bluuebunny/crossref_metadata_2025_split huggingface dataset:
1,3-Dipolar Cycloadditions to Bicyclic Olefins. V. The Stereo- and Regiochemistry of 1,3-Dipolar Cycloadditions to Several Unsymmetrical Bicyclic Olefins
Authors: Taniguchi Hisaji , Ikeda Toshikazu , Imoto Eiji 
Published: July 2006

Abstract
Each of the 1,3-dipolar cycloadditions of phenylglyoxylonitrile oxide (1), methylglyoxylonitrile oxide (2), benzonitrile oxide (3), and phenyl azide to 2-phenylsulfonyl-2-azabicyclo[3.2.1]octa-3,6-diene (6) occurs only to the C6–C7 double bond, affording two exo regioisomers. Each of the cycloadditions of 1, 2, and 3 to 2-phenylsulfonyl-2-azabicyclo[3.2.1]oct-3-ene (7) gives only one exo adduct. The cycloaddition of C,N-diphenylnitrone to 2-methylenenorbornane (8) gives a mixture of two exo adducts. These results show that the “exo rule” can be extended to the 1,3-dipolar cycloadditions to the bicyclic olefins, 6, 7, and 8. Tentative explanations are offered to account for the exo stereoselectivity and the regio-selectivity in these cycloadditions.
Synthetic Bilayer Membranes with Anionic Head Groups
Authors: Kunitake Toyoki , Okahata Yoshio 
Published: July 2006

Abstract
Anionic amphiphiles which possess two normal alkyl groups as the hydrophobic residue and sulfonate, phosphate or carboxylate groups as the hydrophilic residue were prepared. Most of these compounds aggregate extensively in water to form vesicles and lamellae which are probably formed by the molecular bilayer. These aggregates are quite similar to the lecithin liposome with respect to the restricted molecular motion and cholesterol binding.
Location of the ν1, ν2, ν3, and ν5 Fundamental Vibrations of Ethylene-d4
Authors: Ohashi Nobukimi , Kyogoku Tetsuo , Matsuoka Shin-ichi 
Published: July 2006

Abstract
The QQ branch peaks of the ν1, ν2, and ν3 Raman active bands of ethylene-d4 were located at ν1=2260.8±0.1 cm−1, ν2=1518.3±0.1 cm−1, and ν3=984.4±0.1 cm−1, respectively. The band center of the ν5 band which does not have a QQ branch was determined to be ν5=2315.6±0.3 cm−1 from the analys is in the symmetric top approximation.
Medium Effects on Stereochemistry of Acid-Catalyzed Ethanolysis of trans-2,3-Diphenyloxirane
Authors: Inoue Masashi , Taguchi Yoshio , Sugita Toshio , Ichikawa Katsuhiko 
Published: July 2006

Abstract
The acid catalyzed ethanolysis of trans-2,3-diphenyloxirane was examined in a wide variety of binary ethanolic solvent systems. The reaction proceeded with 26% retention and 74% inversion of configuration in pure ethanol at 50 °C. The dilution of ethanol by hexane or benzene produced almost no change in stereochemistry of the ethanolysis. The addition of acetonitrile, nitromethane, or sulfolane to the ethanolic solution resulted in increased degrees of retention. In binary ethanolic mixtures containing DMSO, DMF, or HMPA, increased ratios of inverted product were obtained. The steric course of the ethanolysis could be controlled from 85% retention–15% inversion (CH3NO2:ethanol=20:2 by volume) to 10% retention–90% inversion (HMPA: ethanol=10:12) by the choice of co-solvent. The results are discussed in terms of the solvation-shell concept.
Asymmetric Synthesis of Alanine by Alkylation of Optically Active N-Alkyl-N-formylaminoacetonitriles
Authors: Harada Kaoru , Tamura Minoru , Suzuki Shinnichiro 
Published: July 2006

Abstract
Optically active N-alkyl-N-formylaminoacetonitriles were prepared and the nitriles were alkylated with methyl iodide. The products were hydrolyzed and hydrogenolyzed to form optically active alanine. The optical yields of alanine ranged from 2 to 18%. The effects of the reaction temperature and of the asymmetric moieties on the optical yields were examined. The optical yields were also determined by the NMR spectra of the resulting diastereomeres.
The Reaction of Ethylbenzene with Methylbenzene–AlCl3–HCl Complex
Authors: Nambu Nobuyoshi , Hamanaka Sawako , Ogawa Masaya 
Published: July 2006

Abstract
Toluene, m-xylene, and mesitylene complexes prepared with AlCl3 and HCl, were separated from the upper hydrocarbon layer and allowed to react with ethylbenzene at 2 and 30 °C. The proton exchange between methylbenzenium ions and ethylbenzene, and the transalkylation of ethylbenzene were investigated by 13C NMR spectroscopy.
Catalysis by Supported Metal Crystallites from Carbonyl Clusters. I. Catalytic Methanol Synthesis under Mild Conditions over Supported Rhodium, Platinum, and Iridium Crystallites Prepared from Rh, Pt, and Ir Carbonyl Cluster Compounds Deposited on ZnO and MgO
Authors: Ichikawa Masaru 
Published: July 2006

Abstract
Methanol synthesis by the catalytic hydrogenation of carbon monoxide proceeded under atmospheric pressure and at 150–250 °C over rhodium, platinum and iridium crystallite catalysts, prepared from well-defined Rh, Pt, and Ir carbonyl cluster compounds highly dispersed on ZnO and MgO. The activity and selectivity of methanol formation depended considerably on the kind of metal carbonyl clusters and metal oxides employed as inorganic carriers. The catalysts prepared by the pyrolysis of smaller Rh, Pt, and Ir carbonyl clusters on ZnO, MgO, CaO, and BeO exhibited a higher selectivity of methanol synthesis. A small amount of ethanol was also produced besides methanol in CO–H2 reaction over the pyrolysed catalysts of Rh carbonyl clusters on MgO, CaO, and BeO. Other metal oxides such as SiO2 gel, γ-Al2O3, SnO2, and WO2 were employed for preparation of the dispersed Rh catalysts from carbonyl clusters, which catalysed mainly formation of methane and higher hydrocarbons with negligible selectivity of the oxygenated products under the reaction conditions.
Kinetic Studies of the Aluminium Acetate Complex Formation Reaction in Aqueous Solutions by the Pressure-Jump Method
Authors: Hiraishi Michinori , Harada Shoji , Yasunaga Tatsuya 
Published: July 2006

Abstract
The pressure-jump method was applied to aqueous solutions of aluminium acetate. Relaxation effects were observed in ms and s regions. Both relaxation times depend a great deal on the pH of solution. They were ascribed to the following complex formation reactions.
(Remark: Graphics omitted.)
Detailed studies on the fast relaxation effect revealed that the hydrolyzed ionic species accelerate the overall reaction. The mechanism of the fast reaction was discussed, the kinetic parameters being obtained.
A Convenient Procedure for Esterification of Carboxylic Acids
Authors: Ono Noboru , Yamada Takashi , Saito Tadashi , Tanaka Kazuhiko , Kaji Aritsune 
Published: July 2006

Abstract
A variety of carboxylic acids including simple acids, sterically hindered acids, thermally unstable acids and N-protected amino acids react with alkyl halides in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in benzene to give esters in good yields. The reaction is simple, affording a general method for esterification of carboxylic acids.
The Intrinsic Viscosity of Poly(4-vinylpyridine) of a Low Molecular Weight
Authors: Hirai Yoshiyuki , Yanagida Taira 
Published: July 2006

Abstract
The intrinsic viscosities of poly(4-vinylpyridine) (\barMn:1.37×103–9.67×104) were measured by use of various solvents. For every solvent, log[η]-log\barMn plots gave lines with a slope of 1/2 in the region of low molecular weights (\barMn≤104). These lines were parallel to one another. This viscosity behavior was interpreted in terms of the influence of solvents on short-range interactions in the polymer chains.
Preparation and Properties of Cu(II) Complexes of N-Picolinoyl-S,S-tetramethylenesulfilimine, N-(Trimethylammonio)picolinamidate, and Related Ylides
Authors: Kise Hideo , Sen\={o} Manabu 
Published: July 2006

Abstract
The reactions of N-picolinoyl-S,S-tetramethylenesulfilimine (PS) and N-(trimethylammonio)picolinamidate (PA) with copper(II) chloride dihydrate in ethanol afforded complexes of the formula CuCl2(Y) and CuCl2(Y)2(Y=PA or PS). The structures of these complexes were examined by spectroscopic and magnetic methods, and it was found that all of them have mononuclear chelate structures. It was concluded that in CuCl2(PS), the ligand is coordinated through two nitrogen atoms, whereas in CuCl2(PS)2, the ligands are coordinated through carbonyl oxygens and nitrogens in pyridine rings. The structures of CuCl2(PA), CuCl2(PA)2, and CuCl(PA) are closely similar to each other and the possibility of coordination through ylidic nitrogens with large ionic contributions to the structures was strongly suggested. Several Cu(II) complexes with monodentate sulfilimines and aminimides were also prepared, and the structural analyses revealed that the nature of the coordination depends largely on the structure of the ylides.
Ultrasonic Absorption Studies of the Nickel(II) Amino Acid Complexes in Aqueous Solutions
Authors: Harada Shoji , Higashi Kazumi , Tamura Kiyoshi , Hiraishi Michinori , Yasunaga Tatsuya 
Published: July 2006

Abstract
The ultrasonic absorption has been measured in aqueous solutions of Ni(II) complexes of glycine, β-alanine, 4-aminobutyric acid, and 6-aminohexanoic acid. The relaxation absorption could not be ascribed to one of the steps of the ordinary step-by-step complex formation mechanism. Kinetic data were obtained as functions of the initial concentrations of Ni(II) and amino acids, the pH, and the temperature. The relaxation absorption was attributed to the formation-breaking equilibrium of an intramolecular hydrogen bond due to the carboxylato group of amino acid coordinated to the Ni(II) ion. The rate constant of the hydrogen bond-breaking process has been obtained. The relationship between the relaxation parameters and the acid dissociation constant of the carboxyl group of the amino acid ligands is discussed with reference to the analogous result for the carboxylato ligands reported previously. Supplementary work is also carried out for Ni(II)-aspartato and glutamato complexes.
Thermolysis of Bis(diarylmethylenecarbamoyl) Peroxides
Authors: Suehiro Tadashi , Matsui Yukio , Inoguchi Yoshio 
Published: July 2006

Abstract
Diacyl peroxides of structure (XC6H4)2C=N–C(=O)OOC(=O)–R (R=(XC6H4)2C=N, X=H (1), X=2-CH3 (3), X=4-CH3; R=4-ClC6H4, X=H (2) have been prepared by the reaction between the corresponding carbamoyl chloride and hydrogen peroxide-urea complex in the presence of pyridine or between the carbamoyl chloride and 4-chloroperbenzoate in anhydrous ether at low temperature. Thermolysis of 1–3 follows first order kinetics. The large rates of thermolysis of 1 and 3 relative to those of bis(diphenylmethyleneacetyl) peroxide have been ascribed to steric compressions of 1 and 3 in the ground state and to the concerted cleavage of three bonds. Stable diphenylmethyleneamino radicals do not substitute in toluene by themselves but they do with the aid of aroyloxy radicals. The iminyl radicals abstract hydrogen from the methyl group of toluene, and the rate constant has been estimated to be 5×102–2×103M−1s−1 at 50 °C.
A Molecular Orbital Treatment of the Electronic Spectra of Linear and Cross Conjugated Systems. Thienyl Phenyl Ketones and N-Thenylideneanilines
Authors: Abu-Eittah R , Hilal R 
Published: July 2006

Abstract
The electronic absorption spectral measurements as well as MO calculations have been conducted on representatives of a cross conjugated system, thienyl phenyl ketones, and a linear conjugated system, N-thenylideneanilines. Results have proved that, although the two systems may be “π”-isoelectronic yet, their electronic spectra differ substantially. The nodal properties of the molecular orbitals of the two systems explain nicely their differences in conjugation. Steric factors play no roll concerning the differences in the spectra of the two systems.
Temperature Effects on CD Spectra of α-Cyclodextrin Complexes with m- and p-Nitrophenol
Authors: Harata Kazuaki 
Published: July 2006

Abstract
The CD spectra of α-cyclodextrin complexes with m- and p-nitrophenol were measured at 10, 30, 50, and 70 °C in aqueous solutions of various α-cyclodextrin concentrations. The CD intensity of both complexes was decreased to 14–61% of the intensity measured at 10 °C with the increase of temperature to 70 °C, but no significant change was observed in the spectral shape. The thermodynamic parameters for the complex formation were determined.
Hydrogen Bond of 4-Amino-5H-[1]benzopyrano[3,4-c]pyridin-5-one Derivatives with Alcohols. II. Theoretical Considerations
Authors: Inuzuka Kozo , Fujimoto Akira 
Published: July 2006

Abstract
In a previous paper the experimental considerations on the hydrogen bonding between benzopyranopyridine derivatives including related compounds (pyridine, coumarin, and aniline) and alcohols were made, and the thermodynamic constants for the formation of the hydrogen-bonded complexes were obtained from UV spectroscopic studies. In this paper the molecular orbital calculation by the CNDO/2 method was conducted to further clarify the experimental results. Several conclusions were drawn from the present calculation: (1) Benzopyranopyridine has an intramolecular hydrogen bond between its amino and carbonyl groups. (2) The hydrogen bond energy of 2-alkyl benzopyranopyridines with alcohol is larger than that of the 1-alkyl compounds. (3) Benzopyranopyridine has four positions for hydrogen bond formation with alcohol, that is, the ring nitrogen atom, the carbonyl group, the ring oxygen atom, and the amino group. The ring nitrogen atom gave rise to the largest hydrogen bond energy among the four positions. Therefore, the corresponding hydrogen-bonded complex plays an important role in the benzopyranopyridine–alcohol system. (4) The hydrogen bond energy depended on the charge density of the atom which gave rise to the hydrogen bond with alcohol. Especially, substitution of the electron donating group such as amino and methyl groups at the position which increases the charge density of the atom giving rise to a hydrogen bond with alcohol increases the hydrogen bond energy.
Studies on Aqueous Solutions of Guanidinium Salts. VIII. Free Energy of Mixing of Guanidinium Bromide and Tetrabutylammonium Bromide in Aqueous Solution at 25 °C
Authors: Miyajima Koichiro , Yoshida Hiromitsu , Nakagaki Masayuki 
Published: July 2006

Abstract
Osmotic and activity coefficients have been determined by the isopiestic comparison method on the water–guanidinium bromide–tetrabutylammonium bromide system at 25 °C. The values of the excess free energy change of mixing and the interaction parameter g0 on Friedman’s formalism were large and negative in magnitude. These results have been discussed in terms of the mixed ion pairing and structural change of water.
Trimethylenediamine Complexes. VI. Kinetic and Equilibrium Studies of Ligand Substitution Reactions of the trans-Aquabis(diamine)sulfito- and trans-Bis(diamine)-hydroxosulfitocobalt(III) Complexes
Authors: Ito Yoshiaki , Terada Akira , Kawaguchi Shinichi 
Published: July 2006

Abstract
Substitution reactions of the trans-CoSO3 (H2O or OH) (en or tn)2 complex with Cl−, Br−, CH3COO−, N3−, NO2−, NCS−, CN−, and SO32− have been studied by the spectrophotometric method. The equilibrium constant of anation KH2OX spans many orders of magnitude, e.g. from 1.24 for bromide to 1.23×107 M−1 for cyanide in the case of the en complex, and is correlated to the electron donor constant En which was defined by Edwards. The kinetics of the substitution reactions is adequately interpreted by virtue of the reversible D mechanism via a five-coordinate intermediate CoSO3(AA)2+. Release of the ligand Xn− from trans-CoSO3(X)(tn)2(1−n)+ proceeds 10–25 times faster than from the corresponding bis(ethylenediamine) complex, and the kinetic ring-size effect is attributed to the larger stability of the en complex as compared with the tn complex at the ground state.
Aminocyclitols. 36. Chlorination and Dechlorination of Aminocyclitol and Inositol Derivatives. Preparation of Dideoxy-and Trideoxystreptamines
Authors: Ogawa Seiichiro , Hongo Yuji , Fujimori Hitoshi , Iwata Keiji , Kasuga Akira , Suami Tetsuo 
Published: July 2006

Abstract
Chlorination of four aminocyclitol and six inositol derivatives with sulfuryl chloride gave the chloro substitution products, which were then dechlorinated by hydrogenolysis with Raney nickel or by treatment with tributyltin(IV) hydride giving the corresponding deoxy compounds. Several useful aminocyclitols, including 2,4-dideoxy- and 2,4,5-trideoxystreptamines, were prepared from 2-deoxystreptamine derivatives by these procedures.
Studies of Peptide Antibiotics. XXXVII. Synthesis of [1,1′,3,3′-l-Alanine]-Gramicidin S
Authors: Takiguchi Hideo , Nishikawa Hiroshi , Ando Setsuko , Izumiya Nobuo 
Published: July 2006

Abstract
An analog containing alanyl residues in place of valyl and leucyl residues in gramicidin S, namely [1,1′,3,3′-l-alanine]-gramicidin S, was synthesized to investigate the influence of the bulky side chains of the amino acid residues for antibacterial activity and conformation. The analog has the small aliphatic side chains of alanyl residues on one side of the ring frame in the gramicidin S-structure. In the experiments of optical rotatory dispersion and circular dichroism, this analog gave curves similar in shape to these of gramicidin S, and thus should have a similar conformation to that of gramicidin S. The analog showed, however, no antibacterial activity. Thus the four methyl side chains of alanyl residues in the analog are not sufficient for the substance to exhibit biological activity.
TiN0.07O1.93 Semiconductor Electrodes for Photoassisted Oxidation of Water
Authors: Hirai Taketsugu , Tari Isao , Yamaura Junichi 
Published: July 2006

Abstract
As a new anode for the photoassisted oxidation of water, the TiN0.07O1.93 semiconductor electrode is proposed. Its photoanodic behavior in 0.1 M Na3PO4 was similar to those of n-type TiO2 electrodes, but the photocur-rent response was a little extended toward the long wavelength region. The electrode stability under the irradiation with ultraviolet light was good.
Kinetic Evidence for the Participation of a Diatomic Oxygen Species in Vapor-Phase Oxidation of Butadiene over Silver Catalyst
Authors: Akimoto Masamichi , Echigoya Etsuro 
Published: July 2006

Abstract
The participation of an adsorbed diatomic oxygen species in the oxidation of butadiene with O2 or N2O to maleic anhydride over silver catalyst was confirmed by the following finding: reaction order with respect to O2 or N2O is 0.83 or 1.95, respectively, whereas that to butadiene is negative.
The Preparation of 6-Nitro-3-acetamidotoluene
Authors: Ono Aoi 
Published: July 2006

Abstract
m-Acetamidotoluene was nitrated with fuming nitric acid in acetic acid or in a mixture of acetic and sulfuric acids at 20 °C, affording 6-nitro-3-acetamidotoluene in 38.6 and 53.7% yields respectively. The melting point of the product was found to be different from that reported in the literature.
Catalytic Activities of La2O3, Y2O3, and CeO2 for Decomposition of 4-Hydroxy-4-methyl-2-pentanone and Isomerization of Butenes
Authors: Fukuda Yasuo , Hattori Hideshi , Tanabe Kozo 
Published: July 2006

Abstract
The decomposition of 4-hydroxy-4-methyl-2-pentanone and the isomerization of 1-butene were carried out over La2O3, Y2O3, and CeO2. The activities for both types of reactions were in the following order; La2O3&gt;Y2O3&gt;CeO2. With La2O3, the change in the activity for the decomposition with the pretreatment temperature of the catalyst correlated well with the change in basicity, the activity and basicity maxima being observed when the catalyst was pretreated at 500 °C. Yttrium sesquioxide showed a maximum activity for the decomposition when pretreated at 700 °C. For the isomerizations of 1-butene and cis-2-butene, La2O3 exhibited activity maxima when pretreated at 700 °C. The cis/trans selectivities from 1-butene were considerably greater than unity, and the trans/1 selectivities from 2-butene were less than unity. The coisomerization of cis-2-butene-d0/d8 revealed that the reaction involved an intramolecular H(or D) transfer. The isotope effects for the formation of 1-butene from cis-2-butene were 4–10, while those for the formation of trans-2-butene were about 1.
The Formation of Ethers from Unsaturated Aliphatic Alcohols in the Presence of Boron Trifluoride Etherate
Authors: Nagai Kimiko , Nakayama Mitsuru , Hayashi Shûichi 
Published: July 2006

Abstract
Unsaturated acyclic alcohols of carbon numbers four and five reacted with boron trifluoride etherate to give eight ethers. Of these ethers, novel acyclic di- and tri-ethers were found in the reaction products of 2-methyl-2-propen-1-ol. Boron trifluoride etherate catalyzes double-bond migration, allylic rearrangement, intermolecular dehydration, and Markownikov addition reactions in unsaturated aliphatic alcohols.
Activation of Carbon Dioxide by Tetraphenylporphinatoaluminium Methoxide. Reaction with Epoxide
Authors: Takeda Norikazu , Inoue Shohei 
Published: July 2006

Abstract
α,β,γ,δ-Tetraphenylporphinatoaluminium methoxide reacts reversibly with carbon dioxide in the presence of 1-methylimidazole, and this carbon dioxide is activated to react with propylene oxide to produce propylene carbonate under atmospheric pressure and at room temperature.
ESR Studies on 2,3,5-Triphenyltetrazolyl and 2,3-(2,2′-Biphenylylene)-5-phenyltetrazolyl Radicals
Authors: Deguchi Yasuo , Kawamura Yoshiko , Takagi Yutaka , Kako Saburo 
Published: July 2006

Abstract
2,3-(2,2′-Biphenylylene)-5-phenyltetrazolium chloride has been prepared. The ESR spectra of 2,3,5-triphenyltetrazolyl and 2,3-(2,2′-biphenylylene)-5-phenyltetrazolyl have been measured and their ESR coupling constants determined.
Syntheses of Rare Earth Orthophosphates
Authors: Hikichi Yasuo , Hukuo Ken-iti , Shiokawa Jiro 
Published: July 2006

Abstract
Rare Earth orthophosphates have been synthesized and examined by X-ray diffraction, DTA and TGA. Six types have been found: a) the monazite type RPO4, b) the xenotime type RPO4, c) the hexagonal form RPO4·0.5H2O, d) the weinschenkite type RPO4·2H2O, e) the orthorhombic form DyPO4·1.5H2O and f) the amorphous phosphate.
Synthesis of cyclo(–l-Leucyl–l-lysyl–glycyl–)2 and Its Hydrolysis by Trypsin
Authors: Kosui Nobuo , Kato Tetsuo , Izumiya Nobuo 
Published: July 2006

Abstract
A protected cyclic hexapeptide, cyclo-(–l-Leu–l-Lys(ε-benzyloxycarbonyl)–Gly–)2 (6) was synthesized by doubling cyclization of the corresponding tripeptide azide. Compound 6 was converted by hydrogenolysis into a cyclic hexapeptide, cyclo(–l-Leu–l-Lys–Gly–)2, which was hydrolyzed by trypsin to a tripeptide, H–Gly–l-Leu–l-Lys–OH.
Charge-transfer Absorption of Complex TCNQ Anion Radical Salts: (Cs+)2(TCNQ)3\ewdot\ewdot and (Morpholinium+)2(TCNQ)3\ewdot\ewdot
Authors: Iida Yôichi 
Published: July 2006

Abstract
The charge-transfer transition between ion radical molecules is known to take place in solid ion radical salts. The present paper describes some spectroscopic features of the charge-transfer absorptions observed in complex anion radical salts of (Cs+)2(TCNQ)3\ewdot\ewdot and (Morpholinium+)2(TCNQ)3\ewdot\ewdot. A one-dimensional Hubbard model consisting of equivalent sites with less than half-occupied orbitals was applied to those systems in order to explain the transition energy and the line shape of the charge-transfer absorptions.