bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on Synthetic Ionophores. IX. X-Ray Crystal Structure Analysis of Potassium, Rubidium, and Cesium Salts of a Synthetic Carboxylic Ionophore
Authors: Kasuga Noriko , Nakahama Seiichi , Yamaguchi Kazuo , Ohashi Yuji , Hori Kayako
Published: July 2006

X-Ray crystal structure data are presented for potassium, rubidium, and cesium salts (2, 3, and 4) of 2-[[2-[2-[2-[2-[2-[2-[2-(2-hydroxyethoxy)phenoxy]ethoxy]phenoxy]ethoxy]phenoxy]ethoxy]phenoxy]methyl]benzoic acid (1). The crystals of the potassium salt (2) monohydrate dichloroform solvate (2·H2O·2CHCl3) are triclinic, space group P\bar1 with two molecules in the unit cell dimensions a=14.517(1), b=16.380(1), c=13.315(1) Å, α=72.313(8)°, β=117.313(8)°, γ=120.853(5)°. R=0.102 for 6351 observed reflections. The crystals of 3·H2O·CHCl3 are monoclinic, space group P21⁄a with four molecules in the unit cell dimensions a=24.085(6), b=13.068(2), c=13.983(4) Å, β=105.402(32)°. R=0.068 for 5112 observed reflections. The crystals of 4·H2O·CHCl3 are monoclinic, space group P21⁄n with four molecules in the unit cell dimensions a=24.412(7), b=13.075(2), c=14.077(4) Å, β=106.743(31)°. R=0.071 for 6153 observed reflections. The backbones of 2, 3, and 4 form pseudocycles by head-to-tail hydrogen bonding between the terminal carboxylato and hydroxyl groups (O···O distance, 2.672, 2.699, and 2.706 Å, respectively). The conformations about C–C and C–O bonds are gauche and trans respectively, except for two of the C–O bonds which are gauche to make the pseudocyclic backbone bend like the seam of a tennis ball resulting in the formation of cavities fitted for the size of each cation.
Preparation of Some Polyfunctional Indenes and Indanones: The Reaction of Mercapto-Substituted Cyclopropenium Salts with Alcohols and Thiols
Authors: Yoshida Hiroshi , Takahashi Youko , Kinoshita Hiroaki , Ukishima Sadao , Ogata Tsuyoshi , Matsumoto Kiyoshi
Published: July 2006

The reaction of 1-methylthio-, 1-(4-methylphenylthio)-, or 1-t-butylthio-2,3-diphenylcyclopropenium salts with alcohols, phenols, and thiols in the presence of triethylamine at around 80°C gave 1H-indene-1-thiol derivatives in fair to moderate yields. In contrast, the same reactions at room temperature afforded 1-alkylthio- or arylthio-1-cyclopropene derivatives together with a small amount of the 3-isomer. Some 1-isomers were separated as pure crystals and produced the corresponding indenes in quantitative yields when heated. Kinetic studies of the ring-opening of cyclopropenes suggested a vinylcarbene intermediate based on the small effects of solvent polarities and phenoxyl substituents on the reaction rates. The reaction of diphenylcyclopropenone with thiol in the presence of trifluoroacetic acid yielded 1H-indene-1,3-dithiol detivatives via a 1,3-bis(alkylthio)-or (arylthio)-1-cyclopropene intermediate. On acidic hydrolysis of 3-alkoxyindenes and on heating of 3-allyloxy- and 3-(2-propynyloxy)indenes, polyfunctionally-substituted indanones were obtained in good yields.
Dehydrooligopeptides. XIII. Selective Enzymatic Hydrolysis of N-Protected α-Dehydroglutamic Acid Diesters and Their Analogs Using Papain as Catalyst
Authors: Shin Chung-gi , Takahashi Nobuyuki , Seki Masashi
Published: July 2006

Since the α-ester of α,γ-dimethyl N-benzyloxycarbonyl-α-dehydroglutamate (ΔGlu) was found to be hydrolyzed using papain, a variety of N-protected α-dehydroglutamates and their analogs, both esters of which were the same or different from each other, were newly synthesized and subjected to a similar hydrolysis. Although the substrates, with bulkier ester group at the γ- as well as α-positions, were found to become difficult to hydrolyze, the kind and size of the N-protecting group did not effect the hydrolysis. Moreover, it was found that the length of side chain of the substrate greatly influenced hydrolysis. The present study suggests that papain may become a useful tool for the hydrolysis and coupling of ΔGlu with α-amino acid or peptide.
The Properties of the Multistage Bioreactor Constructed by the LB Technique
Authors: Ohnishi Michihiro , Ishimoto Coe , Seto Jun’etsu
Published: July 2006

A multistage bioreactor consisting of organic ultrathin layers was successfully realized by immobilizing glucose oxidase and glucoamylase by the Langmuir–Blodgett technique (LB technique). Starch as the substrate was quickly converted into gluconic acid and hydrogen peroxide as the products in this bioreactor via the intermediate, glucose. The rate of the sequential reactions was electrochemically measured. This rate increased proportionally with increasing the concentration of starch, and also increased with increasing the amount of glucose oxidase in the LB film. This bioreactor, however, decayed soon. The reason of this decay was considered to be the structural conversion of the LB layers with glucoamylase. The multistage bioreactor constructed by the LB technique will be used not only as a super small-sized, rapid bioreactor or biosensor but also as an investigating means of the reconstitution of membrane enzyme and biomembrane.
ENDOR and TRIPLE Studies of Diphenyl Nitroxide (DPNO)
Authors: Yamauchi Jun , Fujita Hideo , Deguchi Yasuo
Published: July 2006

ENDOR and triple resonance (GTR) of diphenyl nitroxide (DPNO) were observed in solution; it was demonstrated that DPNO is an interesting model radical forming a three-spin system (electron and 1H- and 14N-nuclear spins). The detected 14N-ENDOR belongs to one of the smallest hyperfine cases (AN=0.9653 mT). Its optimum temperature was 210 K, higher than that of the 1H, which is due to the large anisotropic hyperfine interaction of 14N. In the 1H-ENDOR spectra the effect of cross relaxation was observed, as in the case of the 14N-ENDOR lines; their temperature variations of intensity showed two maximum regions, one due to the optimum energy relaxation in the 14N-spin system and the other due to the energy relaxation inherent in the 1H-spin system. In the triple studies new phenomena were pointed out: An enhancement saturation effect due to the large hyperfine interaction and an intensified enhancement or de-enhancement effect due to the cross relaxation.
Cobalt(III) Complexes with [N6−nXn]-Type Ligands. VII. Preparation and Properties of Isomers of the (Salicylamidato)cobalt(III) Complexes with Tris(2-aminoethyl)amine, Triethylenetetramine, and Ethylenediamine Ligands
Authors: Toyota Eiko , Yamamoto Yoshihisa
Published: July 2006

Title complexes of t- and p-[Co(A)(tren)]Cl2·H2O, t- and p-[Co(C)(tren)]Cl·H2O, cis-β1 and β2-[Co(A)(trien)]Cl2·2H2O, cis-β1-[Co(C)(trien)]Cl·H2O, cis-β1-[Co(D)(trien)]Cl·H2O, [Co(A)(en)2]Cl2·H2O, [Co(C)(en)2]Cl·H2O, and [Co(D)(en)2]Cl·H2O have been obtained from a reaction mixture of [CoCl2L]Cl·H2O [L: tren, trien, or (en)2], Ag2O, and salicylamide.

(Remark: Graphics omitted.)

Separations of the A-, C-, and D-type complexes, and of the geometrical isomers of t- and p- or cis-β1 and β2 were attempted by using Dowex 50W-X2 column chromatography. Distinction of the A-, C-, and D-type complexes is described in the IR, 1H, 13C NMR, and absorption spectra; the solubility in DMSO; and the electric conductivities in aqueous solutions. The formation ratio of the A-, C-, and D-type complexes has been dependent upon the pH of the reaction mixture. The chemical shifts (δ=113–115) of the C-l carbon signals for the A-type complexes are at a higher field than those (δ=117–122) of the C- and D-type complexes. The ε values (3400–3700) of the charge transfer band at ca. 340 nm in the absorption spectra for the A-type complexes are greater than those (2500–3000) of the C- and D-type complexes. The C-type and D-type complexes are a linkage isomer. A characteristic property of the linkage isomer has been observed in the absorption and 13C NMR spectra as well as the solubility in DMSO.
Ferromagnetic Spin-Coupling between Gadolinium(III) and Copper(II) Ions in Discrete Binuclear Gd(III)–Cu(II) Complexes
Authors: Sakamoto Masatomi , Hashimura Masayuki , Matsuki Kimihiro , Matsumoto Naohide , Inoue Keiji , Okawa Hisashi
Published: July 2006

Three discrete binuclear gadolinium(III)–copper(II) complexes (CuGd(fsadien)NO3·5H2O (1), CuGd(hsapn)NO3·3H2O (2), and [Gd(pvm)3Cu(A)] (3)) have been synthesized; we use the notation H4fsadien=N,N′-bis(3-carboxysalicylidene)diethylenetriamine, H4hsapn=N,N′-bis(3-hydroxysalicylidene)-1,2-propanediamine, Hpvm=dipivaloylmethane (2,2,6,6-tetramethyl-3,5-heptanedione), and H2A=4-(6-methyl-8-oxo-2,5-diazanona-1,5,7-trienyl)imidazole. Magnetic susceptibility measurements (4.2–300 K) have revealed that the spin coupling between the Gd(III) and Cu(II) ions is ferromagnetic with coupling constants J=+2.3 cm−1 for (1), +5.7 cm−1 for (2), and +0.5cm  −1 for (3), on the basis of the spin-Hamiltonian H=−2JSGd·SCu.
Studies of the Hydrous Zirconium(IV) Oxide Ion Exchanger. II. The Rate of Isotopic Exchange of Sodium Ions between the Exchanger in the Na+ Form and Aqueous Solutions
Authors: Inoue Yasushi , Yamazaki Hiromichi , Narita Tomonori
Published: July 2006

The rate of the isotopic exchange of Na+ between hydrous ZrIV oxide in the Na+ form and aqueous solutions of sodium salts was determined radiochemically. The rate is controlled by particle diffusion, film diffusion, or both, according to the conditions. The exchange rate is controlled by particle diffusion, when the exchanger particles are large (radius, 171 μm), the solutions are more concentrated than 0.1 mol dm−3 Na+ and the flow rate through the exchanger particles is high, whereas under the opposite conditions film diffusion is the rate-controlling step. The activation energies of Na+ diffusion are 30±3 and 18.9±0.5 kJ mol−1 for particle and film diffusion, respectively.
Preliminary Polarographic Studies of Sulfur and Selenium Solutions in Hydrazine Hydrate
Authors: Srivastava S K , Babu K S Chandra , Srivastava O N , Singh Dharam
Published: July 2006

The dropping mercury electrode polarographic behavior of sulfur and selenium solutions in hydrazine hydrate has been studied in highly alkaline aqueous solution containing supporting electrolyte of 0.1 M ammonium tartrate (1 M=l mol dm−3). Both the sulfur and selenium revealed a composite anodic–cathodic waves. The values of E1⁄2 for sulfur and selenium solutions, taken from the cathodic wave of the polarograms corresponded to E1⁄2=−0.78 and −1.03 V vs. SCE respectively. The effect of mercury pressure and concentration of depolarizer on the relative magnitude of the wave heights has also been studied on the basis of typical reactions involved at DME in this solvent medium. No maxima supressor was used in the present study for both cases.
Electrochemical Reactions at Sacrificial Electrodes. VII. Synthesis of Some Unique Mercury(II) Alkoxides and Glycolates and Their Coordination Compounds
Authors: Banait Jagtar Singh , Devi Rani , Singh Baljit
Published: July 2006

The electrochemical oxidation of malononitrile, diethyl malonate, ethyl cyanoacetate, cyanoacetamide, ethyl acetoacetate, and acetylacetone has been carried out in acetonitrile at sacrificial mercury anode using tetrabutylammonium chloride as supporting electrolyte. The products of these reactions have been identified by elemental analysis and IR spectral studies and are found to be mercury(II) alkoxides/glycolates. Electrochemical oxidation of these compounds in the presence of ligands like 1,10-phenanthroline and 2,2′-bipyridyl yields coordination compounds of these alkoxides/glycolates. All these reactions have been found to proceed with a very high current efficiency.
Enhanced Production of Formic Acid by Halobacterium halobium MMT22 by Reduction of Hydrogencarbonate in Aqueous Solution
Authors: Khan Mirza Mohammad Taqui , Bhatt Jayshree
Published: July 2006

Enhanced production of formic acid was observed by reduction of hydrogencarbonate in aqueous solution by Halobacterium halobium MMT22. A one and half fold increase in the production of formic acid was observed in the presence of ascorbic acid as electron donor and [Ru(Bipy)3]2+ as photosensitizer.
Structural Study of the Two Phases of Tetrakis(methylseleno)tetrathiafulvalene (TSeC1–TTF)
Authors: Nakano Chikako , Wang Ping , Mori Takehiko , Maruyama Yusei , Inokuchi Hiroo , Yamochi Hideki , Saito Gunzi
Published: July 2006

The crystal structure of the low-melting point phase (L-phase) of a single component organic semiconductor, TSeC1–TTF, is determined and compared with that of the high-melting point phase (H-phase). The intracolumnar overlap mode and the calculated intermolecular overlap integrals are slightly larger in the L-phase, to which is ascribed the low resistivity of the L-phase. The L-phase, however, does not have two-dimensional networks of intercolumnar Se···Se contacts, which exist in the H-phase. This may be associated with the difference of the melting points.
Deuterium Isotope Effects on Aromatic Carbon-13 Chemical Shifts. III. One-, Two-, and Three-Bond Isotope Effects on the 13C Chemical Shifts of 3-Substituted Pyridines
Authors: Nakashima Yasuki , Ban Sadanori , Itoh Satoru , Takahashi Kensuke
Published: July 2006

The one-, two-, and three-bond deuterium isotope effects (1Δ, 2Δ, and 3Δ) on the 13C chemical shifts of 3-substituted pyridines are reported. 1Δ, 2Δ, and 3Δ are correlated with the 13C chemical shifts of the observed carbons. 1Δ, show a linear correlation with the 13C chemical shifts with a positive slope. On the other hand, 2Δ and 3Δ show linear correlations with the negative slopes. They can thus be interpreted in terms of the π-electron density change by the substituent and the electron release effects by carbons one and two bonds apart from deuterium, respectively.
Facile Production of d-Histidine by Asymmetric Transformation of l-Histidine
Authors: Shiraiwa Tadashi , Shinjo Kazuyuki , Masui Yoko , Ohta Atsushi , Natsuyama Hisashi , Miyazaki Hideya , Kurokawa Hidemoto
Published: July 2006

An asymmetric transformation from l-histidine [l-His] to d-His was achieved by using salicylaldehyde as a catalyst for epimerization, and (2R, 3R)-tartaric acid as a resolving agent, in acetic acid. Treatment of the obtained salt with triethylamine in methanol gave d-His with 100% optical purity in 95% yield based on the starting l-His.
3-Aryl-3-butenoic Acids and Their Esters: Practical Synthesis from Diketene by the Palladium-Catalyzed Grignard Coupling Reaction and Application as Monomers for the Radical Copolymerization with Styrene
Authors: Itoh Kenji , Harada Tatsumi , Nagashima Hideo
Published: July 2006

Treatment of arylmagnesium bromide with an equimolar amount of zinc chloride followed by the reaction with diketene in the presence of a catalytic amount of PdCl2(PPh3)2 provided an improved synthetic method for 3-aryl-3-butenoic acids in a large scale. Application as a monomer for the substituted polystyrenes is exemplified by the copolymerization of methyl 3-phenyl-3-butenoate with styrene.
Reaction of Dichlorotriphenylphosphorane with Bis(trimethylsilyl) Peroxide. A New Method for the Formation of Electrophilic Chlorine Source
Authors: Shibata Kazusato , Itoh Yukinori , Tokitoh Norihiro , Okazaki Renji , Inamoto Naoki
Published: July 2006

Reactions of dichlorotriphenylphosphorane with bis(trimethylsilyl) peroxide in the presence of some organic compounds have been found to give chlorinated products. Aromatic hydrocarbons bearing electron-donating substituents give the corresponding monochloroarenes, while an enol silyl ether is converted into α-chloro ketone. The mechanism is briefly discussed.
Selective Hydroxymethylation of Emodin
Authors: Pal Tarasankar , Pal Anjali
Published: July 2006

Electrochemical oxidation of 1,3,8-trihydroxy-6-methylanthraquinone, emodin, in dry alkaline methanol under a constant current of 0.05 A for 10 h under an applied potential difference of 15 V at room temperature resulted, for the first time, in an efficient and selective hydroxymethylation at C-2. The structure of the product was established from the detailed spectral analyses of its trimethyl ether and tetraacetylated derivative.
Some 13C and 15N NMR Studies on 1,8-Bis (dimethylamino) Naphthalene and Two of Its Salts
Authors: Grech E , Stefaniak L , Ando Isao , Yoshimizu Hiroaki , Webb Graham A
Published: July 2006

13C and 15N NMR data are reported for 1,8-bis(dimethylamino)naphthalene (DMAN) and two of its salts in both the solid state and solutions in CD3CN. Only the 15N results are sufficiently sensitive to show the presence of the fully protonated form of DMAN in the solid state and of a partially protonated structure in solution.
Studies on Stigmasterol Liquid Membranes
Authors: Srivastava M L , Shukla Nikhil K
Published: July 2006

Cellulose acetate supported stigmasterol liquid surfactant membrane has been characterized by measuring membrane potentials, using NaCl solutions of different concentrations. Fixed charge density, φ\barX, permselectivity, Ps, have been estimated from ionic transport numbers. Variation of membrane potential with pH and concentration of NaCl solution has also been examined.
Synthesis and Application of 5-Arylazothiophene Derivatives
Authors: Sabnis Ram Wasudeo , Kazemi Ghadir , Rangnekar Dinesh Wamanrao
Published: July 2006

Synthesis of 5-(hetoarylazo or arylazo)thiophene derivatives (6a–g) was achieved by diazotization of ethyl 5-amino-2,4-bis(ethoxycarbonyl)-3-thiopheneacetate (3) using nitrosyl hydrogensulfate, coupling with suitable heterocyclic hydroxy and N,N-dialkyl-substituted arylamines which resulted in thiophene azo dyes. The key intermediate 3, used as the diazonium component, was synthesized in one pot and in excellent yield from diethyl 3-oxopentanedioate, sulfur and ethyl cyanoacetate following the Gewald Synthesis. The dyes when applied as disperse dyes on polyester fibres gave excellent results.
New Syntheses and Physical Properties of p-Alkylcalix[n]arenes
Authors: Shinkai Seiji , Nagasaki Takeshi , Iwamoto Koji , Ikeda Atsushi , He G-X , Matsuda Tsutomu , Iwamoto Masakazu
Published: July 2006

Calix[n]arenes (n=4, 6, and 8) bearing long p-alkyl groups (R=hexyl and dodecyl) have been synthesized by “direct” acylation of the p-position followed by silane reduction. The method is convenient and the yields are higher than those reported so far. Among them, p-hexanoylcalix[4]arene showed a curious phase transition behavior; with raising the temperature it changed as crystal A→liquid→crystal B→liquid. It was found on the basis of the solid 13CNMR spectra that this behavior is ascribed to a conformational change from “cone” (crystal A) to “partial cone” (crystal B).
Micellar Accelerated Reduction of Ethylenediaminetetraacetatocobaltate(III) by 1-Benzyl-1,4-dihydronicotinamide
Authors: Yamashita Kohichi , Chiba Masahiro , Ishida Hitoshi , Ohkubo Katsutoshi
Published: July 2006

The electrostatic and hydrophobic effects of ionic micelles on the reduction of ethylenediaminetetraacetato cobaltate(III) ([Co(edta)]−) by 1-benzyl-1,4-dihydronicotinamide (BNAH) were investigated with dodecyltrimethylammonium chloride (DTAC) and/or sodium dodecyl sulfate (SDS). Cationic DTAC accelerated the reduction of [Co(edta)]−, while anionic SDS retarded the reaction. The micellar effects of DTAC on the present reaction at 30°C were kinetically analyzed by using the ion-exchange model and the Berezin’s approach: the evaluated rate constant, (1.0±0.1–1.1±0.4)×10−4 mol−1 dm3 s−1, for the micellar-phase reaction was ten times smaller than that, 1.46×10−3 mol−1 dm3 s−1, for the aqueous-phase one. This fact was well-explained by the electron-transfer rate constant calculated with the experimentally determined redox potentials of BNAH and [Co(edta)]−. The cationic DTAC micelles, however, resulted in considerably larger value (3.58×10−3 mol−1 dm3 s−1) of overall reaction rate constant than that (1.46×10−3 mol−1 dm3 s−1) of nonmicellar one, because the apparent concentrations of the reactants in the micellar phase increased remarkably by condensation of BNAH and [Co(edta)]− to the micelles through the hydrophobic interaction and the electrostatic interaction, respectively.
Oxidative Cleavage of Diselenide by m-Nitrobenzenesulfonyl Peroxide. Novel Method for the Electrophilic Benzeneselenenylations of Olefins and Aromatic Rings
Authors: Yoshida Masato , Sasage Shuichi , Kawamura Kyoko , Suzuki Takashi , Kamigata Nobumasa
Published: July 2006

Diphenyl diselenide was found to be readily converted into benzeneselenenyl m-nitrobenzenesulfonate (PhSeOSO2C6H4NO2-m) by treating with m-nitrobenzenesulfonyl peroxide. When the selenenyl sulfonate thus formed was allowed to react in situ with olefins, such as cyclohexene, 1-octene, or styrene, in the presence of various nucleophiles, the adducts of benzeneselenenyl group and a nucleophile were obtained. As the nucleophiles water, methanol, acetic acid, phenol, and anisole could be employed; oxyselenenylated ((Remark: Graphics omitted.) : R=H, Me, Ac, and Ph) and arylselenenylated ((Remark: Graphics omitted.) : R=H and Me) adducts were afforded. Phenol gave oxyselenenylated products in cyclohexene or 1-octene and arylselenenylated products in styrene. Efficient intramolecular cyclizations of unsaturated alcohols and carboxylic acids were similarly performed by the selenenyl sulfonate to afford corresponding benzeneselenenylated cyclic ethers and lactones. The selenenyl sulfonate was also found to be a highly reactive benzeneselenenylating reagent for aromatic rings, such as anisole, phenol, acetanilide, toluene, and benzene.
Aromatic Nucleophilic Substitution of Halobenzenes with Amines under High Pressure
Authors: Ibata Toshikazu , Isogami Yasushi , Toyoda Jiro
Published: July 2006

The nucleophilic substitution reactions of aromatic halides having electron-attracting groups on ortho or para position with various primary and secondary amines were accelerated by high pressure to give the corresponding N-substituted anilines in high yields. The bulkiness of amines affects its reactivity to lower the yields of the products. Although the secondary amines are usually less reactive than primary amines, cyclic secondary amines such as morpholine, piperidine, and pyrrolidine were found very reactive. 1,4-Diazabicyclo[2.2.2]octane and quinuclidine gave N-quaternary ammonium halides in high yields in contrast to the low reactivity of acyclic tertiary amines. Dichloro- and trichloro-nitrobenzenes also react with diethylamine, pyrrolidine, and morpholine to give mono-, di-, and trisubstitution products depending upon the amount of amine and the position of nitro group in these chlorides.
Exciplex Formation between Perylene and N,N-Dimethylaniline in a Ternary Inclusion Compound with γ-Cyclodextrin in H2O–Ethanol (7 : 3) Mixture
Authors: Hamai Sanyo
Published: July 2006

Inclusion compounds in the system of γ-cyclodextrin (γ-CD)-N,N-dimethylaniline (DMA)-perylene (Pe) have been studied in an H2O–ethanol (7 : 3) mixture by means of absorption and fluorescence spectral measurements. A ternary 1 : 1 : 1 inclusion compound of γ-CD–ethanol–Pe is formed by the addition of γ-CD to an H2O–ethanol solution of Pe. In the presence of γ-CD, a further addition of DMA results in the formation of a γ-CD–DMA–Pe inclusion compound followed by association with a 1 : 1 γ-CD–DMA inclusion compound to form a ternary 2 : 2 : 1 inclusion compound of γ-CD–DMA–Pe. The exciplex fluorescence of Pe–DMA within the γ-CD cavity has been observed from the ternary inclusion compound. Equilibrium constants for the formation of these inclusion compounds have been evaluated.
Ion-Exchange Reaction on Cubic Ammonium Molybdate in Acidic and Alkaline Media–Exchange of Structural NEU4+
Authors: Khan Abdul Jabbar , Abe Mitsuo , Kanzaki Yasushi , Tsuji Masamichi
Published: July 2006

The alkali metal ion exchange reaction on cubic ammonium molybdate (CAM) cation exchanger was studied in acidic as well as alkaline media. The ion-exchange reaction and TPD-Mass thermogram of CAM indicated the presence of structural NH4+ as interstitial solid solution. The stuctural NH4+ in the H+ form of CAM (H-CAM) was efficiently exchanged with K+ as compared with other alkali metal ions in the equilibrated solutions. The exchanger was observed to be stable in acid medium, however structural transformations were observed at high pH. The presence of K+ and Cs+ at high pH could act as “Structure Building Ions” for CAM or H-CAM.
Solvent Extraction of Dansyl-Amino Acid Anions by Dicationic Extractants
Authors: Ohki Akira , Dohmitsu Hiroyuki , Maeda Shigeru
Published: July 2006

The extraction of dansyl-amino acid anions from an alkaline aqueous medium was studied by the use of dicationic anion-exchange extractants, polymethylenebis(trioctylphosphonium)s (abbreviated as CnBPs; n=2–12). As for the extraction of dianionic species, such as dansyl-aspartic acid anion (Dns-Asp2−) and dansyl-glutamic acid anion (Dns-Glu2−), the dicationic extractants were greatly superior to a monocationic extractant, butyltrioctylphosphonium (BuMP). However, regarding the extraction of monoanionic species, such as dansyl-serine anion, dansyl-phenylalanine anion, and dansyl-valine anion, the extraction abilities of the dicationic extractants and the monocationic extractant were similar to one another. The extraction ability of dicationic extractants was remarkably dependent on the length of their bridge-chain, which connects the two ionic centers. For extractants having short bridge-chain (C2BP–C4BP), Dns-Asp2− was more extracted than Dns-Glu2−. On the contrary, for extractants with long bridge-chain (C8BP–C12BP) , Dns-Glu2− was more extracted than Dns-Asp2−. The solvent effect on the extraction of Dns-Asp2− and Dns-Glu2− was also studied.
Temperature Effect on the Adsorption and Micelle Formation of Aqueous Dodecyltrimethylammonium Chloride–Hexane System
Authors: Abe Koji , Kajiwara Ichiro , Ikeda Norihiro , Aratono Makoto , Motomura Kinsi
Published: July 2006

The adsorption at water/hexane interface and micelle formation of dodecyltrimethylammonium chloride (DTAC) were studied by measuring its interfacial tension as a function of temperature under atmospheric pressure at various concentrations around the critical micelle concentration (cmc). By applying the thermodynamic equations developed previously, the entropy and energy changes associated with the adsorption from monomeric and micellar states were estimated and compared with those of the DTAC solution–air system. It was found that the entropy and energy of the adsorbed film of DTAC are remarkably depressed by the coexistent hexane phase. This finding explains the positive entropy change associated with the adsorption of DTAC at water/air interface.
Electrochemical Studies of Poly(mercaptohydroquinone) and Poly(mercapto-p-benzoquinone) Films Prepared by Electrochemical Polymerization. V. Spectroelectrochemistry of Ten pH Indicators in the Film
Authors: Arai Gorou , Imai Kenji , Tanaka Ken-ichiro , Yasumori Iwao
Published: July 2006

The electroconductive, almost colorless and transparent poly(mercaptohydroquinone/mercapto-p-benzoquinone) film, prepared by electropolymerization of mercaptohydroquinone on an SnO2/glass electrode, was impregnated with a pH indicator. The film exhibited a clear electrochromic behavior arising from proton release/consumption within the film by electrooxidation/reduction, as verified by spectroelectrochemical measurements. For ten different pH indicators examined, such a color change could be well repeated over a long-term continuous experiment by use of potential steps.
Hydrogenation of 1,3-Butadiene over CaO Catalyst Treated with Methanol
Authors: Matsuda Tsuneo , Sugimoto Masatoshi , Yoshiara Hiroshi
Published: July 2006

When calcium oxide was treated with methanol at low temperature, calcium methoxides i.e., calcium dimethoxide and, calcium hydroxide methoxide, could be easily formed. The catalyst produced by the thermal decomposition of these compounds exhibited remarkably high activity to the hydrogenation of 1,3-butadiene. With the aim to investigate the cause of the high activity, two other calcium oxide catalysts were used for a comparison. The cause was ascribed to the formation of a large amount of electron-donating sites, including both basic ones and those with a high surface area.
Synthesis and Properties of Gramicidin S Analogs Containing d-Lys Residue in Place of Orn Residue
Authors: Tamaki Makoto , Akabori Sadatoshi , Muramatsu Ichiro
Published: July 2006

[l-Lys2,2′]-gramicidin S has been known to possess the same type activity and conformation as that of gramicidin S. The d-isomer of the Lys residue, instead of the Orn residue, was introduced to gramicidin S in order to investigate the contribution of the configurations of the Orn residue in gramicidin S to its activity and conformation. [d-Lys2,2′]- and [d-Lys2, l-Lys2′]-gramicidin S were synthesized by a liquid-phase method. The CD spectra of these analogs showed a pattern similar to that of gramicidin S, suggesting that the conformation of these analogs at the β-turn parts around the d-Phe-Pro sequence resemble that of gramicidin S. These analogs have either a weak or no activity against the Gram-positive microorganisms tested, indicating the importance of the configuration of the Orn residue in gramicidin S for exhibiting strong activity.
Enhanced Enantioselectivity of the Lipase-Catalyzed Hydrolysis by the Addition of a Catalytic Amount of an Amino Alcohol
Authors: Itoh Toshiyuki , Ohira Eri , Takagi Yumiko , Nishiyama Shigenori , Nakamura Kaoru
Published: July 2006

l-Methioninol (l-MetOH) was discovered to be an effective additive for improving the enantioselectivity of lipase-catalyzed hydrolysis. It was found that l-MetOH accelerated the enzyme-catalyzed hydrolysis of (R)-3-acetoxybutyronitrile (1) and inhibited that of (S)-1.
Oxidation of trans-1,2-Cyclohexanediaminetetraacetatocobaltate(II) by Peroxodiphosphate Catalyzed by Ag(I) in Acetate Buffers. A Kinetic Study
Authors: Sivaswaroop Pathaneni , Anandkumar Kondapi , Rao Panuganti V K
Published: July 2006

The kinetics of oxidation of trans-1,2-cyclohexanediaminetetraacetatocobaltate(II) by peroxodiphosphate (PDP) in acetate buffers was studied in the presence of Ag(I). For the first time, this study gives a clear evidence for the involvement of Ag(I)/Ag(II) cycle in the Ag(I)-catalyzed PDP oxidation reactions in acetate buffers. A plausible mechanism consistent with the observed kinetic features is proposed.
Cumulene Hosts: Synthesis and Inclusion Property of Tetraaryl-Substituted Butatrienes. X-Ray Crystal Structures of an Unsolvated Host and Its 1 : 2 Inclusion Compounds with o- and p-Xylene
Authors: Weber Edwin , Seichter Wilhelm , Wang Ru-Ji , Mak Thomas C W
Published: July 2006

A series of tetraaryl-substituted cumulenes were synthesized and characterized by elemental analysis, 1H NMR, and MS spectra. Their inclusion capabilities for a variety of organic solvents were examined. It was found that substitution on the phenyl groups connected to both ends of these cumulenes critically influences their inclusion behavior since the substituents dictate the size and shape of lattice space for accommodation of the guest molecules. The crystal structures of an unsolvated butatriene and its 1 : 2 inclusion compounds with p-xylene and o-xylene were determined by X-ray crystallography. The structural analysis showed that the guest molecules do not simply fit into the free space of the host lattice, but their presence rearranges the packing mode of the host molecules in the inclusion compounds.
Chemical Shift Standards in High-Resolution Solid-State NMR (2) 15N Nuclei
Authors: Hayashi Shigenobu , Hayamizu Kikuko
Published: July 2006

15N NMR spectra of the shift standard compound, pure nitromethane, have been measured with high resolution by spinning the liquid sample at the magic angle. Using the precise resonance position of nitromethane, the chemical shifts of the solid second-standard materials such as ammonium salts and glycine have been measured with great precision.
Synthesis and Molecular Structure of Europium(III) Complex with 2,6-Diacetylpyridine Bis(2-pyridylhydrazone)
Authors: Sakamoto Masatomi , Matsumoto Naohide , Okawa Hisashi
Published: July 2006

The title complex, [Eu(NO3)2(L)(CH3OH)]NO3, has been synthesized and its molecular structure has been determined by a single crystal X-ray analysis, where L denotes 2,6-diacetylpyridine bis(2-pyridylhydrazone). The complex has a ten-coordinate structure with quinquedentate L, two bidentate NO3− ions, and monodentate CH3OH.
The Correct Structure of Cyclic Adducts of (Diphenylmethylene)oxophenylphosphorane with Aromatic Aldehydes
Authors: Kawashima Takayuki , Inamoto Naoki
Published: July 2006

The title cyclic adducts have been reported to be 4-aryl-2,3,3-triphenyl-1,2-oxaphosphetane 2-oxides. However, these compounds are concluded not to be the 1,2-oxaphosphetanes, but 1-aryl-3,4-diphenyl-3,4-dihydro-1H-2,3-benzoxaphosphorin 3-oxides from our detailed NMR studies and the investigation of the chemical behavior of the adduct of benzaldehyde.
Effects of Pretreatment of Yubari Coal by Solvent-Extraction on the Reductive Alkylation with Molten Potassium and Iodoethane
Authors: Miyake Mikio , Tamada Kazushi , Minami Hiroo , Nomura Masakatsu
Published: July 2006

Effects of pretreatments of Yubari coal by solvent-extraction on the reductive alkylation with molten potassium and iodoethane have been investigated by comparing the reactions with and without ultrasonic irradiation. Important roles of electron-transfer agents and secondary bonds between coal macromolecules on the anionization were elucidated.
Depth Profiling of Ultra Thin Film Using Laser Induced Fluorescence Spectroscopy under Normal Incidence Conditions Based on the Reciprocal Principle
Authors: Wu Xing-Zheng , Kitamori Takehiko , Teramae Norio , Sawada Tsuguo
Published: July 2006

Depth profiling for thin film sample using laser induced fluorescence spectroscopy under normal incidence conditions, based on the principle of reciprocity, was studied. A laminated Langmuir–Blodgett model film sample (187 nm in thickness) with a concentration depth profile which varies as a stair-like function with 20.8 nm steps was prepared. Using this model film sample, observation angle dependence of fluorescence intensity was compared with theoretical results based on the principle of reciprocity, and it was shown that the principle held for the thin film sample having a continuous concentration depth profile. Secondly, these data were used to reconstruct the concentration depth profile by the least square method. The quantitative concentration depth profiling results obtained for the model film sample were satisfactory. This method can be used for film samples thinner than the wavelength of the excitation light and its spatial resolution in the depth direction is estimated to be in the order of a nanometer.
X-Ray Crystal Structures of Ti(IV)-4,4′-Methylenebis(antipyrine) Complexes, [Ti(dam)3](ClO4)4. Formation of Eight-Membered Chelate Rings and Aromatic Ring Stacking Responsible for Characteristic Coloration
Authors: Yuchi Akio , Shiro Motoo , Wada Hiroko , Nakagawa Genkichi
Published: July 2006

X-Ray crystallographic studies have been made for two Ti(IV) complexes with 4,4′-methylenebis(antipyrine) (so-called diantipyrylmethane, abbreviated to dam) used for spectrophotometry of Ti(IV). The crystal data and final R values are: [Ti(dam)3](ClO4)4 (1), triclinic, P\bar1, a=15.099(2), b=22.308(2), c=14.015(2) Å, α=100.00(1), β=116.68(1), γ=87.16(1)°, V=4151(1) Å3, Z=2, R=0.124 for 8060 reflections; [Ti(dam)3](ClO4)4·H2O (2), monoclinic, P21⁄c, a=14.075(3), b=29.127(7), c=21.386(6) Å, β=122.42(1)°, V=7401(3) Å3, Z=4, R=0.105 for 6685 reflections. The reagent dam acts as a bidentate ligand to form eight-membered chelate rings. Between a pyrazolone moiety of one ligand and a phenyl ring of another prevails aromatic ring stacking, which gives extra stability to these complexes and is responsible for the characteristic charge transfer band around 385 nm.
Kinetic Studies on the Cobalt(II) Naphthenate Catalyzed Decomposition of “Cumene Hydroperoxide” in Benzene
Authors: Sawada Hideo , Ishigaki Hideyo , Kato Mitsukuni , Nakayama Masaharu
Published: July 2006

The cobalt(II) naphthenate[Co(Nap)2] catalyzed decomposition of cumene hydroperoxide(CHP) gave a mixture of α-cumyl alcohol, acetophenone and di-α-cumyl peroxide in benzene at 25°C. All experimentally observed time courses of disappearing CHP and an increasing of three products compared well with theoretical values.
Structure and Optical Properties of Thermochromic Schiff Bases. Charge Transfer Interaction and Proton Transfer in the N-Tetrachlorosalicylideneaniline and N-Tetrachlorosalicylidene-1-pyrenylamine Crystals
Authors: Inabe Tamotsu , Gautier-Luneau Isabelle , Hoshino Naomi , Okaniwa Kaoru , Okamoto Hiroshi , Mitani Tadaoki , Nagashima Umpei , Maruyama Yusei
Published: July 2006

Two kinds of N-salicylideneaniline derivatives, N-tetrachlorosalicylideneaniline (CL4SA) and N-tetrachlorosalicylidene-1-pyrenylamine (CL4SPY), have been prepared and subjected to structural and optical studies in the crystalline state. A thermochromic-type behavior of the former crystal has been observed as a shift of the absorption edge, while that of the latter crystal is much less pronounced. Fairly short O–H···N hydrogen bonds have been found in both compounds through crystallographic studies, which may be mainly due to a steric effect of chlorine substituents. The difference in the proton transfer behavior of CL4SA and CL4SPY should presumably be caused by an intermolecular charge-transfer interaction in the latter crystal.
NAD(P)H-NAD(P)+ Models. 73. Structure-Stereochemistry Relationship in the Reaction of NAD Analog
Authors: Ohno Atsuyoshi , Mikata Yuji , Goto Mutsuo , Kashiwagi Takeshi , Tanaka Takanori , Sawada Masami
Published: July 2006

Four different NAD(P)H analogs have been oxidized by various substituted and unsubstituted 1,4-benzoquinones in the presence or absence of magnesium ion. The stereospecificity of the reaction depends not only on the reactivity of quinone but also on that of the analogs as well as on the presence or absence of magnesium ion. The results are discussed from the viewpoint of reaction mechanism for the transfer of a (net) hydride ion.
The 2.0 Å Crystal Structure of Cyanide Metmyoglobin Reconstituted with 5,10,15,20-Tetrapropylhemin
Authors: Hata Tadashi , Hata Yasuo , Sato Takao , Tanaka Nobuo , Neya Saburo , Funasaki Noriaki , Katsube Yukiteru
Published: July 2006

Sperm whale metmyoglobin reconstituted with 5,10,15,20-tetrapropylhemin was crystallized in the space group P212121, which was different from the space group P21 of the native. The crystal structure of the reconstituted metmyoglobin was determined by the molecular replacement method. The atomic coordinates were refined to R=0.209 at 2.0 Å resolution. The overall structure is essentially the same as that of the native. The pronounced structural change is observed in the side-chain orientation of Arg 45 moving to the surface of the molecule. This conformational change may reflect a side-chain fluctuation that allows the small ligands to approach the heme pocket from the outside of the protein. The porphyrin ring does not rotate freely about the Fe–Nε (His 93) bond in the crystalline state, although temperature-dependent NMR spectra suggest its free rotation in solution.
Rearrangement of 4-Perfluoroalkyl Quinols
Authors: Uno Hidemitsu , Shiraishi Yasukazu , Matsushima Yuji , Yayama Ayumi , Suzuki Hitomi
Published: July 2006

Treatment of 4-perfluoroalkyl-4-hydroxy-2,5-hexadien-1-one (4-perfluoroalkyl-4-quinol), prepared from the reaction of 1,4-benzoquinone with perfluoroalkyllithium, with acetic anhydride–sulfuric acid gave a mixture of 2,4-diacetoxy-1-perfluoroalkylbenzene and 1,2-diacetoxy-4-perfluoroalkylbenzene in a comparable ratio. When 4-perfluoroalkyl-4-quinols bearing a methyl group ortho to the perfluoroalkyl group were subjected to the rearrangement, acetoxymethyl compounds were obtained in addition to diacetoxybenzene derivatives. Only 1,3-migration was observed in the cases of 2,4-di-t-butyl-4-perfluorooctyl-4-quinol and 4-hydroxy-4-perfluoroalkyl-1(4H)-naphthalenone, while the reaction of 2,6-dimethyl and 2-methoxy derivatives gave only 1,2-shift products. Reaction routes to the apparent 1,2- and 1,3-acetoxyl migration products are discussed.
Reactions of Methoxynaphthalenes with Active Methylene Compounds in the Presence of Manganese(III) Acetate
Authors: Tsunoda Katsunori , Yamane Mitsuyoshi , Nishino Hiroshi , Kurosawa Kazu
Published: July 2006

The reaction of methoxynaphthalenes with malonamide in the presence of magnanese(III) acetate gives 2-acetoxy-2-(1-naphthyl)propanediamides and 2-hydroxy-2-(1-naphthyl)propanediamides. It was found that the propanediamidation reaction did occur when naphthalenes have electron-donating substituents, such as a methoxyl group. The reactions of methoxynaphthalenes with ethyl 3-oxobutanoate, 2-cyanoacetamide, and malononitrile in the presence of manganese(III) acetate also yielded the corresponding substituted naphthalenes, ethyl 2-(acetoxymethyl)naphtho[2,1-b]furan-1-carboxylates, and/or a 4-methylene-1(4H)-naph-thalenone. The reaction mechanisms are discussed.
Synthesis of 5,6-Dideoxy-5-phenylphosphinyl-l-galactopyranoses. The P-in-Ring Sugar Analogs of l-Fucose
Authors: Hanaya Tadashi , Yamamoto Hiroshi , Ohmae Takeshi , Kawamoto Heizan , Armour Margaret-Ann , Hogg Alan M , Yamamoto Hiroshi
Published: July 2006

1,2-O-Isopropylidene-3-O-methyl-6-O-tosyl-β-d-arabino-hexofuranos-5-ulose (9a) and its 3-O-benzyl congener (9b) were prepared from 1,2:5,6-di-O-isopropylidene-β-d-altrofuranose in 4 steps. Addition of methyl phenylphosphinate to 9a and 9b in the presence of DBU, followed by reduction with Raney Ni, afforded (5R and 5S)-5,6-dideoxy-1,2-O-isopropylidene-5-[(methoxy)phenylphosphinyl]-3-O-methyl-β-d-arabino-hexofuranose(11a) and 3-O-benzyl congener (11b), respectively. The latter compound (11b) was debenzylated to 3-O-unsubstituted hexofuranose 11d. By reduction with sodium dihydrobis(2-methoxyethoxy)aluminate, followed by acid hydrolysis, these key intermediates 11a, 11b, and 11d provided the title l-fucoses 13 (together with a minor proportion of d-altropyranoses 14) having as phenylphosphinylidene group in place of the ring oxygen. Compounds 13 and 14 were converted into per-O-acetyl derivatives for structural and conformational analysis by spectroscopy.
NAD(P)H-NAD(P)+ Models. 74. Entropy-Controlled Kinetics, Stereochemistry, and Tunneling Effect
Authors: Ohno Atsuyoshi , Goto Mutsuo , Mikata Yuji , Kashiwagi Takeshi , Maruyama Tetsushi
Published: July 2006

Kinetics have been studied for the reactions of three NAD(P)H analogs and their 4-deuteriated compounds with 2,6-dichloro- and tetrachloro-1,4-benzoquinones. It has been elucidated that the entropy term occupies 50–90% of the Gibbs energy of activation at 298 K. Thus, the reaction is almost entropy-controlled. For certain combinations of the reducing and oxidizing reagents, quantum mechanical tunneling effect plays a large role to determine the reaction rate. The tunneling effect may be another measure of the stereochemistry.
Pressure Effect on Proton Jumps in t-Butyl Alcohol–Water Mixtures at 25°C
Authors: Ueno Masakatsu , Matsukawa Kazuhito , Tsuchihashi Noriaki , Shimizu Kiyoshi
Published: July 2006

The limiting molar conductances, Λ°, of hydrochloric acid and potassium chloride in 2,3,5,7,10, and 25 mol% t-butyl alcohol (TBA)–water mixtures were determined at 25°C as a function of the pressure up to 2000 kgf cm−2 (1 kgf cm−2=0.9807×105 Pa) from the conductances measured within a dilute concentration range. In each solvent mixture the value of Λ° (HCl) was about three- to five-times larger than that of Λ° (KCl) The anomalous excess proton conductance, λ°E, as estimated by the equation [λ°E=Λ° (HCl)−Λ°(KCl)], was found to increase with increasing pressure in 2,3,5,and 7 mol% TBA–water mixtures, but to decrease in 10 and 25 mol% TBA-water mixtures. The rate of increase with pressure of the excess proton conductance normalized to the molar concentration of water in the mixture was largest in a 2 mol% TBA mixture, and its magnitude decreased in the order: 2>3>0>5>>7>>10>>25 mol% of TBA. These results are compared with those obtained in ethanol–water mixtures and are discussed in relation to the effect of alcohol molecules on the water structure in the mixtures: the three-dimensional network of water in TBA–water mixtures is more stable at a lower mol% of alcohol, and collapses more rapidly with increasing alcohol content than in ethanol–water mixtures.
Detection of Surface Resistance in a Gas/Porous-Adsorbent System by Frequency Response Method
Authors: Yasuda Yusuke
Published: July 2006

The frequency-response (FR) method for studying an X\ightleftharpoonsC system (Yasuda, 1982) has been extended to an X\displaystyle\mathop\ightleftharpoonsIA\displaystyle\mathop\ightleftharpoonsIIC system, where X denotes a molecule in the gas phase, A is an adspecies on the external surface of a porous adsorbent, and C is an adspecies within micropores. Based on the characteristic functions for a system derived analytically, it is shown that both rate constants for steps I and II can be determined separately from the FR data. According to actual data of CH4/5A zeolite systems, it has been confirmed that both the adsorption and desorption rate constants for step I, ka and kd, respectively, and also the Fickian diffusional time constant at step II, \ ildeD, can be evaluated. The present method is expected to provide quantitative information conerning the existence and intensity of surface barriers of zeolite crystals.
Contribution of Latin America to Pharmacovigilance
Authors: González Juan Camilo , Arango Victoria E , Einarson Thomas R
Published: July 2006

Background:

Pharmacovigilance activities have been ongoing for 4 decades. However, little is known (especially outside of the area) about the contribution of Latin America to this field.

Objective:

To review and quantify the published literature on pharmacovigilance in Latin American countries.

Data Sources:

We searched electronic databases including MEDLINE (1966–2004), EMBASE (1980–2004), International Pharmaceutical Abstracts (1970–2004), Toxline (1992–2004), Literatura Latino-Americana e do Caribe em Ciências da Saúde (1982–2004), Sistema de Información Esencial en Terapéutica y Salud (1980–2004), and the Pan American Health Organization Web site (1970–2004) for articles on pharmacovigilance or adverse drug reactions in any of the 19 major Latin American countries. Papers were retrieved and categorized according to content and country of origin by 2 independent reviewers.

Study Selection and Data Extraction:

There were 195 usable articles from 13 countries.

Data Synthesis:

Fifty-one of the papers retrieved dealt with pharmacovigilance centers (15 national centers, 10 hospitals, 26 other), 55 covered pharmacovigilance itself (21 theoretical papers, 9 with description of models, 25 educational papers), and 89 were pharmacoepidemiologic studies of adverse drug reactions (69 case reports, 13 observational cohorts, 2 cohort studies, 1 randomized clinical trial, 4 clinical papers on adverse reaction management). Studies have increased exponentially since 1980. Five countries (Argentina, Brazil, Chile, Costa Rica, Venezuela) published reports from national centers. No studies were found from 6 countries: Dominican Republic, El Salvador, Honduras, Nicaragua, Paraguay, or Uruguay. Most studied categories were antiinfectives and drugs affecting the central nervous system, cardiovascular system, and musculoskeletal system.

Conclusions:

Contributions of Latin American countries to the field of pharmacovigilence have been remarkable, considering the constraints on these countries. A need exists for an increased number of formal pharmacovigilance studies and research using methodologically stronger pharmacoepidemiologic models.