bluuebunny/crossref_metadata_2025 huggingface dataset:
Nickel(II) Complexes of Ethylenediaminemonoacetic Acid (EDMA). The Preparation and Thermal Decomposition of Nickel(II)-EDMA Complexes
Authors: Fujii Yuki
Published: July 2006

The following nickel (II) complexes containing ethylenediaminemonoacetate anion(s) (edma) were newly prepared from an aqueous solution containing nickel(II) ion and edma: [Ni(edma)(H2O)3]X (X=Cl and Br), [Ni(edma)I]4, and [Ni(edma)2]·2H2O. By the thermal decomposition of [Ni(edma)(H2O)3]X, [Ni (edma) X]4-type complexes (X=Cl and Br) were also prepared. By absorbing three molecules of water in an atmosphere, two new, mixed-complexes containing a halogen anion and water molecule(s), [Ni(edma)Cl(H2O)2]·H2O and [Ni(edma)Br(H2O)]2·4H2O (dimer), were prepared from [Ni(edma)X]4. By the measurements of the absorption spectra, the magnetic moments, and the dehydrations, their structures were all assigned to octahedral. The [Ni(edma)X]4 complexes (X=Cl, Br and I) were presumed to have the tetramer structure, where four halogen anions are triply bridged to the nickel(II) ion. The difference between the [Ni(edma)(H2O)3]X, [Ni(edma)Cl(H2O)2]·H2O, and [Ni(edma)Br(H2O)]2·4H2O complexes were clearly observed on the basis of their deri-vatographic behavior. The mechanisms of the dehydrations were also discussed.
The Thermal Annealing Behavior of 80Br Recoils Produced by the Nuclear Isomeric Transitions in Alkali Metal Bromates
Authors: Sasaki Teikichi , Shiokawa Takanobu
Published: July 2006

The transient annealing behavior of bromine recoils produced by isomeric transition was studied in five alkali metal bromates. In the case of 80mBr-labelled potassium bromate, the iso-thermal annealing curves were characterized by maximum and minimum points. A numerical treatment of them indicated that, at the earlier stage of the thermal treatment, the annealing processes proceeded very fast, which was ascribed to the characteristics of the isomeric transition recoils. A remarkable effect of the cationic components on the thermal annealing was observed and interpreted in terms of their ionization potentials.
Transformation of Progesterone by Rhizopus nigricans REF 129 as Influenced by Modification of the Fermentation Medium
Authors: El-Refai Abdel-Monem , Sallam Lotfy , El-Kady Ismail
Published: July 2006

Hydroxylation of progesterone with Rhizopus nigricans REF 129 at C-l1, C-6, C-17, C-21 as well as formation of 11α-hydroxy-5α-pregnane-3,20-dione was investigated when the fermentation medium was modified in a different manner. The various transformation products of progesterone were found to be affected qualitatively and quantitatively by the composition of the medium employed. Mg2+, PO43− proved to be indispensable for the transformation processes. Mn2+ and Fe2+stimulated the reactions. Similarly, acetate, malate and riboflavin enhanced the transformation processes. Formation of the various derivatives of progesterone, except for 11α-hydroxy-5α-pregnane-3,20-dione and 6β, 11α-dihydroxyprogesterone, was also favoured by the addition of adenine, adenosine, uracil and guanine to the fermentation medium.
Synthesis of N-Terminal Nonapeptide of Trypsinogen and Its Hydrolysis by Trypsin
Authors: Yoshida Norio , Kato Tetsuo , Izumiya Nobuo
Published: July 2006

An N-terminal nonapeptide fragment of bovine trypsinogen, H-l-Val-l-Asp-l-Asp-l-Asp-l-Asp-l-Lys-l-Ile-l-Val-Gly-OH, was synthesized via two routes and its susceptibility with trypsin was investigated. Protected derivatives, t-butyloxycarbonyl protected nonapeptide t-butyl ester and benzyloxycarbonyl protected nonapeptide benzyl ester, were prepared by stepwise elongation. Removal of the protecting groups was carried out by treatment with trifluoroacetic acid and hydro-genation respectively. The naked peptide was purified with chromatography on ECTEOLA cellulose column using dilute acetic acid as a solvent. Upon lyophilization the desired nonapeptide was obtained as colorless powder, a portion of the product being digested with trypsin. Rate of tryptic hydrolysis of the peptide was found to be unexpectedly low in the absence of calcium ion, while considerable acceleration of the hydrolysis by calcium ion was noted.
Hydrazinolysis of Sugar Sulfonates
Authors: Suami Tetsuo , Shoji Tadao
Published: July 2006

Hydrazinolysis of methyl 4,6-di-O-acetyl-2,3-di-O-tosyl-α-d-glucopyranoside (I) or methyl 2,6-di-O-benzoyl-3,4-di-O-mesyl-α-d-glucopyranoside (VI), followed by catalytic hydrogenation and acetylation, afforded methyl 2,4-diacetamido-3,6-di-O-acetyl-2,4-dideoxy-α-d-idopyranoside (II). Also methyl 2,3-di-O-acetyl-4,6-di-O-mesyl-α-d-glucopyranoside (VII) was treated analogously as described above to give methyl 4,6-diacetamido-2,3-di-O-acetyl-4,6-dideoxy-α-d-galactopyranoside (IX). The structures were studied by means of proton magnetic resonance spectra. And a reaction mechanism was also discussed.
Aminocyclitols. XXIII. A Synthetic Study of Streptozotocin Analogs
Authors: Suami Tetsuo , Machinami Tomoya
Published: July 2006

Streptozotocin is an antibiotic which exhibits wide antimicrobial and antitumor activities, and its structure has been established to be N-carbamyl-N′-methyl-N′nitroso-d-glucosamine. In the present article, streptozotocin analogs in which the pyranose ring was substituted for a cyclohexane ring were prepared. These compounds showed considerable activities against Ehrlich ascites tumor.
Aminosugars. XVIII. Synthesis of 3-Acetamido-3,5-dideoxy-d-ribose
Authors: Ando Hiroaki , Yoshimura Juji
Published: July 2006

3-Acetamido-3,5-dideoxy-1,2-O-isopropylidene-α-d-ribofuranose (5) was synthesized through two pass-ways: 1) starting from 3-acetamido-3-deoxy-1,2-O-isopropylidene-α-d-allofuranose which is obtained from d-glucose, through five steps; periodate oxidation, hydrogenation, 5-O-tosylation, 5-iodination and hydrogenation: 2) starting from l,2-O-isopropylidene-3,5-di-O-tosyl-α-d-xylofuranose through four steps; 5-iodination, hydrogenation, 3-amination and N-acetylation. Total yields in the two pass-ways were 12.7% and 7.6% from the parent aldoses, respectively. Hydrolysis of 5 gave the titled compound as a sirup, which was converted to the crystalline osazone. The structure and conformation of intermediates in these syntheses were examined by NMR spectroscopy.
Measurement of Contact Potential Difference for Organic Crystals. Work Function of Violanthrene
Authors: Kotani Masahiro , Akamatu Hideo
Published: July 2006

A vibrating-reed type cell for measuring contact potential difference was constructed and successfully applied for organic crystals. From the observed contact potential difference for violanthrene against graphite, the work function has been estimated as 4.50±0.1 eV. In association with the activation energy for electrical conductivity, 0.8–0.9 eV, the electronic energy diagram for violanthrene has been illustrated, which revealed the extrinsic nature of semiconduction and the energy gap, 2.3–2.5 eV, being comparable with the first excited singlet state of violanthrene molecule.
A Nuclear Magnetic Resonance Study of Copolypeptides of l-Proline with γ-Benzyl-l-glutamate
Authors: Okabayashi Hirofumi , Sakai Rume , Isemura Toshizo
Published: July 2006

The nuclear magnetic resonance spectra of the copolymers of l-proline with γ-benzyl-l-glutamate were measured in tetradeuteroacetic acid, deuterochloroform, a mixed solvent (CD3-COOD : CDCl3=4 : 1), and trifluoroacetic acid. The time dependence of the α-CH resonance peaks of copoly-(3 : 1)-(l-proline, γ-benzyl-l-glutamate) and copoly-(1 : 1)-(l-proline, γ-benzyl-l-glutamate) was observed. The NMR spectra of copoly-(1 : 3)-(l-proline, γ-benzyl-l-glutamate) showed no time dependence which can be ascribed to the conformational change in tetradeuteroacetic acid and the mixed solvent. From these experimental facts we concluded that copoly(3 : 1)-(l-proline, γ-benzyl-l-glutamate) and copoly-(1 : 1)-(l-proline, γ-benzyl-l-glutamate) can assume a poly-l-proline-like helical structure, while copoly-(1 : 3)-(l-proline, γ-benzyl-l-glutamate) can not. Moreover, the ratios of the γ-benzyl-l-glutamate residues which were incorporated into the stable poly-l-proline-II-like helical structure was estimated in copoly-(3 : 1)-(l-proline, γ-benzyl-l-glutamate) and copoly-(1 : 1)-(l-proline, γ-benzyl-l-glutamate).
Studies of Nylon Monolayers, II. Compression Characteristics of the Nylon 8 Monolayer on Water
Authors: Seimiya Toshiko
Published: July 2006

It was reported in the preceding paper that two types of film, A and B, can be distinguished in F-A curves for monolyers of Nylons 6 and 8 on the basis of the difference in behavior in relation to compression and expansion. In the present experiment, the compression and expansion were repeated for the monolayers of Nylon 8 spread from methyl alcohol in order to study the F-A characteristics of these films in detail. It was found that, during the process of first compression, the pressure drops rapidly and the transition of film A to film B occurs beyond a certain degree of compression of the monolayer. The transition was interpreted as the condensation of the monomer residue of the nylon molecule. The equations of the state for the expanded film were found to apply better than Singer’s equation for both types of film, A and B. Further, the effect of the concentrated sulfuric acid solution (3 and 6 n) as a substrate on the F-A curve was examined. There were little difference in the behavior of the monolayers on 3 n sulfuric acid irrespective of the spreading solvent used, but the difference was marked on dilute hydrochloric acid.
Electronic Structures of the Ring-Protonated Aromatic Amines
Authors: Yamaoka Tsuguo
Published: July 2006

In order to study the electronic spectra and stabilities of the ring protonated aromatic amines, π-electron structure of nineteen amino-substituted pentadienyl cations were calculated by the composite molecule method. The lower electronic transitions of these ions are assigned to the charge transfer from amino groups to the pentadienyl cation. Stability of the ground state depends on the extent of intramolecular charge transfer, which is determined by the position and number of amino-substitution. The amino group on 1-, 3- or 5-carbon atom greatly stabilizes the ground state while contribution of the amino group on the other position is quite small. Occurrence of the ring or amino protonation for various amino-substituted benzenes is shown to be well predicted by the calculated stabilization energy.
Studies of the Nylon Monolayer. III. The Interaction between the Nylon Monolayer and Acid Dye
Authors: Seimiya Toshiko
Published: July 2006

The interaction of the monolayers of the Nylons 6 and 8 with the acid dye Orange II was studied by measuring the surface pressure of the nylon monolayers with and without Orange II in the substrate water. No change in the surface tension with the time was observed for the aqueous solution of Orange II in the concentration and pH ranges studied. The interaction between the nylon monolayers (film B) and Orange II was examined by observing the change in the F-A curve of the nylon monolayer due to the addition of Orange II to the substrate and the spreading of the solution. The presence of dye in a spreading solution has little effect, while the pH’s of the both the spreading solution and the substrate exhibit a marked effect on F-A curves. The observed interaction is compared with the behavior of practical dyeing in bulk of the solution.
Scavengeable Electron Yield in the Radiolysis of Liquid and Solid Hydrocarbons
Authors: Kimura Toyoaki , Fueki Kenji , Kuri Zen-ichiro
Published: July 2006

Yields of scavenged electrons have been measured in MCH, 3MP, cumene and tert-butylbenzene at 20°C and −196°C. It has been found that the yield of scavenged electrons is considerably lower at −196°C in the glassy state than at 20°C in the liquid state. The temperature effect on electron scavenging indicates that the difference in the yields of scavenged electrons between the liquid and glassy states is attributed to the variation not of temperature but of the physical conditions of the matrix. We have also investigated the effect of composition in MCH-MTHF mixtures and that of the viscosity of the matrix upon the yield of scavenged electrons at −196°C, which has led us to the assumption that the extent of interactions between thermalized electrons and the matrix would affect the yield of scavenged electrons at −196°C. Since such interactions may be related to the mean free path of electrons, we have calculated the contribution of the electron jump distance to the electron scavenging efficiency. The calculated results appear to explain qualitatively the experimental results.
The Effect of Intramolecular Hydrogen Bonding on the Polarographic Reduction Potentials of Azomethines
Authors: Uehara Miyoshi , Nakaya Jun-ichi
Published: July 2006

The effects of intramolecular hydrogen bonding on the polarographic reduction potentials (E1⁄2) of several azomethines, such as N-salicylidenemethylamine, N,N′-bis(salicylidene)ethylenediamine, N-salicylideneaniline, N-salicylidene-o-aminophenol, and N-benzylidene-o-amino-p-substituted phenols, have been studied in aqueous and non-aqueous solutions. Contrary to expectations, a larger negative shift of E1⁄2 was observed in the case of o-OH-substituted azomethines than in that of unsubstituted azomethines in buffer solutions. On the other hand, the E1⁄2 of the substituted compounds shifted 0.3–0.4V toward the positive side in dimethylformamide or acetonitrile. The relative strengths of hydrogen bonds, as estimated from the positive shifts of E1⁄2, were 6–10 kcal/mol. It has been proposed, from the hydrogen bond strength, the UV spectra, and the p-substituent effects, that the introduction of an o-OH group into the phenylimino ring provides not a periperpendicular conformation, but a coplanar configuration, by means of the formation of the O–H···N hydrogen bond.
The Hydrolysis of the Copper(II) Ion in Heavy Water
Authors: Kakihana Hidetake , Amaya Toshihiko , Maeda Masunobu
Published: July 2006

The hydrolysis equilibria of the copper(II) ion in heavy water have been studied at 25°C by measuring the deuterium-ion concentration by means of a commercial glass electrode. The total copper(II) concentration was varied between 50 and 90 mm, while the concentration of the perchlorate ion was held constant at 3m by the addition of NaClO4. A hydrolyzed copper(II) perchlorate solution was gradually acidified up to the point where hydrolysis was negligible by the use of constant-current coulometry. The experimental data, which indicate a slight hydrolysis in the log d range from –4.0 to –5.26, can be explained by assuming these equilibria;

& Cu^2++D_2O=CuOD^++D^+,logβ_1,1=-7.71±0.07;

& 2Cu^2++2D_2O=Cu_2(OD)_2^2++2D^+,logβ_2,2=-11.46±0.04.
Synthesis of Chelating Agents. VII. Synthesis and Chelating Behavior of 2,3-Dinitrilo-1,2,3,4-tetrahydro-naphthalene-N,N,N′,N′-tetraacetic Acid
Authors: Yano Tairoku , Kobayashi Hiroshi , Ueno Keihei
Published: July 2006

trans,2,3-Dinitrilo-1,2,3,4-tetrahydronaphthalene-N,N,N′,N′-tetraacetic acid was synthesized by the carboxymethylation of trans-2,3-diaminotetrahydronaphthalene. The acid dissociation constants as well as the chelate stability constants for alkaline earth metal ions were determined by a potentiometric method. The results were compared with the values of other complexane ligands of the cycloalkane family.
The Acid-Catalyzed Ring-Opening of Cyclooctenimine Derivatives
Authors: Fujita Shinsaku , Hiyama Tamejiro , Nozaki Hitosi
Published: July 2006

The acid-catalyzed ring-opening of 9-ethoxycarbonyl-9-aza-bicyclo[6.1.0]nonane (1) and-4-nonene (2) is reported to give normal products 3a and 11a, respectively, together with several transannular products.
Structure and Reactivity of α,β-Unsaturated Ethers. X. The Acid-Catalyzed Hydrolysis of Ring-Substituted Styryl Ethyl Ethers
Authors: Okuyama Tadashi , Fueno Takayuki , Furukawa Junji
Published: July 2006

The acid-catalyzed hydrolysis of cis- and trans-styvyl ethyl ethers (SEE) and several of their ring-substituted derivatives has been kinetically investigated in 80% aqueous dioxane. It has been found that these ethers are less reactive than vinyl ethyl ether by a factor of ca. 500 and that all the cis isomers studied are about twice as reactive as the corresponding trans isomers. The hydrolysis of the substituted ethers at 35°C has proved to obey the Hammett relation with the reaction constants ρ=−1.07 and −0.70 for the cis and the trans isomers, respectively. All these results appear to be interpretable at least qualitatively in terms of the reaction scheme involving the rate-determining protonation to the β-carbon atom.
Properties of Vinyl Chlorides-Ethylene Copolymers
Authors: Misono Akira , Uchida Yasuzo , Yamada Kunikazu
Published: July 2006

Properties of vinyl chloride-ethylene copolymers rich in vinyl chloride have been studied by means of infrared as well as NMR spectroscopy and dynamic mechanical testing. The infrared and NMR spectra of the copolymer indicate that crystallinity decreases with decreasing sequence length of the vinyl chloride segment. The copolymer containing more than 80 mol % vinyl chloride shows optical melting point, a plot of which versus logarithmic composition satisfies Flory’s relationship. Temperature dispersion curve of elastic modulus E′ of the copolymer also indicates that the crystalline region of vinyl chloride segments disappears as the ethylene content increases. Glass transition temperature as determined by loss modulus E″ fits Gordon-Taylor’s relationship well provided the coefficient k equals unity.
Alternating Copolymerization of β-Cyanoacrolein with α-Methylstyrene
Authors: Takemura Ichiro , Sumitomo Hiroshi
Published: July 2006

Alternating copolymer was obtained in the system of β-cyanoacrolein (CAL) and α-methyl-styrene (α-MeSt). In the presence of air copolymerization proceeds even without any radical initiator at room temperature. In the radical initiated copolymerization of α-MeSt (M1) and CAL (M2), the values of monomer reactivity ratios r1=0.033 and r2=0 were obtained. Neither the rate of copolymerization nor viscosity number of the copolymer formed were influenced by the presence of air in the reaction system. The result of copolymerization in the ternary system involving methyl acrylate (MA) could not be entirely explained by the copolymerization equation given by Alfrey and Goldfinger for the three component system. It was found that the composition of the copolymer formed changed with the solvent dilution. Formation of 1 : 1 molecular complex between the monomers was evidenced by the application of the continuous variation method to α-MeSt-CAL system. It was concluded that the molecular complex due to some donor-acceptor type interaction between CAL and α-MeSt plays an important role in the copolymerization.
Pyrolysis-Gas Chromatographic Investigation of Chlorinated Polystyrenes
Authors: Tsuge Shin , Ito Hajime , Takeuchi Tsugio
Published: July 2006

The distribution of chlorine atoms in radically chlorinated polystyrenes was studied by means of pyrolysis gas chromatography. Degradation products such as styrene, benzene, toluene and chlorobenzenes are related to different structures of the chlorinated polymers. The sequence distribution of each structure was discussed over a wide range of degree of chlorination. Chlorine atoms are first substituted with α- then β-hydrogen in the main chain of polystyrene. The first ring substitution of chlorine occurs competitively at p-position even before both α- and β-hydrogens are substituted.
The Electron Spin Resonance of the Mn2+ Ion on the Surface of Magnesium Oxide
Authors: Yamamura Takemi , Hasegawa Akinori , Yamada Yoshio , Miura Masaji
Published: July 2006

The behavior of the Mn2+ ion on the surface of MgO was studied by using the ESR technique. The powder of MgO, the surface of which was doped with the Mn2+ ion, was calcined at different temperatures from 100 to 1000°C in a vacuum, and then the ESR spectra were observed at room temperature. It was noticed that the spectral intensity showed a minimum at about 500°C, that the zero-field splitting parameter, D, increased with the temperature, and that the hyperfine coupling constant, A, decreased enormously at about 700°C. The environments around the Mn2+ ion on the surface of MgO were discussed on the basis of these results. When H2, CO, or O2 was added after the calcination, the D and A values changed in the temperature range above 500°C. Especially when O2 was introduced, the D value fell to zero upon treatment at 1000°C. The crystal field around the Mn2+ ion and the bonding between the Mn2+ ion and its environments were discussed by taking into account the results of the magnetic-susceptibility measurements of the manganese ion on MgO.
The Effect of Chloromethanes on Hydrogen Formation in the Radiolysis of Methylcyclohexane and 3-Methylpentane at −196°C
Authors: Kimura Toyoaki , Fukaya Mitsuharu , Hada Minoru , Wakayama Terunobu , Fueki Kenji , Kuri Zen-ichiro
Published: July 2006

The effect of chloromethanes (CH2Cl2, CHCl3 and CCl4) on hydrogen formation from γ-irradiated methylcyclohexane (MCH) and 3-methylpentane (3MP) at −196°C was investigated. It was found that the decrease in hydrogen yield by the presence of CH2Cl2 was almost the same as that caused by an electron scavenger such as N2O, n-butyl chloride, SF6 or iodobenzene, but the hydrogen yield was much lower in the presence of CHCl3 or CCl4 than other electron scavengers. Although the yield of CCl3. radicals formed from dissociative electron attachment to CCl4 in CCl4-MCH systems was ∼1.4G, the decrease in hydrogen yield was ∼3G. A similar result was obtained for CHCl3-MCH systems. Thus we have ascribed the effect of CH2Cl2 on hydrogen formation to electron scavenging and that of CHCl2 or CCl4 to excitation transfer as well as electron scavenging. ESR studies on radical formation from these systems also support the above interpretation.
Catalytic Activity and Reactivity of Aromatic Nitrile and Alkali Metal Ion Radical Salt. I. Homogeneous and Heterogeneous Catalysis of Benzonitrile-Cesium Ion Radical Salt
Authors: Tsuda Motoyuki , Inokuchi Hiroo
Published: July 2006

Homogeneous and heterogeneous mechanisms of parahydrogen conversion and hydrogen-deuterium exchange reactions were investigated in the presence of benzonitrile–cesium ion radical salt. Studies of their activation energies and rate constants showed that the heterogeneous reaction on the solid-ion radical salt occurs mainly through the “chemisorption mechanism” and the “exchange mechanism”, but the homogeneous reaction over the salt solution in benzonitrile takes place only through the “physical mechanism.” According to these results, it was concluded that the catalytic activity and reactivity of the ion-radical salt must be due to the nature of its solid phase, not to that of its aromatic anion or free-ion radical pair.
Determination of Ion Activity Coefficients from the Measurement of Membrane Concentration Potentials–Activity Behavior of Alkali-metal Cations in Aqueous Solutions at 25°C
Authors: Tamamushi Reita , Goto Shojiro
Published: July 2006

The membrane concentration potentials across a permselective sulfonated polystyrene collodion-base membrane were measured with aqueous solutions of alkali-metal salts at 25.0°C. By assuming the ideal behavior of the membrane, the activity coefficients of the critical cations were determined from the membrane concentration potentials at ionic strengths higher than 0.01. The ion activity coefficients of alkali-metal cations were found to follow the order Li+>Na+>K+ for the chlorides, nitrates, perchlorates, and sulfates. The order of activity coefficients of Na+ in different halide solutions was bromide>chloride>fluoride. Considerable differences were observed between the individual and mean activity coefficients at ionic strengths higher than 0.01. The individual ion activity coefficients determined from the experimental data were analysed by means of the extended Debye-Hückel eauation.
Reactive States of Acridine for the Photoreduction in Tetrahydrofuran
Authors: Miyashita Yoshikatsu , Niizuma Shigeya , Kokubun Hiroshi , Koizumi Masao
Published: July 2006

The photoreduction of acridine in tetrahydrofuran (THF) has been investigated by the steady light experiment and also by the flash technique. The quantum yields in the aerated and deaerated solution were 0.12 and 0.36 respectively. The former value is referred to molecular mechanism while the difference of the two, 0.24, to radical mechanism. It was established that the sensitized reaction occurs with biacetyl (T(n–π*), 19700cm−1) as a triplet energy donor. The probability factor β with which the produced T(π–π*) of acridine (15840 cm−1) reacts with THF was found to be \gtrsim0.6. Anthracene T(π–π*), 14700cm−1) was found to act as a triplet energy acceptor and to reduce the photoreduction. From the decrease of the quantum yield caused by the addition of anthracene, the quantum yield via the lowest T(π–π*) of acridine was evaluated as 0.06. By combining this value with the above β-value, the apparent \varphiST has proved to be \lesssim0.1. This very small value compared with the \varphiST values presented for other solvents (benzene\gtrsim0.25, water\gtrsim0.24, ethanol\gtrsim0.29) leads to the conclusion that in THF, T(n–π*) is also a reactive state for the photoreduction. Further, an interesting aspect of the radical mechanism was elucidated from the comparison of ΦR (quantum yield due to radical mechanism) and ΦO2 (quantum yield of oxygen consumption).
The Chemical Behavior of Low Valence Sulfur Compounds. VI. Decomposition of Tetrasulfur Tetranitride in Aqueous Ammonia Solution
Authors: Shieh Mu-Chang , Katabe Kenichi , Okabe Taijiro
Published: July 2006

The decomposition of tetrasulfur tetranitride in an aqueous ammonia solution has been investigated. Ammonolysis of tetrasulfur tetranitride gives thiosulfate, sulfite, sulfate and sulfamate through the intermediate compound of trithionate. An increase in the concentration of ammonia raises the yield of sulfamate and lowers that of sulfate, but gives no remarkable change in the yield of thiosulfate. Besides this, in a concentration of ammonia higher than 15 n at 100°C an explosive reaction takes place. Addition of copper ion improves the yield of sulfamate, and the sulfite ion reacts with tetrasulfur tetranitride in an ammonia aqueous solution to form sulfate and sulfamate ion quantitatively.
Competitive Inhibition of Pepsin by Carboxylic Acids
Authors: Shin Hong Dae
Published: July 2006

In order to obtain evidence for Tang’s hypothesis that pepsin (EC 3.4.4.1) forms a hydrophobic bond with the nonpolar side chain or its substrates, the inhibitory effect of carboxylic acids (from formic acid to isobutyric acid) on the activity of pepsin to the synthetic dipeptide, N-carbobenzoxy-l-glutamyl-l-tyrosine, was studied. Kinetic study showed that the inhibition by carboxylic acids was of competitive type. The inhibitor constant Ki decreased with an increase in the size of the inhibitor molecule. The free energy change of formation of complex between pepsin and hydrocarbon chain of carboxylic acid, −ΔFHc, increased linearly with the increase in the number of carbon atoms in the hydrocarbon chain of the inhibitor. It was suggested that the hydrophobic interaction between the side chain of amino acid residues in the binding region of the active center of pepsin and the hydrocarbon side chain of the inhibitor was the cause of the inhibition.
Acid-Catalyzed Oxidation of Olefins with Selenium Dioxide
Authors: Javaid Khan A , Sonoda Noboru , Tsutsumi Shigeru
Published: July 2006

A drastic deviation from the usually accepted reaction path was observed when oxidation of olefins was carried out in acetic acid with selenium dioxide in the presence of concentrated sulfuric acid. Oxidation of cyclohexene gave a mixture of cis- and trans-1,2-diacetoxycyclohexane. It was shown that in the oxidation of cyclohexene the organoselenium intermediate which produced 3-acetoxy-1-cyclohexene on pyrolysis, is not the intermediate in the present reaction. A study on reaction variables, such as effect of molar ratio of cyclohexene to selenium dioxide, amount of sulfuric acid, and water, reaction time and temperature, was undertaken. The reaction was extended to 1-octene and 1-hexene. A general structure for the organoselenium compound produced in the oxidation of terminal olefins in acetic acid without sulfuric acid, has been proposed. On the basis of our data and some previous concepts a reaction scheme has also been given.
A Study on the Photochemistry of α,β-Unsaturated γ-Lactones. I. The Structures of the Photodimers of 4-Hydroxycrotonic Acid γ-Lactone
Authors: Ohga Kazuya , Matsuo Taku
Published: July 2006

The structures of the photodimers obtained from 4-hydroxycrotonic acid γ-lactone under several conditions were determined. The products of irradiations in the solution were a pair of anti dimers: one is a head-to-head cyclo-adduct, and the other a head-to-tail adduct. The corresponding product in the solid, state, on the other hand, was a head-to-head cyclo-adduct in the syn form.
Reactions of Ferrocenylcarbene. III. The Addition Reactions of Some α-Ferrocenylcarbenes to 1,1-Diphenylethylene
Authors: Sonoda Akio , Moritani Ichiro
Published: July 2006

The addition reactions of α-ferrocenylcarbenes (ferrocenyl, ferrocenylmethyl, and ferrocenylphenyl carbene) to 1,1 -diphenylethylene have been examined by means of the thermal decomposition of the corresponding acylferrocene tosylhydrazone sodium salts. Then, the reactivities of the ferrocenylcarbenes have been compared with those of the corresponding phenyl and p-anisylcarbenes. It has been found that, of the carbenes investigated, the ferrocenylcarbenes show the lowest reactivity in addition reactions to the olefin. It has been established by a study of the NMR spectra that, in the ferrocenylcyclopropanes only, there is a restricted rotation about the bond between ferrocenyl and cyclopropyl groups. On this basis, the reactivity of the ferrocenylcarbenes has been discussed in terms of the steric hindrance of the bulky ferrocenyl group.
The Cycloaddition Reactions of Benzoylsulfene with Anils
Authors: Tsuge Otohiko , Iwanami Sumio
Published: July 2006

The reactions of benzoylmethanesulfonyl chloride with various anils (Ar–CH=N–R) in the presence of triethylamine have been studied. It has been found that the corresponding (4+2) and/or (2+2) cycloadducts of benzoylsulfene and the anil were obtained, depending on the nature of the substituents, R, in the anils. The reaction of the chloride with benzylidene-n-propylamine in the absence of triethylamine gave only the (2+2) cycloadduct, while the (4+2) cycloadduct was exclusively obtained in the presence of triethylamine. The chloride reacted with dibenzylidenethylenediamine in the presence of triethylamine to give the corresponding bis(4+2) cycloadduct.
2H,5H-Triazolo[4,5-d]triazoles. A New Heteroaromatic System
Authors: Yoshida Masayuki , Matsumoto Akira , Simamura Osamu
Published: July 2006

2-Aryl-5-phenyltriazolo[4,5-d]triazoles and related compounds, a new heteroaromatic system, have been prepared from 4,5-diamino-2-phenyl-1,2,3-triazole. The meso-ionic character of the new ring system is discussed on the basis of proton NMR shifts.
Homolytic Aromatic Isopropyloxycarbonyloxylation Induced by Oxygen
Authors: Nakata Toshio , Tokumaru Katsumi , Simamura Osamu
Published: July 2006

Thermal decomposition of diisopropyl peroxydicarbonate in benzene was carried out at several temperatures ranging from 40 to 70°C under an atmosphere of nitrogen, air or oxygen; the presence of oxygen caused the production of isopropyl phenyl carbonate. For this aromatic isopropyloxycarbonyloxylation induced by oxygen, a mechanism is proposed, which involves reversible addition of an isopropyloxycarbonyloxy radical to an aromatic nucleus to give a cyclohexadienyl intermediate, followed by oxidation with oxygen to produce the carbonate ester. The reaction in a mixture of benzene and hexadeuteriobenzene showed isotope effects for the formation of the ester, kH⁄kD=2.1–2.3, thus supporting the reversibility of the addition step of the isopropyloxycarbonyloxy radical to benzene.
Thermal Decarboxylation of Nitrobenzoic Acids. I
Authors: Manikyam D S , Sundaram E V
Published: July 2006

Thermal decarboxylation of o-, m- and p-nitro benzoic acids was studied in glycerol in the temperature range 210–250°C m- and p-Nitrobenzoic acids exhibited first order rate constants and in support of the proposed SE1 mechanism, the isomers were also studied in aniline at 110–140°C. Pseudo-first order rate constants of the ortho isomer in glycerol suggested a change in mechanism from SE1 to SE2. The rate constants were influenced by boric acid or aniline added to glycerol as the result of a change in pH and confirmed thus the proposed SE1 or SE2 mechanisms. Activation energies, enthalpies and entropies of activation were obtained for the three isomers.
Mechanism of Hydrogenolysis. II. A Molecular Orbitals Study of Hydrogenolysis of Toluene
Authors: Tominaga Hiroo , Arai Hiromichi , Kunugi Taiseki , Amano Akira , Uchiyama Masao , Sato Yoshiki
Published: July 2006

In hydrogenolysis of toluene to produce benzene and methane, atomic cracking process H+C6H5CH3→C6H6CH3 (a) or H+C6H5CH3→C6H5+CH4 (b) has been presumed as rate controlling in chain propagation step of the radical chain mechanism. These two alternative processes are compared on the energetics calculated by the extended Hückel M.O. method. The reaction (a), an addition of the attacking hydrogen atom to phenyl carbon atom adjacent to methyl group followed by an elimination of methyl radical in a concerted manner, is found to be the most likely pathway.
Microwave Spectra of Vinylacetylene and Monodeutero Vinylacetylene in Ground and Excited Vibrational States
Authors: Hirose Chiaki
Published: July 2006

The microwave spectra of vinylacetylene, CH2CHCCH, and monodeutero-vinylacetylene, CH2CHCCD, have been observed in the ground state and several vibrational excited states. The vibration-rotation constants α1(a), α1(b), α1(c), α2(a), α1(b), and α1(c), have been obtained as 1 370, −18.32, −7.73, −907, −2.78, and −8.97 MHz for CH2CHCCH, and 2 010, −16.66, −7.05, −1640, −2.18 and −7.84 MHz for CH2CHCCD, respectively, the error limits being ±50 MHz for α(a)’s and ±0.03 MHz for α(b)’s and α(a)’s. Electric dipole moments obtained are 0.223±0.020 and 0.206±0.008 Debye for CH2CHCCH and CH2CHCCD, respectively, which are quite different from the values reported previously.
An ESR Study of an Al2O3-MoO3-CoO Catalyst in a System with H2 and Thio-β-naphthol
Authors: Ueda Hisashi , Todo Naoyuki
Published: July 2006

This work was planned in order to determine the reaction mechanism of the catalytic, direct desulfurization of organic sulfur compounds on the surface of Al2O3-MoO3-CoO particles. The experimental method consists of quantitative ESR measurements, by means of which the paramagnetic species on the surface of Al2O3, Al203-MoO3, and Al2O3-MoO3-CoO in the presence and in the absence of H2 and thio-β-naphthol were studied. As it is expected that, in an ideal and fast-reacting catalytic reaction system, no reaction intermediate can be found because it will be immediately converted to the final product, several artificial reaction systems were investigated in which either one of the reactants, catalyst components, or reaction conditions (e. g., temperature) was deficient. In such deficient systems, the reaction cycle is cut off and some intermediates are expected to accumulate. The paramagnetic species observed were Co3+, Mo5+, thio-β-naphthol+-O*2− or RS+H–O*2−, and some species formed on the surface of Al2O3, in the temperature region of 20°C–200°C. Mo6+ is concluded to be the electron trap to facilitate the formation of RS+H–O*2−, Co3+ is concluded to oxidize the Mo5+ thus formed to Mo6+, and Co2+ is concluded to reduce the R-S+H2–O*2− species. The latter then decomposes to H2S and R·.
The Temperature Dependence of Hole Injection into Anthracene Crystals
Authors: Yamagishi Akihiko , Soma Mitsuyuki
Published: July 2006

The temperature dependence of dark- and photo-currents was studied for the hole injection into anthracene crystals between 0 and 30°C. It was observed that the photocurrent or, as has been previously established, the electron-transfer rate from an excited anthracene crystal to an acceptor had a small temperature dependence, while the dark current or the electron-transfer rate from the crystal in its ground state to an acceptor had a definite value of activation energy. The observed small activation entropy for the dark reaction was interpreted in terms of Marcus’ theory, and the small polarizability of the organic crystal was, accordingly, suggested to increase the probability of the electron transfer.
Dielectric Absorption in Crystalline Pentachloronitrobenzene
Authors: Aihara Ariyuki , Kitazawa Chikazu , Nohara Akira
Published: July 2006

Dielectric measurements have been performed with pentachloronitrobenzene in polycrystalline state using a trans-former bridge, between 30 Hz and 1 MHz and in the temperature range 20–99°C. The substance shows distinct dielectric absorption in the frequency and temperature ranges, presumably due to molecular rotation in the solid state similar to that of pentachlorotoluene and 1,2,4-trimethyl-3,5,6-trichlorobenzene as has been found by Turney. The frequency factor and the energy of the barrier for the rotation are logA=15.2 (A in sec−1) and ΔH=16.1 kcal/mol. A possible mechanism for the rotational transition of the molecule in the crystalline lattice has been discussed. The dipole moment of this substance in benzene solution has been measured, the result being μ=2.33 Debye.
The Preparation of Nitro-Carbonato and -Acetylacetonato Complexes of Cobalt(III) and Their IR and UV Spectra
Authors: Ichikawa Hiroyasu , Shibata Muraji
Published: July 2006

Two new nitro complexes of cobalt(III), K2[Co(NO2)2CO3acac]·H2O and K3[Co(NO2)4CO3]·H2O, have been prepared by the reaction of tricarbonatocobaltate(III) and the desired ligand. The 700–200 cm−1 region IR spectra for these complexes and the other related dinitro complexes have been measured, and the geometrical structures of these dinitro complexes have been determined as of the cis-form on the basis of the IR data. Furthermore, the absorption spectra of these nitro complexes have also been measured, and the stability of these complexes has been related to the spectral data.
The Crystal Structure of (+)589-Dichlorobis(ethylenediamine)cobalt(III) Chloride Monohydrate
Authors: Matsumoto Keiji , Ooi Shun’ichiro , Kuroya Hisao
Published: July 2006

The crystal structure of cis-(+)589-[CoCl2en2]Cl·H2O has been determined by the X-ray-diffraction method. The crystal is monoclinic with the cell constants: a=12.07, b=11.52, c=8.33 Å, and β=96.9°. The space group is P21 and Z=4. There are two crystallographically-independent complexes in the unit cell, but they have the same configuration and almost identical molecular dimensions. The absolute configuration of the complex cation is consistent with that proposed by McCaffery, Mason and Norman and should be denoted as Λ(δδ).
The Ruthenium Complexes Formed by the Reactions of Nitrosylruthenium(III) with Tin(II) in Hydrochloric Acid Solution
Authors: Mukaida Masao
Published: July 2006

The complexes formed by the reactions of nitrosylrutheniurn(III) in hydrochloric acid solutions with tin(II) chloride were investigated. The following reaction products, (Me4N)2[RuCl3(SnCl3)2-NO], [1]; (Me4N)4[RuCl6(SnCl3)2(NO)2]·H2O, [2]; (Me4N)4[RuCl(SnCl3)5], [3] and K3[Ru2-Cl8(H2O)2N], [4] were isolated as crystals and were characterized. On the basis of chemical and thermal analyses, and on the basis of observations of the magnetic properties, the conductivities, and the infrared spectra, it was concluded that complexes [1], [2], and [3] contain terminal or bridging nitrosyl groups and/or a coordinating SnCl3− group, and that complex [4] contains a bridging nitrido group. The presence of the binuclear complex, “K3[Ru2Cl9(NO)2],” which has both the terminal and singly-bridged nitrosyl groups was also suggested. The relations among those complexes were discussed.
A Study of Electronic Spectra of Square Planar Copper(II) and Nickel(II) Complexes by Circular Dichroism
Authors: Nishida Yuzo , Kida Sigeo
Published: July 2006

Using optically active 1,2-propylenediamine we have synthesized several ligands to form square planar Cu(II) and Ni(II) complexes with optical activity. The CD (circular dichroism) and AB (absorption) spectra of these compounds were measured. The broad absorption bands were resolved in the CD spectra into each component due to a d-d transition, to which a specific d-d transition was assigned. It was found that in these compounds the change in the central atom from Cu(II) to Ni(II) dose not alter the main feature of CD and AB spectra. This seems to be the general rule for the planar Cu(II) and Ni(II) complexes.
Stereoselectivity in Mixed Tris-Type Cobalt(III) Complexes with Glycine and l-Aspartic Acid
Authors: Kawasaki Kiyoshi , Yoshii Junko , Shibata Muraji
Published: July 2006

The reaction of the carbonatobis(glycinato)cobaltate(III) with l-aspartate in the presence of active charcoal led to the stereoselective formation of tris(glycinato-l-aspartato) complexes. By means of ion-exchange chromatography and fractional precipitation, four optically-active complexes, mer-Λ- and fac-Δ-[Co(gly)3−n(l-asp)n]n− (n=1,2), have been isolated, and they have been characterized by means of their absorption and circular dichroism spectra. Furthermore, the percent compositions of the geometrical isomers for the complexes (n=1,2,3) in the reaction mixture and also of Λ- (or Δ-) isomers for each geometrical isomer have been estimated using the spectral data. A marked stereoselectivity (>90%) has been found in the fac-Δ-isomers, while an appreciable selectivity (ca. 70%) has been found for the mer isomers. These stereoselectivities have been explained in terms of an enhanced stability through hydrogen bonding between the β-carboxylate group in the coodinated l-aspartate and the amino group in the adjacent ligand.
Absolute Structure of Acacic Acid
Authors: Varshney I P , Shamsuddin K M
Published: July 2006

Acacic acid, a pentacyclic triterpenic acid, is present as a saponin in various members of the family Leguminosae, but the highest yield is obtained from the pods of Acacia concinna DC. On the basis of degradative studies, transformations, IR, UV, NMR, mass spectrography, and ORD, and CD studies its absolute stereochemistry and structure have been fixed as 3β, 16β, 21β-trihydroxy-18β-olean-12-en-28-oic acid and that in the acetate the rings E and D are in boat and quasi-boat forms, respectively, with D/E rings cis fused.
Kinetic Studies of the Triethylenediamine-catalyzed Hydrolysis of 1,3-Diphenylurea in Dioxane
Authors: Furuya Yoshiaki , Itoho Kazuo , Fukutaka Sakiko
Published: July 2006

The rate of the hydrolysis of 1,3-diphenylurea (abbreviated as DPU) in dioxane in the presence of triethylenediamine (TED) was followed by ultraviolet spectrophotometry. The rate of the reaction satisfied the following equation:

v=&{k_2-k_3h[H_2O]}[DPU][H_2O]+{k_4uh[H_2O]-k_3u}[DPU]^2[H_2O]

&+{k_3c-k_4ch[H_2O]}[TED][DPU][H_2O]+{k_5cuh[H_2O]-k_4cu}

&×[TED][DPU]^2[H_2O].

A probable mechanism which involves a nucleophilic attack of the lone pair of the O-atom of water and of the N-atom of TED on the carbonyl C-atom of DPU, passing through an ion pair of quaternary ammonium salt, is discussed.
Hydrolysis of Dipeptides with Metal Oxides
Authors: Suzuki Shinnichiro , Watanabe Ken-ichi
Published: July 2006

The hydrolysis of three dipeptides, Gly-Gly, Gly-l-Leu, and Gly-l-Phe, with metal oxide catalysts was studied. In most cases, the hydrolysis occurred in the pH range 5–6 accompanied by the formation of metal complexes of amino acids and dipeptides. Copper oxide, nickel oxide, cobalt oxide (III), and alumina have more catalytic activity than copper powder, cuprous oxide, commercial nickel oxide (II), and silica gel. Alumina and silica gel gave no metal complex. It is assumed that the hydrolysis proceeds by means of the formation of an active metal complex of dipeptide or by means of activation on the surface of the catalyst. The order of reactivity of the dipeptides was: Gly-Gly>Gly-l-Leu, Gly-l-Phe.
Ester-Urethane Interchange Reaction
Authors: Suzuki Hajime
Published: July 2006

The ester-urethane interchange reaction has been studied by means of gas chromatography and NMR. The interchange reaction between low-molecular-weight ester and urethane was confirmed by the gas chromatography. Alternating copolyester-urethane was prepared by reacting bis-(hydroxyethyl)terephthalate with hexamethylene diisocyanate in anisole. When the polymer is melted at 190°C in the presence of sulfuric acid as a catalyst, the ester-urethane interchange reaction in alternating copolyester-urethane proceeds and causes a more random arrangement of the segments. This was proved by high-resolution nuclear magnetic resonance spectroscopy. An ethylene glycol residue adjacent to terephthalate on both sides, to diisocyanate on both sides, and to terephthalate and diiosyanate could be identified at 4.93, 4.48, and 4.71 ppm respectively in trifluoroacetic acid.
Synthesis of Corticotropin Peptides. XII. The Effect of Amino-terminal Substitution in the Corticotropin 1-18 Peptide
Authors: Inouye Ken , Watanabe Kunio , Namba Keiko , Otsuka Hideo
Published: July 2006

The synthesis and biological properties are described of an octadecapeptide amide, α-aminoisobutyryl-tyrosyl-seryl-methionyl-glutamyl-histidyl-phenylalanyl-arginyl-tryptophyl-glycyl-lysylprolyl-valyl-glycyl-lysyl-lysyl-arginyl-arginine amide, corresponding to the first eighteen amino acid residues of corticotropin (ACTH) except for the amino terminal residue. The amino-terminal decapeptide as intermediate is built up from a tripeptide (positions 1–3) and a heptapeptide (4–10), where a benzyloxycarbonyl and a benzyl ester groups are used for protection of the terminal α-amino group and the γ-carboxyl group of 5-glutamic acid, respectively. These protecting groups are removed in the final step with hydrogen fluoride. The new method is successfully applied to the corresponding 1-β-alanine octadecapeptide amide, which has been synthesized previously by a different procedure. Adrenal-stimulating properties of the 1-α-aminoisobutyric acid peptide are compared with those of the 1-β-alanine peptide to show that the former peptide is more active than the latter when assayed by the adrenal-ascorbic acid depletion and the in vivo steroidogenesis methods. The lipotropic activity of the new peptide is also shown to be more prolonged than that of the 1-β-alanine peptide.
Tri(hetero) substituted Carbonium Ions. VI. An Anomalous Reaction of 2-Methylthio-1,3-dithiolanylium Ion with N,N-Dimethyldithiocarbamate Anion
Authors: Nakai Takeshi , Okawara Makoto
Published: July 2006

The reaction of 2-methylthio-1,3-dithiolanylium ion (III) with N,N-dimethyldithiocarbamate anion (−SN) has been studied with a view toward demonstrating the ambident character of the cation III. It was found that (i) the reaction afforded S-β-(N,N-dimethyldithiocarbamyl)ethyl-S′-methyltrithiocarbonate (IV; normal) together with ethylene bis(N,N-dimethyldithiocarbamate) (V; abnormal); (ii) methylthioxanthate anion (−SS) was formed in the reaction; (iii) the formation of the abnormal product (V) was more favorable and this could not be ascribed to the attack of −SN on the normal product (IV). The ambident reactivity of cation III has been compared with that of closely related cations, tris(methylthio)carbonium ion and 2-methylamino-1,3-dithiolanylium ion (Ia). It was also found that the reaction of Ia with ethylthioxanthate anion (−SS′) afforded the S′-ethyl analog of IV (normal) together with a small amount of abnormal V. The mechanism for the formation of the abnormal product (V) both from III and −SN and from Ia and −SS′ has been suggested.
Steric Effects of Alkyl Substituents upon the Opening of the Lactone Ring of Coumaran-2,3-diones
Authors: Matsuura Teruo , Kawai Masao , Butsugan Yasuo
Published: July 2006

The stability of the lactone rings of alkyl substituted coumaran-2,3-diones against hydrolysis and alcoholysis is greatly affected by the positions of alkyl substituents. From UV spectral studies it was suggested that methyl substitutions at positions adjacent to the lactone ring contribute to stability for steric reasons.