bluuebunny/crossref_metadata_2025 huggingface dataset:
The Fluorometric Determination of Magnesium with 2,2′-Dihydroxy-4,4′-dimethylazobenzene
Authors: Aoki Izuo , Saito Atsushi , Watanabe Kunihiro
Published: July 2006

In an alkaline medium, magnesium reacts with 2,2′-dihydroxy-4,4′-dimethylazobenzene to emit a strong fluorescence, which is about 5 times as intense as that obtained with its parent compound (2,2′-dihydroxyazobenzene). Nonextraction (water–ethanol–dioxane, a mixed solvent) and extraction (an isopentyl alcohol solvent) procedures for the fluorometric determination of magnesium with this reagent were established. 0.1 μg to 4.0 μg of magnesium can be rapidly determined by the nonextraction procedure. In the extraction procedure, 1000-fold excesses of calcium did not interfere even when no masking agent was used.
Rotational Isomerism in Fluorene Derivatives. XVI. Conformational Equilibria of 9-Substituted 9-(2′-Bromomethylphenyl)fluorene Derivatives
Authors: Nishida Akiko , Shirakawa Shinsuke , Yamamoto Masuji , Watanabe Shigeki , Fujisaki Shizuo , Kajigaeshi Shoji
Published: July 2006

(Eight 9-substituted 9-(2′-bromomethylphenyl)fluorene derivatives) (1) were prepared. Their conformational equilibria (ap\ightleftarrowssp) are discussed on the basis of kinetic data for internal rotation obtained by 1H NMR spectroscopy.
Tellurium-Assisted Cyclopropanation and Alkylidenation of α,β-Unsaturated Carbonyl Compounds with Dibromomalonic Esters
Authors: Matsuki Toshiaki , Hu Nan Xing , Aso Yoshio , Otsubo Tetsuo , Ogura Fumio
Published: July 2006

Dibutyl telluride assists cyclopropanation of α,β-unsaturated ketone, ester, and nitrile with dibromomalonic esters without solvent at room temperature. In addition, it effects alkylidenation of aldehydes including α,β-unsaturated aldehyde with the same reagent.
The Utility of t-Butyldimethylsilane as an Effective Silylation Reagent for the Protection of Functional Groups
Authors: Yamamoto Keiji , Takemae Makoto
Published: July 2006

Treatment of compounds containing functional groups, such as alcohols, amines, and carboxylic acids, with t-butyldimethylsilane in the presence of a catalytic amount of palladium on carbon is described to provide a new, convenient method for the introduction of a t-butyldimethylsilyl (TBDMS) group.
Stereoselective syn-Reduction of (R)-4-Acyl-2,2-dimethyl-1,3-dioxolanes with Metal Hydride Reagents
Authors: Chikashita Hidenori , Nikaya Toshiki , Uemura Hiromitsu , Itoh Kazuyoshi
Published: July 2006

Lithium tri-s-butylborohydride and lithium aluminum hydride were found to be efficient reducing agents for the stereoselective preparation of syn-glycerol derivatives from (R)-4-acyl-2,2-dimethyl-1,3-dioxolanes. The scope and limitation of the stereoselective l-Selectride reduction of (R)-4-acyl-2,2-dimethyl-1,3-dioxolanes were also described.
The Thermodynamics of Chemical Reactions at High Pressures
Authors: Hamann Sefton Davidson
Published: July 2006

A “thermodynamic” derivation by Jee of a simple proportionality between the effects of pressure on the enthalpy change ΔH and the entropy change ΔS for a chemical reaction in solution, is shown to be erroneous.
A Mechanistic Study of a Gas-Phase Ion/Molecule Reaction between CH2NH2+ and CH4
Authors: Okada Satoshi , Abe Yasuo , Taniguchi Setsuo , Yamabe Shinichi , Minato Tsutomu
Published: July 2006

A gas-phase ion/molecule reaction starting from (CH4+ and N2O)/(CH4 and N2O+) is studied using a pulsed-discharge high-pressure mass spectrometer and the ab initio MO calculation. Two dominant ions, C2H6N+ and C3H8N+, are recognized; they are formed by the methylation of CH4N+. The C2H6N+ is formed via the following two reactions:

CH2NH2+(or CH3NH+)+CH4 → (CH3)2NH2+ (5)

(CH3)2NH2+ → CH3NHCH2++H2 (7)

The methylation is composed of the heterolytic CH3+–H− addition to the C=N bond of CH4N+ and the subsequent H2 elimination. The growth of the ion by the methylation is largely exothermic, while the H2 elimination has a large energy barrier on the potential energy surface.
The Addition Effects of Methyl Halides on Ethane Ignition Behind Reflected Shock Waves
Authors: Takahashi Kazuo , Inomata Tadaaki , Moriwaki Takao , Okazaki Satiko
Published: July 2006

Ignition delay times were measured in C2H6–O2–CH3X(X:Cl, Br or I) mixtures highly diluted with argon behind reflected shock waves. The measurements covered a temperature range of 1200–1900 K and the pressure range of 1.4–2.9 atm. The times were longer than those without CH3X, indicating that CH3X inhibits ethane ignition. This was contrary to the previous results which showed that CH3X promoted methane ignition. To clarify the addition effects of CH3X from the viewpoint of the reaction mechanism, computational analyses were performed in C2H6–O2–CH3Br and CH4–O2–CH3Br mixtures. The analytical results showed that different chain cycles for Br-containing species were formed in the two mixtures. The opposite effects of CH3Br on ethane and methane ignitions could be interpreted in terms of these different cycles.
Dynamics of Exciplex Formation in Cholesteric Liquid Crystals Containing Carbazolyl and Terephthaloyl Group
Authors: Kawaguchi Koji , Sisido Masahiko , Imanishi Yukio , Kiguchi Masashi , Taniguchi Yoshio
Published: July 2006

Dynamics of exciplex formation was studied on cholesteric liquid crystals consisting of cholesteryl 3-(9-ethyl-3-carbazolyl)propanoate (3Cz-2), cholesteryl 5-phenylpentanoate (Ph-4), and cholesteryl methyl terephthalate (CMT) with different amounts of CMT. Transient fluorescence spectrum and the analysis of fluorescence rise and decay curves of the exciplex emission indicated that two types of exciplex are present at low temperatures. Rate constants of exciplex formation were obtained at different temperatures in the cholesteric and isotropic phases. The activation energy for the rate constant was nearly zero in the cholesteric phase, but it was positive (3–6 kcal mol−1) in the isotropic phase. The difference was interpreted in terms of different mechanisms of exciplex formation in the two phases.
Electronic Spectra of Square-Planar Bis(biuretato)cobaltate(III)-Type Complexes
Authors: Komorita Takashi , Fujita Masanori B , Kanamori Kan , Hayashi Sawako , Shimura Yoichi
Published: July 2006

Several square-planar cobalt(III) complexes of bis(biuretato)-type were synthesized with new quadridentate ligands, alkylenebis(biuret)’s, where alkylene bridging group is (R,S)- or (R)-propylene, 1,1-dimethylethylene, cis-1,2-cyclohexylene, or tetramethylethylene. Faraday parameters for possible CT transitions in the complexes were expressed as functions of MO coefficients and energies. From the examination of the magnetic circular dichroism, the intense absorption band observed at ca. 20×103 cm−1 was assigned to ligand-to-metal charge-transfer transitions of ligand π(au of D2h) to metal dyz and dzx′, and the ground state was inferred to be one close to D4h symmetry. The band assignment was also consistent with the resonance Raman spectrum of potassium bis(biuretato)cobaltate(III). Absorption spectra of the complexes occasionally lost intensity with decrease of temperature. Origin of the thermochromism, which was found to be reversible, was also discussed.
The Polymerization of Toluene and Its Analogs Catalyzed by a Copper(I) Chloride–Aluminum Chloride–Oxygen System
Authors: Toshima Naoki , Kanaka Keiichi , Ishiyama Naoko , Hirai Hidefumi
Published: July 2006

The polymerization of aromatic compounds other than benzene (such as toluene, xylene, ethylbenzene, mesitylene, and biphenyl) was performed by using a copper(I) chloride–aluminum chloride–oxygen system which caused benzene to polymerize. Excess aluminum chloride, with respect to copper(I) chloride, was required for these compounds to polymerize, as was also true for benzene. For example, the treatment of toluene with aluminum chloride and copper(I) chloride (15:3:1 in molar ratio) under 1 atm of oxygen at 50°C for 24 h gave toluene polymer in 204% yield based on copper(I) chloride. This fact suggests that copper(I) chloride also worked as a catalyst in the case of the polymerization of toluene. The toluene polymer was obtained as both solid and liquid products, both of which were soluble in various organic solvents. The solid product has a complicated, crosslinked and “quinonoid-like” structure. On the other hand, the liquid product has a structure that is nearly identical with that of methylated poly(1,4-phenylene). Other alkylbenzenes gave the only liquid polymerization products, except for o-xylene which gave a small amount of solid products. The polymerization of biphenyl gave a low-molecular-weight poly(1,4-phenylene).
Substituent Effect on the Enantiomer-Differentiating Reaction of Lithiomethyl p-Tolyl Sulfoxide with Meta- or Para-Substituted (R)-(−)-Menthyl Benzoates
Authors: Kunieda Norio , Nakanishi Takeshi , Kinoshita Masayoshi
Published: July 2006

Treatment of (R)-(−)-menthyl benzoates, which have a variety of meta- or para-substituents, with 2 equivalents of racemic lithiomethyl p-tolyl sulfoxide displays the feature of an enantiomer-differentiating reaction, affording the corresponding optically active β-keto sulfoxides. The degree and the direction of enantioselectivity were affected by the nature of the substituent on benzene ring. The electron-releasing substituents trend to increase the %e.e. value. The reversal in the configuration with the variation in the substituent which has a high electron-withdrawing p-CN group was also observed. The R⁄S values thus obtained gave a good correlation with Hammett’s a values (r=0.975), affording a negative straight line. Based on these observations, a plausible stereochemical course of this reaction has been discussed.
Structure and Optical Properties of a Thermochromic Schiff Base. Low-Temperature Structural Studies of the N,N′-Disalicylidene-p-phenylenediamine and N,N′-Disalicylidene-1,6-pyrenediamine Crystals
Authors: Inabe Tamotsu , Hoshino Naomi , Mitani Tadaoki , Maruyama Yusei
Published: July 2006

The crystal structure of N,N′-disalicylidene-p-phenylenediamine (BSP) has been determined at 108 K. This compound shows a thermochromic-type behavior in the crystalline state; this chromism has been interpreted in terms of an intramolecular proton transfer from the hydroxyl oxygen to the imine nitrogen through the O–H···N hydrogen bond. In comparison with the room-temperature structure, no significant differences in the molecular structure and the molecular packing in the lattice have been observed. The room-temperature and low-termperature structures of another N,N′-salicylideneaniline derivative, N,N′-disalicylidene-1,6-pyrenediamine (DSPY), have also been determined. In contrast to BSP, the absence of a thermal proton-transfer process in DSPY is suggested by optical measurements. Comparative studies of these two compounds indicate that a conjugation system which is not included in a π-electron configurational change by the proton transfer must be coplanar with the hydrogen-bonded chelate ring for the thermal proton transfer.
Crystal Structures and Electrical Properties of Tetrakis(methylseleno)tetrathiafulvalene (TSeC1-TTF) and Two Phases of (TSeC1-TTF)I3
Authors: Wang Ping , Inabe Tamotsu , Nakano Chikako , Maruyama Yusei , Inokuchi Hiroo , Iwasawa Naoko , Saito Gunzi
Published: July 2006

The crystal structure and the electrical property of TSeC1-TTF as well as those of the new complex (TSeC1-TTF)I3 with two kinds of phases are reported. The crystal structure of TSeC1-TTF was determined to be monoclinic, space group P21⁄a, a=7.728(1), b=20.952(4), c=5.315(1) Å, and β=90.57(2)° having a unit cell volume of 860.6(3) Å3. By an electrochemical method and a diffusion method, TSeC1-TTF gave two forms of single crystals of (TSeC1-TTF)I3. The crystal data of one form; monoclinic, space group P2⁄a, a=24.359(1), b=11.831(3), c=7.842(6) Å, β=96.71(4), V=2244(1) Å3 and those of the other; monoclinic, space group P2⁄a, a=23.174(5), b=11.727(3), c=8.960(5) Å, β=110.54(2)°, a=2280(1) Å3. The former complex has lower resistivity, 4.1×104Ω cm, compared with the latter one 1.1×108Ω cm. The dimerization is more noticeable in the latter complex than in the former one.
The Ab Initio Modeling of Hammett-Type Correlations. The Separation of Inductive Effects from Mesomeric Effects in Aromatic Systems
Authors: Niwa Jun
Published: July 2006

Substituent effects have been modeled using both substituted hydrogens and substituted benzenes perturbed with point charges in order to separate the inductive (field) effect from the mesomeric effect with the use of ab initio techniques. Several pure dipole ‘substituents’ have been introduced to derive the scale of inductive effects common to both aliphatic and aromatic systems. In the above systems the interaction energies have been estimated by dividing into electrostatic interaction and polarization. Calculations with the use of 4-31G basis set show satisfactory correlations with the experimentally determined substituent constants. The propriety of the present approach has also been examined for the gas-phase acidities of phenols.
Chelate Stability Constants of N-(o-Hydroxybenzyl)iminodiacetic Acid (HBIDA) with Yttrium and Lanthanoid Ions
Authors: Yoshida Isao , Sagara Fumio , Ueno Keihei
Published: July 2006

Chelate stability constants of N-(o-hydroxybenzyl)iminodiacetic acid with yttrium and some lanthanoid ions (M3+) were determined by the potentiometric method at 25 °C and at an ionic strength of 0.1 with potassium nitrate. The computation of the titration data indicated that four kinds of complexes, ML, ML23−, M(HL)+, and M(HL)2− (except for thulium and lutetium) were formed on each metal ion and the values of the stability constants increased with the increase of atomic number of the element. The values found for the stability constants of yttrium complexes are between those for gadolinium and terbium ions.
Thermotropic Behavior of Proteins and Acylated Proteins in Monolayers
Authors: Mita Tomoyoshi
Published: July 2006

In order to obtain information concerning the effect of proteins on the thermotropic properties of biological membranes, the temperature-dependences of monolayers of different proteins and some acyl derivatives of bovine serum albumin (BSA) have been investigated. The hydrophobic proteins such as hemoglobin, β-lactoglobulin, and β-casein formed dilute monolayers, whereas the hydrophilic proteins such as cytochrome C and lysozyme formed concentrated monolayers. BSA showed an intermediate isotherm between those of dilute and concentrated films. The monolayers of BSA, cytochrome C, and lysozyme were gradually expanded with increasing temperatures. However, the temperature-dependences of the monolayers of hemoglobin, β-lactoglobulin, β-casein, and acyl derivatives were significantly different from those of the monolayers of hydrophilic proteins. In detail, the monolayers of hemoglobin and β-lactoglobulin formed the most compact structures around 20 °C and 30 °C, respectively, while the monolayers of β-casein formed the most expanded structure around 30 °C. In addition, the monolayers of acetyl and propionyl derivatives formed the most compact structures around 30 °C. These results suggest that the hydrophobicity of protein is an important factor relating to thermal stability of proteins in monolayers.
The Synthesis and Oxidation of Mixed Cobalt(III) Complexes with Dimethyldithiocarbamato and Diamine Ligands, and the Crystal Structure of (+)500CD-Dimethyldithiocarbamatobis(ethylenediamine)cobalt(III) Bis[μ-(R,R)-tartrato]dianxtimonate(III) Pentahydrate
Authors: Kita Masakazu , Yamanari Kazuaki , Shimura Yoichi
Published: July 2006

Dithiocarbamato complexes, [Co(dtc)3−n(diamine)n]n+ (n=1 and 2 and dtc=dimethyldithiocarbamate) were newly prepared and characterized by means of their absorption, CD, and MCD spectra. (+)500CD-[Co(dtc)(en)2][Sb2(R,R-C4H2O6)2]·5H2O crystallized in the monoclinic space group of P21 with a=14.630(3), b=9.300(1), c=12.023(5) Å, β=110.78(3)°, V=1529.4(8) Å3, and Z=2. The refinement of 3346 reflections (Mo Kα radiation) led to R=0.073. The dtc complex had a Λ configuration. The Co–N bond trans to the dtc sulfur atom was longer by 0.026 A than the cis one. A novel oxidation derivative, [Co{(dimethylamino)thioxomethanesulfinato-O,S}(en)2]2+, was prepared and characterized by means of its XPS spectrum.
The Esterification of Carboxylic Acid with Alcohol over Hydrous Zirconium Oxide
Authors: Takahashi Kyoko , Shibagaki Makoto , Matsushita Hajime
Published: July 2006

The esterification of carboxylic acids with alcohols proceeded efficiently with hydrous zirconium oxide to give the corresponding esters in the vapor phase, in the liquid phase, and in an autoclave. The steric hindrance of carboxylic acids and alcohols affected the esterification by lowering the reactivity. With a rise in the reaction temperature, the conversion of the carboxylic acid increased. The dehydration of alcohols was prevented by using hydrous zirconium oxide in spite of the high reaction temperature. The reaction rate is first-order with respect to the concentration of the catalyst and an alcohol and is inversely proportional to that of the carboxylic acid. Transesterification also proceeded efficiently.
A Resonance Raman Study of Polymeric Thiolato Cobalt(III) Complexes: Possible Bridging Modes
Authors: Kanamori Kan , Ino Sonomi , Mizuno Yumiko , Kanesaka Isao , Kawai Kiyoyasu , Hidaka Jinsai
Published: July 2006

The resonance Raman spectra of polymeric CoIII {SCH2CH(NH2)COOH-S}3 and Na3CoIII (SCH2COO-S)3 complexes were investigated. The complexes gave two totally symmetric Co–S stretchings, indicating the presence of two different Co–S–Co bridging modes in the complexes. Possible bridging modes are discussed in relation to their structures.
Adsorption-Assisted Desorption and Cross Desorption of CO and H2 on Nickel Polycrystalline Surfaces
Authors: Yamada Taro , Zhai Runsheng , Iwasawa Yasuhiro , Tamaru Kenzi
Published: July 2006

The rates of adsorption and desorption during co-adsorption process of CO and H2 on the Ni polycrystalline surface were measured. The desorption rate of CO(a) was enhanced by the presence of CO(g) or H2(g) in the gas phase. The desorption rate of adsorbed hydrogen was accelerated by CO(g) but not by H2(g).
A Flow-Through Detector Based on the Photoelectrochemical Reaction of an Anthraquinone-2,6-disulfonate Dianion/Cationic Perfluoro Polymer Complex
Authors: Egashira Naoyoshi , Fujisawa Toshirou , Ohga Kazuya
Published: July 2006

A glassy carbon electrode modified with an anthraquinone-2,6-disulfonate dianion/cationic perfluoro polymer complex was used as the working electrode of a flow-through detector based on a photoelectrochemical reaction. Several α-amino acids gave anodic photocurrents. The photocurrent-peak area of proline increased linearly with the concentration in the range of 0.5–10 mmol dm−3 and the detection limit (S/N=2) was 5×10−5 mol dm−3.
Photoreaction of (E)-1-Mesityl-2-(2,4,6-tri-t-butylphenyl)diphosphene
Authors: Yoshifuji Masaaki , Sato Takahiro , Inamoto Naoki
Published: July 2006

Photoirradiation of (E)-1-mesityl-2-(2,4,6-tri-t-butylphenyl)diphosphene gave 1,2-bis(2,4,6-tri-t-butylphenyl)diphosphene via a cyclotetraphosphane.
Convenient Syntheses of Condensed Phenalenones. The Synthesis of Indeno[1,2-a]phenalene-6,8-dione and Its Dication
Authors: Kuroda Shigeyasu , Hirooka Syuzi , Tanaka Eishi , Fukuyama Yuriko , Tsuchida Tomohiko , Nakagawa Koichi
Published: July 2006

Convenient and general syntheses of condensed phenalenones with various ring systems fused at the 7 and 8-positions are described together with the synthesis of indeno[1,2-a]phenalene-6,8-dione (quinone) and the formation of its di-cationic species in strong acidic media.
Insolubilizing Studies of Water-Soluble Poly(Lys Tyr) by Tyrosinase
Authors: Nagai Akira , Yamamoto Hiroyuki
Published: July 2006

Insolubilization of water-soluble synthetic poly(Lys Tyr) was examined using tyrosinase in water and simulated seawater systems. Tyrosinase oxidized tyrosine aromatic nuclei, causing intermolecular crosslinking reactions. The salinity, system pH and α-chymotrypsin are considered to play roles in the insolubilizing reaction.
Nucleophilic Displacement of Bis(perfluoroalkanoyl) Peroxides with Perfluoroalkanoate
Authors: Yoshida Masato , Sasage Shyuichi , Kamigata Nobumasa , Sawada Hideo , Nakayama Masaharu
Published: July 2006

Bis(perfluoroalkanoyl) peroxide ((RFCO2)2) suffered a nucleophilic displacement with perfluoroalkanoate (RF′CO2−) to give new mixed peroxide (RF(CO)OO(CO)RF′). When thiophene was reacted with bis(perfluoroalkanoyl) peroxide in the presence of pyridinium perfluoroalkanoate, not only the perfluoroalkyl group (RF) of the peroxide, but also perfluoroalkyl group (RF′) of perfluoroalkanoate, was introduced into thiophene.
Nitrogen-15 NMR Chemical Shifts in Metal–Ammine Complexes. II. Cobalt(III) Ammine and Amine Complexes
Authors: Nakashima Yoshiaki , Muto Masayuki , Kawano Keiichi , Kyogoku Yoshimasa , Yoshikawa Yuzo
Published: July 2006

15N nuclear magnetic resonance spectra were measured for [CoX(15NH3]n+ (X=CN−, 15NH3, H2O, and Br−) and cis-[CoX2(en-15N,15N)2]n+ (X2=(CN−)2, (NO2−)2, en-15N,15N, ox2−, and (H2O)2; en-15N,15N and ox2− represent the 15N-enriched ethylenediamine and oxalate ion, respectively). Two sharp signals of 15N NMR were observed for [CoX(15NH3)5]n+ except for the cases of X=15NH3 and NO2−. The signals of 15N NMR in cis-[CoX2(en-15N,15N)2]n+, were assigned on the basis of the selectively proton irradiated spectra at frequencies which had been already assigned to each amino proton. The chemical shifts of 15N NMR are correlated to the Co–N bond strength; it is expected that the stronger is the Co–N bond, the greater is the shift of the 15N NMR signal to a higher field. When we express [CoX(15NH3)5]n+ and cis-[CoX2(en-15N,15N)2]n+ as [CoXN5]n+ and cis-[CoX2N4]n+, the effect on the 15N NMR chemical shifts by the substituent X is roughly additive.
A Complex Generated in a Cationic Surfactant-Aromatic Additive System
Authors: Hirata Hirotaka , Kanda Yumi , Sakaiguchi Yuko
Published: July 2006

Aqueous binary solutions of hexadecyltrimethylammonium bromide (HTAB) and o-iodophenol (OIPh) exhibit remarkable viscoelasticity. From the centrifuged sediment of such a solution a crystalline product was isolated on long standing. Elementary analysis of the crystals for C, H, and N gave an estimated composition consistent with a one-to-one molar ratio of the two substances. Comparisons with DSC and IR measurements on the crystal and equimolar mechanical mixtures suggested that a crystalline complex was formed characterized by low thermal stability.
Solution Properties of Sodium Perfluoroalkanoates. Heats of Solution, Viscosity B Coefficients, and Surface Tensions
Authors: Tamaki Kunio , Ohara Yoko , Watanabe Sumiko
Published: July 2006

The heats of solution, the viscosity B coefficients, and the surface activities of sodium perfluoroalkanoates, F(CF2)nCOONa, n=1–4, 6, 7), in water were measured. The changes in the heat capacity for dissolution in water, ΔCp∞, calculated from the heats of solution at 15, 25, and 35 °C, were positive for the salts, and the ΔCp∞ values increased with an increase in n. The increment in the ΔCp∞ values per CF2 group was 93 J K−1 mol−1. The viscosity B coefficients increased with the chain length at a definite temperature, and the increment in the viscosity B coefficients per CF2 group was 0.119 dm3 mol−1 at 25 °C. Further, the viscosity B coefficients for all the salts decreased with the increase in the temperature between 15 and 35 °C. Traube factors, as obtained from the surface tensions, were found to be 3.0 for the homologs from C2 salt to C7 salt. The results are discussed in comparison with those of sodium alkanoates, H(CH2)nCOONa.
Effects of Temperature on the Solvent Extraction of Zinc and Cadmium Complexes with 8-Quinolinol and 2-Methyl-8-quinolinol into 1,1,2,2-Tetrachloroethane, 1-Octanol, and p-Xylene
Authors: Nakayama Eiichiro , Sohrin Yoshiki , Isshiki Kenji , Karatani Hajime , Yamada Etsu
Published: July 2006

The effects of temperature on the extraction of zinc(II) and cadmium(II) complexes with 8-quinolinol (HQ) and 2-methyl-8-quinolinol (HR) into three different types of organic solvents whose boiling points are relatively high were studied. 1) In the case of 1,1,2,2-tetrachloroethane (TCE), the extraction equilibrium can be written as follows (except for that of zinc with 2-methyl-8-quinolinol):

2M2++6HQ(o)+X−\ightleftarrowsM2Q3(HQ)3+(o)+X−(o)+3H+,

where X− refers to various inorganic anions. An ion-pair of the binuclear complex (complex ion pair) dissociates into a complex cation and an inorganic anion in the organic phase. The distribution ratios decrease remarkably with an increase in temperature. 2) In the 1-octanol (S) extraction system, zinc and cadmium are extracted as solvent-adducts, such as MQ2·S2. The distribution ratios are almost constant with a change in temperature. 3) In the p-xylene extraction system, a hydrated metal complex, MQ2·2H22H2O, may precipitate and be deposited at the interface of both phases, except for the extraction of zinc with 2-methyl-8-quinolinol. 4) The zinc complexes of 2-methyl-8-quinolinol are extracted into TCE and p-xylene as anhydrous complexes, such as MR2. The distribution ratios increase with an increase in temperature. Moreover, zinc can be separated from cadmium at high temperatures using 2-methyl-8-quinolinol and TCE.
Solvent Effect on the Liquid–Liquid Partition of 21H,23H-Porphine between Various Organic Solvents and Acidic Aqueous Solutions
Authors: Wakui Yoshito , Imura Hisanori , Suzuki Nobuo
Published: July 2006

The liquid–liquid partition equilibrium of 21H,23H-porphine has been investigated at 25 °C. Organic phases were heptane, dodecane, carbon tetrachloride, benzene, toluene, chloroform, dichloromethane, and 1-octanol. The acidic aqueous phases were 5×10−2–5×10−1 M hydrochloric acid. Porphine is present in such acidic solutions as a diprotonated form and no dimerization was found in any of the systems. The organic solvent effect on the partition coefficient of porphine is discussed with the aid of regular solution theory, and the solubility parameter of porphine is estimated as 10.7±0.6 cal1⁄2 cm−3⁄2.
Structures and Spectral Properties of Some Bis(β-diketonato)copper(II)Diazole Complexes. I. The 1:4 and 1:1 Adducts of Bis(1,1,1,5,5,5-hexafluoro-2,4-pentanedionato)copper(II) and 3-Methyl-1H-pyrazole
Authors: Kogane Tamizo , Ishii Minoru , Harada Kazumasa , Hirota Reiko , Nakahara Masayoshi
Published: July 2006

Cu(hfac)2(5-Hmpz)4 (1) and Cu(hfac)2(5-Hmpz) (2) (Hhfac=1,1,1,5,5,5-hexafluoro-2,4-pentanedione; 5-Hmpz=5-methyl-1H-pyrazole) have been prepared by the stoichiometric reactions of Cu(hfac)2 with 3-methyl-1H-pyrazole in petroleum ether. The structures of 1 and 2 have been determined by X-ray analyses. Crystal data for 1: triclinic, P\bar1, a=9.531(1), b=10.286(2), c=8.891(2) Å, α=95.85(2), β=95.52(2), γ=85.41(1)°, V=860.9(3) Å3, Z=1, and R=0.061. Crystal data for 2: triclinic, P\bar1, a=9.647(6), b=12.075(9), c=9.130(5) Å, α=107.43(5), β=99.30(5), γ=87.20(6)°, V=1001.3(12) Å3, Z=2, and R=0.064. In 1, the geometry about each copper atom is approximately that of a tetragonal bipyramid, with four nitrogen atoms from 5-Hmpz molecules in the equatorial plane and two oxygen atoms from each hfac ligand in the axial positions. Each of the uncoordinated oxygen atoms of hfac ligands is intramolecularly hydrogen-bonded with two imino groups of adjacent 5-Hmpz molecules. In IR spectra, the split bands of νC–O were observed at 1648 and 1659 cm−1. In 2, each copper atom is approximately in an environment of a tetragonal pyramid, with an oxygen atom from a hfac ligand at the apex and a nitrogen atom from a 5-Hmpz molecule in the basal plane. The copper atom is located slightly above the plane. The split bands of νC–O were observed at 1644, 1662, 1669 cm−1. An interpretation of the observed IR spectral bands is proposed.
Selective Fluorimetric Determination of Trace Amounts of Cobalt(II) with the System of Fluorescein–Hydrogen Peroxide–Tiron
Authors: Mori Itsuo , Fujita Yoshikazu , Nakahashi Yoshihiro , Ikuta Kinuko , Kato Keiji
Published: July 2006

The decomposition reactions of fluorescein (Fl) or its halo derivatives in the basic region were systematically investigated in the presence of an oxidizing agent such as hydrogen peroxide and/or a metal ion such as cobalt(II) and/or catalytic agent such as tiron as an activator. Moreover, a highly selective spectrophotofluorimetric method for the determination of trace amounts of cobalt(II) was established by measuring the difference in relative fluorescence intensities (ΔF) between Fl–tiron–hydrogen peroxide and Fl–tiron–hydrogen peroxide-cobalt(II) solutions at an emission wavelength of 510 nm, with an excitation wavelength of 490 nm (the calibration graph was linear in the range of 0–6 ng cobalt(II) per 25 cm3). The applications to the assay of cobalt in cyanocobalamine (vitamin B12) preparations and its eye drops were also investigated, the results were relatively good.
Substituent Group Electronic Effects on Inversion and Proton-Exchange Rates at Chiral Nitrogen Centers for a Series of Bis(β-diketonato)(N-methylethylenediamine)cobalt(III) Complexes
Authors: Ma Guilin , Kojima Masaaki , Fujita Junnosuke
Published: July 2006

The rates of the base-catalyzed proton exchange (deuteration, kD) and inversion (epimerization, kep) at chiral nitrogen centers of [Co(Xacac)2(Me-en)]+ (Xacac: NO2acac=3-nitro-2,4-pentanedionate, Clacac=3-chloro-2,4-pentanedionate, CH3acac=3-methyl-2,4-pentanedionate; Me-en=N-methylethylenediamine) in aqueous solutions have been measured at 34.0 °C, and the results were compared with one another and with those of the corresponding acac complex (acac=2,4-pentanedionate) in order to investigate the substituent influence on the rates. The kD and kep values of the NO2acac complex are ca. 104 and ca. 106 times, respectively, larger than those of the CH3acac complex. The effect of substituents is electronic and the Hammett relationship was found to hold for both deuteration and epimerization rates. The reduction (Co3+/Co2+) half-wave potential, E1⁄2 obtained by rotating glassy carbon electrode voltammetry increases from −0.59 V (vs. SCE) for the CH3acac complex to −0.08 V for the NO2acac complex. A linear dependence was observed between E1⁄2 and the Hammett parameter.
Use of Polyoxetane Resin-Supported Quaternary Onium Salts as a Polymeric Phase-Transfer Catalyst for Preparing Ethers from Hydroxy Compounds and Alkyl Halides
Authors: Motoi Masatoshi , Shimamura Katsuhiko , Shimamura Chikako , Muramoto Satoru , Kanoh Shigeyoshi , Suda Hiroshi
Published: July 2006

As a polymer support for preparing polymeric phase-transfer catalysts (PTC), soft, moderately polar polyoxetane resins were employed which were synthesized by a cationic ring-opening copolymerization of oxetanes Br(CH2)nOCH2–X with bisoxetanes X–CH2O(CH2)nOCH2–X, where X=3-methyl-3-oxetanyl and n=4 or 6. In a few cases of those polymerizations, 3-(2-oxadecyl)-3-methyloxetane was used as a comonomer with a lipophilic pendant. The terminal bromine of the pendant groups of such polyoxetane resins was quaternized with tributylamine or tributylphosphine in DMF in order to examine the phase-transfer catalyzing ability of the resultant quaternary onium bromides in the etherification reaction between alkyl halides and alcohols or phenols. These reactions gave the desired products in fairly good yields within reaction periods of 1–3 h, indicating that the catalytic activities of those PTCs are comparable to that of tetrabutylammonium bromide. A fairly high catalytic activity of the polymeric PTC was observed at each of ten stages in a process using the polymeric PTC repeatedly for the etherification reaction of 3-hydroxymethyl-3-methyloxetane with 1,4-dibromobutane.
Nucleophilic Substitution Reactions of Alkyl Halides by Using New Polymer-Supported Reagents Containing Hemin
Authors: Saito Kiyoshi , Harada Kaoru
Published: July 2006

A new polymer reagent consisting of hemin, divinylbenzene, and 2-methyl-5-vinylpyridine was synthesized by suspension copolymerization. Substitution reactions of primary, secondary, and tertiary alkyl halides with the hemin copolymer combined with cyanide, azide, and thiocyanate ions were given satisfactory yields. This reaction mechanism was revealed to be a SNi type on the basis of stereochemical study. The hemin copolymer was not only a polymer-supported reagent with functional capabilities, but also served to separate the product from the reaction mixture.
Polymerization of Amino Acids in Liposomal Membrane under Reduced Pressure and Normal Pressure
Authors: Shibata Akira , Yamashita Sinsuke , Ueno Satoru , Yamashita Takuya
Published: July 2006

Incorporation of polypeptides with hydrophobic side groups into lipid bilayers was achieved by the polymerization of N-carboxy anhydrides of γ-dodecyl l-glutamate and of γ-benzyl d-glutamate in DMPC liposomal membrane under reduced pressure and normal pressure. The effects of polypeptide conformations on the barrier properties of liposomal membrane incorporating polypeptide were examined. There was little difference in the trapping volume when liposomes prepared under reduced pressure and normal pressure were compared. The incorporation of polypeptides into the membrane bilayer had a tendency to decrease the volume trapping efficiencies. It was found that in the membrane-free aqueous phase, polymerization of N-carboxy amino acid anhydrides promoted formation of β-structure and in the membrane bilayer formation of α-helix structure was enhanced. The content of α-helical polypeptide was maximum for liposomes prepared under reduced pressure. The activation energies for water permeation across the liposomal membrane were lowered by the incorporation of polypeptdes into the membrane bilayer. The incorporation of α-helical polypeptide was more ceffective than that of β-structured one for the lowering of activation energies. The permeability barrier properties of liposomal membrane were larger for liposome incorporating poly(γ-dodecyl l-glutamate) (PDOLG) than for liposome incorporating poly(γ-benzyl d-glutamate)(PBDG). This seems to be due to a difference in miscibilities with lipid in the membrane bilayer.
Addition of 9-Diazofluorene to Unsubstituted and Chloro-Substituted 1,4-Benzoquinones. A Comparison with the Addition of Diphenyldiazomethane
Authors: Oshima Takumi , Nagai Toshikazu
Published: July 2006

Unsubstituted 1,4-benzoquinone (1a) reacted at the C=C double bond with 9-diazofluorene (9-DF) to give norcarene dione 2a and 4,7-dihydroxy-3H-indazole 4a. Similarly, the reaction of 2-chloro-1,4-benzoquinone (1b) with 9-DF yielded norcarene dione 2b and 4,7-dihydroxy-3H-indazole 4b, together with tricyclic dione 3b. 2,3-dichloro-1,4-benzoquinone (1c) and 9-DF produced norcarene dione 2c, 4,7-dihydroxy-3H-indazole 4c, and its fluorenyl ether 5c. Reactions of 2,5- and 2,6-dichloro- and trichloro-1,4-benzoquinones (1d, 1e, and 1f) with 9-DF provided norcarene diones 2d, 2e, and 2f and tricyclic diones 3d and 3e, respectively. On the other hand, tetrachloro-1,4-benzoquinone (1g) converted 9-DF into 9,9′-bifluorenylidene possibly via a 1:1 betaine intermediate arising from the C=O double bond addition. These results were markedly different from those of the previous diphenyldiazomethane reactions and are discussed in terms of structural changes of these diazoalkanes.
Oxidation Using Quaternary Ammonium Polyhalides. III. An Effective Oxidation of Alcohols and Ethers by the Use of Benzyltrimethylammonium Tribromide
Authors: Kajigaeshi Shoji , Kawamukai Hiroshi , Fujisaki Shizuo
Published: July 2006

The reaction of primary alcohols or simple ethers and α,ω-diols or cyclic ethers with a stoichiometric amount of benzyltrimethylammonium tribromide (BTMA Br3) in carbon tetrachloride in the presence of Na2HPO4 aq or in acetic acid in the presence of CH3CO2Na aq at 60–70 °C gave dimeric esters and lactones respectively in good yields. The reaction of secondary alcohols with 1 equiv of BTMA Br3 in the presence of a buffer at 60 °C gave ketones.
Syntheses of Cholesta-5,7-diene-3β,25-diol and Cholesta-5,7-diene-1α,3β,25-triol
Authors: Tachibana Yoji , Yokoyama Shinji , Tsuji Masahiro
Published: July 2006

Adducts of 3β-acetoxy- and 1α,3β-diacetoxy-23,24-dinorchola-5,7-dien-22-al (7 and 14) with 4-phenyl-3H-1,2,4-triazole-3,5-dione prepared by the ozonolysis of the corresponding adducts of ergosteryl acetate and 1α-acetoxyergosteryl acetate were transformed into 22-bromo-3β-tetrahydropyranyloxy- and 22-iodo-1α,3β-bis(tetrahydropyranyloxy)-23,24-dinorchola-5,7-diene (11 and 26). The halide derivatives (11 and 26) were coupled with 2-methyl-4-phenylsulfonyl-2-(tetrahydropyranyloxy)butane (6) to afford 23-phenylsulfonyl-3β,25-bis(tetrahydropyranyloxy)- and 23-phenylsulfonyl-1α,3β,25-tris(tetrahydropyranyloxy)cholesta-5,7-diene (12 and 27). The reductive desulfonylation and deprotection of the tetrahydropyranyl group of 12 and 27 provided the title compounds, cholesta-5,7-diene-3β,25-diol (1) and cholesta-5,7-diene-1α,3β,25-triol (2).
Preparation of 3,6-Disubstituted Pyridazines from 3-Thiapentane-1,5-diones via 2,7-Dihydro-1,4,5-thiadiazepines
Authors: Nakayama Juzo , Konishi Toru , Ishii Akihiko , Hoshino Masamatsu
Published: July 2006

A series of 3-thiapentane-1,5-diones condense with hydrazine in the presence of a catalytic amount of p-toluenesulfonic acid in refluxing ethanol to give 2,7-dihydro-1,4,5-thiadiazepines in excellent yields. Thermal decomposition of the latter compounds in refluxing diethylene glycol affords the corresponding pyridazines in high yields with evolution of hydrogen sulfide. The above procedure is generally applicable to the preparation of a wide variety of 3,6-disubstituted pyridazines which are of structural interest and otherwise difficult to prepare.
Catalytic Oxygenation of Benzene. Catalyst Design and Its Performance
Authors: Kunai Atsutaka , Wani Takayuki , Uehara Yasushi , Iwasaki Fumiaki , Kuroda Yasushi , Ito Sotaro , Sasaki Kazuo
Published: July 2006

A catalyst system for oxygenation reaction of benzene has been discussed. The catalyst system is composed of Pd and Cu species and operates in neat benzene under ambient conditions by feeding hydrogen and oxygen to the system. By selecting the reaction conditions properly, either phenol or benzoquinone is obtained as the major product.
Total Synthesis of Erythronolide A
Authors: Nakata Masaya , Arai Masayuki , Tomooka Katsuhiko , Ohsawa Naoki , Kinoshita Mitsuhiro
Published: July 2006

The enantiospecific total synthesis of erythronolide A (1) through (9S)-9-deoxo-9-hydroxyerythronolide A (2) from the chiral C1–C6, C7–C9, and C10–C13 synthetic segments is described. The C10–C13 segment, (3R,4R,5R)-5-O-benzyl-2-iodo-3,4-O-isopropylidene-4-methyl-1-heptene-3,4,5-triol (11) was synthesized in 16 steps and an 8.3% overall yield from d-ribose. The C7–C9 segment, (S)-(+)-2-(2-bromo-1-methylethyl)-1,3-dioxolane (47) was prepared from methyl (S)-(+)-3-hydroxy-2-methylpropionate in 8 steps and a 49% overall yield. The coupling of the Grignard reagent, prepared from magnesium and 47, and the C1–C6 segment, 3,5,7-tri-O-benzyl-1,4,6-trideoxy-4,6-di-C-methyl-keto-l-ido-2-heptulose (13), afforded 5,7,9-tri-O-benzyl-2,3,6,8-tetradeoxy-2,4,6,8-tetra-C-methyl-l-threo-l-ido-nonose ethylene acetal (48) and its C4-epimer in 79% and 8% yields, respectively. 5,7,9-Tri-O-benzyl-4-O-t-butyldimethylsilyl-2,3,6,8-tetradeoxy-2,4,6,8-tetra-C-methyl-l-threo-l-ido-nonose (12), derived from 48, was subjected to coupling reaction with the lithium reagent prepared from 11 to afford about 5:1 excess of the “Cram” product 50. The homogeneous hydrogenation of 50 with [ClRh(Ph3P)3] gave 1,3,5,13-tetra-O-benzyl-6-O-t-butyldimethylsilyl-2,4,7,8,10,14,15-heptadeoxy-11,12-O-isopropylidene-2,4,6,8,10,12-hexa-C-methyl-d-arabino-d-gluco-l-ido-pentadecitol (54) and its C10-epimer in 41% and 7% yields from 12, respectively. The conversion of 54 to 2 was accomplished by a sequence of reactions including the Corey–Nicolaou lactonization method in a 17% overall yield. Selective 3,5-O-benzylidenation of 2 followed by PCC oxidation and debenzylidenation gave 1 in 52% yield.
Preparation of Perfluoroalkyl Ketones by the Reaction of Perfluoroalkyllithiums with Esters
Authors: Uno Hidemitsu , Shiraishi Yasukazu , Suzuki Hitomi
Published: July 2006

A variety of esters react with perfluoroalkyllithiums in situ generated from perfluoroalkyl iodides and methyllithium to give perfluoroalkyl ketones in good yields. Perfluoroalkyllithiums add to α, β-unsaturated esters only in the 1,2-addition mode even in the presence of copper salt. Exception was observed in the reaction with maleates where perfluoroalkylated succinic esters and normal 1,2-addition products are obtained in comparable amounts.
Compensation Effect in the Electrical Conduction Process in Polyene Incorporated Lipid Films
Authors: Sarkar D , Misra T N
Published: July 2006

Phosphatidylcholine films doped with polyenes show compensation behavior at low polyene concentration and follow a three constant semiconduction equation σT=σ0′ exp (E/kT0) exp (–E/kT), σ0′ and T0 being constants for the lipid and the other parameters having their usual meanings. Consistent values of the constants σ0′ and T0 obtained from various methods of evaluation suggest that the compensation effect has a physical origin. Significant change in the semiconduction activation energy of lipid film on various polyene doping suggests strong lipid–polyene interaction in the doped films.
Electrochemical Generation and Properties of the p-Dinitrobenzene Radical Anion in N,N-Dimethylformamide
Authors: Sauer Alexandra , Wasgestian Fritz , Nickel Ulrich
Published: July 2006

Potentiostatic reduction of p-dinitrobenzene in N,N-dimethylformamide yielded the anion radical. By careful exclusion of water and oxygen it was obtained free from by-products. It was stable for several hours at room temperature. Its UV-visible absorbance was determined in combination with polarographic analysis. The behavior towards water and oxygen is reported.
Studies on Organomercury(II) Complexes of Maltol
Authors: Bhatia Sangeeta , K. Kaushik Narender , S. Sodhi Gurvinder
Published: July 2006

A number of organomercury(II) complexes involving maltol (1) of the type RHgL (2) [R=phenyl (C6H5), o-, p-hydroxyphenyl (o-, p-HOC6H4), p-acetoxyphenyl (p-AcOC6H4), 2-furyl (2-C4H3O); HL=maltol] have been synthesized and characterized. Conductance measurements indicate that the complexes are nonelectrolytes. From IR and UV studies, it is concluded that maltol acts as a bidentate ligand, coordinating to the mercury(II) ion through phenolic and carbonyl oxygen atoms. 1H and 13C NMR support the stoichiometry of the complexes. Fluorescence spectra have been recorded for o-, p-HOC6H4HgL complexes. For C6H4HgL, p-HOC6H4HgL, and p-AcOC6H4HgL complexes, thermal studies (TG and DSC) have been carried out and relevant kinetic and thermodynamic parameters have been enumerated. In addition, the fragmentation pattern of the complexes has been analyzed on the basis of mass spectra.
Cluster Chemistry. Catalytic Behavior of [H2Ru4(CO)12]2− in Reduction of Benzaldehyde and Nitrobenzene
Authors: Wada Fumio , Shimuta Masanori , Matsuda Tsutomu
Published: July 2006

The dianion, [H2Ru4(CO)12]2−, showed excellent catalytic activity for the reduction of nitrobenzene, but not of benzaldehyde. In the presence of benzaldehyde under H2 pressure, the dianion was converted to a new species of good catalytic activity, which is closely similar to a complex obtained from the reaction of [H2Ru6(CO)18] with DBU (1,8-diazabicyclo[5.4.0]undec-7-ene).
Fluorescence Polarization Spectra along the Rotational Contour of the 10a01 Absorption Band of Pyrazine Vapor
Authors: Ohta Nobuhiro , Sekiguchi Osamu , Takemura Takeshi
Published: July 2006

Fluorescence polarization spectra for the 10a01 perpendicular absorption band belonging to the S0→S1 transition of pyrazine vapor have been obtained at room temperature. The spectra are well reproduced theoretically by considering the resonance fluorescence from fully resolved rotational levels in S1 and by employing a symmetric top approximation.
The Crystal and Molecular Structure of 2:2 Complex of 1,1,6,6-Tetraphenyl-2,4-hexadiyne-1,6-diol (DD) with 1-Methyl-2-(3-pyridyl)pyrrolidine (Nicotine)
Authors: Fukawa Ken-ichi , Harada Shigeharu , Kasai Nobutami , Toda Mari (née Segawa) , Mori Koji , Toda Fumio
Published: July 2006

X-Ray crystal structure analysis of the title complex is described. 2(C30H22O2),2(C10H14N2), F.W. 1153.5, monoclinic, space group P21, a=28.913(2), b=12.353(1), c=9.340(1) Å, β=98.20(1)°, V=3301.7(6) Å3, Dc=1.16 g cm−3 for Z=2. Two DD molceules are bound by two nicotine by four O–H···N hydrogen bonds to form a 2:2 complex. The crystal consists of these asymmetric 2:2 complexes.
The Resonance Raman Study on the Visible Absorption Spectrum of Tris(dithiooxalato-S,S)cobaltate(III)
Authors: Kanamori Kan , Ono Akiko , Ino Sonomi , Kanesaka Isao , Kawai Kiyoyasu , Hidaka Jinsai
Published: July 2006

The Raman bands due to the totally symmetric ν(C–C)+ν(C–S) and ν(Co–S) modes of tris(dithiooxalato-S,S)cobaltate(III) exhibit resonance enhancements with excitation lines in the visible region. The resonance Raman excitation profiles of the two modes reveal the presence of a charge-transfer transition in the visible absorption spectrum of the complex.
Solubility and Coupling Reactivity of Protected Peptides in Highly Polar Solvents
Authors: Morii Hisayuki , Ichimura Kunihiro
Published: July 2006

The solubility of protected peptides as well as the coupling rate was quantitatively examined in highly polar solvents. Symmetrical anhydrides in dimethyl sulfoxide (DMSO) containing N,N-dimethylformamide (DMF) or DMF solution of lithium chloride and diethyl phosphorocyanidate with triethylamine in DMSO–DMF were proved to be efficient coupling reagents for solid phase synthesis of hardly soluble peptides.
Organic Photochemical Reactions. XXXII. Photochemical Ring-Cleavage Reactions of 2,2-Diaryloxetanes in the Presence of Electron Donor
Authors: Nakabayashi Kenichi , Fujimura Shin , Yasuda Masahide , Shima Kensuke
Published: July 2006

Photochemical ring-cleavage reactions of 2,2-diaryloxetanes in the presence of triethylamine gave 1,1-diarylethenes selectively.
The Enantiomeric Purity of (S)- and (R)-4-Methylfarnesols Synthesized from Artificial Substrates by Means of a Farnesyl Diphosphate Synthase Reaction
Authors: Ohnuma Shin-ichi , Koyama Tanetoshi , Ogura Kyozo
Published: July 2006

Both (S)- and (R)-4-methylfarnesols, synthesized respectively from (E)- and (Z)-3-methyl-3-pentenyl diphosphates by means of farnesyl diphosphate synthase reactions, were demonstrated to be of almost 100% enantiomeric purity.
Syntheses of Polypeptides by Hydrogenolysis of N-Benzyloxycarbonyl-Amino Acid Anhydrides
Authors: Munegumi Toratane , Meng Yan-Qing , Harada Kaoru
Published: July 2006

When anhydrides of N-benzyloxycarbonyl-Dl-aspartic acid (Z-Dl-Asp), Z-l-Asp, N-Z-Dl-glutamic acid (Z-Dl-Glu), Z-l-Glu, and N-Z-3-aminoglutaric acid (Z-β-Agl) were hydrogenolyzed in N,N dimethylformamide (DMF), polypeptides were obtained in high yields. Hydrogenolyses of Z-Dl-Glu and Z-l-Glu in dioxane gave pyroglutamic acid.
The Absolute Configuration of 4,6-Decadiyne-1,3,8-triol Isolated from Gymnopilus spectabilis
Authors: Hashimoto Masaru , Yanagiya Mitsutoshi , Okuno Toshikatsu , Shirahama Haruhisa
Published: July 2006

The absolute configuration of 4,6-decadiyne-1,3,8-triol, isolated from Gymnopilus spectabilis, was established as (3S,8S) by the comparison of degradated compounds with synthetic ones.
The Effect of Starting Source on the Concentration Distribution of Nickel Supported on Alumina
Authors: Fujitani Tadahiro , Ueki Osamu , Echigoya Etsuro
Published: July 2006

The concentration profile and particle size of nickel supported on alumina spheres were easily controlled by varying the starting source materials of the impregnation solution. Further, the reduction behavior of nickel oxide supported on alumina was influenced by the starting nickel source material.