bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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&gt;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&lt;l-val&lt;l-isoleu&lt;l-thr&lt;l-phe∼l-tyr&lt;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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.