bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Indeno[1,2-d]azepine Derivatives
Authors: Kimura Masaru , Satake Kyosuke , Yonemori Shigeaki , Morosawa Shiro
Published: July 2006

4-Ethoxyindeno[1,2-d]azepine(18) and 10-bromo-4-ethoxyindeno[1,2-d]azepine were prepared by O-ethylation of indeno[1,2-d]azepin-4-ol(12ab) and 10-bromoindeno[1,2-d]azepin-4-ol(13ab) with Et3OBF4 in 62 and 69% yields, respectively. 12ab was obtained by bromination of 1,2,3,4,5,10-hexahydro-4-indeno[1,2-d]azepine(3) or 1,2,3,4-tetrahydroindeno[1,2-d]azepin-4-one with NBS, and subsequent dehydrobromination of the corresponding bromide formed in situ on basic alumina in 10% yield. When the bromination time was over 20 h, only 13ab was isolated in 20% yield. Direct dehydrogenation of 3 with DDQ gave 10-chloroindeno[1,2-d]azepin-4-ol in 27% yield. The NMR and electronic spectra of 18 indicated the presence of a fully conjugated 14-pi ring system in it. We also investigated the possibility for dehydrogenation of 3-ethoxycarbonyl-1,2,3,4,5,5a,10,10a-octahydroindeno [1,2-d] azepin-10-one.
Photochemical Ethoxycarbonylation, Formylation, and Ethoxymethylation of Ruthenocene in Ruthenocene–Polychloromethane–Ethanol Systems
Authors: Sugimori Akira , Matsui Masaru , Akiyama Takeo , Kajitani Masatsugu
Published: July 2006

Similar to ferrocene the UV-irradiation of ruthenocene–polychloromethane–ethanol systems brings about substitution (ethoxycarbonylation for CCl4, formylation for CHCl3, and ethoxymethylation for CH2Cl2) and oxidation. When CHCl3 and CH2Cl2 are used, substitution is dominant. In the irradiation of ruthenocene–CCl4–ethanol system, [Ru(C5H5)2]+[RuCl4]− and cyclopentenes substituted by chlorine and trichloromethyl are obtained. The excitation of the CT-complex between ruthenocene and polychloromethane initiates the reaction.
One-step Synthesis of 3-(Dialkylamino)indolizines by the Palladium-catalyzed Reaction of α-Bromopyridine, Propargyl Alcohol, and Secondary Amine
Authors: Ohsawa Akio , Abe Yoshihito , Igeta Hiroshi
Published: July 2006

3-(Dialkylamino)indolizines were synthesized in one step by the reaction of 2-bromopyridine, propargyl alcohol, and secondary amines in the presence of Pd(PPh3)2Cl2–CuI as a catalyst. 3-(2-Pyridyl)-2-propyn-1-ol and 3-(2-pyridyl)acrylaldehyde were suggested to be intermediates of the reaction. 3-Dialkylamino derivatives of pyrrolo[1,2-a]quinoline, pyrrolo[2,1-a]isoquinoline, and pyrrolo[1,2-b]pyridazine were obtained from the corresponding α-haloazaaromatics in a similar way.
Cyclization of Isothiosemicarbazones. III. Formation of Thiazolines and Thiazoles through Potential Sulfonium Salts from N,S-Disubstituted Isothiosemicarbazones
Authors: Yamazaki Chiji
Published: July 2006

The reaction of 3,4-disubstituted isothiosemicarbazones with α-bromo ketones led to the formation of 4-thiazoline derivatives, the substituents on the sulfur atom being cleaved as bromides. They are identical with the compounds obtained by the condensation of the corresponding thiosemicarbazones, having significantly lower E⁄Z ratios in certain products than in those from thiosemicarbazones. The yields of 4-thiazolines widely vary with the substituents on the N-4 and the sulfur atom in the isothiosemicarbazones and also with halo ketones. A mechanism has been suggested which deals with a sulfonium-formation and dissociation process at the apparently less nucleophilic sulfur atom of isothiosemicarbazone. The mechanism might explain the effect of changes in the substituents on the sulfur atom upon the yield of 4-thiazolines, the higher contents of (Z)-4-thiazoline from (E,E)-2,6-dichlorobenzaldehyde 3-allyl-4-methylisothiosemicarbazone, and the inertness or less reactivity of anisaldehyde 2,3-dimethylisothiosemicarbazone and salicylaldehyde 3-allyl-4-phenylisothiosemicarbazone. Differentiation between isomeric thiazole and 4-thiazoline compounds was also described.
Studies on Heteropentalenes. II. Cycloaddition of Imidazo[2,1-b]thiazoles, Thiazolo[3,2-a]benzimidazole, and Imidazo[2,1-b]benzothiazole with a Reactive Acetylenic Ester
Authors: Abe Noritaka , Nishiwaki Tarozaemon , Komoto Noriko
Published: July 2006

Cycloaddition of imidazo[2,1-b]thiazoles with dialkyl acetylenedicarboxylate follows dual courses depending on the polarity of the solvent, affording pyrrolo[2,1-b]thiazoles in an aprotic nonpolar solvent, or imidazo[1,2-a]pyridines and imidazo[3,4-a]pyridines, together with thiophenes, in an aprotic polar solvent. Thiazolo[3,2-a]benzimidazole and imidazo[2,1-b]benzothiazole were also found to react with the acetylenedicarboxylate to give pyrido[1,2-a]benzimidazole and pyrrolo[2,1-a]benzothiazole, respectively. The reactions would be accounted for in light of the Diels-Alder reaction in an aprotic nonpolar solvent and the 1,4-dipolar cycloaddition in an aprotic polar solvent.
Coordinative Role of Alkali Cations in Organic Reactions. V. The Perkin Reaction
Authors: Poonia Narinder S , Sen Swagata , Porwal Prafulla K , Jayakumar A
Published: July 2006

The Perkin condensation of benzaldehyde (PhCHO) and acetic anhydride (Ac2O) in the presence of an alkali acetate (M+OAc−) involves extensive participation of M+ and takes place best with K+OAc−. Employing an excess of meticulously dehydrated K+OAc−, a record high yield of cinnamic acid (≈75%) can be obtained in a 60 min reaction. The product of the reaction before hydrolysis is not PhCH=CHCOOCOCH3 as usually believed but potassium cinnamate plus K+(OAc, HOAc)−. Conductometric solution stability studies on M+-ligand (M+=Na+ and K+; Ligand=PhCHO, o-NO2C6H4CHO, o-HOC6H4CHO) systems in 2-propanol show that stability sequences for PhCHO and o-NO2C6H4CHO are NaOAc<KOAc and KOAc<NaOAc, respectively. These are in line with the catalytic efficiency these salts displayed during the condensation reaction, o-HOC6H4CHO, for which the Perkin condensation is extremely poor, is practically non-complexing with M+OAc− in 2-propanol.
Configuration Analysis and Electronic State Properties. III. Ten-π-electron Systems
Authors: Buemi Giuseppe
Published: July 2006

The electronic state properties of the nonbenzenoid hydrocarbons fulvalene, heptatriafulvalene, dimethylenebenzocyclobutene, [5]radialene, 8-vinylheptafulvene, 1,2-benzofulvene and 2,3-benzofulvene have been studied by means of MIM and PPP-configuration analyses. The resonance integrals evaluated by Kon’s equation are satisfactory for the MIM method but not for PPP. On the whole the general spectral trend is fairly predicted by both approximations, the wavefunction composition being in line with the first electronic transitions. The lower energy electronic transitions are found to be a mixture of locally excited and charge transfer states while those computed at higher energy have prevailing charge transfer character.
Purification of Methylthymol Blue and Methylxylenol Blue by High-Performance Liquid Chromatography
Authors: Nakada Shoji , Yamada Mutsuo , Ito Tasuku , Fujimoto Masatoshi
Published: July 2006

Relatively large amounts of 3,3′-bis[bis-(carboxymethyl)aminomethyl]thymolsulfonphthalein (Methylthymol Blue, MTB) and 3,3′-bis[bis(carboxymethyl)aminomethyl]-p-xylenolsulfonphthalein (Methylxylenol Blue, MXB) are easily purified by high-performance liquid chromatography (HPLC).
The Synthesis of 1,3,5-Thiadiazinylium Salts
Authors: Shibuya Isao
Published: July 2006

1,3,5-Thiadiazinylium salts were synthesized in good yields by the reaction of N-acyl imidoyl chlorides with thioamides or the treatment of 4H-1,3,5-thiadiazines with trityl salts.
A 13C NMR and CNDO/2 Calculation Study of the Transannular Interaction in [2.2]Metacyclophanes
Authors: Tokita Kazushi , Kondo Shoichi , Mori Nobuo
Published: July 2006

The substituent effects on the chemical shifts and CNDO/2 total electron densities of the facing aryl carbons, C-8 and C-16, in [2.2]metacyclophanes are reported.
The Reaction of Thiocumulenes with Fulvene
Authors: Saito Takao , Musashi Teruhiko , Motoki Shinichi
Published: July 2006

S-(9-Fluorenylidene)-N-(p-tolylsulfonyl)sulfimide and bis(p-tolylsulfonyl)sulfur diimide reacted as 1,3-dipoles with fulvenes to form (2+3)cycloadducts.
Michael Addition of p-Styrenesulfinate to Acrylic Compounds
Authors: Kamogawa Hiroyoshi , Kusaka Hiroyuki , Nanasawa Masato
Published: July 2006

Acrylic compounds CH2=CHX, where X represents -COOH, –CONH2, –CN, and –COOCH2CH2OH, were converted into the corresponding 3-(p-vinylphenylsulfonyl)- and 3-(p-tolylsulfonyl)propionic acids and their derivatives by the Michael addition with p-styrene- and p-toluenesulfinates, respectively, in the presence of acid as proton source.
Studies on Biologically Active Pteridines. V. Synthesis of (6S)-5,6,7,8-Tetrahydro-1,3,5,6-tetramethyllumazine
Authors: Sugimoto Takashi , Matsuura Sadao
Published: July 2006

(+)-5,6,7,8-Tetrahydro-1,3,5,6-tetramethyllumazine, a compound derived from enzymically reduced (−)-5,6,7,8-tetrahydro-6-methylpterin, was shown to be of (S)-configuration at the C-6 chiral center by a synthesis, which was performed by condensation of 5-bromo-6-chloro-1,3-dimethyluracil and (2S)-1-amino-2-(methylamino) propane. The structure of the condensation product was determined unequivocally by an independent synthesis using a regioselective methylation of 5,6,7,8-tetrahydro-1,3,6-trimethyllumazine.
Thermodynamic Study on Mixed Monolayers of Butyl Eicosanedioate and Tetradecanoic Acid
Authors: Hayami Yoshiteru , Yano Takeshi , Motomura Kinsi , Matuura Ryohei
Published: July 2006

In order to clarify the behavior of mixed monolayers of butyl eicosanedioate and tetradecanoic acid, the surface pressure was measured as a function of mean area at various compositions and temperatures. Four types of phase transition were observed. By use of the thermodynamic treatment previously developed, the apparent molar entropy and energy changes associated with the phase transition were evaluated. It was concluded on thermodynamic considerations that the butyl eicosanedioate and tetradecanoic acid monolayers are immiscible in condensed states and their phase diagram has a two-dimensional eutectic point.
Electrochemical Aspects of a NADH/FAD Model System
Authors: Sasaki Kazuo , Kitani Akira , Kunai Atsutaka , Miyake Hitoshi
Published: July 2006

A model system of the NADH/FAD redox couple has been studied by the use of electrochemical techniques. The system studied was composed of 1-benzyl-1,4-dihydronicotinamide (BNAH) and riboflavin (RF), which were used in place of NADH and FAD respectively, dissolved in a DMSO solution. The results obtained were as follows. RF is reduced either by BNAH or sodium borohydride, obeying a second-order rate law, presumably by the mechanism of hydride-ion transfer. The resultant product is inactive to the electrochemical reduction at a mercury-pool electrode. Entirely different products were produced when RF was reduced electrochemically. RF was reduced at a rate of 1 F/mol at the initial stage of controlled potential electrolysis to form, probably, a dimeric compound, but the latter product underwent further reduction and the total quantity of electricity necessary for the complete reduction exceeded 10 F/mol. Interestingly, the electrolytic reduction gives the same product as that obtained by BNAH when electrolysis is performed in the presence of a sufficient amount of BNAH, indicating that the initial product of electrochemical reduction receives the hydride ion rather than further electrons.

2RF+2e\ightleftarrows(RF)_2^2-\overset+H^-,+H^+→2RFH^-

The Zn2+ added to the BNAH/RF system was found to act as the oxidizing agent of RFH− and regenerated the neutral RF. This is markedly different from the case of BNAH/organic carbonyl compounds, where the metal ions behave as catalysts to promote the reaction.
A Contribution to the Theory of Pulse Polarography. I. Theory of Current-Potential Curves
Authors: Matsuda Hiroaki
Published: July 2006

A general theory of pulse polarographic current-potential curves is developed for a simple electrode reaction proceeding at the expanding plane electrode. It is shown that when the ratio of the sampling time to the pre-electrolysis time is smaller than 1/30, this condition being satisfied in usual pulse polarographic practice, the equation of current-potential curves can be greatly simplified. The theory developed is applied to the three modes of pulse polarography nowadays practically employed, i.e., normal pulse, scan-reversal pulse and differential pulse polarography. For each mode, the dependence of current-potential curves on the kinetic parameters of electrode reaction as well as on the experimental variables is discussed.
Adsorption of Alkaline Earth Cations on Mercury as Studied with the Perbromate Kinetic Probe
Authors: Osaka Tetsuya , de Levie Robert
Published: July 2006

Reduction of perbromate was used as a kinetic probe of double layer parameters for weak specific adsorption of double layer parameters for weak specific adsorption of alkaline earth cations at the mercury/electrolyte solutions interface. The results are interpreted as evidence for weak specific adsorption of Sr2+ and particularly Ba2+ in 10 mM solutions at negative electrode charge densities. The limitation of the use of an anionic probe for the quantitation of cation specific adsorption is discussed.
Infrared Multiple Photon Dissociation of Cyclobutanone
Authors: Koda Seiichiro , Ohnuma Yasushi , Ohkawa Tadashi , Tsuchiya Soji
Published: July 2006

The multiple photon dissociation of cyclobutanone was discussed on the basis of the observed relative significance of two reaction channels. Cyclobutanone was irradiated by a TEA CO2 laser beam of 9.6 μm R(14) line in a parallel and a focussed geometry. The detected products were ethylene, ketene, and cyclopropane under parallel geometry irradiation. Propylene and acetylene were also produced in focussed geometry irradiation. The kind of the products as well as the effects of reaction conditions on their yields led to the conclusion that the dissociation proceeds along two channels, in one of which ethylene and ketene are produced and in the other cyclopropane and CO. The experimental results agreed almost with the result simulated by a statistical model calculation based on the hypothesis that the energy absorbed in cyclobutanone molecules is statistically distributed among all vibrational degrees-of-freedom.
1H NMR Study of Interaction of Probe Molecules with the Phosphate Ion on the Iron Core of Horse Spleen Ferritin
Authors: Imai Noboru , Arata Yoji , Fujiwara Shizuo
Published: July 2006

The surface of the iron core of ferritin was investigated by 1H NMR using small probe molecules which have different sizes and charges. It was shown that the parameter k, which is the linewidth for each NMR probe normalized by the total concentration of iron in ferritin, is dependent on the content of phosphorus in ferritin. At pH 7.4, the k values are 1–10 for positively charged probes, 2×10−2–8×10−2 for negatively charged probes and 0.1–0.2 for neutral probes. Above pH 7, the k values for positively charged probes increase with an increase in pH, whereas those for negatively charged probes decrease. By contrast, the k values for neutral probes remain constant over the entire pH range. It was concluded that the k values reflect the mode of interactions of small molecules with the phosphate which exists on the surface on the iron core of ferritin, and that these interactions are determined primarily by the electrostatic force between the small molecules and the negative charge of the phosphate of ferritin. Furthermore, it was shown by using t-butylamine as a probe that K+ ion binds strongly to ferritin and that chelating agents interact with ferritin in a wide concentration range.
Proton Magnetic Resonance Study of Interaction between Penicillin G and Hen Egg White Lysozyme
Authors: Mitsumori Fumiyuki , Arata Yoji , Fujiwara Shizuo
Published: July 2006

Interaction between penicillin G and hen egg white lysozyme has been studied using NMR and gel chromatography. It has been demonstrated that the stoichiometry of the interaction is one to one with an association constant of approximately 1.9×102 M−1 (1M=lmol dm−3). It has also been shown that the phenacyl side chain of penicillin G is interacting with the tryptophan-123 residue of the lysozyme molecule.
Studies of Inorganic Ion Exchangers. V. The Preparation of the Granulated Product from Titanium(IV) Bis(hydrogenphosphate) and Carbonaceous Materials, and Its Ion-exchange Properties
Authors: Kobayashi Etsuro , Kanayama Tadao
Published: July 2006

In order to develop an inorganic ion exchanger for industrial use, a mixture of titanium(IV) bis (hydrogenphosphate), a carbonaceous material (sugar, flour, or sodium ligninsulfonate), and an additive (H2SO4 or H3PO4) was sintered, and the resultant sintered product was crushed to obtain a granulated product, the ion-exchange property of which was then investigated. The mixing ratio of the titanium phosphate to the carbonaceous material has an influence on the ion-exchange capacity and the durability of the granulated product. In consideration of this influence, the weight ratio of the titanium phosphate to carbon included in the carbonaceous material was expediently chosen as 1 : 0.5. The acid additives promoted the carbonization of the carbonaceous material, whereby the sintered product of porosity was obtained. The weight ratio of the carbonaceous part to the titanium phosphate in the product decreased with an increase in the temperature within the range from 185 to 350 °C. In a batch method, a granulated product including Ti(HPO4)2·H2O adsorbed Na+, but not K+. A granulated product including Ti(HPO4)2·1/2H2O, however, adsorbed these ions, the equilibrium ion-exchange capacities toward Na+ and K+ being 1.28–1.78 and 1.56–2.34 meq/g respectively, and the selectivity quotient and the distribution coefficient toward K+ showed larger values than those toward Na+. In a column method, when a NaCl (26.66 g/l)KCl (0.67 g/l) aqueous solution flowed into a column which had been packed with the granulated product (5 g) including the hemihydrate, the ion-exchange capacities of this granulated product toward Na+ and K+ were 1.1–1.2 and 0.38–0.58 meq/g, respectively, showing the separation factor (αNaK) of 18–25. When artificial brackish water also flowed into the column, very small quantities of the Mg2+ and Ca2+ were adsorbed; consequently, a selective ion-exchange property of the granulated product toward K+ was recognized. Also, the carbonaceous part in the granulated product adsorbed such coloring matter as Methylene Blue.
Studies on High-pressure Reaction of Er2O3 or Yb2O3 with VO2
Authors: Shin-ike Tsutomu , Adachi Gin-ya , Shiokawa Jiro , Shimada Masahiko , Koizumi Mitsue
Published: July 2006

The reaction of erbium sesquioxide (Er2O3) or ytterbium sesquioxide (Yb2O3) with vanadium dioxide (VO2) at 1400 °C and 50 kbar and 30 kbar pressures was studied. Quadrivalent vanadium ions were reduced to the trivalent state, erbium vanadite (ErVO3) or ytterbium vanadite (YbVO3) being obtained. The crystal structure of ErVO3 obtained at 50 kbar pressure was vaterite-type isostructural with ErBO3 belonging to a hexagonal system, and that obtained at 30 kbar calcite-type belonging to a rhombohedral (pseudo-hexagonal) system. In the reaction of Yb2O3 with VO2 at high pressure, a perovskite-type crystal was obtained. The electrical and magnetic properties of the vaterite- and the calcite-type ErVO3 were studied.
Solubility Isotherms of Systems Containing Optically Active Tris(ethylenediamine)cobalt(III) Ion. I. Reciprocal Salt-pairs, (Λ-[Co(en)3]3+, Δ-[Co(en)3]3+)–(Br−, (R,R)-C4H4O62−), at 25 °C
Authors: Fuyuhiro Akira , Yamanari Kazuaki , Shimura Yoichi
Published: July 2006

A four-component solubility isotherm consisting of (Λ-[Co(en)3]3+, Δ[Co(en)3]3+)–(Br−,(R,R)-C4H4O62−)–H2O was determined at 25 °C. It was found that three double salts, rac-[Co(en)3]Br3·3H2O, Λ-[Co(en)3]Br(d-C4H4O6)·5H2O, and Λ-[Co(en)3]0.48·Δ-[Co(en)3]0.52(d-C4H4O6)1.5·5H2O and a gelatinous precipitate exist, six invariant points appearing. Application of this phase diagram to practical optical resolutions is discussed. The solubility of each salt in the system was measured in the range 5–65 °C in water, that of Λ and Δ-[Co(en)3](d-C4H4O6)1.5·nH2O being found to be reversed at 42 °C.
Resonance Raman Spectra of Tetracyanoethylene Anion Dimers
Authors: Yokoyama Kenji , Maeda Shiro , Etoh Chisumi , Matsuzaki Susumu , Toyoda Koichi
Published: July 2006

The resonance Raman spectra of TCNE-M+ (M=Na, K, Rb, Cs) in MTHF solutions have been measured at 100 K by exciting radiations within the long wavelength absorption band characteristic of the dimer (TCNE−)2. Two remarkably resonant lines have been observed at about 180 cm−1 and 150 cm−1, showing an obvious change of the relative intensity depending on the counter cation species. The resonance behavior definitely indicates that the stretching vibration of interradical bond is responsible for these lines. Formation of two different types of dimer salts has been proposed as the most probable interpretation of the observed spectral behaviors.
On the Enhancement of the Selectivity of Organic Sulfonate Ion Electrode by Alkylphenols
Authors: Hara Hirokazu , Okazaki Satoshi , Fujinaga Taitiro
Published: July 2006

An enhancing effect of alkylphenols on the selectivity of the liquid membrane electrode responsive to organic sulfonate ion has been investigated. The interference of perchlorate ion expressed in terms of the selectivity coefficient decreased to one eighthundredth in the presence of p-t-octylphenol. This effect was attributed to the formation of the hydrogen bonding between the phenol and sulfonate. The dependence of the potentiometric behavior, paticularly with respect to the selectivity on the membrane components was examined. The optimum composition of the ion-exchanger for sulfonate was found to be 0.05 mol dm−3 trioctylmethylammonium p-toluenesulfonate with 0.5 mol dm−3  p-t-octylphenol in o-dichlorobenzene. The decrease of the selectivity coefficient for perchlorate due to the phenol was also discussed in relation to ion-exchange equilibrium constants, ionic parameters, and dissociation constants of the ion-pair. The effect of the membrane solvents was also discussed in terms of their solubility parameters.
Analysis of the Heat of Breaking Glass Ampoules
Authors: Morimoto Tetsuo , Kiriki Masafumi
Published: July 2006

The heat of breaking was measured on three series of ampoules, containing N2 at various pressures, N2 at various pressures as well as saturated H2O vapor, or different amounts of liquid H2O as well as the saturated vapor in the unfilled space, respectively. This report gives the method to analyze the heat of breaking of ampoules into three factors: the release of mechanical strain stored in the ampoule under a pressure, heat of evaporation of immersion liquid, and rush-in effect of the liquid.
The Dehydration of d-Fructose to 5-Hydroxymethyl-2-furaldehyde
Authors: Nakamura Yoshio , Morikawa Shunichi
Published: July 2006

The continuous dehydration of d-fructose is carried out under mild conditions, using the strongly acidic ion-exchange resin with a low divinylbenzene content as the catalyst and dimethyl sulfoxide as the solvent, to give 5-hydroxymethyl-2-furaldehyde in a high yield.
The Dynamical Behavior of the Sodium Cation in Some Crown Ether–Na+–TCNE− Ternary Complexes as Studied by ESR
Authors: Kohama Hiroyuki , Yoshinaga Mayumi , Ishizu Kazuhiko
Published: July 2006

ESR observations were performed for the ternary complexes formed with Na+–TCNE− and 5O-crown ethers. The temperature dependence of the observed Na hyperfine line width was analyzed by applying Bloch’s twojump model, and the thermodynamical parameters of the complex formation were determined. The stability of the ternary complexes were found to be much affected by the substitution of either the fused benzene ring or the 2,2′-biphenyldiyl group, which acts as a steric restriction during the optimum metal binding to the flexible crown ring.
Synthetic Photochemistry. XXL. The Sensitized Photooxygenation of Calarene. A Facile Hock Cleavage of an Allylhydroperoxide and Structure Revision for Aristolenols
Authors: Takeshita Hitoshi , Shimooda Isao , Hatsui Toshihide
Published: July 2006

An allylic hydroperoxide formed by the sensitized photooxidation of calarene causes a Hock cleavage. A revised stereochemistry of an aristolenol is given on the basis of the direction of oxygenation.
The Precipitation of Traces of Copper, Cadmium, and Lead with 6-Anilino-1,3,5-triazine-2,4-dithiol and Its Application to X-Ray Fluorescence Spectrometry
Authors: Watanabe Hiroto , Ueda Takashi
Published: July 2006

A selective enrichment procedure for copper, cadmium, and lead is described. This method is based on precipitating the three elements with 6-anilino-1,3,5-triazine-2,4-dithiol (ATD) or with a combination of ATD and benzyldimethyltetradecylammonium chloride (BMTAC), filtering the precipitates to form a suitable X-ray sample, and then analyzing the sample by means of X-ray fluorescence. Microgram amounts of the three elements were precipitated quantitatively with ATD from 50 cm3 or less of aqueous solutions of pH 7. Several to several tens mg amounts of such other elements as aluminium, iron(III), vanadium(V), zinc, arsenic(III, V), nickel, cobalt, and manganese(II) do not form any precipitates in the presence of citrate. Quantitative recoveries of the three elements from aqueous solutions ranging from 200 to 500 cm3 were also possible when BMTAC was present as a coagulant aid. ATD was used for the determination of the three elements in reference materials (Orchard Leaves and Pepperbush Leaves). The results agreed with the certified values and with those obtained by isotope-dilution mass-spectrometry, and the precisions were satisfactory. The three elements in hot-spring water at levels from several to several tens ppb were determined by using a combination of ATD and BMTAC.
Polarographic Trace Analysis of Cadmium(II) after Solvent Extraction Using the Salting-out Method
Authors: Fujinaga Taitiro , Nagaosa Yukio
Published: July 2006

A selective and sensitive method is presented for the determination of cadmium(II), based on polarography after salting-out extraction into acetonitrile. The effect of nonaqueous solvents, salting-out agents, and the concentration of reagents has been studied. Under the conditions established, the cadmium(II) iodide complex extracted into the solvent gives a well-defined d.c. wave and a sharp a.c. peak, with E1⁄2 and Ep=−0.72 V vs. SCE respectively. Down to 0.50 ppm of cadmium(II) in the original aqueous solution can be determined by the proposed method. Lead(II) and In(III) do not interfere up to a 1000-fold amount relative to Cd(II). Interference from Fe(III) and Tl(III) can be eliminated by the addition of ascorbic acid.
Mechanisms of Stannyl–Carbon Bond Cleavages by Reactions with Benzoyl Peroxide
Authors: Kozuka Seizi , Naribayashi Ikuya , Nakagami Jun-ichi , Ogino Kenji
Published: July 2006

The mechanism for the process giving trimethyl(benzoyloxy)stannane by the reaction of benzoyl peroxide with trimethylphenylstannane or tetramethylstannane has been investigated. The kinetic results exclude the possibility that the decomposition of the peroxide is induced by the stannanes. The addition of dicyclohexylcarbodiimide as a trapping agent for benzoic acid markedly depressed the yield of the benzoyloxystannane by the reaction of trimethylphenylstannane, suggesting that the benzoyloxystannane is mainly or exclusively produced by the protodestannylation reaction of trimethylphenylstannane with benzoic acid. In the reaction of tetramethylstannane with benzoyl peroxide, trimethyl(benzoyloxy)stannane was formed only when a large excess of the stannane was used, and dicyclohexylcarbodiimide showed no significant effect upon the formation of the benzoyloxystannane. A homolytic process has been suggested for the reaction giving the benzoyloxystannane from tetramethylstannane.
Reactions of α-Aminoacetonitriles with Isothiocyanates. Synthesis of 1,3-Disubstituted 5-Imino-2-thiohydantoins
Authors: Kinoshita Takeshi , Watanabe Hiroko , Sato Sadao , Tamura Chihiro
Published: July 2006

The reactions of α-aminoacetonitriles with isothiocyanates gave 1-cyanomethyl-1,3-disubstituted thioureas or 1,3-disubstituted 4-amino-4-imidazoline-2-thiones depending upon the reaction conditions. In the presence of polar organic solvents such as methanol the former products were easily cyclized to the latter. 1,3-Disubstituted 4-amino-4-imidazoline-2-thiones were autoxidized in methanol affording 1,3-disubstituted 5-imino-2-thiohydantoins.
Adsorption of n-Aliphatic Alcohols on Mercury Electrode and Their Effect on Electrode Kinetics
Authors: Niki Katsumi , Takizawa Yumiko
Published: July 2006

The adsorption parameters of butyl alcohol, amyl alcohol, and hexyl alcohol at mercury electrode were evaluated by means of the electrocapillary measurements and compared with those obtained by differential capacity measurements. A marked difference is observed both in the interaction parameters between adsorbed molecules and in the maximum surface excess, Γmax. The inhibition effect by these alcohols on the electrode kinetics of the vanadium(III)/vanadium(II) couple in 0.5 M H2SO4 and of the europium(III)/europium(II) couple in 1.0 M HCl depends only on the surface coverage, θ=Γ⁄Γmax, of the electrode and is independent of the chain length of the adsorbed alcohol. The blocking effect is predominant in the inhibition of the electrode process by these alcohols.
A Novel System Consisting of a Soluble Inorganic Reagent Caged in the Network Structure of Gels
Authors: Matsumoto Yoshio , Shirai Michiko , Kawashima Takeshi
Published: July 2006

A new type of system was prepared which consisted of a water-soluble macromolecular metal complex caged in the network structure of a gel particle, the caged reagent being soluble in nature in an aqueous solution, but unable to get out of the gel particle into the outside solution by going through the network because of its large molecular size. This system was further proved to be useful as a convenient capturer of heavy metal ions in an aqueous solution.
Microscopic Evaluation of Surfactant–Water Interaction in Apolar Media
Authors: Sunamoto Junzo , Hamada Tomiko , Seto Takafumi , Yamamoto Shinji
Published: July 2006

Under the very limited conditions where the mole ratio of water to surfactant is about unity or so, the tightness of the interaction between various ionic surfactants and water solubilized in apolar media was evaluated using the O–H vibrational mode of water in the near infrared spectral region. Water solubilized in apolar solvents containing surfactant exhibited two absorption bands in the region. One of the two arises from water existing in bulk organic phase and appears around 1900–1910 nm. Another band arises from water bound to surfactant and appears over a range of 1920–2020 nm; it is affected primarily by the ionic head group of surfactant rather than by the counter ion. The cationic surfactants were thought to form more rigid micelles than the zwitterionic or anionic ones. The copper (II) ion cosolubilized in the system hardly altered the O–H vibrational energy of water. The dependence of the near infrared absorption band on water, the chemical shift and line width of water proton resonance in NMR, and the fluorescence intensity of terbium chloride all displayed an inflection at the point where the mole ratio of water to surfactant is about unity. This was interpreted in terms of the two step hydration mechanism.
Reflection Spectrum of the Single Crystal of Wurster’s Blue Perchlorate
Authors: Iyechika Yasushi , Yakushi Kyuya , Kuroda Haruo
Published: July 2006

The visible and near-infrared reflection spectrum of the single crystal of Wurster’s blue perchlorate was measured at various temperatures over the range of 30–300 K, by using the microspectrophotometric method. The absorption spectra were derived by Kramers-Kronig transformation of the reflection spectra. The intensity ratio of the (0-0) and (0-1) vibronic bands of the local-excitation associated with the π-π* (2B1u←2B2g) transition of TMPD+ was found to be anomalous when the spectrum was measured with the light polarized parallel to the b-axis, while not in the spectrum polarized parallel to the a-axis. The Davydov splitting between B3u and B2u components of this absorption band was found to be about 400 cm−1. In the antiferromagnetic (low temperature) phase below 190 K, the charge-transfer band appeared in the a-axis spectrum, showing its absorption maximum at 11.6×103 cm−1, and its intensity increased on lowering the temperature. At the same time, a marked temperature dependence was observed in the local-excitation band. These changes are interpreted in terms of the singlet-triplet model of the dimeric interaction of TMPD+ ions in the low-temperature phase.
Electrophoresis and Diffusion Studies of the Solubilization of Polar and Nonpolar Oily Compounds with Sodium Dodecyl Sulfate. II
Authors: Ogino Keizo , Takeshita Nobuo
Published: July 2006

The solubilization of polar and nonpolar oily materials into an aqueous sodium dodecyl sulfate (SDS) solution with and without sodium chloride was studied. Normal paraffins and their derivatives, with carbon numbers of C7, C8, and C10, were used as solubilizates, the extents of solubilization, the relative viscosities of the solutions, the diffusion coefficients, and the electrophoretic mobilities of the micelles in the solutions were observed, and the effective specific volumes, the effective radii, the ζ-potentials, and the effective charge of the micelles were derived assuming that the micelles were spherical. The micelles of SDS showed increasing mobilities when they incorporated octanoic acid, 1-octanol, and decanoic acid, while the mobilities decreased when they incorporated heptane, octane and 1-decanol. On the basis of these results, we discussed the mechanism of the solubilization of polar and nonpolar oily compounds with SDS.
Cotton Effect Induced in Optically Inactive Molecules and Molecular Complexes by Optically Active Environment. II. Acridine and Phenazine in Cellulose Diacetate Film
Authors: I’Haya Yasumasa J , Aoi Taka-aki , Sano Tatsuji
Published: July 2006

Ultraviolet absorption spectra and induced circular dichroism (ICD) of acridine and phenazine were measured in cellulose diacetate film. The induced Cotton effect corresponding to each absorption maxima of these systems appeared. From the correspondence between the maxima of ICD and the peaks of the resolved absorption spectra, it was found that the sign of ICD is negative in the region where the molecular long-axis polarized transition plays a part in the CD induction and it is positive in the region where short-axis polarized transition does. A mechanism of CD induction tentatively proposed is that a dye molecule is imprisoned in a cage formed by an assembly of the folded chains of cellulose diacetate and the Cotton effect is induced by an electrostatic interaction between electronic transition dipole moments of the dye and of the chromophores involved in the cellulose diacetate cage.
Structural Studies of Asymmetric Hydrogenation. IV. The Crystal Structures of [(R)-1-Cyanoethyl][(S)(−)-α-methylbenzylamine]bis(dimethylglyoximato)cobalt(III) at 293 K and 173 K
Authors: Ohashi Yuji , Sasada Yoshio , Takeuchi Seiji , Ohgo Yoshiaki
Published: July 2006

The structure of [(R)-1-cyanoethyl][(S)(−)-α-methylbenzylamine]bis(dimethylglyoximato)cobalt(III) has been determined by X-ray analysis at 293 K and 173 K. The crystal is monoclinic; the space group is P21; Z=2, with a=8.665(2), b=13.485(3), c=9.584(3) Å and β=96.95(3)° at 293 K, and a=8.786(2), b=13.500(2), c=9.243(2) Å, and β=98.09(3)° at 173 K. The structures were deduced by the heavy-atom method and refined by the block-diagonal least-squares technique to the final R values of 0.055 and 0.038 for 1940 and 1948 observed reflections at 293 K and 173 K respectively. The bis (dimethylglyoximato)cobalt moiety is twisted around its long axis because of the steric repulsion from the (R)-1-cyanoethyl group and the optically active amine. The degree of the twist is the same as that observed in the structure of [(R)-1-(methoxycarbonyl)ethyl] [(R)(+)-α-methylbenzylamine]bis(dimethylglyoximato)cobalt(III). The conformation of the amine ligand was ascertained to be influenced by the substituted alkyl group through the bis(dimethylglyoximato)cobalt moiety.
Dielectric Study of Aliphatic Esters in Cyclohexane Solutions at the Frequency of 100 GHz
Authors: Kano Yoshikazu , Minami Ryuichi , Takahashi Hiroaki
Published: July 2006

The dipole relaxation mechanism of carboxylic esters has been studied through the dielectric measurements of seventeen aliphatic esters in cyclohexane solution at 25 °C. The dielectric relaxation times obtained in this experiment are compared with those obtained for a number of rigid molecules under the same conditions. This result indicates that the dipole relaxation process of these esters RC*OOR′ is dominated by intramolecular rotation around the C–C bonds and/or the O–C bond rather than that around the C*–O bond.
Catalytic Properties of Iron Oxide. III. Oxidative Dehydrogenation of Butenes over Iron Oxide Catalysts
Authors: Misono Makoto , Sakata Kanji , Ueda Fumio , Nozawa Yasuaki , Yoneda Yukio
Published: July 2006

Oxidative dehydrogenation of butenes was investigated by use of a flow reactor over three iron oxide catalysts having different structures, i.e., α-Fe2O3, γ-Fe2O3, and Fe3O4, which were prepared in situ by controlled reduction and reoxidation with a pulse method. Under the working conditions of catalytic oxidation, the structures of α- and γ-Fe2O3 remained unchanged, while Fe3O4 was oxidized to γ-Fe2O3, the oxidation state of iron being Fe(III) in all of three iron oxide catalyst. These results are consistent with the kinetics that the reaction was of zeroth order in the partial pressure of oxygen and of nearly first order in the butene partial pressure. γ-Fe2O3, as well as γ-Fe2O3 formed from Fe3O4 under the catalytic conditions, was very active and selective for the reaction, as expected from the results obtained previously with a pulse reactor. It was concluded from the following facts that the oxygen species responsible for this reaction is lattice oxygen of γ-Fe2O3 and that the reaction proceeds by the redox cycles of γ-Fe2O3\ightleftharpoonsγ-Fe2O3−x. i) Reactivity of γ-iron oxide surface in the stoichiometric oxidation of butenes to butadiene did not change, when the surface oxygen was stepwisely removed by CO-pulses from γ-Fe2O3 to γ-Fe2O2.8. ii) Formation of butadiene from a butene pulse was little affected by whether butenes were pulsed with oxygen or not.
Effect of pH on Brdicka Currents Produced by Cytochrome c
Authors: Ikeda Tokuji , Yamane Yoshiyuki , Kinoshita Hideaki , Senda Mitsugi
Published: July 2006

Effect of pH and buffer concentrations on Brdicka currents produced by horse heart cytochrome c was investigated in the presence of hexaamminecobalt(III) chloride in ammonia, tris(hydroxymethyl)aminomethane, N,N-dimethylglycine, borate, and carbonate buffer solutions at pH varying between 8.2 and 10.7. The Brdicka current-activity of the protein varied with pH and the kind and concentration of buffers, but, if corrected for the effect of the buffer salts, showed a sigmoidal pH-dependence. The pH-dependence was interpreted as due to the protonic dissociation of Lys-79 of the protein. Brdicka currents of the protein were observed also in unbuffered solutions containing no proton donor except water. The current intensity was explained by taking into account the change of pH at electrode surface. The results indicate that a main proton donor in the Brdicka reaction is a water molecule.
Preparation and Stereochemistry of Cobalt(III) Complexes with Tetramines Derived from 1-(2-Pyridyl)ethylamine
Authors: Suzuki Toshishige M , Kimura Tetsuo , Fujita Junnosuke
Published: July 2006

The optically active ligands, (2S,7S)-2,7-di(2-pyridyl)-3,6-diazaoctane (S,S-peaen) and (2R,8R)-2,8-di(2-pyridyl)-3,7-diazanonane (R,R-peatn) have been prepared. The dichlorocobalt(III) complexes of these ligands have been prepared and several isomers isolated. The ligand, S,S-peaen yielded one cis-α and two types of cis-β isomers, while the R,R-peatn gave only one cis-β isomer. Oxalato and dinitro derivatives of the R,R-peatn complexes have been isolated and characterized and the stereochemistry of the isolated complexes discussed.
The Kinetics of the Thermal Deammonation of [RhX(NH3)5]X2 in the Solid State
Authors: Kohata Susumu , Kawaguchi Hitoshi , Itoh Noriko , Ohyoshi Akira
Published: July 2006

The isothermal kinetics of the substitution reaction of an ammonia with an outer-sphere anion was studied in the solid state; [RhX(NH3)5]X2(s)→[RhX2(NH3)4]X(s)+NH3(g) (X=Cl, Br, I). The kinetic parameters provided some evidence for a dissociative mechanism.
Syntheses and Electronic Spectra of 4,4′-Diacetyl-2,2′-isopropylidenedi-8-quinolinol, Its Nickel(II), Copper(II), and Zinc(II) Chelates
Authors: Yamamoto Yoshinori , Shibahara Kunio , Takei Shinsuke
Published: July 2006

The title nickel chelate, which has a planar four-coordinated form, gave an intense new band, no corresponding band of which was observed with the other chelates, at the position between the first and second π-π* bands. The spectra were compared with those of the corresponding compounds free from the acetyl group.
Structure Determination of the Fluorescent Base from Geotrichum candidum Phenylalanine tRNA
Authors: Mochizuki Akihiko , Omata Yoshiaki , Miyazawa Yuji
Published: July 2006

The chemical structure of the fluorescent base purified from Geotrichum candidum phenylalanine tRNA was determined as peroxywybutine by the use of MS, UV, and NMR measurements.
Synthesis of Cyclopentadecanone by Ring Contraction of Cyclohexadecanone
Authors: Kato Tetsuya , Kondo Hisao , Miyake Akihisa
Published: July 2006

Cyclopentadecanone has been synthesized from cyclohexadecanone. 2,2,15-Tribromocyclohexadecanone, upon treatment with sodium methoxide, underwent the Favorskii rearrangement via methyl 2-bromo-1-cyclopentadecene-1-carboxylate to produce a mixture of methyl 2-methoxy-1-cyclopentadecene-1-carboxylate, methyl 2-methoxy-2-cyclopentadecene-1-carboxylate, and methyl 2,2-dimethoxycyclopentadecane-1-carboxylate which was converted into cyclopentadecanone.
Synthesis of 5,7-Dihydroxy-2′,4′,5′-trimethoxyisoflavone and Its 7-Methyl Ether (Robustigenin)
Authors: Nakayama Mitsuru , Ohira Susumu , Matsui Takanao
Published: July 2006

The treatment of 2,4,6-trihydroxy-2′,4′,5′-trimethoxydeoxybenzoin with benzyl chloride gave a dibenzyl ether. The condensation of the ether with ethyl formate, followed by the debenzylation of the resulting isoflavone, afforded 5,7-dihydroxy-2′,4′,5′-trimethoxyisoflavone, which was then converted into a pentamethoxyisoflavone. The partial demethylation of the pentamethoxyisoflavone gave 5-hydroxy-2′,4′,5′,7-tetramethoxyisoflavone, which was identical with natural robustigenin.
Correlation NMR Spectroscopy with a Water Signal Subtracting System
Authors: Akutsu Hideo , Kyogoku Yoshimasa , Kagawa Isao
Published: July 2006

A modified correlation NMR method which includes the baseline correction systems in both hard- and softwares has been developed. By applying this method the proton signals of cytochrome b5 and adenosine 5′-monophosphate at low concentration in H2O solutions were obtained.
A Polarographic Rate Study on the Acid Hydrolysis of Several Halogeno Cobalt(III) Complexes
Authors: Yamada Akifumi , Yoshikuni Tadatsugu , Kato Yoshikiyo , Tanaka Nobuyuki
Published: July 2006

A polarographic rate study of the acid hydrolysis of [CoX(NH3)5]2+- and trans-[CoX2(N)4]+-type complexes (X=Cl− and Br−; (N)4=(NH3)4, (ethylenediamine)2, (propylenediamine)2 and (1,2-cyclohexanediamine)2) has been carried out in 0.1 M acetate buffer solutions. These complexes gave two polarographic waves; the first wave corresponds to the reduction of Co(III) to Co(II) and the second one, to the reduction of Co(II) to Co(0). The relation between the current and the time of the first wave in a positive potential was dependent on the dissolution wave caused by halogenide ions produced by acid hydrolysis and also on the parallel ECE mechanism. The acid-hydrolysis rate of tervalent cobalt complexes was determined from the variation in the current of the first wave. The rates are: 1.31×10−6 s−1 for [CoCl(NH3)5](NO3)2, 6.25×10−4 s−1 for trans-[CoCl2(NH3)4]ClO4, 3.20×10−5 s−1 for trans-[CoCl2(en)2]NO3, 4.28×10−5 s-1 for trans-[CoCl2(pn)2]ClO4, 1.53×10−4 s−1 for trans-[CoCl2(chxn)2]ClO4·H2O, 5.80×10−6 s−1 for [CoBr(NH3)5](NO3)2, 4.19×10−3 s−1 for trans-[CoBr2(NH3)4]ClO4, 1.51×10−4 s−1 for trans-[CoBr2(en)2]NO3, 3.30×10−4 s−1 for trans-[CoBr2(pn)2]ClO4·0.5H2O and 5.10×10−4 s−1 for trans-[CoBr2(chxn)2]NO3 at 25 °C and an ionic strength of 0.1.
Electrochemical Oxidation and Reduction of Ferredoxin Adsorbed on Mercury Electrode Surface. Phase-selective A. c. Polarography at DME
Authors: Kakutani Tadaaki , Toriyama Kazunobu , Ikeda Tokuji , Senda Mitsugi
Published: July 2006

The electrochemical behavior of Clostridium pasteurianum ferredoxin (Cl.Fd) was studied by a.c. polarography with the dropping mercury electrode. The a.c. polarograms observed in acidic media (pH<7) were assigned to RSH/RSHg redox reaction of the cysteine residues of apoferredoxin, whereas those observed in basic media (pH>8) were assigned to a two-step one-electron transfer (EE mechanism) to the iron-sulfur clusters of Cl.Fd adsorbed on the mercury electrode surface ((Cl.Fd)ad). The a.c. polarographic behavior of (Cl.Fd)ad observed in basic media was interpreted by theory of a.c. polarography of a two-step surface redox reaction. The formal standard oxidation-reduction potential of (Cl.Fd)ad was determined to be −0.33 V vs. NHE at pH 7.0, and its pH dependence was −30 mV/pH between pH 8 and 10.
Syntheses and Magnetic Properties of Three Modifications of Dichloro[2-(hydroxymethyl)pyridine N-oxide]copper(II)
Authors: Muto Yoneichiro , Tokii Tadashi , Nakashima Michio , Kato Michinobu , Jonassen Hans B
Published: July 2006

Three modifications of dichloro[2-(hydroxymethyl)pyridine N-oxide]copper(II), CuCl2(2-CH2OH·pyo), were prepared and characterized by the temperature dependences of their magnetic susceptibilities and their IR spectra. The greenish-yellow modification shows ferromagnetic behavior (θ⁄K=+20), whereas both the yellow and deepgreen modifications exhibit a dimer type of antiferromagnetism (J/cm1=−585 and −565). The hemi adducts with the empirical formula of CuCl2(2-CH2OH·pyo)·1/2L, where L=C2H5OH and H2O, were also isolated. The structural assignments for the three modifications and the two adducts were made on the basis of the similarity of their magnetic and spectral properties to those of dimeric copper(II) pyridine N-oxide complexes, and the whole preparative scheme of these complexes was interpreted in terms of their structural features.
Stereochemical Nonrigidity of {Poly(1-pyrazolyl)borato}palladium(II) Complexes Containing a Metal–1-Alkenyl or –Alkyl Bond
Authors: Onishi Masayoshi , Hiraki Katsuma , Shironita Masaharu , Yamaguchi Yuzo , Nakagawa Shigeki
Published: July 2006

New{poly(1-pyrazolyl)borato}palladium(II) complexes, [Pd{CH=CCl–CMe2(NMe2)–1-C,N}(BPz4)] (Pz=1-pyrazolyl) 1, [Pd{CH2CMe(OMe)–CH2S–t-Bu–1-C,S}(BPz3Y)] (Y=Pz or H), and [Pd{CH2CMe(OMe)–CH2NMe2–1-C,N}(BPz3Y)] were prepared and characterized by means of elemental analysis and IR and 1H-NMR spectroscopy. The stereochemical nonrigidity of these complexes was discussed on the basis of 1H-NMR data. The fluxional behavior of the BPz4 ligand in 1 was analyzed in detail by means of an approximate method based on the Bloch equation, and found to consist of three kinds of motions: inversion of the Pd—(N–N)2–B boat-type six-membered ring, rotation of the BPz4 ligand about the Pd-pyrazolyl nitrogen bond accompanying the inversion, and a tumbling process.