bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies of Carbenium Ion on Unsaturated Carbon. II. Exclusive Formation of Benzofurans via Vinyl Cations in the Solvolytic Reactions of 1-Aryl-2,2-bis(o-methoxyphenyl)vinyl Halides
Authors: Sonoda Takaaki , Kobayashi Shinjiro , Taniguchi Hiroshi
Published: July 2006

The reactions of 1-aryl-2,2-bis(o-methoxyphenyl)vinyl halides (4)–(7) in 80% aqueous ethanol (80% EtOH), acetic acid (AcOH), or 70% aqueous N,N-dimethylformamide gave benzofurans (8)–(10), respectively. The kinetic results i.e., 1) first-order reaction rates, 2) large α-substituent effect (ρ=−4.12 against σ+), 3) large leaving group effect (kBt⁄kCl=85 in 80% EtOH and 28 in AcOH) and 4) the solvent effect (m=0.53), are consistent with the formation of the intermediate vinyl cations (3) which are captured exclusively by the β-o-methoxyl group. In the reaction of vinyl bromide (7), the formation of 7–9% of benzofuran (11) results from the β-o-methoxyphenyl migration in the vinyl cation (17) followed by cyclization. The exclusive intramolecular cyclization of the vinyl cations is discussed in terms of the proximity effect of the β-o-methoxyl group.
Theory for Longitudinal Ion Cyclotron Resonance Power Absorption: Application to Line Shape for Nonreactive Ion
Authors: Aoyagi Katsuyuki
Published: July 2006

The rf electric field in circular concave electrodes for longitudinal ion cyclotron resonance is investigated. The potential equation of this rf electric field is theoretically derived from Laplace’s equation. The equation of the motion of an ion which moves under the simultaneous application of the magnetic field and this rf electric field was solved. The solution of this equation is used to obtain the instantaneous and total power absorptions of the ion from the rf electric field. The power absorption expression is used to derive the line-shape expresssions of the longitudinal ion cyclotron resonance.
Solvation of Metal Acetylacetonate in Organic Solvents
Authors: Kawaizumi Fumio , Matsumiya Norifumi , Miyahara Yutaka
Published: July 2006

The velocities of ultrasonic waves in solutions of metal acetylacetonate in organic solvents were measured with an ultrasonic interferometer operating at 4MHz at 5 and 15 °C. The solvation behavior was marked in the [Mg(acac)2]–methanol system. The results are compared with those of such different methods as IR and NMR spectroscopies.
Circular Dichroism of Nickel(II) and Copper(II) Complexes with Optically Active Diamines Containing a Pyrrolidinyl Group
Authors: Murakami Tasuku , Kitagawa Sadao , Hatano Masahiro
Published: July 2006

Nickel(II) and copper(II) complexes of diamines containing a (S)-pyrrolidinyl group were prepared and their absorption and CD spectra were measured.
Cobalt(II) and Nickel(II) Complexes with Schiff Bases Obtained from Salicylaldehyde Derivatives and N-(2-Aminoethyl)-piperazine
Authors: Kuma Hiro , Yamada Shoichiro
Published: July 2006

Cobalt(II) and nickel(II) complexes have been synthesized with Schiff bases derived from ring-substituted salicylaldehydes and N-(2-aminoethyl)-piperazine. Bis(Schiff base)-metal(II complexes have been isolated. All of them have an octahedral structure, in which the Schiff bases are terdentate. The results are compared with those for complexes of related ligands.
Preparation of 2,3,4,6-Tetra-O-benzyl-d-mannose
Authors: Koto Shinkiti , Morishima Naohiko , Miyata Yoko , Zen Shonosuke
Published: July 2006

2,3,4,6-Tetra-O-benzyl-d-mannopyranose was prepared from methyl α-d-mannopyranoside. Improved preparations of 2,3,4,6-tetra-O-benzyl-α-d-glucopyranose and -galactopyranose are described.
The Formation of Ethers from dl-Citronellol in the Presence of Boron Trifluoride Etherate
Authors: Nagai Kimiko
Published: July 2006

dl-Citronellol reacted with boron trifluoride etherate to give a mixture of a novel cyclic dicitronellyl ether (IX) and an acyclic dicitronellyl ether (X), along with eight minor products. Both major ethers were produced in equilibrium in the presence of the above reagent.
Conductance of Some High Valence Type Electrolytes in Mixed Solvents. I. Conductance of Tris(1,10-phenanthroline)iron(II) Sulfate and Chloride in Water-Methanol Mixtures at 25 °C
Authors: Kubota Eiji , Yokoi Masatoki
Published: July 2006

The conductance of tris(1,10-phenanthroline)iron(II) sulfate, Fe(phen)3SO4, and chloride, Fe(phen)3Cl2, has been measured in water-methanol mixed solvent at 25 °C. The data of the sulfate could be explained by means of the Fuoss-Onsager equation (1957) and the Fuoss-Onsager-Skinner equation (1965) on the assumption that the salt is completely dissociated in the entire composition range of the solvent system. Application of the Fuoss-Hsia equation which contains a c3⁄2 term gave association constants increasing from a value of KA=40 in water to KA=3900 in methanol. The logKA  vs. 1/D plot is in good agreement with ion association theoreies. The limiting equivalent conductance of Fe(phen)32+ ion was estimated to be 34.3 in water and 62.3 in methanol.
Important Role of Fluorescence Reabsorption Mechanism in Sensitized Reaction of Unsaturated Lactones. Evidence against “the Orbital Symmetry Correlations in Sensitization”
Authors: Sakuragi Hirochika , Ono Isao , Hata Norisuke , Tokumaru Katsumi
Published: July 2006

Evidence are presented against Ullman’s “the orbital symmetry correlations” between excited aromatic hydrocarbon sensitizers and 4-benzylidene-2-phenyl-5-oxazolone. It is now shown that the oxazolone efficiently quenches the triplet sensitizers regardless of Ullman’s classification, and the fluorescence emitted from the sensitizers is reabsorbed by the oxazolone and its wavelength seems to govern the reported reaction course.
Studies of the Removal of Dye Ions by Adsorbing Particle Flotation
Authors: Kobayashi Koichi , Watabe Nobuhiro , Sasaki Tsunetaka
Published: July 2006

The removal of an anionic dye, Scarlet Red, a zwitterionic dye, Congo Red, and a cationic dye, Crystal Violet, from aqueous solutions was studied by the method of adsorbing particle flotation, using bentonite and benzylhexadecyldimethylammonium chloride as flotation agents. More than 99% of the Crystal Violet and Scarlet Red and 96% of the Congo Red could be floated under optimum conditions. It was found that a larger amount of a cationic surfactant was required for the flotation with an increase in the anionic nature of the dye ions, although the flotation was efficient irrespective of the ionic nature of dyes used. From this fact, the flotations of anionic and cationic dyes were confirmed to differ from each other in that the cationic-dye ions are floated by a direct exchange adsorption on bentonite, while the anionic-dye ions are floated by the adsorption on bentonite through the bimolecular layer of the cationic surfactant. The flotation efficiency of a dye ion, particularly of zwitterionic dye, was confirmed to depend on the pH.
The Reactions of Sodium Diethyldithiocarbamate and Tetraethylthiuram Disulfide with Mercury(II) Chloride
Authors: Kobayashi Norio , Fujisawa Tamotsu
Published: July 2006

Sodium diethyldithiocarbamate (1) and tetraethylthiuram disulfide (2) have been found to react with excess mercury(II) chloride (HgCl2) in water to give complexes with the general formula Et2NCS2HgS2CNEt2·(HgCl2)m−1, where the m value can be as high as five. The complex with m=2 was isolated and characterized. The reaction pathway was discussed in some detail. Also studied were the reactions of 2 with HgCl2 in organic solvents.
Kinetics and Mechanism of the Reactions of Butenenitrile with Imidazoles
Authors: Yamada Fukiko , Kitano Osamu , Shindo Soichi , Ueda Harunori
Published: July 2006

The reaction kinetics of 3- and 2-butenenitriles with 2-alkylimidazoles were studied by using NMR, and a mechanism consistent with the results is proposed. The imidazoles were active in isomerizing 3-butenenitrile to 2-butenenitrile, and then reacted only with the 2-butenenitrile to give the corresponding 1-(2-cyano-1-methylethyl)imidazoles. These consecutive reactions, isomerization and cyanoethylation, are second-order over all. For example, in the reaction of 3-butenenitrile with imidazole, the rate measurements of the isomerization at various temperatures, ranging from 30 to 90 °C, afforded the activation parameters of Ea=14.6 kcal/mol and ΔS\eweq=−35.3 cal/degree. On the other hand, in the case of 2-butenenitrile with imidazole, the measurements of the cyanoethylation at 60–100 °C gave these parameters; Ea=15.3 kcal/mol and ΔS\eweq=−45.7 cal/degree. In this case, the rates of the isomerization (k1=6.0×10−6 l/mol s at 60 °C) are approximately ten times larger than those of the cyanoethylation (k2=0.53×10−6). A mechanism is discussed on the basis of their NMR spectral and kinetic data.
Studies on O→N Acyl Migration in O-Acyl-2-deoxystreptamines
Authors: Kurisu Takao , Yamashita Michio , Nishimura Yoshio , Miyake Toshiaki , Tsuchiya Tsutomu , Umezawa Sumio
Published: July 2006

Preparations of mono-N-protected 2-deoxystreptamines (racemates of 5, 8, 9, 10, 11, 12) from 4(and 6)-O-acyl-1,3-di-N-benzyloxycarbonyl-2-deoxystreptamines by O→N acyl migration were described. O→N Acyl migration of 2-deoxy-tri-O-ethoxycarbonylstreptamine (15) led to several protected derivatives (racemates of 16, 17, 18) which also should serve for the preparation of glycosides and other derivatives of 2-deoxystreptamine.
A Comparative Study of Electrochemical Kinetic Parameters by the Potential Step Method. Electrode Reactions of CyDTA and EDTA Complexes of Cu(II) at DME
Authors: Bhat G A
Published: July 2006

By using the same current-time (I-t) curves, electrochemical kinetic parameters are determined by two methods, (a) using the ratio of current at a given potential to the diffusion-controlled limiting current and (b) curve fitting method, for the reduction of Cu(II)–CyDTA complex. The analysis by the method (a) shows that the rate determining step involves only one electron although the overall reduction of the complex involves two electrons suggesting thereby the stepwise reduction of the complex. The nature of I-t curves suggests the adsorption of intermediate species at the electrode surface. Under these circumstances more reliable kinetic parameters can be obtained by the method (a) compared to that of (b). Similar observations are found in the case of reduction of Cu(II)–EDTA complex.
Racemization Catalyst for Amino Acids. III. Racemization of Alanine Induced by 4-Nitrosophenol
Authors: Hirota Kazuhiro , Koizumi Hisanori , Hironaka Yoshio , Izumi Yoshiharu
Published: July 2006

The racemization of d-alanine was carried out with several derivatives of 4-nitrosophenol in the presence of cupric ion. Their racemization activities have been found to decrease with an increase in the bulk of alkyl group in 4-nitrosophenol. The racemization is accompanied with the decomposition of 4-nitrosophenol, and has been found to be catalyzed by an unidentified product generated in the reaction mixture. The proposed mechanism involves an autoaccelerating reaction.
Epoxide Rearrangement. VIII. The Acidic and Basic Properties of TiO2–SiO2–MgO and Its Catalytic Activities
Authors: Yamada Teruaki , Arata Kazushi , Itoh Masayoshi , Hattori Hideshi , Tanabe Kozo
Published: July 2006

Four kinds of TiO2–SiO2–MgO having different molar ratios, TiO2–SiO2–MgO (1 : 1 : 1, 10 : 10 : 1, 1 : 10 : 10, and 10 : 1 : 10), were prepared, their acidic and basic properties being examined by titration with butylamine and benzoic acid in benzene, respectively. The acidity of TiO2–SiO2–MgO was attributed to that of TiO2–SiO2 and SiO2–MgO. The amount of strong acid sites of H0≤–5.6 decreased with the addition of MgO to TiO2–SiO2. The basicity of TiO2–SiO2–MgO was attributed to that of TiO2–MgO and decreased with the increase in SiO2 content. Catalytic activities for the isomerization of 1-butene and the decomposition of 4-hydroxy-4-methyl-2-pentanone are correlated with the acidity and basicity, respectively. For isomerization of 1-methylcyclohexene oxide and d-limonene oxide, TiO2–SiO2–MgO and TiO2–SiO2 showed high activities for the preferential formation of ketones except TiO2–SiO2–MgO (10: 1: 10) over which allyl alcohols were produced preferentially. The selectivities for the isomerization of two epoxides were interpreted in terms of the acidic and basic properties of the catalysts.
Associated Complex Formation in a Binary Solution and the Concentration Fluctuation: The Chloroform–Diethyl Ether System
Authors: Iwasaki Kenji , Katayanagi Yumiko , Fujiyama Tsunetake
Published: July 2006

The relations between the associated complex formation and the concentration fluctuation in a binary solution were derived. The concentration fluctuation of a chloroform–diethyl ether system was determined by observing light-scattering spectra at various concentrations. The theoretical values of the concentration fluctuation of this system were calculated from the proposed relation by the use of the shape and the number population of the associated complex, as determined from the infrared absorption intensity measurements. The observed and calculated concentration fluctuations agreed quite well.
Circular Dichroism Spectra of Cobalt(III) Complexes Containing One or Two Azido, Isothiocyanato, and Nitro Ligands. I. The Bis(ethylenediamine) Complexes of cis Type
Authors: Yamasaki Kiyoshi , Hidaka Jinsai , Shimura Yoichi
Published: July 2006

Circular dichroism spectra have been measured for the cis[Co(X)(NH3)(en)2]2+, cis-[Co(x)2(en)2]2+, and cis-[Co(X)(X′)(en)2]+ complexes in the visible and ultraviolet region (X and X′=N3−, NCS−, or NO2−). The absolute configurations of the complexes have been assigned from the circular dichroism pattern in the first d-d absorption band, region and correlated with that in the near ultraviolet region of the so-called specific absorption band. The origin of the specific absorption band has been discussed.
Studies of the Cobalt(III) Complexes of 8-Amino-3,6-diazaoctanate Ion. II.The Preparation and Some Properties of the Complexes with a Carbonate, Oxalate, or Malonate Ligand
Authors: Watanabe Kiyokatsu
Published: July 2006

The following new cobalt(III) complexes containing the quadridentate 8-amino-3,6-diazaoctanate ion (adao) have been prepared: α-[Co(adao)(ox)], α-[Co(adao)(mal)] (mal, malonate ion), β-mer(N)-[Co(adao)(CO3)], β-mer(N)-[Co(adao)(mal)], β-fac(N)-[Co(adao)(CO3)], β-fac(N)-[Co(adao)(ox)] and β-fac(N)-[Co(adao)(mal)]. The geometrical isomers have been separated by the chromatographic technique. The configurations of the complexes have been identified by means of the electronic absorption spectra and the proton NMR spectra.
Racemization of Alanine Induced by Copper(I) Oxide
Authors: Tai Akira , Okada Kotaro , Masuda Tsutomu , Izumi Yoshiharu
Published: July 2006

Copper(I) oxide was found to be an excellent initiator for the racemization of alanine in alkaline aqueous solutions. The rate studies indicate that copper(I) oxide itself is not a catalyst for the racemization but is a precatalyst producing real racemization catalysts in the reaction system. The real catalytic system for racemization was found to consist of acetaldehyde and copper(II) ions. Acetaldehyde and copper(II) ions were produced by the oxidation of alanine and copper(I) oxide with oxygen in air, respectively. The function of copper(I) oxide is considered to produce oxidants by reaction with oxygen, which effects the oxidation of alanine.
Studies on Reactions of the N-Phosphonium Salts of Pyridines. XIX. Carbonylation of Amines with Carbon Dioxide by Means of Phosphorus Chlorides in Tertiary Amines
Authors: Yamazaki Noboru , Tomioka Tatsuya , Higashi Fukuji
Published: July 2006

Reactions of carbon dioxide and disulfide with primary amines in the presence of phosphorus chlorides gave the corresponding symmetrically disubstituted ureas and thioureas in high yields under atmospheric conditions. Phosphorus trichloride and di- and mono-chlorophosphites were remarkably effective for the reactions, whereas phosphorus pentachloride and phosphoryl chloride were ineffective. The presence of tertiary amines such as pyridine satisfactorily favored the reactions. The reaction seems to proceed via the N-phosphonium salts of pyridines as those obtained from diphenyl and triaryl phosphites, on the basis of their IR spectroscopic analyses, stoichiometric relationship between reactants and the steric effect of tertiary amines.
Self-Immolative Asymmetric Synthesis. III. Allylic Rearrangement of Optically Active Trichloroacetimidate
Authors: Yamamoto Yukio , Shimoda Hiroshi , Oda Jun’ichi , Inouye Yuzo
Published: July 2006

The [3,3]sigmatropic rearrangement of (2E)-(1R)-1-methyl-3-phenyl-2-propenyl trichloroacetimidate to give N-[(2E)-(1R)-1-phenyl-2-butenyl]trichloroacetamide was effected thermally with nearly complete transfer of chirality via a doubly suprafacial transition state. The application of the self-immolative asymmetric synthesis to optically active carveols afforded carveylamines of the predicted configuration.
Oxidation of Olefins with Thallium(III) Acetate in Diols
Authors: Uemura Sakae , Miyoshi Haruo , Toshimitsu Akio , Okano Masaya
Published: July 2006

The oxidation of styrene, α- and β-methylstyrene, and 1-octene with thallium(III) acetate in diols, HO(CH2)nOH (n=2, 3, and 4), has been investigated. From styrene the derivatives of 1,3-dioxolane, 1,3-dioxane, and 1,3-dioxepane were mainly obtained for n=2, 3, and 4 respectively, while the reaction of 1-octene in 1,2-ethanediol afforded 1-acetoxy-2-(2-hydroxyethoxy)octane as the main product. A new alkoxythallate of styrene, C6H5CH(OCH2CH2OH)CH2Tl(OAc)2, has been isolated under milder conditions.
Carbonylation of Saturated Hydrocarbons Catalyzed by Copper(I)Carbonyls in FSO3H–Sb5F
Authors: Souma Yoshie , Sano Hiroshi
Published: July 2006

Saturated hydrocarbons react with carbon monoxide in the presence of copper(I) carbonyl catalysts in FSO3H-SbF5. Tertiary-carboxylic acid and secondary-carboxylic acid were obtained in high yields at −2 to +2 °C and at 1 atm of carbon monoxide. For the isomerization process of intermediate carbonium ions, the cleavage of the C–C bond was recognized, and stable t-butyl cations were formed.
Studies on Nucleosides and Nucleotides. V. Selective Aroylation of 5′-Hydroxyl Group of Uridine and Adenosine
Authors: Shimokawa Satoru , Kimura Junji , Mitsunobu Oyo
Published: July 2006

When uridine was allowed to react with diethyl azodicarboxylate, triphenylphosphine and either benzoic or p-nitrobenzoic acid at room temperature, 5′-O-aroyluridines were selectively obtained in good yields. Similarly, adenosine gave 5′-O-aroyladenosine. In this case, however, a small amount of N3,5′-cycloadenosine was formed.
Radiotracer Studies of the Adsorption of Surface Active Substances at Aqueous Surfaces. VI. Urea Adsorption on an Adsorbed Monolayer of a Nonionic Surfactant
Authors: Tajima Kazuo
Published: July 2006

The surface tension and adsorption were observed by the Wilhelmy plate and radiotracer methods at the air-solution interface of an aqueous solution of urea and α-dodecyl-ω-hydroxyhexa(oxyethylene) (D(EO)6). The adsorption of D(EO)6 was dependent on the concentration of urea below the CMC values, but above the values it was independent of the concentration. Urea adsorption occurs positively for low-surface packing of the poly(oxyethylene) group of D(EO)6, but negatively for the closest packing of the group and high concentrations of urea. It was confirmed that D(EO)6 adsorption took place at the solution surface according to the Gibbs adsorption isotherm, which was taken into account as an activity coefficient in an empirical equation for the interactions of D(EO)6 and urea in solution. Urea adsorption for the adsorbed monolayer of D(EO)6 above the CMC value was interpreted assuming that urea, as for the nonionic micelle, was non-penetrating, which was examined by gel permeation.
The Mass Spectra of 3-Aryl-1,2,3-oxathiazolidine 2-Oxides
Authors: Yamada Fukiko , Nishiyama Tomihiro , Samukawa Hiroshi , Takeuchi Yasunari
Published: July 2006

The mass spectra of a series of 3-aryl-1,2,-3-oxathiazolidine 2-oxides were obtained. The fragment ions were chiefly formed by the elimination of SO2 from the M+ ion. In this step, both the effects of the ring substituent and the torsion angle of the oxathiazolidine ring on the rate of the elimination were observed.
Measurements of the Interactions between Polyethylene Glycol and Organic Compounds by Gas Chromatographic Technique
Authors: Kawakami Mitsuyasu , Egashira Makoto , Kagawa Shuichi
Published: July 2006

A gas-liquid chromatographic technique was employed to measure the thermodynamic properties of the solutions consisting of polyethylene glycol (PEG) and some organic compounds. Three kinds of PEG with different molecular weights were used as a stationary liquid, and six kinds of organic compounds as a solute. For most of the compounds examined, the retention volume varied with the sample size injected. By using the retention volume at an infinitesimal sample size, thermodynamic properties of organic compounds at infinite dilution in PEG, such as the activity coefficient based on weight fraction, Henry coefficient based on weight fraction, and the partial molar excess enthalpy, were determined. From the results it was found that the particular interactions between organic compounds and PEG such as the hydrogen bond formation is not significant, and the solutions can be regarded as a regular solution. The solubility parameters of PEG-600, -1000, and -4000 at 67.3 °C were found to be 10.0, 9.8, and 9.5, respectively.
Stereochemistry and Reactivity of Metal–Schiff-base Complexes. I. Preparation and Thermodynamic Stereoselectivity of Mixed Ligand Cobalt(III) Complexes Containing N,N′-Ethylenebis(salicylideneamine) Dianion (sal2en) or N,N′-Ethylenebis(7-methylsalicylideneamine) Dianion (7,7′-Me-sal2en) and l-Amino Acid Anion
Authors: Fujii Yuki , Isago Takashi , Sano Mitsuo , Yanagibashi Noriko , Hirasawa Shigeru , Takahashi Sozo
Published: July 2006

Two series of new mixed ligand cobalt (III) complexes with the general formulas of [Co(sal2en)(l-aa)] and [Co(7,7′-Me-sal2en)(l-aa)] (where l-aa=anion of l-ala, l-val, l-leu, l-isoleu, l-met, l-thr, l-phe, l-tyr, or l-trp) have been prepared and characterized. All are labile for both isomerization and substitution reactions and each exists in an equilibrium mixture of ΛL- and ΔL-cis-β1(fac)-isomers (ΛL>ΔL)in methanol. The isomer’s ratios, ΛL/ΔL were estimated from their PMR spectra, and the following facts were found: The increasing order of the ratios is l-ala∼l-met∼l-leu<l-val<l-isoleu<l-thr<l-phe∼l-tyr<l-trp, and the ratios are larger in 7,7′-Me-sal2en-complexes than in sal2en-complexes for each amino acid.
The Dye-sensitized Photolysis of Aryl Aryldiazo Sulfone
Authors: Yamase Toshihiro , Hisada Hiroshi , Suzuki Sadao , Ikawa Tsuneo
Published: July 2006

The amethyst violet (AV)-sensitized photolysis of p-tolyl p-anilinobenzenediazo sulfone (TABS) has been investigated in a ethanol–water (9.3 : 0.7, v/v) solution. The experimental data on the quantum yield of the sensitized photolysis and the AV fluorescence or phosphorescence intensity were explained in terms of AV-excited singlet sensitization. Studies of both the photoproducts and the heterogeneous photopolymerization of acrylamide supported the mechanism involving the homolytic dissociation of diazosulfone.
Acyl Cyanide. III. Thermal and Base-Catalyzed Reactions of Phenylcarbamoyl Cyanide
Authors: Oku Akira , Suzuki Takamasa , Koura Hajime , Mashio Fujio
Published: July 2006

Phenylcarbamoyl cyanide (1), under thermal conditions or base-catalysis, behaves as a source of bothphenyl isocyanate and hydrogen cyanide in the syntheses of carbamates, cyanohydrins, and iminohydantoins. The reaction mechanism of 1 with methanol in the presence of tertiary amine was investigated. The following observations (i–iii) led us to deduce that phenyl isocyanate was not involved as the intermediate and that the rate-determining step involves nucleophilic displacement of 1 by the alkoxyl group, reinforced by the base: (i) the N–H exchange was too fast to be rate-determining; (ii) d-labelling experiments showed kH/kD=1.8–1.9 in any of the reactions, 1-d1+MeOH, 1-d0+MeOD, and 1-d1+MeOD, and (iii) diphenylcarbamoyl cyanide reacted only 7.2 times slower than did 1.
Synthesis of Protected Peptide Fragments Related to Porcine Motilin
Authors: Mihara Shigeru , Shimizu Fumio , Miyamoto Seiji
Published: July 2006

Syntheses are described of three protected peptide fragments which correspond to positions 1–6, 7–11, and 12–22, respectively, of the entire amino acid sequence of porcine motilin, a gastric motoractivity-promoting polypeptide. Stable tosyl group was used for the protection of ε-amino group of lysine and guanidino group of arginine. These protected peptide fragments were mainly constructed in step wise manner using benzyloxycarbonyl amino acid by mixed anhydride method in the presence of N-hydroxysuccinimide. For preparation of the C-terminal undecapeptide, fragment condensation method was employed using two protected tripeptide azides. The protected peptides and intermediates could be readily purified by simple procedure.
The Gas-phase Emission Spectrum of Carbon Disulfide Excited by an N2 Laser–Magnetic Quenching Effect
Authors: Matsuzaki Akiyoshi , Nagakura Saburo
Published: July 2006

The time-resolved emission spectrum and its temperature dependence were observed with gaseous CS2 excited by an N2 laser. The spectrum was found to consist of three band systems, one of them being demonstrated to be emission from the 1A2 state. The collision-free lifetimes and the collisional quenching constants were determined for the three band systems. The emission from the 1A2 state was found to be quenched by a magnetic field because of the enhancement of an intramolecular energy-transfer process. This is the first observation of the magnetic quenching of emission from an excited singlet state.
Enthalpy-Controlling Adsorption of Hydrocarbons on 1,3,5-Trinitrobenzene as Revealed by Gas Chromatography
Authors: Akimoto Masamichi , Echigoya Etsuro
Published: July 2006

Equilibrium adsorption constants for a series of olefins and paraffins on 1,3,5-trinitrobenzene were enhanced upon increasing the electron-donating nature of the hydrocarbons; the trend in the adsorption constants was entirely due to variations in the enthalpy change of adsorption rather than the entropy one. These results are characteristics of the adsorption in which the donation of electrons from a hydrocarbon molecule is strongly predominant.
Amination of Decyl Alcohol over the Binary Metal Oxide Catalysts
Authors: Takita Yusaku , Nishida Yasuo , Seiyama Tetsuro
Published: July 2006

Catalytic amination of decyl alcohol was examined over binary oxide catalysts containing molybdenum, and the selective formation of decylamine was observed over TiO2-, SnO2-, and Fe2O3–MoO3 catalysts. The reaction was often accompanied by the formation of 1-decene. It was found that catalytic activity for the amination of aliphatic alcohol was associated with the acidic property of metal oxide catalysts.
The Infrared and Raman Spectra of p-Azoxyanisole in the Crystalline, Nematic and Isotropic Liquid Phases
Authors: Shibata Kazuo , Kutsukake Masaki , Takahashi Hiroaki , Higasi Keniti
Published: July 2006

The infrared and Raman spectra of p-azoxyanisole were measured in the crystalline, nematic, and isotropic liquid phases. In the internal vibrational region, abrupt changes in intensity were observed at the crystalline-nematic phase transition; however, no appreciable change was detected at the nematic-isotropic liquid phase transition. In the external vibrational region, some of the Raman lattice bands, which eventually vanish in the isotropic liquid phase, persist in the nematic phase, while some of the infrared lattice bands disappear and a new band appears as the crystalline-nematic phase transition point is reached and traversed. The assignments of the infrared and Raman bands which appear or disappear in the nematic phase are discussed.
Kinetic Studies of the Crystallization of Vitreous Beryllium Fluoride
Authors: Tamura Seiichi , Yokokawa Toshio
Published: July 2006

The kinetics of the crystallization of vitreous beryllium fluoride were studied using the quantitative X-ray diffraction and calorimetric methods. Analysis of the data using the Johnson-Mehl-Avrami equation shows that the crystallization proceeds through spherulitic growth. The activation energy of 222 kJ mol−1 was obtained from the temperature dependence of the crystallization rate using a modified Johnson-Mehl-Avrami equation.
Composition of Single Crystals of Chromium Chalcogenide Spinels Grown by Chemical Vapor Transport
Authors: Ametani Kohei
Published: July 2006

Compositional analyses using atomic absorption spectrophotometry were carried out on the vapor-phase grown single crystals of copper-based spinels with the nominal formulas such as CuCr2S3Cl, Cu1−xFexCr2S4 (x≤1), Cu0.5In0.5Cr2S4, CuCr2Se3Cl, and CuCr2Se3Br, and the cadmium-based spinels of CdCr2S4 and CdCr2Se4, including crystals doped with indium, silver, and copper. The grown crystal usually had a composition different from the nominal formula and a tetrahedral-site deficiency of the copper-based spinels is reported for the first time. All crystals of Cu1−xFexCr2S4 and Cu0.5In0.5Cr2S4 were contaminated with a considerable amount of chlorine and some of the crystals had a substantial cation deficiency on the tetrahedral sites; the cation deficiency increases with increasing copper or chlorine content. For the CuCr2S3Cl and CuCr2Se3Br crystals, a large copper deficiency was also found while the halogen content was close to that expected for the nominal compositions, or somewhat higher. Of all the copper-based spinels, the least tetrahedral-site deficiency was observed in the CuCr2Se3Cl crystals, but the chlorine content was much less than the stoichiometric content. The cadmium-based spinels usually satisfied the stoichiometric formula CdCr2S4 or CdCr2Se4.
Chemical Synthesis of N-Acetylmuramyl Peptides with Partial Structures of Bacterial Cell Wall and Their Analogs in Relation to Immunoadjuvant Activities
Authors: Kusumoto Shoichi , Tarumi Yuzo , Ikenaka Kazuhiro , Shiba Tetsuo
Published: July 2006

N-Acetylmuramyl peptides of successive length corresponding to the partial structures of cell wall in Staphylococcus aureus were synthesized in order to elucidate the minimum effective structure responsible for immunoadjuvant activity of bacterial cell walls. In view of the finding that N-acetylmuramyl-l-alanyl-d-isoglutamine was the least structure moiety for exhibition of the activity, nine analogs of either N-acetylmuramyl amino acid or N-acetylmuramyl dipeptide were also synthesized.
2-Chloro-1,3,5-trithiane and 2-Chloro-1,3-dithiane. Their Ionic Dissociation and Reactions with Nucleophiles
Authors: Arai Kazutaka , Oki Michinori
Published: July 2006

2-Chlorol,3,5-trithiane and 2-chloro-1,3-dithiane have been prepared by chlorination of the corresponding polythianes with N-chlorosuccinimide. These chlorides afford various substitution products when treated with nucleophiles, whereas nuclear substitution of the aromatic ring occurs when the chlorides are treated with phenol or N,N-dimethylaniline. 1H NMR spectra of these chlorides show remarkable solvent dependence which is explained by assuming ionic dissociation of the chlorides to produce polythianyl cation and chloride anion. Free energies of activation for the dissociation in various solvents indicate that the dissociation of 2-chloro-1,3,5-trithiane is more sluggish than that of 2-chloro-1,3-dithiane. The results are attributed to the difference in availability of electrons on the sulfur atoms in two systems.
Preparation and Properties of Cobalt(II) and -(III) Complexes of (2-Aminoethylthio)acetic Acid
Authors: Hori Kiichi
Published: July 2006

The cobalt(II) and -(III) complexes of (2-aminoethylthio) acetic acid (HL), [CoL2]·H2O, trans-(N)-[CoL2]Cl and cis(N)-[CoL2]Cl·2H2O were prepared and characterized. These complexes are octahedral in which the ligand is coordinated through the N, S and O atoms as a terdentate ligand.
Structure of C-2801X, a New Cephamycin-type Antibiotic
Authors: Fukase Hiroshi , Iwasaki Hidesuke
Published: July 2006

The C-3 side chain moiety of C-2801X, a new cephamycin-type antibiotic, was almost quantitatively obtained by Dowex 50-catalyzed hydrolysis, and its structure was established as 3,4-dihydroxy-α-methoxycinnamic acid (I) by spectroscopic analyses and synthesis. The full structure of C-2801X was also assumed to be XIII by NMR analysis.
Preparation of Reinforcing Fillers from Japanese Acid Clays with Lime and by Calcination. IV. Investigation on the Structure, Physicochemical Properties and Morphology of M Hard Clay in Relation to the Reinforcing Effect
Authors: Rai Hideki , Yamada Junkichi
Published: July 2006

In order to find the optimum conditions for the preparation of satisfactory reinforcing filler from Matsune (M) acid clay, two series of fillers of M hard clay (CaO 0–9%: drying 110 °C, 5 hr for M-1 series; calcination 600 °C, 1.5 hr for M-2 series: wet ball-milling 6–24 hr) were investigated with respect to their structure, physicochemical properties and morphology. Treatment with hydrated lime (CaO 3%), followed by calcination (600 °C, 1.5 hr) and mechanical disintegration (wet ball-milling 18 hr) was found to give good results. Calcination after the lime treatment gives rise to adequate dehydroxylation as well as dehydration of the montmorillonite, calcium silicate hydrates (CSH) and excess silica remaining. This process helps to restrain the great surface activity of acid clay and facilitate pulverization of the final products combined with the effect of inhibiting polycondensation of the montmorillonite and α-cristobalite due to an even formation of the CSH distributed on the interlayer surfaces and the interfaces of the minute crystallites.
The Many-body Effects in (N2)n Systems
Authors: Hashimoto Masao
Published: July 2006

Many-body effects in (N2)n systems are discussed on the basis of CNDO/2-Clementi SCF calculations of the deviation from the pairwise additivity. The manybody effects cancel each other out, and this makes the deviation from the pairwise additivity only a small percentage of the pairwise interaction in the rather high n-mers.
Rearrangement of 4,5-Benzo-3-thiatricyclo[4.1,0.02,7]heptenes Promoted by Butyllithium: A New Synthetic Route to 3,4-Benzo-2-thiabicyclo[3,2.0]hepta-3,6-dienes
Authors: Tatsuoka Toshio , Murata Ichiro
Published: July 2006

The reaction of 4,5-benzo-3-thiatricyclo-[4.1.0.02,7]heptenes (1a–d) with butyllithium followed by quenching with water or methyl iodide at −60 °C gives the expected bridgehead substituted products, whereas the same reaction conducted at somewhat higher temperature gives the skeletal rearrangement products, 3,4-benzo-2-thiabicyclo-[3.2.0]hepta-3,6-dienes (2a–f), almost quantitatively. A mechanism in line with the results is proposed.
New A-nor-B-homo-ent-Kauranoids (Grayanotoxin XVI and XVII) from Leucothoe Grayana Max.
Authors: Gasa Shinsei , Ikeda Ry\={u}z\={o} , Hamanaka Nobuyuki , Matsumoto Takeshi
Published: July 2006

Two physiologically active diterpenoids, grayanotoxin XVI and XVII, have been isolated from Leucothoe grayana Max., and the structures have been determined to be 6-O-acetylgrayanotoxin II and 3,6-didehydrograyanotoxin III respectively on the basis of spectral and chemical evidence.
Adsorption and Desorption of Molecular Oxygen in Solid State of Polymeric Hemochrome
Authors: Honda Kenji , Hata Seiji , Tsuchida Eishun
Published: July 2006

The oxygenation of a pyridine-hemochrome bound to a polymer ligand has been studied in solid state. The oxygenation rate and the amount of oxygen adsorbed were determined by volumetry. The rate of adsorption of oxygen depends upon the structure of polymer matrix. Pyridine hemochrome included in a polyion complex takes up oxygen more rapidly than others. The rate of adsorption depends a great deal upon the surface condition of polymer matrix in case of oxygen binding in solid state. The degree of oxygenation was nearly equal in all cases. The difference in the rate of adsorption of oxygen may be due to the difference in gas permeability of the polymer matrix. This was supported by the fact that the hemochrome bound to a porous polymer matrix adsorbs oxygen more rapidly than the hemochrome bound to a non-porous polymer matrix. The surface condition of the polymer matrix greatly affects the reversibility of oxygenation.
Heteropolytungstates Containing Cobalt(II) or Cobalt(III)
Authors: Komura Akitoshi , Hayashi Mutsuo , Imanaga Hiroto
Published: July 2006

The reactions of tungstophosphate with cobalt ion and the properties of heteropolytungstates containing cobalt have been investigated. Unsaturated heteropolyanion PW11O397− produced by the partial degradation of the parent 12-tungstophosphoric acid reacts with cobalt ion to give 11-tungstocobaltophosphate PCoW11O40H25−. Discussion is given on the presence of cobalt in the heteropolyanion and on the above reaction. Both 12-tungstocobaltate-(II) and -(III) are very resistant to acid, but 11-tungstocobaltophosphates lose cobalt ion in strongly acidic solutions to give the parent 12-acid. Some aspects of the spectra of the heteropolytungstates, in which cobalt(II) and cobalt(III), respectively, are present in the specific site, are discussed.
Partial Molal Volumes of Surfactants in Methanol–Water Mixtures
Authors: Kaneshina Shoji , Manabe Masahiro , Sugihara Gohsuke , Tanaka Mitsuru
Published: July 2006

The partial molal volumes of surfactants in the micellar state (\barVm) and in the singly dispersed state (\barVs) have been determined at 25 °C in methanol-water mixtures up to the composition of 25 mol% methanol. The \barVm of sodium dodecyl sulfate (SDS) increases gradually with the addition of methanol across the plateau region (3–15 mol% methanol). On the other hand, the \barVs values of SDS and its homologous salts containing the alkyl chain of carbon numbers from 6 to 10 decrease initially with the addition of methanol and then increase up to 25 mol% methanol via the minimum at 3 mol% methanol. The value of \barVm–\barVs reaches its maximum at 3 mol% methanol and then approaches zero at about 30 mol% methanol. The latter behavior is an indication of the lack of any micelle formation. In order to elucidate the solute-solvent interactions, the split of \barVs into the contributions of the ionic and the hydrophobic part was attempted. Consequently, the variation in \barVs with the solvent composition can primarily be attributed to the behavior of the hydrophobic group in solutions. On the basis of these results, the interactions between the hydrophobic part of the solute and the binary solvent were discussed.
Electronic Structure and Spectra of Acrylic Acid in the Vapor and Condensed Phases
Authors: Morita Hiroshi , Fuke Kiyokazu , Nagakura Saburo
Published: July 2006

Near and vacuum UV absorption spectra of acrylic acid were measured at room temperature in the vapor phase and at 77 K in the condensed phase. From a comparative study of the observed spectra, a Rydberg excitation band was observed at 7.46 eV in addition to valence-shell transition bands. The estimated value of the quantum defect (δ=1.01) indicates that the Rydberg orbital is 3s. A new modified CNDO-CI method applicable to planar molecules was developed and applied to acrylic acid to investigate the valence-shell transitions, the observed bands at ∼5.0 and 6.71 eV being assigned to the transitions to the n-π* and π-π*, respectively.
Palladium-catalyzed Reaction of Olefins and Acetylenes with Iodoferrocenes
Authors: Kasahara Akira , Izumi Taeko , Maemura Mitsugi
Published: July 2006

Iodoferrocene (1) reacts readily with olefinic compounds in the presence of a catalytic amount of palladium(II) acetate to produce alkenylferrocene derivatives. In the presence of a copper(I) iodide and palladium complex, 1 also reacts with acetylene to afford diferrocenylacetylene.
The Hindered Internal Rotation of Amide Groups of Polyacrylamide of Low Molecular Weights
Authors: Hirai Yoshiyuki , Yukawa Mitsuyoshi , Imamura Yoshio
Published: July 2006

Polyacrylamides of low molecular weights (average degrees of polymerization(‾DP) : 7.2, 18.3, 21.3, and 45.4) were prepared by radical polymerization, and their PMR spectra were observed over the temperature range of 30–90 °C. From the temperature dependence of the PMR spectra, the values of the energy barrier to the internal rotation about C–N bonds were determined by means of a total line-shape analysis. The energy barriers for the polymers above ‾DP : 18.3 were 10.6 kcal/mol, while those for the polymer of ‾DP : 7.2 were 9.2 kcal/mol. These results were interpreted in terms of the local environment around the amide groups. The intramolecular hydrogen bonding was also investigated.
Pyrolysis of Acetylene behind Shock Waves
Authors: Ogura Hiroo
Published: July 2006

The pyrolysis of acetylene was investigated behind the reflected shock waves in a single-pulse shock tube over the temperature range from 1000 to 1670 K. The major products were 1-buten-3-yne, 1,3-butadiyne, and hydrogen. The main primary C4 product, however, changes from 1-buten-3-yne to 1,3-butadiyne with the increase of temperature. At the lower temperatures the formation of 1-buten-3-yne dominates the pyrolysis of acetylene. The rate of 1-buten-3-yne formation is second order with respect to acetylene concentration, and its second-order rate constant is expressed as follows:

k(cm^3 mol^-1s^-1)=10^14.39±0.26exp((-46400±1400)/RT)

The isotopic distribution of 1-buten-3-yne in the pyrolysis of the equimolar C2H2 and C2D2 mixture, proved that the pyrolysis proceeds via a free-radical mechanism. A free-radical chain mechanism initiated by the bimolecular reaction of acetylene, 2C2H2→C4H3+H, was proposed.
The Formation of Amino Acids and Related Oligomers from Formaldehyde and Hydroxylamine in Modified Sea Mediums Related to Prebiotic Conditions
Authors: Hatanaka Hiroshi , Egami Fujio
Published: July 2006

Amino acids and related oligomers were produced from formaldehyde and hydroxylamine in modified sea mediums at pH 5.5 and 105 °C. The modified sea mediums are characterized by a lower concentration of sodium chloride and a higher concentration of essential transition metal ions (Zn2+, Mo6+ as MoO42−, Fe3+, Cu2+, Co2+, and Mn2+) than in sea water; generally small amounts of clays (kaolin and montmorillonite) were added. About 40 species of amino acids were detected in the automatic amino acid analyzer, and 20 of them were tentatively assigned. Glycine, alanine, and serine among the protein amino acids and β-alanine were further confirmed by thin-layer chromatography. Oligomers with molecular weights of about 200–1000 were produced which gave rise to an amino acid mixture by acid hydrolysis. From the ratio (maximum, about 5) of the content of the amino groups after to before hydrolysis and the molecular size, the oligomers were tentatively regarded as oligopeptides of an unknown nature, resistant to pronase digestion. The large-molecular fraction (M. W. about 700) had a phosphatase-like activity able to hydrolyze p-nitrophenyl phosphate.
The Effect of Axial Ligands on the Reductions of Co(III) Complexes with a Macrocyclic Schiff-base Ligand by Fe(edta)2−
Authors: Kurimura Yoshimi , Saito Hiroshi , Nakajima Ikuko , Fujii Yuki
Published: July 2006

The second-order rate constants for the reduction of cobalt(III) complexes with a macrocylic Schiff-base ligand, Co(dop)L22+ (dop=N,N′-bis(2-hydroxyimino-1-methylpropylidene)-1,3-propanediamine and L=primary amine), by Fe (edta)2− are very sensitive to the nature of the axial ligands. The rate increases with a decreases in the basicity of the axial ligands: the order is methylamine, ethylamine, 2-aminoethanol, toluidine, aniline, and bromoaniline derivatives. It is shown that there is a linear relationship between the logarithmic second-order rate constant and the pKa of the axial primary amine ligand. Among the series of primary amine derivatives, the differences in the free energy of the activation for the reduction can be considered to be mainly dependent upon those in the enthalpy of the activation for the bond stretching of the Co–N (axial ligand) prior to the electron-transfer.
Synthesis and Magnetic Properties of Iron(III) Complexes with Several Quadridentate Schiff Bases
Authors: Nishida Yuzo , Oshio Shuhei , Kida Sigeo
Published: July 2006

New iron(III) complexes containing quadridentate Schiff bases, [Fe(L)AB]n+, were prepared, where H2L represents a quadridentate Schiff base, and A and B, unidentate ligands, such as imidazole, pyridine derivatives, and cyanide ions. The magnetic moments of the complexes are in the range of 1.9–6.0 B.M. at room temperature. Based on the magnetic susceptibilities at various temperatures (90–295 K), these compleses were classified into four types: (1) high-spin (S=5⁄2), (2) low-spin (S=1⁄2), (3) intermediate spin (S=3⁄2), and (4) cross-over complexes, the last of which have a ligand-field strength near the cross-over point of high-spin and low-spin types. From the ESR spectra obtained, the existence of a spin-equilibrium was established for the cross-over complexes.
Spin Trapping of Aryl and Arylcyclohexadienyl Radicals by N-t-Butyl-α-phenylnitrone (N-Benzylidene-t-butylamine Oxide) and α,N-Diphenylnitrone (N-Benzylideneaniline Oxide)
Authors: Kamimori Mariko , Sakuragi Hirochika , Suehiro Tadashi , Tokumaru Katsumi , Yoshida Masayuki
Published: July 2006

Monosubstituted phenyl radicals produce only aryl spin adducts in the reaction with nitrones described in the title, while polyhalo-substituted phenyl radicals add to solvent benzene, in competition with the formation of aryl spin adducts, to give arylcyclohexadienyl radicals, which in turn are trapped by the nitrones giving nitroxides incorporating the solvent benzene (Scheme 3).
Rishitin I. The Isolation and Structure Elucidation
Authors: Masamune Tadashi , Murai Akio , Takasugi Mitsuo , Matsunaga Akira , Katsui Nobukatsu , Sato Norio , Tomiyama Kohei
Published: July 2006

A modification of the isolation procedure and the details of the structure elucidation of rishitin (1) are described.
Solid-state Reactions between CVD–TiO2 and BaCO3
Authors: Suyama Yoko , Kato Akio
Published: July 2006

The solid-state reactions between CVD–TiO2 powders of anatase- and rutile-forms with various particle sizes and BaCO3 were investigated in O2 and CO2. The reactivity of the TiO2 powders and the apparent activation energy for the reaction were independent of the crystal type of TiO2. The reactivity of the TiO2 powders increased remarkably as the particle sizes grew smaller than 0.15 μm. When such fine CVD–TiO2 powders were used, the reaction proceeded to completion at temperatures below 1000 °C in both O2 and CO2 and gave fine BaTiO3 powders. The particles of BaTiO3 produced appeared single-crystalline and kept a shape similar to that of the starting TiO2 particle. The sizes of the BaTiO3 particles were controlled by those of the starting TiO2 and were independent of those of BaCO3.
The Theoretical Estimation of the G-Values for the Ionization and Excitation of Thirty-eight Gaseous Compounds Irradiated by 100 keV Electrons
Authors: Okazaki Kiyoshi , Yamabe Masaki , Sato Shin
Published: July 2006

The G-values for the ionization and excitation of thirty-eight gaseous compounds irradiated by 100 keV electrons have been calculated by combining the binary-encounter-collision theory with the theory of the degradation spectrum, which is based on the continuous-slowing-down approximation (CSDA). The thirty-eight compounds include C2–C6 alkanes, cycloalkanes, C2–C4 olefins, acetylene, 1,3-butadiene, benzene, toluene, phenol, pyrrole, furan, several alcohols, ethers, ketones, acetaldehyde, carbon dioxide, and hydrogen cyanide. Most of the calculated G-values of the electrons were in fair agreement with the experimental values. In the cases of several hydrocarbons, the dissociation from the superexcited state into the neutral fragments was taken into account, since the data for the fragmentation ratios were available. In the case of acetylene, the discrepancy in the G-values of electrons obtained experimentally and theoretically suggests that excited acetylene gives rise to a chemiionization reaction. In order to check the CSDA, the Fowler equation for helium has been calculated and the results compared with those obtained under the CSDA. The discrepancy in the G-values obtained by the two methods did not exceed 7%.