bluuebunny/crossref_metadata_2025 huggingface dataset:
The Photoconductivity of the Titanium Dioxide Crystal
Authors: Iida Takeaki , Nozaki Hiroshi
Published: July 2006

The photoconductivity of titanium dioxide (rutile type) synthesized by the flame-fusion method was studied. The photoconductivity spectra showed three peaks. The first is the maximum response around the edge of the fundamental absorption of rutile; the second is the peak at 630 mμ (1.98 eV), and the third is the broad-band spectra in the near infrared region of 1.0–1.9 μ. From the facts that Fe is found by chemical analysis to be a major impurity in rutile, that the peak at 630 mμ is enhanced by the increase in Fe concentration from 0.006 mol% to 0.02 mol%, and that the infrared quenching band of photoconductivity is observed at 1.23 μ (1.01 eV) in Fedoped rutile, it is concluded that this peak at 630 mμ results from the excitation of the electron from the Fe3+ level. The broad-band spectra at 1.0–1.9 μ are enhanced by the reduction and are decreased by the oxidation of the crystal, so these excitation spectra are ascribed to lattice defects originating from the non-stoichiometry of TiO2. These defects have much influence on the photoconductivity of rutile, i. e., on the relation between the photocurrent and the electrical applied field, and on the change the photocurrent versus the time.
The Synergistic Effect in Solvent Extraction. The Effect of Carboxylic Acid on the Solvent Extraction of Europium(III) with Benzoyltrifluoroacetone
Authors: Shigematsu Tsunenobu , Tabushi Masayuki , Matsui Masakazu , Honjyo Takaharu
Published: July 2006

The effects of carboxylic acids, such as formic, chloroacetic, acetic, propionic, butyric and caproic acid, on the extraction of europium with benzoyltrifluoroacetone were studied. The extraction is enhanced by the adduct formation between metal chelates and carboxylic acids in the organic phase, while it is hindered by the formation of metal-complex ions with anions of carboxylic acids in the aqueous phase. Caproic acid acts as an organic Lewis base and shows the synergism, but formic and chloroacetic acids have a masking effect. Acetic acid, propionic acid, and butyric acid behave both as synergists in the organic phase and as masking agents in the aqueous phase. Gaproic acid forms more stable adducts than does n-hexyl alcohol, and the composition of the chelate adduct is estimated to be Eu(BFA)3·2CH3(CH2)4COOH.
Determination of Niobium by Photon-Activation Analysis Based on Internal-Reference Method
Authors: Oka Yoshinaga , Pung Tong-Chuin , Saito Tatsuya
Published: July 2006

The internal-reference method proposed previously has been applied to the photon-activation analysis of niobium using molybdenum as the reference element. For the determination of niobium, 92mNb produced by the (γ,n) reaction was utilized and 95mNb or 96Nb activities coming from molybdenum by the (γ,p) processes were used as reference. A series of molybdenum and niobium mixtures with known compositions were irradiated by bremsstrahlung photons with a maximum energy of 17 MeV for an hour. After niobium activities were separated chemically, their γ-ray spectra were measured with a lithium-drifted germanium detector. A good proportionality was obtained between the activity ratio, RA0, and the weight ratio, RW. Niobium down to 5μg can be determined with a relative error within ±3% under the present experimental conditions.
The Hydrolysis of the Uranyl Ion in Heavy Water
Authors: Maeda Masunobu , Kakihana Hidetaka
Published: July 2006

The hydrolysis equilibria of the UO22+ ion in heavy water containing 3m NaClO4 as an ionic medium were studied at 25°C by potentiometric titrations, employing a technique of constant-current coulometry. The deuterium-ion concentration was measured by means of a glass electrode. The most probable hydrolysis scheme chosen in the range of the total uranyl concentration from 1 to 10mm was: (UO2)2(OD)22+−(UO2)3(OD)42+−(UO2)3(OD)5+; the respective stability constants were −log β2,2=6.80±0.02, −log β4,3=14.00±0.07, and −log β5,3=18.63±0.02. The above results reveal that the composition of the hydrolysis species in heavy water are generally the same as those in light water, while the values of the stability constants are smaller in heavy water than in light water.
On the Photochemical Hydrogen Shifts in Arylcycloheptatrienes
Authors: Tezuka Takahiro , Kimura Masaru , Sato Aiya , Mukai Toshio
Published: July 2006

Photochemically-induced hydrogen shifts in 7-(p-chlorophenyl), 7-phenyl, 7-(p-methoxyphenyl) and 7-p-tolylcycloheptatrienes (Ia—d) were studied. The possibility of hydrogen 1,7 and 1,3 shifts in these compounds was examined on both experimental and theoretical grounds. It was concluded that the hydrogen 1,7 shift is the only suprafacial hydrogen shift possible in the excited cycloheptatriene system. In this study all the isomers of p-chlorophenylcycloheptatriene were separated by applying the Diels-Alder reaction to the photo-reaction mixture; the method of preparing each of those isomers will also be described.
Syntheses and NMR Spectra of the Substituted Methylferrocenes
Authors: Sato Masaru , Koga Michinao , Motoyama Izumi , Hata Kazuo
Published: July 2006

Several 1′- and 2-substituted 1-methylferrocenes were prepared, and their NMR spectra were measured. From the consideration of the chemical shifts, the transmission coefficient of the electronic effect through the ferrocene nucleus was calculated to be 0.28. 1′-Substituted 1-acetylferrocenes were also prepared, and their NMR spectra were discussed in connection with those of methylferrocenes.
Synthesis of Corticotropin Peptides. XI Synthesis and Biological Properties of [1-β-Alanine]-ACTH(1-18)-Octadecapeptide Amide
Authors: Inouye Ken , Tanaka Akira , Otsuka Hideo
Published: July 2006

The synthesis is described of an octadecapeptide amide, β-alanyl-tyrosyl-seryl-methionyl-glutamylhistidyl-phenylalanyl-arginyl-tryptophyl-glycyl-lysyl-prolyl-valyl-glycyl-lysyl-lysyl-arginyl-arginine amide, corresponding to the first eighteen amino acid residues of corticotropin except for the amino end which has been substituted by a β-alanine for the serine in native hormone. The adrenalstimulating activities of the octadecapeptide amide are compared with those of the corresponding 1-serine or 1-glycine octadecapeptide amide to show that the 1-β-alanine peptide is remarkably more active than the latter when assayed by in vitro, subcutaneous and intamuscular approaches, and that the activities of the former are maintained for a longer period of time than those of the latter. The 1-β-alanine peptide as a lipotropic agent is also shown to be more active than the synthetic analogs and a native corticotropin on rat adipose tissue. The differences among these octadecapeptide analogs in the biological properties are discussed in terms of their susceptibility toward the action of aminopeptidase.
Proton Magnetic Resonance Studies on Specifically Deuterated Sucrose Acetates
Authors: Suami Tetsuo , Otake Toshiki , Ogawa Seiichiro , Shoji Tadao , Kato Naoyuki
Published: July 2006

In the proton magnetic resonance spectrum of octa-O-acetylsucrose, an individual acetoxy group signal was assigned by direct comparisons of the spectra of specifically deuterated octa-O-acetylsucroses and that of nondeuterated one. The structures of 2,3,6,3′,4′-penta-O-acetylsucrose and 2,3,4,3′,4′-penta-O-acetylsucrose were further confirmed definitively by the present studies.
The Reaction of Sulfenyl Chlorides with Thioethers. II. Kinetic Studies
Authors: Oki Michinori , Kobayashi Keiji
Published: July 2006

The rates of the reaction of methyl α-phenethyl sulfide with benzenesulfenyl chloride were measured by means of product analyses. It was found that the reaction was general-acid-catalyzed and autocatalyzed. The rate-determining step was suggested to be the formation of a sulfonium ion derived from the reactants. Mechanisms for the formations of the products are suggested.
The Reaction of Sulfenyl Chlorides with Thioethers. III. The Configuration and the Isomerization of cis- and trans-α-Methylthio-β-phenylthiostyrenes
Authors: Oki Michinori , Kobayashi Keiji
Published: July 2006

Various α-methylthio-β-arylthiostyrenes were prepared by the action of arenesulfenyl chloride on α-methylthiostyrene. The configuration of the stereoisomers of the styrene derivatives was determined by studying the nuclear Overhauser effect in the proton magnetic resonance. The relative stabilities of α-methylthio-β-phenylthiostyrene isomers were determined by equilibrating with the aid of hydrogen chloride at various temperatures.
Studies on Dithiocarbamates. XII. Kinetic Studies on the Hydrolysis of Mesoionic 4,5-Diphenyl-1,3,4-thiadiazole
Authors: Talukdar P B , Banerjee S , Chakraborty A
Published: July 2006

Kinetic studies of the compound given in the title were conducted in aqueous alcohols over a wide range of pH. The observed rate constants are dependent on the hydroxide-ion concentration as well as polarity of the medium. Hydrolytic decomposition is characterised by a small magnitude of entropy (ΔS*) and negative salt-effect. Mechanism consistent with these facts has been suggested.
Temperature Dependence of Fluorescence Spectra and Fluorescence Polarization of Some Organic Compounds in Polar Solvents. The Franck-Condon Excited States
Authors: Baba Hiroaki , Mugiya Chie
Published: July 2006

Fluorescence and absorption spectra and fluorescence polarization were measured at different temperatures, ranging from room temperature to 77°K, for 9,10-diazaphenanthrene, 2-naphthol and 2,3-naphthalenediol in polar solvents. At about 120°K, the fluorescence spectra shifted rapidly to the blue as the temperature was lowered. This observation is quantitatively interpreted on the basis of a kinetic scheme involving competitive rate processes, viz., radiative transition from the Franck-Condon excited state, as defined for the dipole orientation of the solvent, and relaxation of the Franck-Condon state into the equilibrium excited state. The Franck-Condon destabilization energies are evaluated from the observed blue shifts. Along with the fluorescence blues hifts, the degrees of polarization increased rapidly, but at a somewhat higher temperature of about 140°K. This phenomenon is related to the rotational relaxation of the solute molecule, and is discussed in comparison with the fluorescence blue shift.
The Solution Properties of Poly-o-methylstyrene
Authors: Matsumura Kimiyoshi
Published: July 2006

The solution properties of poly-o-methylstyrene in toluene were measured by the light-scattering and viscosity methods, and the results were compared with those obtained from poly-o-chlorostyrene and other polystyrene derivatives. The dependencies of the intrinsic viscosity, the second virial coefficient, and the end-to-end distance of the polymer chain on the molecular weight are as follows:

& [η]=9.22×10^-5·M_w^0.72(dl/g), A_2=3.89×10^-2·M_w^-0.38 (mol·cc/g^2)

& and 〈L^2〉^1/2=0.197×M_w^0.62 (Å).

It was made clear that the unperturbed dimension of poly-o-methylstyrene was larger than that of poly-p-methylstyrene, and that the cause of this difference is the large steric repulsion between the side groups of the former. Moreover, the unperturbed dimension of poly-o-methylstyrene was smaller than that of poly-o-chlorostyrene. From these results, it is considered that the large extension of poly-o-chlorostyrene was affected by the electrostatic repulsion between the side groups.
NMR Study of Amino Acids and Peptides; Glycine and Valine Peptides
Authors: Nagai Makoto , Nishioka Atsuo , Yoshimura Juji
Published: July 2006

The PMR spectra of 22 amino acids and peptides were measured in a D2O solution. From the change in the NMR parameters in amino acids and their di- and tripeptides, it has been concluded that a tripeptide is a good model for polypeptides. The chemical shift of the α-proton of an aminoacid residue in tripeptide can be obtained from those of amino acid and dipeptide. The spin-spin coupling constant of an amino acid grows larger, and the population of a trans rotamer becomes larger, as its amino (or carboxyl) group forms a peptide bond. The PMR spectra of two diasteroisomers of valyl-valyl-valine were also measured, and the influences of the configuration of an aminoacid residue on the NMR parameters of its peptides were investigated.
The Chemical Behavior of Low Valence Sulfur Compounds. V. Decomposition and Oxidation of Tetrathionate in Aqueous Ammonia Solution
Authors: Naito Kunishige , Shieh Mu-Chang , Okabe Taijiro
Published: July 2006

The decomposition and oxygen oxidation of tetrathionate in aqueous ammonia solution have been investigated. In the decomposition, thiosulfate, sulfate and sulfamate were formed through penta- and trithionate as intermediate compounds. The molar ratio of the products (SO42−+SO3NH2−)/S2O32− was roughly equal to 2/7, where 0.1n ammonia solution was used. The deficient use of ammonia made the solution neutral or weakly acidic and the precipitation of sulfur and the formation of higher polythionates were observed. The polythionate was detected by means of TLC (Thin Layer Chromatography). In the oxidation, tetrathionate was supposed to go through the following three sequent steps. 1) Decomposition of tetrathionate to form thiosulfate, tri- and pentathionate, and further decomposition of pentathionate to thiosulfate. 2) Oxidation of thiosulfate to tetrathionate and partly to sulfate. 3) Decomposition of trithionate to form sulfate, sulfamate and thiosulfate.
Derivatographic Studies on Transition Metal Complexes. III. The Thermal trans-cis Isomerization of [CoCl2pn2](H5O2)Cl2 in Solid-Phase
Authors: Tsuchiya Ryokichi , Murai Kiyoko , Uehara Akira , Kyuno Eishin
Published: July 2006

The thermal decomposition of trans-[CoCl2pn2](H5O2)Cl2 in solid-phase was measured by derivatography and the isothermal method with a thermobalance. It was found by the latter that dehydration and dehydrochlorination took place with partial isomerization below 170°C. The rate of isomerization gradually increased with temperature until it became equal to the rate of dehydration and dehydrochlorination above 170°C. The activation energies for dehydration and dehydrochlorination and for isomerization were calculated from the isothermal measurement below 170°C to be 10 kcal/mol and 23 kcal/mol, respectively. The activation energy obtained from DTA curve analysis at about 144°C in the derivatogram was 33 kcal/mol. The reaction was explained in terms of “aquation-anation” mechanism. Since the trans-cis isomerization in anhydrous state at 180°C gave a larger activation energy in DTA analysis, the “twisting” mechanism might be preferable to “aquation-anation” for the reaction.
Studies on the Baudisch Reaction. II. The Copper(II)-Hydroxylamine Complex
Authors: Tanimoto Iwao
Published: July 2006

Kinetic investigation of the Baudisch reaction indicates that the reaction follows first-order kinetics, and the isokinetic temperature lies at −11°C. Both kinetic studies and product studies require the formation of a phenol-copper-hydroxylamine-hydrogen peroxide complex during the course of the reaction. It was found that the yield of o-nitrosophenol which is the main product of the Baudisch reaction is counterbalanced by that of catechol according to the pH of the reaction system. Maximum yield of o-nitrosophenol is attained in the lower pH region (pH=2.5–3.5). Catechol which is the main product in the higher pH region (pH>4) seems to be produced through the same complex.
Bis-Type Cobalt(III) and Chromium(III) Complexes with Related Compounds of Iminodiacetic Acid
Authors: Uehara Akira , Kyuno Eishin , Tsuchiya Ryokichi
Published: July 2006

The geometrical structures and some properties of the following complexes were investigated: K[Co(ida)2]·H2O (I), K[Co(ida)2]·2H2O (II), K[Cr(ida)2]·3H2O (III), Ba[Cr(ida)2]2·6H2O (IV), K[Co(mda)2] (V), K[Cr(mda)2] (VI), K[Co(eda)2]·H2O (VII) and K[Cr(eda)2]·H2O (VIII), where ida, mda and eda are the abbreviations of iminodiacetate, methyliminodiacetate and ethyliminodiacetate ions, respectively. IV, VII and VIII are new compounds. On the basis of electronic spectra, it was found that VII and VIII have the trans form with respect to nitrogen atoms in the ligands, and IV, the cis form. Comparison of the properties and structures of the cobalt-(III) complexes with those of the corresponding chromium(III) complexes were also made.
Liquid Phase Chlorination of Olefins with Cupric Chloride
Authors: Koyano Takashi
Published: July 2006

Reactions of olefins with cupric chloride were studied in methanol at 100–140°C. The reactivity of olefins was in the order, ethylene>propylene>1-butene>2-butenes. A considerable amount of 1-chloro-2-methoxy compounds were found in the reaction products of 1-olefins. Competitive formation of dichloride and methoxychloride was suggested. Chlorination of 2-butenes leads to meso- and dl-2,3-dichlorobutanes, their ratio being invariable regardless of the starting material cis- or trans-2-butene. The mechanism is discussed in terms of ionic intermediates.
The Photoreaction of p-Substituted β-Benzoylacrylic Acids
Authors: Sugiyama Noboru , Kashima Choji , Kataoka Hiroshi , Tanaka Keiko
Published: July 2006

This paper will describe the photoreaction of trans-β-(p-ethylbenzoyl)acrylic acid (II) in methanol to give 5-(p-ethylphenyl)-5-methoxy-2-oxo-2,5-dihydrofuran (III), β-(p-ethylbenzoyl)-α-methoxypropionic acid (IV), and its methyl ester (V). The kinetic study of this reaction has revealed that II gives III and IV parallel by the first-order reaction and that IV then changes into V. Furthermore, the irradiation of p-substituted β-benzoylacrylic acids has been studied. From the product ratio and the substituent effects at the para position, the mechanism of the photoreactions of γ-oxoacrylic acids in methanol is proposed. This mechanism is also supported by the HMO calculations.
The Insertion Reaction of Isoprene into Metal-Ethyl Bonds in Various Transition-Metal Salt-Ethylaluminum Compound System
Authors: Takegami Yoshinobu , Suzuki Toshimitsu , Shirai Takashi
Published: July 2006

The insertion reaction of isoprene into metal-ethyl bonds in various transition-metal salt (VCl4, Fe(AA)3, Co(AA)2, CoCl2, Ni(AA)2, or NiCl2-ethylaluminum compound (AlEt2Cl or AlEt3)) catalyst systems was studied. With the vanadium and the nickel catalysts, 2-methyl-2-hexene and 2-methyl- 1-hexene were mainly formed by the methanolysis of the reaction mixture, showing that metal alkenyls, (Remark: Graphics omitted.) and (Remark: Graphics omitted.) respectively, are formed in the reaction system. However, in the iron catalyst, only 2-methyl-2,5-hexadiene and 3-methyl-2,5-hexadiene were formed from (Remark: Graphics omitted.) and (Remark: Graphics omitted.) respectively by the elimination reaction. These results suggest that the stability of metal alkenyls decreases in the order: V>>Ni>Co>Fe.
Ribonuclease T1 Peptides. IV. Synthesis of a Protected Heptapeptide Corresponding to Sequence 17–23
Authors: Mitsuyasu Nobuo , Waki Michinori , Kato Tetsuo , Makisumi Satoru , Izumiya Nobuo
Published: July 2006

A protected heptapeptide corresponding to sequence 17–23 of ribonuclease T1, namely benzyloxycarbonyl-l-seryl-l-threonyl-l-alanyl-l-glutaminyl-l-alanyl-l-alanyl-glycine ethyl ester (XIV), was synthesized by two routes. One consisted of the coupling of benzyloxycarbonylseryl-threonine azide with a pentapeptide ester, alanyl-glutaminyl-alanyl-alanyl-glycine ethyl ester. The other consisted of the coupling of benzyloxycarbonyl-seryl-threonyl-alanine azide with a tetrapeptide ester, glutaminyl-alanyl-alanyl-glycine ethyl ester. These four peptide segments were built up by the method of stepwise synthesis. Optical rotations, melting points and chromatographic behavior of XIV prepared by these two routes were found to be identical. Stereochemical homogeneity of the protected heptapeptide ester XIV was established by the digestion of the deblocked heptapeptide ester with leucine aminopeptidase.
Tri(hetero)substituted Carbonium Ions. I. Neighboring-Group Participation of the N,N-Dimethyldithiocarbamate Function Involving the Intermediacy of 2-Dimethylamino-1,3-dithiolanylium Ion
Authors: Nakai Takeshi , Ueno Yoshio , Okawara Makoto
Published: July 2006

The equimolar reaction of 1,2-dichloroethane with sodium N,N-dimethyldithiocarbamate was studied in various solvents. As major products, ethylene bis(N,N-dimethyldithiocarbamate) and 2-dimethylamino-l,3-dithiolanylium salt (the perchlorate or the tetraphenylborate) were obtained in yields, largely varying with the solvent used. On the basis of the solvent effect on the product ratio, and kinetic experiments it has been verified that neighboring-group participation of the N,N-dimethyldithiocarbamate function would be involved through the intermediacy of the isolated anchimeric carbonium ion, and that such participation is more predominant in nonpolar aprotic solvents such as dioxane and tetrahydrofuran. The mechanism of the reaction between 2-dimethylamino-l,3-dithiolanylium ion and the dithiocarbamate anion was established.
Synthetic Studies of Bacitracin. VI. Synthesis of Unprotected Thiazoline Peptides
Authors: Hirotsu Yoshihiro , Shiba Tetsuo , Kaneko Takeo
Published: July 2006

For a total synthesis of bacitracian A, a synthetic method to secure unprotected thiazoline peptides must be established. 2-Aminomethyl-R-Δ2-thiazoline-4-carboxamide, 2-aminomethyl-R-Δ2-thiazoline-4-carboxylic acid, 2-aminomethyl-R-Δ2-thiazoline-4-carbonyl-l-leucine were synthesized by either the iminoether coupling method or by the dehydration method using N-benzyloxycarbonyl group and benzyl ester as protecting groups.
Studies on Associated Solutions. I. Excess Volume of Binary Systems of Alcohols with Various Organic Liquids
Authors: Nakanishi Koichiro , Shirai Hideko
Published: July 2006

Excess volumes of mixing have been determined at 25.00°C by pycnometry for eleven binary solutions of methanol and two binary solutions of ethanol with organic liquids. The second components include three aliphatic amines, n-butyraldehyde, ethyl acetate, isopropyl ether, anisol, chlorobenzene, acetonitrile, pyridine and nitromethane. The excess volumes of binary solutions containing aliphatic alcohols, which are evaluated from the available density data, were critically reviewed and compared with the present results.
Some Semi-Empirical SCF MO Calculations on Norbornadiene, Norbornene, and Their 7-Cations
Authors: Konishi Hideyuki , Kato Hiroshi , Yonezawa Teijiro
Published: July 2006

Using a semi-empirical SCF MO method for valence electron systems proposed previously by the present authors, the electronic structures of norbornadiene (NBD), norbornene (NBE), and their 7-cations are discussed, together with the configurational problem of the 7-cations. In NBE and NBD, the interaction between the π AO’s in the double bond and the AO’s of the other parts of the molecules is made clear by the charge densities and the bond orders. For the first electronic transition assigned to a π–σ* or σ–π* in NBD, the present calcuation gives a rather larger excitation energy than does the experiment. For 7-norbornenyl and 7-norbornadienyl cations, the presence of structures distorted from NBE and NBD respectively can theoretically be concluded. The delocalization of the positive charge and the bonding interaction between the bridged carbon atom and the double bond carbon atoms support the concept of the so-called non-classical carbonium ions.
Hydrogen Ion Titration of Poly-S-carboxymethyl-l-cysteine
Authors: Ikeda Shoichi
Published: July 2006

Potentiometric titration curves have been determined for aqueous solutions of poly-S-carboxymethyl-l-cysteine. A pH-induced transition of the polymer conformation is manifest from the occurrence of a transition region around pH 5, where the solution has an essentially infinite buffer action. The titration curve at higher ionization corresponds to that of a random coil. At lower ionization the polymer is associated to form a β-structure and its titration behavior is qualitatively accounted for by the Gouy model for a uniformly charged sheet. Deviation from the model would partly be ascribed to the aggregation of sheets in the β-form. The standard free energy of transition from random coil to β-form has been estimated for the unchanged polymer and is found to depend on the molecular weight of polymer. It is suggested that fine structure of the β-form and its mode of aggregation vary with polymer chain length.
Metal Halide Complexes with Trimethylstibine Sulfide
Authors: Saito Takayuki , Otera Junzo , Okawara Rokuro
Published: July 2006

2 : 1 complexes of trimethylstibine sulfide (TMSS) with zinc(II), cadmium(II), mercury(II) and cobalt(II) halides were prepared. 1 : 1 complexes were also obtained with cadmium bromide and mercuric iodide. On the basis of infrared spectra, it was found that TMSS coordinates to the metal through the sulfur atom and that Hg(TMSS)I2 has a sulfur-bridged structure. The electronic spectral parameters of the tetrahedral Co(TMSS)2X2 (X=Cl, Br and I) complexes are quite close to those of trimethyl-phosphine and -arsine sulfide complexes. These results indicate that for Co–S interactions, polarizability of the thioxo ligand is more important than polarity.
Kinetics for Reversible Menschutkin Reactions. The Effects of Variations in Reactant Structures on the Sensitivity of the Reaction Rate to Solvent Variations
Authors: Matsui Takeki , Tokura Niichiro
Published: July 2006

The reaction rates and equilibrium constants for quaternization of N,N-dimethylaniline and its derivatives with methyl iodide have been measured in acetonitrile, acetone, tetrahydrofuran, nitrobenzene, benzene, benzyl alcohol, and methanol at various temperatures. There is an approximate tendency for the solvent dependence of the reaction rates to diminish linearly with increasing reactivity of nucleophile. This could be interpreted in terms of the theory of an absolute reaction rate and of the concept of the rise of interaction term. In this connection it was proposed that such a problem must be considered in terms of the unitary term of rates. Using the data of rates of the reaction between pyridine and methyl iodide in various solvents, the activity coefficients of dimethylaniline and its derivatives in methanol relative to that of pyridine are estimated. Some inferences have been drawn concerning the nature of SN2 transition state from effects of solvents on both rates and equilibria.
Synthesis of Adamantane Derivatives. IX. The Ritter Reaction of 1-Hydroxymethyladamantane with Acetonitrile
Authors: Sasaki Tadashi , Eguchi Shoji , Toru Takeshi , Ito Katsumi
Published: July 2006

The Ritter reactions of 1-hydroxymethyladamantane (1) and 3-homoadamantanol (14) with acetonitrile in coned, sulfuric acid were investigated. Two products, N-3-homoadamantyl acetamide (2) and N-1-adamantylmethyl acetamide (3) were isolated. Their total- and relative yields were determined in various reaction conditions by GLG analysis, indicating the facile conversion of N-3-homoadamantyl acetonitrilium cation (12) into N-1-adamantylmethyl acetonitrilium cation (13).
Reaction of Glycylglycine with Formaldehyde in the Presence of Cupric Ion
Authors: Noda Kosaku , Bessho Motoaki , Kato Tetsuo , Izumiya Nobuo
Published: July 2006

The reaction mixture of glycylglycine with formaldehyde in an alkaline aqueous solution containing cupric ion at 100°C gave seven ninhydrin positive components which were identified as follows; α-hydroxymethylserine, serine, glycine, 3-carboxymethyl-4-imidazolidone, α-hydroxymethylseryl-glycine, serylglycine and glycylglycine. The yield of serylglycine increased in proportion to the amount of cupric ion, whereas the yield of 3-carboxymethyl-4-imidazolidone was maximum when no cupric ion was added. A single-step synthesis in preparative scale of serylglycine or 3-carboxymethyl-4-imidazolidone under the best condition was achieved in a good yield.
Cyanoethylation of Copper, Nickel, and Palladium Glycinates
Authors: Shono Toshiyuki , Yamashoji Yuko , Shinra Koichiro
Published: July 2006

The present authors attempted the cyanoethylation of the methylene group in glycine by means of the reaction between acrylonitrile and copper, nickel, and palladium glycinates. The cyanoethylation of N-salicylideneglycinato-aquo copper (II) was also carried out. Four kinds of cyanoethylated complexes were obtained by changing the reaction conditions in the case of copper glycinate. In general, acrylonitrile reacted only with the hydrogen atoms of the amino group. In the case of N-salicylidene-glycinato-aquo copper (II), which has no hydrogen atom on the nitrogen atom, however, two methylene hydrogens were cyanoethylated with acrylonitrile.
Photochemical Reactions of Uranyl Ions with Organic Compounds. I. The Mechanism of the Uranyl Ion-Photosensitized Oxidation of Lactic Acid
Authors: Sakuraba Shukichi , Matsushima Ryoka
Published: July 2006

The photochemical reaction of lactic acid with uranyl ions in an aqueous solution was studied with radiations of 4050 and 4360 Å. The quantum yields and molar ratios of the reaction products were measured under various conditions. Two competing photo-reactions appeared to take place; through them lactic acid was oxidized to form pyruvic acid at a lower pH and to form acetaldehyde, with an evolution of carbon dioxide, at a higher pH. The results obtained can be well explained by assuming that the excitation of the uranyl lactate complex is involved in the formation of acetaldehyde and that a collision between lactic acid and the excited uranyl ion, without any complex formation, is involved in the formation of pyruvic acid.
Synthesis of Corticotropin Peptides. IX. Synthesis of [1-Glycine]-ACTH(1–18)-Octadecapeptide Amide
Authors: Otsuka Hideo , Shin Masaru , Kinomura Yasuhiko , Inouye Ken
Published: July 2006

The synthesis is decribed of an octadecapeptide, glycyl-tyrosyl-seryl-methionyl-glutamyl-histidyl-phenyl-alanyl-arginyl-tryptophyl-glycyl-lysyl-prolyl-valyl-glycyl-lysyl-lysyl-arginyl-arginine amide, corresponding to the first eighteen amino acid residues of corticotropin except for the amino end which has been replaced by a glycine for the serine in the native hormone. The protected end product was obtained by two different coupling procedures, the active ester and the catalyzed carbodiimide, from the amino-terminal decapeptide and the octapeptide of carboxyl end. The over-all yields of the peptide, for the final coupling, deblocking and purification steps, in the active ester and the carbodiimide procedures were approximately forty and thirty per cent, respectively. The synthetic octadecapeptide amide has been shown to possess a high adrenal corticotropic activity, which is comparable to that of the corresponding 1-serine octadecapeptide amide, and a lipolytic activity which is significantly lower than that of the 1-serine analog.
The Polarography of Alkyl Hydroperoxides in an Aqueous Solution
Authors: Hayano Shigeo , Shinozuka Noriko
Published: July 2006

The polarographic behavior of alkyl hydroperoxides was studied. n-Propyl, n-butyl, n-hexyl, and n-octyl hydroperoxide in an aqueous solution all show diffusion-controlled irreversible waves. The effect of the pH on the E1⁄2 and nα values is very small. The length of the alkyl group has a marked effect on E1⁄2 and nα. The longer the chain length of the alkyl group, the larger the value of nα and the more positive the E1⁄2. The linear free-energy relationship was found for the four alkyl hydroperoxides examined. The relation of Taft’s polar substituent coefficient to E1⁄2 has a negative reaction constant, which indicates a reaction promoted by high electron density in the reactive group. The electrode process seems to be the rupture of the –O–O– bond, followed by the protonation of the ions produced on the electrode.
cis-Tricarbonylbistriphenylphosphinemanganese and the Related Compounds
Authors: Nakayama Hiroaki
Published: July 2006

Tricarbonyl-methylcyclopentadienylmanganese(I) (I) gives two manganese carbonyl triphenylphosphine compounds when treated with triphenylphosphine in the presence of a sodium dispersion, with tetrahydrofuran used as the solvent. One compound is a known diamagnetic (CH3-C5H4)Mn(CO)2(PPh3)(II) (38% yield) formed by a ligand substitution reaction without any change in the oxidation number of the central manganese (+1). The other compound is a novel paramagnetic manganese(0) compound, cis-Mn(CO)3(PPh3)2 (III) (25% yield), which may be formed by a reductive phosphination reaction. A cis trigonal bipyramidal configuration, as in the case reported for Fe(CO)3(o-(AsMe2)2C6H4), is proposed for III on the basis of the results of infrared spectroscopy. The compound III gives the following derivatives: BrMn(CO)3(PPh3)2, VI, CH3Mn(CO)3(P-Ph3)2, VII, and Mn(CO)3(PPh3)2·1/2· CHCl3, VIII.
Cationic Arylation. II. Phenylation of Substituted Benzenes with Phenylazo-p-tolylsulfone in Acidic Solutions
Authors: Kobayashi Michio , Minato Hiroshi , Kobori Nobumasa
Published: July 2006

The acid-catalyzed decomposition of phenylazo-p-tolylsulfone was studied in PhX, PhX-CH3CN and PhX-DMSO (X=OCH3, C2H5, CH3, Cl, CO2CH3, NO2). The decomposition was of first order but was faster with greater concentration of trifluoroacetic acid. The orientation and the partial rate factors for the phenylation of substituted benzenes were quite different from those for the radical phenylation but quite similar to those for the phenylation with phenyl cation generated from PhN2+BF4−. Experiments with deuterated compounds indicated that the abstraction of proton from the phenylated complex was not rate-determining. A mechanism involving phenyl cation was proposed for the acid-catalyzed decomposition of azosulfone.
The Stereoselectivity of the Methylcarbenoid of Zinc in the Reaction with Styrene, Indene, and Naphthalene
Authors: Nishimura Jun , Furukawa Junji , Kawabata Nariyoshi
Published: July 2006

The stereoselectivity of the methylcarbenoid generated from diethylzinc and ethylidene iodide was investigated in the reactions with styrene, indene, and naphthalene. 1-Methyl-2-phenylcyclo-propanes (cis/trans=4.1) were obtained from styrene in a 13% yield. Indene gave exclusively the endo-isomer of 6-methyl-2,3-benzobicyclo[3.1.0]hex-2-ene in a 28% yield. From naphthalene, three isomers of 5,8-dimethyl-2,3-benzotricyclo[5.1.0.04,6]oct-2-ene were obtained favorably to the syn-form, as in the cases with styrene and indene, but two isomers of 7-methyl-2,3-benzobicyclo[4.1.0]-hepta-2,4-diene were formed favorably to the anti-form. This anti-selectivity was explained by the step-by-step addition mechanism which had previously been proposed for the ring-expansion reaction of alkylbenzene by the methylcarbenoid.
Thermal Decomposition of Lead Carbonate Tablets Prepared by Compressing Fine Particles
Authors: Komoda Ryozo , Nishi Yasuhide , Kano Matsutaro , Imoto Tatsuya
Published: July 2006

The thermal decomposition of lead carbonate tablets was kinetically studied in a nitrogen gas stream at temperatures of 240, 320, and 360°C. The tablets used in this work were prepared by compressing lead carbonate particles in a steel mold under pressures of 2–15 ton/cm2. The decomposition reaction for the tablet was represented in two ways. Rate expressions were developed from the unreacted-core shrinking model applied to the individual particles (for the first of the two decomposition processes) and to the whole tablet (for the second). The effect of the pressure applied in preparing the tablet on the decomposition rate was attributed to the deviation in the pressure profile for carbon dioxide in a tablet (for the first process) or to the variation in the effective diffusivity and bulk density of the tablet (for the second).
Isotopic Exchange between Hydrogen Sulfide and Deuterium on the Surface of Cuprous Sulfide
Authors: Fueki Kazuo , Inaba Hideaki , Mukaibo Takashi
Published: July 2006

The isotopic exchange between H2S and D2 has been followed in the temperature range 425–525°C on a cuprous sulfide specimen. At high sulfur activities of Cu2S, the predominant reaction is H2S+D2=H2+D2S, and at moderate sulfur activities the same reaction is predominant in the initial period. Analysis of kinetic data shows that the exchange reaction is first order. From the first-order rate constant, ki, the rate constant of sulfidation of Cu2S by “hydrogen sulfide”* and ki′, the rate constant of reduction of Cu2S by “hydrogen”* are determined. It is shown that ki is inversely proportional to the sulfur activity of Cu2S and that ki′ is independent of it. Dependence of ki and ki′ on sulfur activity is interpreted on the basis of a theory proposed by Kobayashi and Wagner. The formation of HD becomes remarkable as the sulfur activity of Cu2S decreases. This finding shows that the reaction, H2S+D2=HD+HDS, becomes appreciable with the decrease in sulfur activity.
The Crystal Structure of Bis-(2-hydroxyacetophenone)trimethylenediiminocopper(II)
Authors: Iida Kiyoto , Oonishi Isao , Nakahara Akitsugu , Komiyama Yoshimichi
Published: July 2006

The crystal structure of bis-(2-hydroxyacetophenone) trimethylenediiminocopper(II), [Cu-(hapt)], has been determined on the basis of the X-ray diffraction data. The crystals are monoclinic. The cell dimensions are: a=17.746, b=9.467, c=10.646 Å, and β=114.06°. The space group is Cc, with four formula units in the unit cell. The structure has been refined from threedimensional data by the least-squares method with anisotropic temperature factors to an R-value of 0.093. The copper atom is four-covalent, with the two planar 2-hydroxyacetophenone groups oriented so as to give a flattened tetrahedral co-ordination geometry. The six-membered coppertrimethylenediamine ring takes a “twisted boat” configuration. The Cu–O bonds are 1.88 and 1.89 Å in length, while the Cu–N bonds are 1.94 and 1.97 Å. The angle between the mean planes of the 2-hydroxyacetophenone moieties is 46.2°.
The Interaction of Polymer Ions with Counterions. II. Polymethacrylates
Authors: Tamaki Kunio , Horiuchi Teruo
Published: July 2006

The equivalent conductivities and the electrophoretic mobilities of sodium, tetramethyl-, tetraethyl-, and tetrabutyl- ammonium salts of polymethacrylic acid (PMA) in 0.05 m solutions of the simple salts of the corresponding cations are measured at 25°C, and the results obtained are interpreted in terms of the counterion binding. The calculated values of the apparent degree of ionization for sodium, tetramethyl-, and tetraethylammonium salts of PMA are found to be larger than those of the corresponding salts of polyacrylic acid (PAA), indicating that the methyl groups in PMA generally hinder the binding of counterions with polyions. With tetrabutylammonium salt of PMA, the apparent degree of ionization is nearly equal to that of the tetrabutylammonium salt of PAA. This fact suggests hydrophobic interaction between the methyl groups in PMA and tetrabutylammonium ions.
Association of a Reduced Riboflavin Derivative with Purities, Pyrimidines and Nicotinamide
Authors: Yu Byung Sul , Kyogoku Yoshimasa
Published: July 2006

Hydrogen bonding of a reduced riboflavin derivative in chloroform has been studied by infrared spectra measurements. The self-association of the reduced form of riboflavin tetraacetate is much stronger than that of the oxidized form. The reduced form can also form hydrogen bonded complexes with some aminopurines, aminopyrimidines, aminopyridines and nicotinamide derivatives. In the bonding with aminopyridines the contribution of a proton transfer must be predominant. At partial reduction states the formation of radicals, semiquinone forms, was detected with the aid of the electron spin resonance. The concentration of free radicals, however, is about 1 per cent of dissolved riboflavin tetraacetate. The infrared spectra at various stage of reduction can be interpreted by the sum of the two individual spectra of the fully reduced and oxidized forms.
The Crystal and Molecular Structure of Bis(acetylacetonato) manganese(II) Dihydrate
Authors: Onuma Shigeki , Shibata Shuzo
Published: July 2006

The crystal and molecular structure of bis (acetylacetonato)manganese(II) dihydrate, Mn-(C5H7O2)2·2H2O, has been determined from three-dimentional X-ray diffraction data. The compound has a center of symmetry. The octahedral arrangement of the ligand atoms about the central manganese atom is distorted; the Mn–O(1) and Mn–O(2) distances are 2.129 and 2.150 Å, Respectively, the Mn–O(H2O) distance is 2.267 Å. The metal atom lies 0.561 Å out of the least-squares plane of the chelate ring. The chelate is isostructural with the cobalt, nickel, and magnesium analogues.
An Electron Spin Resonance Study of 1,1′- and 2,2′-Biazulenyl Anion Radicals
Authors: Ikegami Yusaku , Seto Shuichi
Published: July 2006

The electron spin resonance (ESR) spectra of the anion radicals of 1,1′- and 2,2′-biazulenyls have been examined. The ESR spectrum of the latter shows that the unpaired spin is distributed equally between both azulene rings of the molecule. Theoretical calculation of the spin densities by the McLachlan procedure gave satisfactory agreement with the experimentally estimated densities. The ESR spectrum of the anion radical of 1,1′-biazulenyl, which could only be generated by an electrolytic technique, is explained by the fact that the spin exchange between the two halves of the molecule is slow. However, the ESR spectrum of the anion radical of the 3,3′-dicarbethoxy derivative of 1,1′-isomer showed rapid spin exchange through 1,1′-bond.
Oxidation of Substituted Glycollic Acids by Ce(IV) in Sulphuric Acid Solutions
Authors: Grover V K , Gupta Y K
Published: July 2006

A comparison of the rate constants, dissociation constants, tendency of complex formation and catalytic activity of Mn(II) in the oxidation of substituted glycollic acids (benzilic, Dl-atrolactic, 2-hydroxyisobutyric, p-chloromandelic, p-bromomandelic, mandelic and lactic acids) by Ce(IV) in sulphuric acid solutions has been made. Hydrolyzed species of Ce(IV) are reactive and the kinetics conform to the empirical rate law

-\fracd[Ce(IV)]dt=\frackK[Ce(IV)][Org. Acid][HSO_4^-]^2([H^+]+K[Org. Acid])

The reactivity and the chelating tendency of the acids seem to follow the substituent order, C6H5> CH3>H. The catalytic activity of Mn(II) appears to follow the same order as in the oxidation of these acids by Mn(III).
Polarographic Study of Metal Complexes. X. The Disulfitotetracyanocobaltate(III) Complex
Authors: Maki Nobufumi , Yamamoto Kouei
Published: July 2006

The sodium disulfitotetracyanocobaltate(III), Na5[CoIII(SO3)2(CN)4]·3H2O, was found to be irreversibly reduced in one step to the cobalt(I) state in a 0.5m Na2SO3 aqueous solution at the dropping mercury electrode(DME). As for the resulting cobaltate(I) complex, neither further reduction to the metal nor oxidation was observed in the potential range of 0–−2.0V (vs. SCE). Above 40°C, a partial reduction to the metal was observed to take place at about −1.9 V (vs. SCE). The reduction was interpreted as being of the “inert-inert” type, as shown below:

trans-[Co^III(SO_3)_2(CN)_4]^5- \overset2e→ trans-[Co^I(SO_3)_2(CN)_4]^7-.

Here, the disulfito complex was presumed to take a trans-configuration rather than that of a cis-form on the evidence of its polarographic behavior and the absorption spectrum. That is, the tetracyano complexes with a cis-configuration are considered to be reduced to the metal, whereas those with a trans-configuration are reduced to the cobalt(I) state, and not to the metal polarographically, at the DME.
Studies of the Ion-pairing of Hexylate and Picrate Ions with Alkali Metal Ions by Capillary Analysis
Authors: Sano Kazuaki , Sakuma Michio , Motomizu Syoji , Iwachido Tadashi , Tôei Kyoji
Published: July 2006

The hexyl (Dipicrylamine) anion, hexylate, and picrate form weak ion-pairs with alkali metal cations in an aqueous solution. The composition and the association constants of the ion-pairs are determined by capillary analysis based on the difference in the adsorbability of the anions and of the ion-pairs on a filter paper. A new constant temperature-humidity apparatus is devised, and by means of it the analysis is successfully carried out. The compositions of the cation and the anion in the ion-pairs formed are 1:1, in either case; the association constants of the ion-pairs for Li, Na, K, Rb, and Cs cations are about 102, and they tend gradually to decrease with the ionic radii.
A New Method of Preparing θ-Alumina and the Interpretation of Its X-Ray-powder Diffraction Pattern and Electron Diffraction Pattern
Authors: Yamaguchi Goro , Yasui Itaru , Chiu Wen-Chau
Published: July 2006

Highly crystallized θ-alumina was obtained by a two-step treatment, by hydrothermal and thermal treatment, of η-alumina. Its X-ray-powder diffraction pattern was interpreted based on the structure of θ-gallia, and least-squares refinements were carried out. The electron diffraction pattern of θ-alumina from boehmite was also interpreted, and the directional relations between the phases were established.
Ring-opening Reactions of Cyclic Ethers. VIII. Acid-catalyzed Ring-opening Reactions of Isobutylene Oxide in Alcohols
Authors: Sekiguchi Shizen , Matsui Kohji , Yasuraoka Yoshihiro
Published: July 2006

The rates of the ring-opening reaction of isobutylene oxide have been measured in methyl, ethyl, w-propyl and isopropyl alcohols in the range from 10 to 40°C under conditions where the molar ratio of an alcohol to the epoxide was kept at 10 and the range of the concentration of boron trifluoride etherate was ca. 1.0×10−3 to ca. 4.0×10−3 mol/l. The rate equation is expressed as follows: −d[epoxide]⁄dt=k2[C0][epoxide], where [C0] is the initial concentration of the catalyst and [epoxide] is the instantaneous concentration of the epoxide at time t. The rate constants (k2) decreased in the order, CH3OH>C2H5OH>n-C3H7OH>i-C3H7OH. The entropies of activation decreased in the same order, while the energies of activation were not appreciably changed. A plot of logk2 against 1/D (D, the dielectric constant of the mixture of each alcohol and the epoxide) was found to be linear, its slope being −61.2. The results support the fact that the reaction is bimolecular.
Cyclizations of Thioureas with a Hydroxy Group at the β-Position of the N-Substituent. I. Reaction with Cupric Acetate
Authors: Iwakura Yoshio , Kaya Tadahiro , Kurita Keisuke
Published: July 2006

The reaction of 1-(3-phenoxy-2-hydroxypropyl)-3-phenyl-2-thiourea (thiourea I) with cupric acetate was investigated. The desulfurization reaction by the cupric ion proceeded in refluxing ethanol to yield 2-anilino-5-phenoxymethyl-2-oxazoline. At room temperature, thiourea I and cupric acetate gave a copper complex and the oxazoline. When the complex was heated in ethanol, the same oxazoline and thiourea I were obtained, along with inorganic copper compounds. On the basis of an investigation of the structure of the complex and the decomposition of the complex, the reaction mechanism involving copper-complex formation was discussed. On the other hand, the reaction of 1-(3-phenoxypropyl)-3-phenyl-2-thiourea with cupric acetate under the same conditions gave 1-(3-phenoxypropyl)-3-phenyl-3-acetylurea.
Synthesis of [9]Heterophanes from 2-Cyclododecenone
Authors: Fujita Shinsaku , Kawaguti Takeyuki , Nozaki Hitosi
Published: July 2006

[9](3,5)Pyrazolophane (V) and 11-methyl[9](2,4)furanophane (IX) were prepared from 2-cyclododecenone (I) and their spectral properties were discussed. A new route to I from cyclododecanone is described.
The Dipole Moments of α,ω-Alkanediols
Authors: Toshiyasu Yoshio , Kimura Ko , Fujishiro Ryoichi
Published: July 2006

The electric dipole moments of α,ω-alkanediols such as HO–(CH2)n–OH (n being varied from 2 to 5) were measured both in dioxane and in a mixed solvent of dioxane with carbon tetrachloride at 25°C. The observed dipole moments increase with the increasing n until n=4, and then decrease for n=5, while the calculated dipole moments based on the vector addition of group moments on the assumption of the random coil model for alkane chains increase monotonously as n increases from 2 to 5. It is concluded that for both propanediol and butanediol the conformations forming the intramolecular hydrogen-bond which have the larger dipole moments contribute appreciably to the observed dipole moments. The dipole moment of pentanediol is close to the calculated one for the random coil model, whereas that of ethylene glycol suggests the existence of the intramolecular hydrogen-bond. Population analysis of the hydrogen-bonded species in solutions is also given.