the presence of naphthalene, suggesting that naphthalene as sensitizer interacts with dibenzoyl peroxide in a specific orientation in the sensitization process.
The Stoichiometry and Promoter Role of Chlorosulfuric and Fuming Sulfuric Acids for α-Halogenation of Aliphatic Acid
Authors: Ogata Yoshiro , Watanabe Shinya 
Published: July 2006

Abstract
The stoichiometry for the chlorosulfuric acid promoted α-halogenation and the role of fuming sulfuric acid instead of chlorosulfuric acid have been studied. In the α-bromination with molecular bromine, 1 mol of halogen afforded 2 mol of aliphatic α-bromo acid just as the α-iodination, but it is different from α-chlorination which affords only 1 mol of α-chloro acid. Fuming sulfuric acid instead of chlorosulfuric acid was found to be effective for α-bromination, but the yield was lower, while no α-iodination was observed with fuming sulfuric acid.
Photoinduced Decomposition of Peracetic Acid in Isopropylbenzene
Authors: Ogata Yoshiro , Tomizawa Kohtaro 
Published: July 2006

Abstract
Irradiation of peracetic acid in isopropylbenzene with 254 nm and over 290 nm lights gave as aromatic products mainly t-butylbenzene, 2-phenyl-2-propanol, and 2,3-dimethyl-2,3-diphenylbutane. The yield of t-butylbenzene was higher in 254 nm photolysis than that with &gt;290 nm, while the yield of hydroxylated aromatics, i. e., 2-phenyl-2-propanol, was much higher with &gt;290 nm than that with 254 nm. The distribution of products was little affected by the intensity of light. These results are discussed by a mechanism involving radicals of different reactivity derived from peracetic acid decomposition.
12,13-Epoxy-C-nor-D-homosteroids. VI. Reaction of 17-Oxygenated 12,13-Epoxyetiojervanes with Boron Trifluoride Etherate
Authors: Murai Akio , Iwasa Noriaki , Takeda Masami , Masamune Tadashi 
Published: July 2006

Abstract
17-Oxygenated 12,13-epoxyetiojerv-5-en-3-one 3,3-ethylene acetals (1A–10A) were treated with boron trifluoride etherate in benzene at room temperature. The epoxy ring cleavage reactions proceeded slowly with increase of electronegativity of the 17-substituents without and/or with deacetalization to give a variety of compounds including rearranged products (23A and 23B). The results summarized in Table 1 indicated that the reactions produced compounds formed by initial cleavage at less electronegative C-12 rather than at C-13 except several compounds (11A, 20A, 20B, and 34A). Formation of the latter compounds was attributed by hydride shift or neighboring participation of the 17-acetoxyl groups.
Studies of the Anodic Oxidation of the Cyanide Ion in the Presence of the Copper Ion. III. Identification of the Reaction Intermediate by Means of ESR Spectroscopy
Authors: Yoshimura Seiji , Katagiri Akira , Deguchi Yasuo , Yoshizawa Shiro 
Published: July 2006

Abstract
The formation of the tetracyanocuprate(II) ion (Cu(CN)42−), which was expected as a reaction intermediate in the anodic oxidation of the cyanide ion in the presence of the copper ion, has been investigated by means of ESR measurement. When a potassium cyanide solution containing a small amount of copper(I) cyanide was electrolyzed, an intermediate copper(II) species was found at the anode in the dissolved state. The ESR spectrum of the intermediate in the solidified state was obtained by freezing the solution in the resonant cavity. The intermediate was identified as Cu(CN)42− by a comparison of its spectrum to that of Cu(CN)42− already reported by other authors. When the ratio of the total copper(I) concentration to the total cyanide concentration in the solution was not too small, solid copper(II) cyanide was deposited on the anode during electrolysis.
Studies of the Anodic Oxidation of the Cyanide Ion in the Presence of the Copper Ion. IV. The Kinetics and Mechanism of the Decomposition of the Intermediate Tetracyanocuprate(II) Ion
Authors: Yoshimura Seiji , Katagiri Akira , Deguchi Yasuo , Yoshizawa Shiro 
Published: July 2006

Abstract
The kinetics and mechanism of the decomposition of the tetracyanocuprate(II) ion (CuII(CN)42−) have been investigated by ESR measurements. Aqueous solutions of potassium cyanide with a small amount of copper(I) cyanide were electrolyzed in a cell the platinum anode of which was set in the resonant cavity of an ESR spectrometer. Since CuII(CN)42−, which is formed as an intermediate, gives a definite ESR spectrum, its concentration in the anode compartment is estimated from the intensity of the first-derivative spectrum at a fixed magnetic field. From the decay curves of the ESR intensity after the steady-state electrolysis currents have been switched off, a rate equation for the decomposition of CuII(CN)42− is derived; v=k0[CuII(CN)42−]2⁄[CN−]2, where k0 is calculated to be 74 mol·dm−3·s−1 at 25 °C. This rate equation is also confirmed by ESR measurements during steady-state electrolysis, where the value of k0=60 mol·dm−3·s−1 is obtained. On the basis of the kinetics, two possible mechanisms are proposed: the formation of CuII(CN)3−, followed by the rate-determining bimo-lecular reaction of CuII(CN)3− to give 2CuI(CN)2−+(CN)2 (Mechanism A), and the formation of a binuclear complex, CuII2(CN)62−, followed by the rate-determining decomposition of CuII2(CN)62− to give 2CuI(CN)2−+ (CN)2 (Mechanism B). The kinetics and the mechanism are compared with those of the chemical reaction between the copper(II) ion and the cyanide ion.