bluuebunny/crossref_metadata_2025 huggingface dataset:
Liquid Crystal Formation in Binary Systems. VIII. Induction of Smectic Phases by the Addition of 4-Alkoxynitrobenzene or 4-Alkoxybenzonitrile to N-(4-Propoxybenzylidene)-4-hexylaniline
Authors: Chino Eiji , Matsunaga Yoshio
Published: July 2006

When 4-alkoxynitrobenzenes are mixed with N-(4-propoxybenzylidene)-4-hexylaniline, smectic A phases which are not found with the component compounds, are produced. The liquid crystals are stable if the number of carbon atoms in the alkoxyl group is eight or more, the maximum temperature being 49 °C with dodecyloxyl group, but they are entirely metastable if the number of carbon atoms is six or less. The extrapolation of the partly-observed smectic A-isotropic transition point curve indicates that 4-(dodecyloxy)nitrobenzene has a latent transition point at about −25 °C and that all the examined p-disubstituted benzenes are potentially smectogenic. Smectic A phases are also induced by the addition of 4-alkoxybenzonitriles to the above Schiff base. The transition to the induced mesophase is enantiotropic when the alkoxyl group is decyloxyl or dodecyloxyl. The replacement of the propoxyl group in the Schiff base with an ethoxyl group makes the induced smectic A phases thermally less stable. The change is drastic when the alkoxyl group in the p-disubstituted benzene is hexyloxyl or shorter.
Salt Effect on the Solubility of Copper and Beryllium Chelates of 4,4,4-Trifluoro-1-phenyl-1,3-butanedione
Authors: Yoshimura Yasuki , Sato Nobuyoshi , Kikuchi Makoto
Published: July 2006

In order to examine whether the substitution of a trifluoromethyl group for a methyl group in metal chelates of 1-phenyl-1,3-butanedione (BA) affects the salt effect on the solubility of these chelates, the solubility of copper and beryllium chelates of 4,4,4-trifluoro-1-phenyl-1,3-butanedione (BFA) in water and in some aqueous salt solutions was measured at 25 °C. The solubility in water (S0) was 9.07±0.22×10−7 mol dm−3 for the copper chelate and 4.85±0.08×10−6 mol dm−3 for the beryllium chelate. These solubility values are compared with those of the corresponding BA chelates and an influence of fluorination on the solubility of these BA chelates is discussed. It was found that the solubility of the above BFA chelates in the aqueous salt solutions (S) could be expressed satisfactorily by the equation, log(S0⁄S)=a\sqrtCs+bCs, where Cs is the concentration of salt. This result suggests that introduction of CF3 group brings about a specific interaction between the fluorinated chelates and their surroundings.
Bis(2-aminoethanol)cadmium(II) Tetracyanonickelate(II)-Pyrrole (1/1) and 2-Aminoethanolcadmium(II) Tetracyanonickelate(II)-Benzene (1/2). Variation of Metal Complex Host Structure with the Size of Aromatic Guest Molecule
Authors: Nishikiori Shin-ichi , Iwamoto Toschitake
Published: July 2006

Two modifications of the host structures analogous to that of Hofmann-type Cd(NH3)2Ni(CN)4 have been found in the crystal structures of Cd(mea)2Ni(CN)4·C4H5N and Cd(mea)Ni(CN)4·2C6H6 which were prepared using mea (2-aminoethanol=monoethanolamine) in place of the NH3 as the ligands in the host metal complexes. In the former pyrrole clathrate, Hofmann-mea-type(1), the mea behaves as a unidentate ligand like the NH3 in Hofmann-type, but in the latter benzene one, Hofmann-mea-type(2), it behaves ambidently like the en in Hofmann-en-type host Cd(en)Ni(CN)4. In Hofmann-mea-type(1) host, the layered metal cyanide network is puckered, whereas that in Hofmann-ema-type(2) host is coplanar. The size of the guest molecule appears to control the behavior of mea and the structure of the metal cyanide network.
Synthesis and Characterization of a New Quinquedentate Ligand Consisting of Salen Skeleton and Phenolic Tail Capable of Axial Coordination and Its Metal Complexes
Authors: Kanda Wakako , Okawa Hisashi , Kida Sigeo
Published: July 2006

A New quinquedentate ligand N,N′-disalicylidene-2-methyl-4-(2-hydroxy-5-methylphenyl)-1,2-butanediamine (H2(sal-Hpen)) has been prepared, which is a salen derivative containing a phenolic tail capable of axial coordination. It formed the complexes of a general formula [M(sal-Hpen)] with copper(II), nickel(II), and cobalt(II) ions. Based on infrared, electronic and ESR spectra, the complexes were revealed to assume a planar coordination, free from axial coordination of the phenolic tail. On the other hand, distorted octahedral cobalt(III) and tetragonal pyramidal iron(III) complexes, [Co(sal-pen)py] and [Fe(sal-pen)], were obtained, where sal-pen3− acts as a quinquedentate ligand.
An X-Ray Diffraction Study on the Structures of Bis- and Tris(ethylenediamine)copper(II) Complexes in Solution
Authors: Fujita Tadao , Ohtaki Hitoshi
Published: July 2006

The structure of copper(II) complexes with ethylenediamine (en) in solution has been determined by means of X-ray diffraction. The measurements were performed at 25 °C for aqueous ethylenediamine solutions of copper(II) nitrate, the mole ratio (en/Cu) in the solutions being 2.09 and 5.14. In the former solution the bis(ethylenediamine)copper(II) complex was contained as the main species, while the tris(ethylenediamine)copper(II) complex was predominantly formed in the latter solution. The analysis of the X-ray scattering data of the solutions showed that in the bis-complex four nitrogen atoms of the two ethylenediamine molecules coordinated to the central metal ion at the distance of 1.93 Å in a planar form and oxygen atoms of two water molecules were located at 2.92 Å above and below the plane. Since the axial Cu–OH2 bond distance is very long, the structure of the bis-complex can be regarded as square-planar. In the tris-complex the equatorial Cu–N bond length was 1.92 Å, which was practically the same as that within the bis-complex. The axial Cu–N distance was 2.22 Å.
A Calorimetric Study on the Relative Thermal Stabilities of Some Cobalt(III)–Ammine Complexes in Solid Phase
Authors: Tsuchiya Ryokichi , Uehara Akira , Nakayama Takashi
Published: July 2006

The enthalpy changes (ΔH) in the reaction of [CoXn(NH3)6−n]X3−n type complexes with an alkaline sodium sulfide solution were calorimetrically measured at 25 °C, where X is Cl−, Br−, I−, NO3−, or ClO4−. The thermal stabilities were found to decrease in the following orders: in the hexaammine series, chloride>bromide>nitrate>iodide>perchlorate; in the pentaammine series, chloride>bromide>nitrate; and in the trans-tetraammine series, chloride>bromide and chloro>bromo complexes. In addition, in the tetraammine series, the possibility of trans-to-cis isomerization, which has actually been observed, was reasonably explained on the basis of the difference in lattice energies between trans- and cis-[CoCl2(NH3)4]Cl.
Extended X-Ray Absorption Fine Structure Studies in Some Aqueous Copper(II) Solutions
Authors: Sano Mitsuru , Maruo Tetsuya , Yamatera Hideo
Published: July 2006

With a laboratory EXAFS apparatus consisting of a usual X-ray generater, an LiF crystal, and a position sensitive X-ray detector with a self-scanning photodiode array, EXAFS spectra were obtained for aqueous [Cu(NH3)4]SO4, [Cu(en)2]Cl2 (en=ethylenediamine), and CuSO4 solutions. By reference to similar spectra of the corresponding crystals, the solution spectra were analyzed by the curve-fitting method. The values obtained for the distances between the metal and its first-shell atoms in the ammine and sulfate solutions are 2.03 (±0.02) and 1.98 (±0.03) Å, in accordance with those derived from the X-ray diffraction experiments. The Cu–N distance of [Cu(en)2]2+ in solution is 2.02 or 2.04 (±0.02) Å. These values obtained for the solutions are very close to those of corresponding solid complexes.
The Crystal and Molecular Structure of [Pd(tfac)(tfac-O){P(o-tolyl)3}] Containing an O-Unidentate 1,1,1-Trifluoro-2,4-pentanedionate Anion as a Ligand
Authors: Ooi Shun’ichiro , Matsushita Toshio , Nishimoto Kichisuke , Okeya Seichi , Nakamura Yukio , Kawaguchi Shinichi
Published: July 2006

The title complex crystallizes in the monoclinic space group C2/c with a=24.900(6) Å, b=8.272(2) Å, c=30.437(9) Å, and β=97.23(2)°. The structure analysis, which converged at R=0.061 and Rw=0.083 with 3017 reflections for which Fo2>3σ(Fo2), showed that the palladium has a complete square-planar coordination geometry. While one of the tfac ligands is chelating, the other is bound to the metal only through the carbonyl oxygen adjacent to CH3. The O-unidentate tfac ligand lies trans to the CF3CO moiety of chelating tfac and has a planar structure in which the dangling CF3CO group is situated trans to the bonding oxygen atom with respect to the C=C bond. The ab initio MO calculation for the Z,Z-form of the tfac anion indicated that the coordination ability of the acetyl oxygen is higher than that of the trifluoroacetyl oxygen in consistence with the observed structure.
Pressure Dependence of Carboxypeptidase A Action
Authors: Fukuda Mitsuhiro , Kunugi Shigeru , Ise Norio
Published: July 2006

The effect of pressure on the peptide hydrolysis by carboxypeptidase A and its inhibition by several substrate-analogs were investigated. The activation volumes for kcat were −4 and −8 ml mol−1 for the hydrolysis of 3-(2-furyl)acryloyl–Gly–l-Phe and 3-(2-furyl)acryloyl–l-Phe–l-Phe, respectively. The reaction volumes for the binding process (ΔVass) for these dipeptide substrates and for the competitive inhibitors of the peptide hydrolysis (peptide-like inhibitors), such as Gly–l-Tyr and l-Phe, were about 30 ml mol−1. In contrast, ΔVass values for 3-phenyllactate and l-mandelate, both of which are classified as the noncompetitive inhibitors for the peptide hydrolysis (ester-like inhibitors), were comparably small, 5 and 6 ml mol−1, respectively. Furthermore the pressure dependence of the inhibition by d-Phe or d-mandelate was largely different from that of the corresponding l-form; namely ΔVass for d-Phe was 4 ml mol−1 and that for d-mandelate was 21 ml mol−1. The pH dependence of the inhibition constant was classified into two groups; Gly–l-Tyr and l-Phe inhibited more strongly at higher pH while 3-phenyllactate and others did more effectively at lower pH. Taking into account the previously published result of the X-ray crystallographic studies (e. g., J. A. Hartsuck and W. N. Lipscomb, “The Enzymes,” 3rd ed, ed by P. D. Boyer, Academic Press, New York (1971), Vol. 3, p. 1), the present results were accounted for in terms of two different (electrostatic) interactions between the substrate or inhibitor and the active site of the enzyme.
The Reaction of Cyanoguanidine with Formaldehyde. I. Hydroxymethylation and Methoxymethylation of Cyanoguanidine
Authors: Takimoto Michiaki , Ebisuno Toichi , Shiba Ryuichi
Published: July 2006

In order to examine the reactivity of cyanoguanidine (CG) with formaldehyde, CG was first hydroxymethylated, then methoxylated, and finally exhaustively hydroxymethylated with a large excess of formaldehyde. 4-Cyanoimino-3-methoxymethylperhydro-1,3,5-oxadiazine was isolated as a major reaction product of 1,3-bis(methoxymethyl)-2-cyanoguanidine with formaldehyde. This product is an adduct of 3 mol of formaldehyde per mole of CG and a six-membered cyclic ether. Minor products were further methoxylated and 3,5-bis(methoxymethyl)-4-methoxymethyl(carbamoylimino)perhydro-1,3,5-oxadiazine was isolated. This is an adduct of 2 mol of formaldehyde to the amidinated product derived from the major product by the hydration of the cyano group. The ring structure of perhydro-1,3,5-oxadiazine was so stable that it could not be decomposed under acidic conditions if the methoxymethyl groups were fully acid-hydrolyzed.
Studies on the β-Turn of Peptides. VI. Nuclear Magnetic Resonance Study on the Conformations of N-(2,4-Dinitrophenyl)tetrapeptide p-Nitroanilides Related to the β-Turn Part of Gramicidin S
Authors: Higashijima Tsutomu , Sato Kazuki , Nagai Ukon
Published: July 2006

The conformations of N-(2,4-dinitrophenyl)-l-Leu–X–l-Pro–l-Val p-nitroanilides (I, X=D-Ala; II, X=Gly; III, X=l-Ala) were studied by nuclear magnetic resonance and circular dichroism spectroscopies. The l-Val-NH group of compound I takes part in an intramolecular hydrogen bonding, and the folded conformation is considered to be type II′ β-turn structure as in the case of [d-Ala4,4′]-gramicidin S. The populations of β-turn conformer were considered to be in the order of I>II>III≈0 in methanol and N,N-dimethylformamide solutions, and decreased in dimethyl sulfoxide solution. Compound II in dimethyl sulfoxide and III in all the three solvents do not take a β-turn conformation. The data obtained from NMR and CD experiments showed a good correlation between the magnitudes of the Cotton effects (250–400 nm) and the populations of the β-turn conformation of these peptides. The proximity of the two chromophores was ascertained directly for compound I in N,N-dimethylformamide solution by nuclear Overhauser effects experiment. In addition, the β-turn preference of these peptides were in good accordance with the antibiotic activities of the gramicidin S analogs having the same tetrapeptide sequences at their β-turn parts.
Reactions of 3-Acetyltropolone and Its Methyl Ethers with 1,2-Ethanediamines
Authors: Sudoh Yasunori , Onitsuka Katsunobu , Imafuku Kimiaki , Matsumura Hisashi
Published: July 2006

3-Acetyltropolone reacted with 1,2-ethanediamine to give N,N′-bis(3-acetyl-2-oxo-3,5,7-cycloheptatrienyl)-1,2-ethanediamine (3) and 5-acetyl-3,4-dihydro-2H-cyclohepta[b]pyrazine (4), along with a small amount of by-products, which were 8-acetyl-1,2,3,4-tetrahydro-5-quinoxalinecarbaldehyde (5), 5-acetyl,2,3,4-tetrahydroquinoxaline (6), and 2-methyl-5,6-dihydro-4H-pyrrolo[1,2,3-de]quinoxaline (7). The minor products (5–7) resulted from the contraction of the seven-membered ring of the compound 4. 2-Acetyl-7-methoxytropone (2a) also reacted with 1,2-ethanediamine to give the same products (3–7) in higher yields. On the other hand, the same reaction of 3-acetyl-2-methoxytropone (2b) readily gave 4–7. The reaction of 2a with N-methyl-1,2-ethanediamine gave N-(3-acetyl-2-oxo-3,5,7-cycloheptatrienyl)-N′-methyl-1,2-ethanediamine (14), 5-acetyl-1-methyl-2,3-dihydro-1H-cyclohepta[b]pyrazine (15), 8-acetyl-4-methyl-1,2,3,4-tetrahydro-5-quinoxaline-carbaldehyde (16), 5-acetyl-1-methyl-1,2,3,4-tetrahydroquinoxaline (17), and 2,6-dimethyl-5,6-dihydro-4H-pyrrolo[1,2,3-de]quinoxaline (18). The same reaction of 2b also gave the products (15–18). The several reactions of these products are also described.
Determination of Fe–O Bond Energy in Water-gas Shift Catalyst
Authors: Sengupta G , Prasad Keshav , Sen S P
Published: July 2006

Oxygen catalyst bond energy may play an important role in determining the catalytic activity in water-gas shift reaction. In the present investigation a method for determining this parameter from electrical conductivity has been suggested.
Phosphorescence Studies of 3ππ* Benzaldehyde, Acetophenone, and 1-Indanone in Benzoic Acid Host
Authors: Nagaoka Shin-ichi , Hirota Noboru
Published: July 2006

We have made a vibrational analysis of the phosphorescence spectra of benzaldehyde, deuterated benzaldehydes, acetophenone, and 1-Indanone in benzoic acid host. The emissions coming from different sites of benzaldehyde were separated with the help of microwave induced delayed phosphorescence (MIDP) spectroscopy. From the phosphorescence excitation spectra the locations of the 3nπ* states were estimated to be about 2000 cm−1 above the 3ππ* states. Contrary to the previous assignment, it was found that the aldehyde H wag is active in the spectra of benzaldehyde as in the cases of other host. The spectra of acetophenone and 1-indanone are similar to those obtained in other hosts, although the 0-0 bands are relatively stronger. The C=O stretching mode is, however, not clearly observable in all the systems studied here, suggesting that this mode is not active in the spectra of nearly pure 3ππ* aromatic carbonyls. The main radiative mechanisms are discussed based on the present results and are compared with those of other aromatic carbonyls. Possible effects of hydrogen bonding on these properties are discussed.
Synthesis and Properties of Novel Type Binuclear Copper(II) Complexes Whose Coordination Units Are Linked by a Flexible Polyatomic Chain
Authors: Takahashi Kazuhiro , Nishida Yuzo , Kida Sigeo
Published: July 2006

Binuclear copper(II) complexes with two bis(2-benzimidazolylmethyl)amine moieties linked by a flexible polyatomic chain were prepared. Their ESR spectral properties were highly dependent on the bridging chains linking two coordination units.
Decomposition of Methylamine over Ruthenium Black
Authors: Orita Hideo , Naito Shuichi , Onishi Takaharu , Tamaru Kenzi
Published: July 2006

The decomposition of methylamine over Ru black was investigated in the presence and absence of hydrogen, and the dependence of reaction rate on the pressures of reactants was also examined. Methylamine decomposes rapidly to gaseous ammonia and deposited carbon species (CHx(a)) over clean Ru black in the absence of hydrogen. The hydrogenation of CHx(a) after the decomposition of amines produced hydrocarbons in the range C1–C4 whose distribution was dependent on the way CHx(a) was accumulated.
Amorphous Ni–Ti and Ni–Zr Alloys for Water Electrolysis Cathode Materials
Authors: Machida Ken-ichi , Enyo Michio , Toyoshima Isamu , Miyahara Koshiro , Kai Kenzo , Suzuki Kenji
Published: July 2006

Amorphous Ni–Ti and Ni–Zr alloys for their possible use in water electrolysis cathode materials were investigated. The hydrogen electrode reaction in 1 M NaOH (1 M= 1 mol dm−3) proceeds via the Volmer-Tafel reaction route with mixed rate-determining characteristics. The electrocatalytic activity is augmented significantly with a treatment of the alloy electrodes with aq HF. Thus, the exchange current density reaches 10−3A cm−2 (apparent) at 303 K. The activation energy values are 9.4, 5.5, and 6.1 kcal mol−1 (1 cal=4.184J) for the Volmer and Tafel step and the overall reaction, respectively. Surface analyses of the electrodes have indicated that such a high activity is caused by a stable porous Ni layer which is formed on the surface by the acid treatment. Such a porous Ni layer was not effectively formed if the alloys were in crystalline states.
Phase Equilibria in the Ln2O3–V2O3–V2O5 (Ln=Eu and Yb) Systems at 1200 °C
Authors: Kitayama Kenzo , Sou Hidehiko , Katsura Takashi
Published: July 2006

Phase equilibria in the systems, Eu2O3–V2O3–V2O5 and Yb2O3–V2O3–V2O5, were established at 1200 °C by changing the oxygen partial pressure from −0.68 (air) to −13.00 atm in terms of logPo2. In the Eu2O3–V2O3–V2O5 system, 0.81Eu2O3·0.19V2O5 (Eu1.62V0.38O3.38) was stable; in the Yb2O3–V2O3–V2O5 system, a new compound Yb7V3O16 was stable; and in both systems Ln2O3, LnVO4, LnVO3, VnO2n−1(n=2–7), and VO2 were stable under the present experimental conditions. On the basis of the established phase diagrams, Gibbs energies of these reactions, 31/50 Eu2O3+19/50 EuVO3+19/100 O2= Eu1.62V0.38O3.38, EuVO3+1/2O2= EuVO4, 2 Yb2O3+ 3 YbVO3+1/2O2=Yb7V3O16, Yb7V3O16+O2=2 Yb2O3+ 3 YbVO4, and YbVO3+1/2O2=YbVO4, were determined to be −58.9, −126.0, −134.0, −210.0, and −117.7 kJ respectively. EuVO4, Eu1.62V0.38O3.38, YbVO4, Yb7V3O16, V2O3, and VO2 have nonstoichiometric compositions.
Crystal and Molecular Structure of μ-Imidazolato-bis{[tris(2-methylthioethyl)amine]copper(II)}perchlorate
Authors: Suzuki Masatatsu , Ueda Ikuhiko , Kanatomi Hajime , Murase Ichiro
Published: July 2006

The structure of the title complex, [Cu2(NS2-Me)2im](ClO4)3, has been determined by the single-crystal X-ray diffraction method, where NS3-Me is tris(2-methylthioethyl)amine and im is imidazolate anion. The complex crystallizes in the monoclinic space group P21/a with a unit cell with the dimensions of a=13.114(3), b=28.045(6), c=10.481(2) Å, β=98.70(2)°, V=3810.2(13) Å3, and Z=4. The structure was solved by the heavy atom method. The residual R value was 0.0594 for 4431 independent reflections. The coordination geometries of the two copper atoms are different from each other; the Cu(1) is in a trigonal bipyramidal geometry with three sulfur atoms in the equatorial plane and two nitrogen atoms in the axial positions, while the coordination geometry of the Cu(2) can be best described as an intermediate between a trigonal bipyramidal and a square pyramid. The intramolecular Cu(1)···Cu(2) distance is 5.930(2) Å. Temperature-dependent magnetic susceptibility data showed a strong antiferromagnetic exchange interaction with a coupling constant –J=63 cm−1. The Cu(1)–N(1)–C(1) and Cu(2)–N(2)–C(1) angles, which have been considered to be related to the magnitude of the antiferromagnetic exchange interaction, are 132.1(5) and 127.0(6)°, respectively. The magnetism of the complex is discussed in connection with the structural data.
Alkyd Resin Paint as a New Membrane Material of Ion-selective Electrode
Authors: Katsu Takashi , Togawa Keiko , Fujita Yuzaburo
Published: July 2006

A new membrane material, alkyd resin paint, was used for a silver iodide-based ion-selective electrode. The electrode was easily prepared in the laboratory by mixing silver iodide precipitate and alkyd resin paint. The electrode responded to both iodide and silver ions with the deviations from a Nernstian response due to adsorption and desorption of ions. Silver ions tended to adsorb more strongly on the electrode surface. The preparation and properties of the present electrode are described in view of an analytical utilization of the electrode.
The Solvent Effects on the Photochemical Isomerization of 5-Cyano-5H-benzocycloheptene
Authors: Kobayashi Hisako , Takatoku Keizo , Kato Masahiko , Miwa Toshio
Published: July 2006

The photochemical reaction of 5-cyano-5H-benzocycloheptene (1b) has been studied kinetically in various solvents. The main reactions were (1) a 1,7-hydrogen shift, with simultaneous cyclization, to give 7b-cyanola,7b-dihydro-1H-cyclopropa[a]naphthalene and (2) a 4π-electrocyclic ring closure to give cyclobutenes. The former reaction was found to show rather complicated solvent effects, but the latter was accelerated in less polar solvents. The conformational equilibrium between exo- and endo-forms was also observed in the NMR spectra of 1b under various conditions. From a consideration of the solvent effects on the product distribution, the ground-state conformations of 1b could be reflected in the ratio of the exo and endo forms of the cyclization products.
One-step Synthesis of Long-chain Aliphatic α,ω-Dicarboxylic Acids Utilizing the Copper-catalyzed Reaction of β-Propiolactone with α,ω,-Di-Grignard Reagents
Authors: Fujisawa Tamotsu , Sato Toshio , Kawara Tatsuo , Tago Hideyuki
Published: July 2006

Copper-catalyzed reaction of β-propiolactone with α,ω-di-Grignard reagents, followed by esterification gave six-carbon homologated α,ω-dicarboxylic acid esters in good yields.
The Reaction Nitrile Oxides with Alkyl- and Alkyl-halo-substituted p-Benzoquinones
Authors: Shiraishi Shinsaku , Holla B Shivarama , Imamura Kiyoshi
Published: July 2006

Various aromatic nitrile N-oxides, sterically stabilized and unstabilized ones, were allowed to react with several alkyl- and alkyl-halo-substituted p-benzoquinones with a view to studying the influence of quinone substituents on the mode of the addition reaction. Mono-, di-, and tri-substituted quinones with such substituents gave isoxazoline derivatives formed through addition of nitrile oxides to the C=C bond of the quinones. 2-Chloro-5- and -6-methyl-p-benzoquinones gave two kinds of C=C adducts, one formed through the addition to the C=C of methyl-substituted side and the other to that of chlorine-substituted side, and the latter adducts were not isolable due to the prompt dehydrochlorination forming the fully-conjugated isoxazoloquinones and subsequent C=O addition of another nitrile N-oxide forming spirodioxazole derivatives.
Mechanism of the Photooxidation of and Photoepoxidation with Cyclic α-Diketones
Authors: Sawaki Yasuhiko
Published: July 2006

The photooxidation of phenanthrenequinone (PhQ) under oxygen afforded diphenic acid and its peroxy acid, while acenaphthenequinone (AcQ) predominantly yielded 1,8-naphthalenedicarboxylic anhydride. The photolysis of PhQ or AcQ in the presence of olefins afforded predominantly 1 : 1 cycloadducts and the photoepoxidation was a very minor one accompanying significant amount of C–C cleavage of olefins. These results show that the photoreaction of PhQ, or AcQ with olefins is very fast and competitive with the quenching and/or reaction with oxygen. The photoepoxidation of stilbene in the presence of dimethyl sulfoxide resulted in a high selectivity (>98%) for the trans-epoxide. The same was true for the epoxide formed in the coautoxidation of benzaldehyde and stilbene. These facts suggest that the photoepoxidation with cyclic α-diketones as a minor reaction proceeds chiefly by way of acylperoxyl radical, accompanying the epoxidation with peroxy acids produced concomitantly. Mechanisms of the photooxidation of and photoepoxidation with the cyclic diketones are discussed in comparison with the case of acyclic diketones.
Sweetness of Hesperetin Dihydrochalcone Derivatives Linked to ω-Amino Acid or Its Oligomer
Authors: Kawai Masao , Kuwabara Kyoko , Kimura Ritsuko , Sekido Sachiko
Published: July 2006

Derivatives of hesperetin dihydrochalcone having ω-amino acid, oligoglycine, or oligo-(γ-aminobutyric acid) were synthesized and tasted. The hydrophobicity of the introduced group is important for understanding the structure-sweet taste relationship of these compounds, though other factors than hydrophobicity also must be taken into account.
C-Sulfinylation of Grignard Reagents and Enamines with Sulfinic Acid
Authors: Noguchi Yoshihide , Kurogi Kenkichi , Sekioka Minako , Furukawa Mitsuru
Published: July 2006

Direct C-sulfinylation of Grignard reagents with sulfinic acid (4) in the presence of activating reagents, such as phenyl phosphorodichloridate (1), diphenyl phosphorochloridate (2), and 3-phthalimidooxy-l,2-benzisothiazole 1,1-dioxide, were investigated. β-Keto sulfoxides were also formed by the reaction of enamines with 4 using 1 and 2 under similar conditions.
Physicochemical Studies of Alkali Metal Solutions in Tetrahydrofuran
Authors: Lagoste Jacques , Schué Francois
Published: July 2006

We have studied the rate of alkali metal dissolution in THF as a function of its nature and of the cryptand (C). The selectivity has been estimated through the equilibrium constant of the following equilibrium:

M−+C\leftrightarrowsM+C+2esolv.−

Both ΔH° and ΔS° for this reaction are negative. The entropy decrease reveals that the sum of the energies bonds between the cation and the ligand and the electrons and the solvent is higher than that necessary to desolvate and dissociate M−.
Production of Ethylene and Propylene by the Vapor-phase Catalytic Oxidative Dehydrogenation of Butane with Carbonyl Sulfide
Authors: Akimoto Masamichi , Sakatani Takashi , Echigoya Etsuro
Published: July 2006

Ethylene and propylene were produced at high yields, additionally to butenes and butadiene, by the vapor-phase oxidative dehydrogenation of butane with COS over SiO2, Al2O3, MgO, and TiO2 catalysts at 873–923 K. The results of kinetic and mechanistic studies indicate that ethylene and propylene are produced by the oxidative dehydrogenation through a homolytic mechanism followed by β-scission of the carbon–carbon bond.
One-pot Synthesis of Acid Anhydrides from Acids Using N,N,N′,N′-Tetramethylchloroformamidinium Chloride under Mild Conditions
Authors: Fujisawa Tamotsu , Tajima Kazuhisa , Sato Toshio
Published: July 2006

N,N,N′,N′-Tetramethylchloroformamidinium chloride reacted smoothly with a variety of carboxylic and phosphoric acids in the presence of a tertiary amine to give the corresponding acid anhydrides in high yields.
Palladium Catalyzed Reaction of Trimethylsilyltributyltin with α-Halo Ketones. Preparation of Enol Silyl Ethers
Authors: Kosugi Masanori , Ohya Takao , Migita Toshihiko
Published: July 2006

The reaction of trimethylsilyltributyltin with α-halo ketone in the presence of a catalytic amount of palladium chloride plus twice molar amounts of trimethyl phosphite gave enol silyl ethers in good yields.
Charge-carrier Transport in Nematic 2-(p-Decyloxybenzylideneamino)-9-Fluorenone
Authors: Okamoto Ken-ichi , Nakajima Shu , Itaya Akira , Kusabayashi Shigekazu
Published: July 2006

2-(p-Decyloxybenzylideneamino)-9-nuorenone (DBAF), with a large π-electronic group, showed a transient photocurrent induced by the strongly-absorbed light from a N2 gas laser in the nematic, monotropic smectic, and isotropic liquid states. This photocurrent seemed to be due to the space-charge-limited current. The drift mobilities of the positive and negative charge carriers (μp and μn respectively) were determined from the peak time. The μn was ten times larger than μp, while the activation energies were identical. The modified Walden rule was valid in the nematic state ranging from 90 °C to 135 °C. The nematic mixtures of DBAF and N-(p-methoxybenzylidene)-p-butylaniline also showed a similar transient photocurrent, the magnitude of which increased significantly with an increase in the DBAF content. The mobilities were independent of the DBAF content and were nearly equal to those in nematic DBAF at the same viscosity, η: that is, μn=3×105, and μp=2.5×10−6 cm2/V s at η=0.026 Pa s. These facts indicate that the nature of the carrier transport of the photoconduction is not electronic, but ionic. The O2− and the cation radical of DBAF are proposed as the ionic carrier species for both nematic DBAF and the nematic mixtures.
Pressure-Volume-Temperature Relations of Supercooled Liquid and Glass of Triphenylchloromethane/o-Terphenyl Mixture
Authors: Naoki Motosuke , Matsushita Manabu
Published: July 2006

Volumetric data on the supercooled liquid state and on the glassy state are reported for a binary mixture of triphenylchloromethane and o-terphenyl. In the supercooled liquid state, the thermal expansivity, the isothermal compressibility, and their temperature dependences of the mixture are much samller than those of simple molecular liquids and are almost the same order of magnitude as those of polymer liquids. The glass of the mixture also closely resembles polymer glasses in the apparent thermodynamic properties. Some representative lattice-like liquid theories are applied to the pressure-volume-temperature relations of the supercooled liquid sample, with the aid of the principle of corresponding states.
Photochromic Behavior of Schiff Base–Metal Complexes. I. Photoinduced Hydrolysis of Pyridoxal 5′-Phosphate- and Salicylaldehyde-α-amino Acid–Zinc(II) Complexes
Authors: Kurauchi Yoshiaki , Ohga Kazuya , Yokoyama Akihiko , Morita Shigeru
Published: July 2006

Pyridoxal 5′-phosphate-α-amino acid–Zn(II) complexes and their salicylaldehyde analogues showed photochromic behavior in borate buffer at pH 9.5. A detailed comparison of UV spectral changes during the thermal back reaction with those for the complex formation indicates that the photoexcitation of the complexes induces the hydrolysis of the Schiff base ligands and that the back reaction corresponds to regeneration of the complexes.
Interaction of Cationic Dye and Anionic Detergent above and below the Critical Micelle Concentration as Revealed by Fluorescence Characteristics
Authors: Sato Hiroyasu , Kawasaki Masahiro , Kasatani Kazuo , Nakashima Nobuaki , Yoshihara Keitaro
Published: July 2006

The interaction of 3,3′-diethylthiacarbocyanine iodide, a cationic dye, with sodium dodecyl sulfate (SDS), an anionic detergent, was studied as a function of the concentration of SDS ([SDS]) above and below the critical micelle concentration (cmc). The [SDS]-dependent fluorescence spectra, quantum yield and decay measurements revealed the deaggregation of the dye above the cmc and the formation of the dye–SDS aggregate below the cmc.
Transient Intermediate Produced from 5-Aminouracil in Reaction with Dichloride Anion Radical
Authors: Masuda Takahiro , Gunji Ryoji , Kimura Takako , Yamauchi Kotaro
Published: July 2006

A transient absorption, which is relatively long-lived, was found in a flash photolysis of aqueous potassium chloride containing 5-aminouracil. The transient absorption with a peak at about 335 nm was assigned to an intermediate produced from 5-aminouracil through a one-electron oxidation by dichloride anion radical. For the intermediate, a possible structure is proposed to explain its long life-time. On the basis of the transient absorption, a determination of the rate constant for the reaction of 5-aminouracil with dichloride anion radical was carried out by use of a competition kinetics. The value of (2.9±0.2)×108 dm3 mol−1 s−1 was obtained as the rate constant on the basis of rate constants of several reference compounds. By comparing the values obtained by the competition method with those estimated by a direct analysis of the decay rate of dichloride anion radical, the validity of the competition method was examined.
Pyrolytic Sulfurization Gas Chromatography. XV. Simultaneous Determination of the Atomic Ratio between C, H, O, and N in an Organophosphorus Compound
Authors: Hara Tadashi , Fujinaga Kaoru , Okui Fujio , Arai Akihiro
Published: July 2006

In order to confirm whether or not pyrolytic sulfurization gas chromatography can be applied to organophos-phorus compounds, many kinds of organophosphorus compounds were examined; C-rich compounds gave satisfactory results while C-poor ones gave lower oxygen values. The application limit of this method to various organophosphorus compounds was determined by the use of the C/O value and a structural factor for a sample, and the application limit was established. The structural factor of a sample varied with the kind of X1, X2, X3, and X4 in the general formula X1X2X3P=X4, where X1=OH, OR, R; X2=OH, OR′, R′; X3=OH, OR″, R″; and X4=O, S.
Development of Hydrogen Ion Selective Electrode with Lithium Phosphate Glasses for the Use in Solutions Containing Hydrofluoric Acid
Authors: Nomura Tsuyoshi , Nakagawa Genkichi
Published: July 2006

In order to determine reproducible and stable potential response conditions of the hydrogen ion in hydrofluoric acid solutions, lithium phosphate glass membranes of various constituents were developed. The glass membranes contained various metal oxides: Ag2O, Li2O, P2O5, MgO, BeO, WO2, and Al2O3. The response characteristics of the glass electrode depend strongly on the glass compositions. For the examination of the selectivity coefficient and the electrode function of hydrogen ion activities, the glass composition of 10 Ag2O : 20 Li2O : 50 P2O5 : 10 MgO : 10 WO2 is the most suitable one. The potential response is linear over the hydrogen ion activities of (100.3–10−4) mol/dm3, and has a slope of 44.5 mV/decade change in the hydrogen ion activity at 20 °C. The dynamic response time was within a minute in the range 10−1 to 10−4 mol/dm3. The intereference of the various cations on the activity of about 0.1 mol/dm3 can be ignored during the determination of the hydrogen ion activities at pH below 3. Physical and chemical properties, such as glass transition temperature, softening temperature, thermal expansion, membrane resistance, and chemical durability were measured and compared with those of other glasses.
One-step Synthesis of (2-Amino-2-carboxyethylthio)dopas (Cys-dopas) from Dopa and Cysteine by Hydrogen Peroxide in the Presence of Iron–EDTA Complex
Authors: Ito Shosuke
Published: July 2006

5-(2-Amino-2-carboxyethylthio)dopa, 2-(2-amino-2-carboxyethylthio)dopa, and 2,5-bis(2-amino-2-carboxyethylthio)dopa were synthesized from dopa and cysteine by oxidation in a neutral buffer with H2O2 in the presence of iron–EDTA complex. H2O2, iron salt, and EDTA were essential for the reaction. Ultimate oxidizing species seem to be hydroxyl and superoxide radicals.
Synthesis and Properties of Cationic Polynucleotide Analog Binding RNase A
Authors: Shimidzu Takeo , Murakami Akira , Yamana Kazushige
Published: July 2006

A new type of cationic polynucleotide analog binding RNase A and its related compounds were synthesized from an insoluble cross-linked poly(4-vinylpyridine). The cross-linked poly(4-vinylpyridine) was converted into an aldehyde derivative by the reaction with cyanogen bromide. The aldehyde derivative was used for the binding of RNase A and 9-(2-aminoethyl)adenine through their amino groups. The cationic adenine polynuleotide analog binding RNase A favorably interacted with nucleotides containing uracil base through the base-specific interactions. This analog showed the considerable selectivity in the hydrolysis of uridine polynucleotide owing to the template effect.
Constituents of the Root Bark of Ailanthus altissima SWingle. Isolation and X-Ray Crystal Structures of Shinjudilactone and Shinjulactone C and Conversion of Ailanthone into Shinjudilactone
Authors: Ishibashi Masami , Tsuyuki Takahiko , Murae Tatsushi , Hirota Hiroshi , Takahashi Takeyoshi , Itai Akiko , Iitaka Yoichi
Published: July 2006

Two new quassinoids, shinjudilactone and shinjulactone C were isolated from the root bark of Ailanthus altissima SWingle and their structures were established to be 1β,11α-dihydroxy-2,16-dioxo-13(12→11α)abeo-picras-3-en-12,20-olide and 1α,12α : 5α,13α-dicyclo-1β,12β,20-trihydroxy-9βH-picras-3-ene-2,11,16-trione, respectively, by X-ray diffraction analysis. Shinjudilactone was prepared from ailanthone by benzilic acid rearrangement.
Structure Determination of Bitter Principles in Ailanthus altissima. Structure of Shinjulactone A and Revised Structure of Ailanthone
Authors: Naora Hirokazu , Ishibashi Masami , Furuno Tetsuo , Tsuyuki Takahiko , Murae Tatsushi , Hirota Hiroshi , Takahashi Takeyoshi , Itai Akiko , Iitaka Yoichi
Published: July 2006

The structure of a new bitter principle, shinjulactone A, isolated from Ailanthus altissima SWingle was determined to be 11β,20-epoxy-1β,2α,11α,12α-tetrahydroxypicrasa-3,13(21)-dien-16-one and the configuration of a hydroxyl group at C-12 of ailanthone was revised to α-orientation by X-ray analysis.
Chemiluminescences in the Carbon Monoxide–Active Nitrogen System
Authors: Washida Nobuaki , Bandow Hiroshi , Inoue Gen
Published: July 2006

Chemiluminescences produced in the reaction of CO with active nitrogen were measured in the region from infrared to vacuum ultraviolet. The infrared emission from vibrationally excited CO was measured by means of a FTIR spectrometer. A vibrationally excited CO up to v″=18 was observed. The quenching and relaxation of vibrationally excited CO were measured by the addition of other gasses. The formation of carbon atoms was observed by the absorption of carbon resonance lines, and the recombination reaction of C+N+M→CN*+M is proposed as the mechanism of the violet and red emission of CN. The reaction of CO*(a3Π)+CO\eweq→C+CO2 is proposed as the carbon-atom source. The emission of the fourth positive band of CO was observed in the vacuum UV region. The effect of self-absorption by the vibrationally excited CO was reduced by the addition of CO2. It is suggested that the apparent abnormal vibrational distribution in CO(A1Π) can be reduced by considering the effect of the quenching of CO(A1Π).
NMR Lanthanoid-probe Analyses of Conformational Properties of 8,2′-S-Cycloadenosine 3′-Monophosphate in Aqueous Solution
Authors: Yokoyama Shigeyuki , Oida Tetsuya , Uesugi Seiichi , Ikehara Morio , Miyazawa Tatsuo
Published: July 2006

The advanced method of NMR lanthanoid-probe analyses was used for studying the molecular conformations of 8,2′-anhydro-8-thio-9-β-d-arabinofuranosyladenine (8,2′-S-cycloadenosine) 3′-monophosphate in aqueous solution. From the observed ratios of Pr(III)-induced shifts, Gd(III)-enhanced relaxation rates as well as vicinal spin-coupling constants, the most probable values (and standard deviations) of the fractional populations of the local conformations for the C5′–C4′ bond, sugar ring, C3′–O3′ bond, and O3′–P bond and the internal rotation angles of the two forms about the C3′–O3′ bond were determined by the program COFLEM. The internal rotation equilibrium about the C3′-O3′ bond was found to be interrelated with the puckering of the sugar ring. The advanced lanthanoid probe method is thus useful for the analyses of the conformational characteristics of cyclonucleotides as well as of unmodified nucleotides in aqueous solution.
A Study of Inorganic Ion Exchangers. VII. The Synthesis of γ-NH4ZrH(PO4)2 and Ion-exchange Properties of γ-Zr(HPO4)2·2H2O
Authors: Kobayashi Etsuro
Published: July 2006

The conditions for the synthesis of γ-NH4ZrH(PO4)2 and the ion-exchange properties of γ-Zr(HPO4)2·2H2O were investigated. The influence of the mole ratio of MH2PO4 (M=Na, K, and NH4) to ZrOCl2 on the formation of γ-zirconium phosphate using NaH2PO4 as MH2PO4 was such that the γ-form was obtained not in the NaH2PO4/ZrOCl2 mole ratio of 4, but in are of 8.3 or more. In case of the Na or K salt, a non-stoichiometric compound, MxZrH2−x(PO4)2, was obtained. When using the NH4 salt, a stoichiometric compound was synthesized at 120–280 °C in accordance with the following equation: ZrOCl2+NH4H2PO4→NH4ZrH(PO4)2+NH4Cl+HCl+H2O. Using an autoclave lined with Hastelloy-B and equipped with a stirrer, the synthesis was carried out by a reaction at 150–160 °C for 18–54 h. γ-Zr(HPO4)2·2H2O was prepared from NH4ZrH(PO4)2, and its ion-exchange capacity at pH 4.5 and selectivity quotient toward alkali metals and ammonium ions were measured. The measured values increased in the order of Li+<Cs+<Na+<K+<NH4+.
Stereoselective Epoxidation of Allylic Alcohols and Dehydrogenative Oxidation of Secondary Alcohols by Means of t-Butyl Hydroperoxide and Aluminium Reagents
Authors: Takai Kazuhiko , Oshima Koichiro , Nozaki Hitosi
Published: July 2006

Treatment of a solution of geraniol and (t-BuO)3Al in benzene with t-BuOOH at 5 °C gives (2R*, 3R*)-2,3-epoxy-3,7-dimethyl-6-octenyl acetate in 83% yield after acetylative workup. Eight allylic alcohols are converted to α,β-epoxy alcohols in preparative yields. The epoxidation of secondary (E)-allylic alcohols shows opposite stereoselectivities to t-BuOOH–VO(acac)2 system. Asymmetric epoxidation with a chiral hydroxamic acid as a ligand gives unsatisfactory degrees of enantiomeric excess. The same system can also convert secondary alcohols into ketones in excellent yields, while primary ones react very slowly.
Structures of Halogenated Chamigrene Derivatives, Minor Constituents from the Red Alga Laurencia nipponica Yamadan
Authors: Suzuki Minoru , Segawa Makoto , Suzuki Teruaki , Kurosawa Etsuro
Published: July 2006

Three halogenated chamigrane-type sesquiterpenes have been isolated as the minor metabolites from the red alga Laurencia nipponica, collected at Sannai, near Wakkanai. The absolute structures of these compounds were confirmed by spectral and chemical methods.
The Volumetric Behavior of Several Ammonium Chlorides in Aqueous 18-Crown-6 Solutions
Authors: Harada Shigeharu , Sahara Hideko , Nakagawa Tsurutaro
Published: July 2006

The complexation of 18-crown-6 with primary ammonium chlorides [H(CH2)nNH3Cl, n=0, 1, 2, and 4] caused an increase in volume, which was attributable to the dehydration of the ammonium moieties. On the other hand, the apparent molal volumes of (CH3)4−nNHnCl (n=0–2) were not affected appreciably by the presence of the crown ether, and their complex stability seemed to be insignificant.
Effects of the Oxyethylene Chain Length of Fluorocarbon Surfactants on Demixing of Micelles of Fluorocarbon and Hydrocarbon Surfactants
Authors: Funasaki Noriaki , Hada Sakae , Neya Saburo
Published: July 2006

The critical mole fraction of hydrocarbon surfactant decreases with an increase in the oxyethylene unit of either fluorocarbon surfactant or hydrocarbon surfactant. This tendency is explicable in terms of regular solution theory if the depth of water penetration into the micellar interior is assumed to increase with an increase in the oxyethylene unit.
Preparations and Strucutures of Silver(I) Complexes with cyclo(Glcyl-l-histidyl), cyclo(l-Methionyl-l-histidyl), and cyclo(l-Histidyl-l-histidyl)
Authors: Kojima Yoshitane , Yamashita Tetsushi , Ishino Yoshio , Hirashima Tsuneaki , Miwa Toshio
Published: July 2006

The structures of silver(I) complexes with cyclo(glycyl-l-histidyl), cyclo(l-methionyl-l-histidyl), and cyclo(l-histidyl-l-histidyl) were examined using 1H and 13C NMR. The NMR measurements suggest that the silver(I) ion links to the sulfur atom of thioether and the nitrogen atom of imidazole group of the above cyclic peptides, but not to their amide groups.
Synthesis of 2,2-Diphenyl-3-oxetanol Derivatives and Their Thermal or Acid-catalyzed Decomposition
Authors: Shimizu Nobujiro , Yamaoka Shintaro , Tsuno Yuho
Published: July 2006

A series of five different 2,2-diphenyl-3-oxetanols was synthesized by photocycloaddition of benzophenone and enol trimethylsilyl ethers followed by protolysis of the resultant 3-trimethylsiloxyoxetanes. Thermal cleavage and acid-catalyzed rearrangement of these oxetanes are described.
Preparation of Aryltributyltin Having Electron-withdrawing Group by Palladium Catalyzed Reaction of Hexabutylditin with Aryl Iodide
Authors: Kosugi Masanori , Ohya Takao , Migita Toshihiko
Published: July 2006

Nitro-, acyl-, and cyanophenyltributyltin can be prepared by the reaction of hexabutylditin with the corresponding aryl iodide in the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium.
Hydrolysis of p-Nitrophenyl Esters by Histidine-containing Linear and Cyclic Peptides
Authors: Kodaka Masato
Published: July 2006

Hydrolysis of p-nitrophenyl acetate (PNPA) and p-nitrophenyl hexanoate (PNPH) catalyzed by several linear and cyclic peptides containing histidine and other amino acid residues was studied. The catalytic activity of the peptides was less than that of imidazole for PNPA and PNPH. On the other hand, in the presence of a cationic surfactant and a hydrophobic peptide the hydrolysis of PNPH was significantly enhanced.
A Rate Equation System Having a Mnemonic Function
Authors: Iwamoto Kazutoshi , Mitomo Shun-ichi , Sen\={o} Manabu
Published: July 2006

A chemical system having a mnemonic function is constructed and its behavior is analyzed. The system consists of a subsystem having seven steady states and, under suitable conditions, it stays in a stable steady state or in an oscillating state depending on the initial state. Moreover, the system can show an additional oscillating state around the oscillating state and transitions between two different oscillating states occur by a little change in a certain parameter value(input), which is the characteristic point in this system. Therefore, a response behavior of the system to an input differs drastically depending on the states, i.e., oscillating or stationary. This property could be related to appearance of a mnemonic function. Moreover, it is demonstrated that the system could be linked with an excitable subsystem to show more clearly the mnemonic function proposed here.
A Simple Pressurized High-temperature Proton NMR Apparatus for the Thermal Degradation of Polymers
Authors: Shimokawa Shigezo , Yamada Eiji , Makino Kazuo
Published: July 2006

A simple pressurized, externally heated, high-temperature proton NMR apparatus for the temperature range from 293 to 823 K and pressure range from 0.1 to 40 MPa is reported. The sample cell has a capillary opening and the vessel is pressurized by inert gas. An application of this apparatus to the thermal degradation of poly(vinyl chloride) is presented.
Infrared Intensities in Methyl Chloride. I. The Fundamental Bands
Authors: Kondo Shigeo , Koga Yoshinori , Nakanaga Taisuke , Saëki Shinnosuke
Published: July 2006

The integrated intensities of the fundamental bands of CH3Cl and CD3Cl molecules have been measured by the pressure broadening technique. The Coriolis intensity perturbation between ν3 and ν6 bands of CD3Cl has been analysed to determine the sign to be negative. The intensity analysis has been carried out to determine the correct signs of (∂p/∂Qi). The resulting signs are (−++) for A1 and (−+−) for E species. The (∂p/∂SjR) values as well as the atomic polar tensors have been obtained.