bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on the Fragment Ion Distribution and Their Reactions by the Use of a Charge Spectrometer. II. The Charge Exchange Reactions in Methanol with Fast Positive Ions
Authors: Nagatani Toshio , Yoshihara Kenji , Shiokawa Takanobu
Published: July 2006

Distribution of fragment ions after bombardment of a methanol molecule with various positive ions has been studied by the use of a double mass spectrometer. It was found that the internal energy distribution function has fine structures. The appearance potentials of the fragment ions were re-estimated. From the results the mass spectra of methanol by electron impact were interpreted fairly accurately. The successive ion-molecule reactions after the charge exchange were studied by increasing pressure in the reaction chamber. The behaviors of the metastable ions were also investigated.
Alkoxy and Phenoxy Bridged Dimeric Copper(II) Complexes with Salicylaldimine Ligands
Authors: Miners J O , Sinn E
Published: July 2006

The tridentate SchifF base N-3-hydroxy-n-propylsalicylaldimine can be coordinated with copper(II) to form three kinds of dimeric oxy-bridged antiferromagnetic complexes (metal: ligand ratio—1: 1), as well as the normal monomeric complex. In one of the dimeric complexes pairs of copper atoms are bridged by pairs of the deprotonated alcoholic oxygens of the ligands. The others have an extra ligand X (X=–Cl, –ONO2) per copper atom, the metals are bridged by phenolic oxygens, the alcoholic hydroxyls are not deprotonated, but are either coordinated (if X=Cl) to five-coordinated copper atoms in discrete dimer molecules, or participate in intermolecular hydrogen bonding linking individual dimeric molecules in which the copper atoms are four-coordinated. In the presence of pyridine, ammonia, or mild inorganic base, a rearrangement reaction can be induced, resulting in conversion of the phenolic-bridged (five-coordinated copper) dimer into the related alcoholic-bridged (fourcoordinated copper) dimer. This behaviour is not followed by N-hydroxyethylsalicylaldimine which appears to form only one kind of copper complex [Cu(Lig)X] (X=–C1, –ONO2); in which the metal atoms are essentially planar and do not take part in strong antiferromagnetic interactions.
Cadmium and Silver Sulfide-impregnated Silicone Rubber Membranes as Selective Electrodes for Cadmium Ions
Authors: Hirata Hiroshi , Date Kenji
Published: July 2006

Silicone rubber membranes impregnated with mixtures of cadmium sulfide and silver sulfide were developed as selective electrodes for cadmium ions in a solution. Both co-precipitated and sintered mixtures could be used as the active materials for the electrode membrane, but here the membrane which contained a mixture in which cadmium sulfide had been added to silver sulfide after they had been precipitated individually did not show the satisfactory response characteristics. The Nernstian slope was obtained in the activity range from 10−1 to 10−5 M Cd2+, while the analytical range was from 10−1 to 10−6 M. These potentials did not change at pH values from 2.5 to 7.5. Among common ions, silver, copper(II), mercury(II), iron(III), sulfide, and iodide ions interfered seriously. About 10–100 times as many lead and bromide ions and more than 1000 times as many alkali metals, alkaline earth metals, zinc, aluminum, nickel, manganese(II), cobalt, nitrate, and perchlorate ions were tolerated in coexistence with cadmium ions.
Polarographic Studies of the Anodic Oxidation of Mercury. I. Anodic Waves of Ammonia and Several Amines in N,N-Dimethylformamide
Authors: Matsui Yoshihisa , Kurosaki Yukio , Date Yoshio
Published: July 2006

The behavior of ammonia and several amines at the dropping mercury electrode was studied in N,N-di-methylformamide containing 0.10m Et4NClO4 by means of DC polarography and amperometric titration. Ammonia gave a diffusion-controlled anodic wave, which was attributed to the reversible oxidation of mercury to the 1:2 complex of mercury(II) with ammonia. A dilute solution of methylamine or dimethylamine gave a diffusion-controlled anodic wave similar to that of ammonia. A concentrated solution of each amine gave a prewave due to the adsorption of the electrolysis product, Hg(am)22+, on the electrode surface. Trimethylamine also gave an anodic wave, but it was attributed to the oxidation of the amine itself to the corresponding cation radical. Ethylenediamine and 1,2-diaminopropane each gave a well-defined anodic wave over the concentration range examined. The wave was diffusion-controlled and was attributed to the reversible oxidation of mercury to the chelate compound of the Hg(diam)22+ type. No adsorption phenomena were observed in this case. Aromatic amines such as aniline and β-naphthylamine gave no anodic waves. The overall stability constants of the 1:2 complexes of mercury(II) with ammonia, methylamine, dimethylamine, ethylenediamine, and 1,2-diaminopropane were evaluated by the analyses of the waves to be 1016.9, 1017.1, 1015.0, 1023.5, and 1024.0m−1 respectively.
Asymmetric Hydrogenation of C=O Double Bond with Modified Raney Nickel. XXVII. Asymmetric Hydrogenation of Acetylacetone
Authors: Tanabe Tadashi
Published: July 2006

The asymmetric (enantioselective) hydrogenation process of acetylacetone (AA), which is a highly enolized compound, was studied by the use of catalysts modified with d-tartaric acid, and l-glutamic acid. AA corroded the Raney nickel catalyst during the hydrogenation. The modification protected the catalyst from corrosion, and the protective effects by the amino acids were greater than that by the hydroxy acid. The modification with tartaric acid increased the hydrogenation velocity of AA, but the amino acid hardly affected the hydrogenation velocity. The glutamic acid on the catalyst surface reacted with AA to form a Schiff base during the hydrogenation. The hydrogenation proceeded mainly by means of a two-step process via 2-pentanol-4-on. The modifying pH and temperature affected the asymmetric activity of the catalyst. In the first step of the hydrogenation, the catalyst modified with d-tartaric acid showed a high asymmetric activity, but the one modified with l-glutamic acid exhibited a low asymmetric activity as a result of the Schiff base formation. In the second step, the modification with d-tartaric acid promoted the formation of racemic 2,4-pentanediol (II), and the l-glutamic acid increased the production of meso II.
A Kinetic Study on the Decomposition of Benzyl N-(Hydroxymethyl)carbamate in Alkaline Solution
Authors: Takeuchi Shigeya
Published: July 2006

The decomposition of benzyl N-hydroxymethylcarbamate (N-BHMC) by potassium hydroxide was carried out in a mixed solvent dioxane-water. The following rate equation was obtained. R0=k[N-BHMC]0[KOH]0, where [N-BHMC]0 and [KOH]0 denote the initial concentrations of N-BHMC and potassium hydroxide, respectively. The equation is analogous to that of Ugelstadt obtained for the hydroiytic decomposition of N-hydroxy-methylbenzamide. Thus the reaction was assumed to proceed via the three steps:

1) C6H5CH2OCONHCH2OH+OH−\ightleftarrowsC6H5CH2OCONHCH2O−+H2O

2) C6H5CH2OCONHCH2O−\ightleftarrowsC6H5CH2OCONH−+CH2O

3) C6H5CH2OCONH−+H2O\ightleftarrowsC6H5CH2OCONH2+OH−
Chemistry of Mixed Transition-metal Complexes. V. The Preparation of Several Mixed Transition-metal Complexes with Two μ-Diphenylphosphido Groups
Authors: Yasufuku Katsutoshi , Yamazaki Hiroshi
Published: July 2006

Several mixed transition-metal complexes with two μ-diphenylphosphido groups as bridging ligands were prepared from bis(diphenylphosphine)metal complexes and diiodometal complexes by means of the action of amine or a Grignard reagent.
Syntheses of Some Cyanine Dyes of Bunte Salt Type
Authors: Yamamoto Masashi , Nakamura Shigeo , Yoshimura Kunio , Yuge Masuo , Morosawa Shiro , Yokoo Akira
Published: July 2006

In order to investigate the photosensitivity of compounds such as photosensitizing dyes of Bunte salt type which have not been synthesized yet, the following compounds were prepared: 1,1′-di-(2-potassiumsulfothio-ethy)-4,4′-tricarbocyanine acetate (VI), 1,1′-di-(2-potassiumsulfothioethyl)-2,2′-tricarbocyanine acetate (VII), 6,6′-dimethyl-3,3′-di-(2-potassiumsulfothioethyl)dithiacarbocyanine acetate (VIII), and 3-(2-bromoethyl)-3′-(sulfothioethyl)-5,6,5′,6′-tetramethoxydithiacarbocyanine (XII).
Branched-Chain Sugars. II. On the Configuration of Branched-Chain Sugars from Methyl 2-O-Benzoyl-4,6-O-benzylidene-α-d-ribo-hexopyranosid-3-ulose
Authors: Yoshimura Juji , Sato Ken-ichi , Kobayashi Kazuhiko , Shin Chung-gi
Published: July 2006

Stereoselectivities in diazomethane and nitromethane reaction of methyl 2-O-benzoyl-4,6-O-benzylidene-α-d-ribo-hexopyranosid-3-ulose were examined. Reduction of the epoxidation product (2) gave an epimeric 3-C-methyl derivative in contrast with that obtained by the Grignard reaction. Comparison of NMR spectra of the corresponding di-O-acetate of the both epimers proved that 2 has the gluco-configuration. Ring-opening of the epoxide with alkali, methanolic ammonia, and acid gave the corresponding 3-C-hydroxymethyl, 3-C-aminomethyl (17), and de-O-benzylidenated product, respectively. Hydrogenation of the 3-C-nitromethyl derivative (21) obtained by nitromethane condensation, in the presence of Raney nickel, accompanied with benzoyl-migration to give 3-C-benzamidomethyl derivative (22). De-benzoylation of 22 with methanolic potassium hydroxide gave 3-C-aminomethyl derivative (26) and an orthoester-type compound. Comparison of 26 with 17 and their derivatives indicated that 21 has the allo-configuration. The both configurations were also supported by the optical rotation of 3-C-benzamidomethyl derivatives in cuprammonium solution.
Optically Active Triptycenes. VI. Optical Resolution of 2,5-Dihydroxy-8-methoxycarbonyltriptycene and Absolute Configuration of 2,5-Dimethoxy-8-methoxycarbonyltriptycene
Authors: Shimizu Yasumi , Naito Taketoshi , Ogura Fumio , Nakagawa Masazumi
Published: July 2006

After several unsuccessful attempts, optical resolution of 2,5-dihydroxy-8-methoxycarbonyltriptycene could be attained by means of bis-camphanate derivative. The absolute configuration of (+)-2,5-dimethoxy-8-methoxycarbonyltriptycene derived from (+)-2,5-dihydroxy-8-methoxycarbonyltriptycene was determined as 1R,6S by chemical correlation with (+)-2,5-dimethoxy-7-dimethylaminotriptycene hydrobromide whose absolute configuration had been proved to be 1R,6S by the X-ray structure analysis using the Bijvoet method.
Studies on Nitro Sugars. III. The Synthesis of 3-Nitrohexofuranose Derivatives
Authors: Takamoto Tetsuyoshi , Yokota Yoh-ichi , Sudoh Rokuro , Nakagawa Toshio
Published: July 2006

The oxidation of l,2;5,6-di-O-isopropylidene-3-oximino-α-d-ribo-hexofuranose (1) with trifluoroperacetic acid at a low temperature afforded, in a 75% yield, the corresponding 3-nitro-allofuranose (3), but at a high temperature it gave at least three nitro compounds, i.e., 3, 3-deoxy-1,2-O-isopropylidene-3-nitro-α-d-allofuranose (6) and 3,6-anhydro-3-nitro-α-d-glucofuranose (8). 6 was converted to 5,6-di-O-acetate (7) and confirmed by comparison with the 3-epimer (11), which was prepared by the acetonation of 3-deoxy-3-nitro-d-glucose, partial hydrolysis and acetylation. The structure of 8 was instrumentally determined and supported by the fragmentation pathways in its mass spectrometry. The formation of 8 was assumed to proceed through nitronic acid (5) as an intermediate.
The Acid-catalyzed Isomerization of α-Ylangene and α-Ylangene Epoxide
Authors: Ohta Yoshimoto , Hirose Yoshio
Published: July 2006

Upon treatment with dilute mineral acid, α-ylangene afforded two alcohols with amorphane carbon skeletons, 10β-hydroxyamorpha-4-ene (16) and 10α-hydroxyamorpha-4-ene (17). The carbonic acid-induced isomerization of α-ylangene epoxide yielded 3α-hydroxy-α-amorphene (19), 3α-hydroxy-δ-amorphene (20), and 3α, 10α-dihydroxyamorpha-4-ene (21). The structures of these compounds were strictly determined, and the revised structure 16 of δ-cadinol proposed by Lin was shown to conflict with the results of the isomerization of α-ylangene and with the previously-reported conversion of α-copaene into δ-cadinol (10) and T-muurolol (11) under similar conditions.
Circular Dichroism Studies of Ring-conf ormational and rotational Equilibria in 2-Isopropenylcyclohexanones
Authors: Watanabe Satoru
Published: July 2006

The temperature-dependent circular dichroism of optically active β,γ-unsaturated ketones, (2S, 5R)-(−)-2-isopropenyl-2,5-dimethylcyclohexanone (2) and (2S, 5R)-(−)-2-isopropenyl-5-methylcyclohexanone (3), and of the corresponding saturated ketones, (2S, 5R)-(−)-2-isopropyl-2,5-dimethylcyclohexanone (1), has been measured at the n→π* transition in order to determine the relative disposition between the carbonyl group and the ethylenic bond of the isopropenyl group of the β,γ-unsaturated ketones. The compound (2) exhibited the sign of a Cotton effect opposite to that of the corresponding saturated compound (1), and the circular dichroism of the compound (3) behaved quite differently from menthone (4). The result has been discussed mainly in terms of the geometry of the carbonyl group and the ethylenic bond of the isopropenyl group. Thus, it has been concluded that the preferred conformations of the compounds (1), (2), and (3), are 1A, 2A-III, and 3A-I respectively.
A Temperature-jump Study of the Kinetics of the Complex Formation of Iron(III) with m-Nitrophenol
Authors: Tamura Kiyoshi
Published: July 2006

By a new method here proposed, an expression of the relaxation time has been obtained for the formation of the monocomplex of iron (III) with a univalent anionic ligand. The method enables us to express the rate equation in a manner analogous to the second-order reaction, and to calculate the relaxation time with less mathematical labor. The validity of the treatment has been confirmed by applying it to the analysis of the complex formation reaction of iron (III) with m-nitrophenol. The kinetic measurement was performed with the temperature-jump method in an acidic aqueous solution at 25°C and at an ionic strength of 0.10. Over the acidity range studied (0.005≤[H+]≤0.026 M), the complex formation occurs significantly via one path: FeOH2++m-NO2C6H4OH\ightleftharpoonsm-NO2C6H4OFe2++H2O. The forward and backward rate constants obtained are 5.9×102 M−1s−1 and 1.8×102s−1 respectively. These results have been confirmed by examining the earlier kinetic data on similar reactions.
Excited States and Intermediates in the Photochemistry of Chromium(III) Complexes Studied by Flash Method
Authors: Ohno Takeshi , Kato Shunji
Published: July 2006

Photoreactions of K3[CrIII(NCS)6] and NH4[CrIII(NCS)4(NH3)2] were investigated by means of a flash technique. At low temperature (−87°C), the lowest excited doublet states (2Eg) of the complexes were easily observed on d-d excitation in acetone, the yields decreasing rapidly with rising temperature. In methanol-ethyl–eneglycol-water, 2Eg states of both complexes were easily observed at dry-ice temperature, but not at −46°C. Thus, the lowest excited quartet state (4T2g), the precursor of 2Eg state, should rapidly undergo photolysis at room temperature before being converted into the 2Eg state. The rate of thermal degradation of 4T2g state including chemical reactions was calculated to be ca. 1010 s−1 at room temperature. The decay rate of 2Eg state was estimated to be ca. 105 s−1 at room temperature. In the presence of organic compounds having carbonyl group, a strong and sharp absorption band near the UV region was observed at room temperature. Irradiation of UV light produced (NGS)2− radical for both complexes.
Initiation Step of Methane Pyrolysis. Further Studies on Initiation Step of Methane Pyrolysis
Authors: Yano Takayuki
Published: July 2006

The pyrolysis of diluted mixture of equimolar CH4 and CD4 were performed in a shock tube between ∼1500 K and ∼1600 K, and pyrolysis products were quantitatively determined. A small amount of oxygen contaminating the sample gases had no influence on the results. The isotope exchange reactions in the equimolar lean mixture of H2 and D2 were also performed under the same conditions of methane pyrolysis. The results explained that the isotope exchange reaction between H2 and D2 had no influence on the hydrogen isotopic distribution produced by the CH4-CD4 pyrolysis. From the hydrogen isotopic distribution of the products of CH4-CD4 pyrolysis, methyl radical mechanism was confirmed as the initiation step of methane pyrolysis.
An Investigation of a Surface Reaction between Pyrrhotite and the Hydrogen–Hydrogen Sulfide Mixture
Authors: Katsumoto Masayuki , Fueki Kazuo , Mukaibo Takashi
Published: July 2006

The isotopic exchange between H2S and D2 has been studied in the temperature range from 480°C to 551°C on a pyrrhotite specimen. The isotopic exchange reaction proceeded via these steps:

H2S+D2=D2S+H2

H2+D2=2HD

From the analysis of the kinetic data, the rate constant of the sulfurization of Fe1−XS by “hydrogen sulflde,” ki, and that of reduction by “hydrogen,” ki′, were determined. It was found that ki is inversely proportional to the sulfur activity of Fe1−XS, as, and that ki′ is independent of it. It was found that the rate equation for the sulfurization of Fe1−XS in the “hydrogen”-“hydrogen sulfide” gas mixture could be expressed in the form of v=kP“H2S”aS−1–k′P“H2”. A possible mechanism of the reaction at the surface of Fe1−XS is discussed.
Studies on Fragment Ion Distribution and Reactions by the Use of a Charge Spectrometer. III. Reactivities of the Excited Ions from Methylamine after Charge Exchange with Positive Ions
Authors: Nagatani Toshio , Yoshihara Kenji , Shiokawa Takanobu
Published: July 2006

The behavior of the excited ions produced by positive ion impact in methylamine has been studied in the reaction chamber of a double mass spectrometer at elevated pressure. The ion-molecule reactions have been discussed for three energy regions. Metastable transitions taking place in the reaction chamber and in the Giese lens have also been studied in the corresponding regions.
The Properties of Water in Macromolecular Gels. VI. The Relationship between the Rheological Properties and the States of Water in Macromolecular Gels
Authors: Aizawa Masuo , Suzuki Shuichi , Suzuki Teruo , Toyama Hiroshi
Published: July 2006

The relationship between the rheological properties and the states of water in macromolecular gels is investigated by both the rheological and nuclear magnetic resonance methods. In accordance with the stress-strain curve, macromolecular gels are shown to be classifiable into: (1) an agarose type of gel which shows great gel strength and brittleness at breaking; (2) a κ-carrageenan type of gel showing great gel strength, but ductility at breaking, and (3) a λ-carrageenan type of gel, which has very little gel strength and is pasty. The dependence of the NMR line-width of water in gels on the polymer concentration and on the temperature reveals that the motional state of water in gels is restricted in this order: the agarose type of gel>the κ-carrageenan type of gel>the λ-carrageenan type of gel. These results show that the state of water is closely related with the rheological properties of macromolecular gels.
Laser Photolysis Studies on the Ionization of N-Vinylcarbazole and N-Ethylcarbazole in the Presence and Absence of Electron Acceptors
Authors: Taniguchi Yoshio , Nishina Yasuzo , Mataga Noboru
Published: July 2006

Formation of solvated ion radicals in the N-vinylcarbazole (VCZ)-and N-ethylcarbazole (ECZ)-electron acceptor systems in polar solvents has been studied by means of laser photolysis, transient photoconductivity and transient absorption measurements. Ion radical formation due to the encounter collision between an excited VCZ or ECZ and electron acceptor was confirmed directly. In the absence of electron acceptor, formation of cation radicals of carbazoles due to biphotonic process was observed in polar solvents. The Sn←S1 spectra of these molecules were observed both in polar and nonpolar solvents.
The Ultraviolet Absorption Spectra and Hydrolysis of Bis (acetylacetonato) nickel (II) in Dichloromethane
Authors: Isobe Kiyoshi , Nakamura Yukio , Kawaguchi Shinichi
Published: July 2006

The ultraviolet spectrum of Ni(acac)2 in dichloromethane shows two maxima, at 265 and at 300 nm. The intensity ratio of these two bands is very sensitive to the water content of the solvent, the high-energy band decreasing and the low-energy band increasing with the water content. It is thus suggested that the trimeric Ni(acac)2might have only one absorption band, at 265 nm, in dichloromethane completely free from donor impurities. The UV spectrum of Ni(acac)2 in dichloromethane changes with time due to the hydrolytic reaction. Even in the solvent containing 4.54×10−3m water, acetylacetone was freed from the complex in the yield of 34.4% after 48 hours’ standing. A minute amount of the residual complex was isolated; its tetrameric structure is suggested on the basis of its UV spectrum in methanol.
Kinetics of the Reaction at the Silver–Silver Sulfide Interface
Authors: Mizusaki Junichiro , Fueki Kazuo , Mukaibo Takashi
Published: July 2006

The reaction rate at the Ag/Ag2S interface was determined as a function of silver activity of Ag2S in the temperature range 215–400°C. The silver activity of Ag2S at the interface was measured electrochemically by means of an Ag/AgI electrode. The reaction rate was measured by the direct sulfurization method (Wagner’s pellet method) and by Rickert’s method using Ag/AgI/Ag2S/Pt cell. The rates obtained by the two methods were in good agreement. It was found that this is a first-order reaction with respect to the activity of sulfur in Ag2S and that the rate equation is given by

v=1.0×104{exp(−18000⁄RT)}aseqv cm−2s−1 (i)

The following reaction mechanism prevails at the interface.

2Ag(A)+S(Ag2S)→2Ag+(Ag2S)+S2−(Ag2S) (ii)
Chemical Analysis of Mixtures of Metals by a Logarithmic Extrapolation Method
Authors: Nagaosa Yukio , Yonekubo Tatsuo
Published: July 2006

Decomposition of the ternary molybdophosphoric acid of titanium(IV), vanadium(V), zirconium(IV) and niobium(V) by complexing agents such as oxalate, citrate or tartrate was found from a kinetic study to be of first-order with respect to each metal ion. The half lives and activation energies of decomposition were also examined. From the results chemical analysis of mixtures of the metals was studied by a logarithmic extrapolation method, utilizing the difference in decomposition rate. Metals in binary systems such as Zr–Nb, V–Zr, Nb–V, Ti–V and Ti–Nb could be determined simultaneously within a relative error of ±5%. Determination of 0.01∼0.2 mg of vanadium was carried out in the presence of titanium (0.1 mg), zirconium (0.5 mg), niobium (0.5 mg) and other diverse ions. Iron(III), aluminum, germanium(IV) and iodide interfered with the determination.
Potential-step Anodic Stripping Voltammetry
Authors: Komatsu Masahiro
Published: July 2006

The application of anodic potential-step stripping voltammetry for the determination of metal ion was investigated. From the dependence of stripping current (ia,d) on electrode radius, the rotational speed of the stirring rod in electrodeposition and electrodeposition time for Cd(II) in 1 M KCl, the diffusion-controlled process could be theoretically predicted. The calibration curves of Cd(II), Mn(II), Ni(II), Zn(II), and Sb(III) were found to be linear in the range 0.01–0.1 ppm, and those of Tl(I), Cu(II), Pb(II), Sn(II), Bi(III), and In(III) in the range 0.02–0.2 ppm, by analysis at time t=1.25 sec on current-time curves. The ratio ia,d⁄ia,p increased in the order n=3<2<1, where ia,d is the anodic diffusion current obtained by the potential-step method, and ia,p the anodic peak current obtained by the linearly varying potential method. The ratio of irreversible electron transfer reaction differed from that of the reversible one. The coefficient of variation in the measurement of peak heights was ±3% for 0.1 ppm or 0.2 ppm of metal ion.
The Internal Friction of Glasses Containing Alkali under an Electric Field
Authors: Sakamura Hiroyasu , Imaoka Minoru
Published: July 2006

The change of the internal friction of sodium silicate and sodium borate glasses under an electric field was studied by means of a torsion pendulum technique. It was found that the internal friction increased under an electric field and that the increase was related to the numbers of vibration, the strength of the electric field, and the Na2O content. The increase in internal friction in the glasses with a high Na2O content was large because of the electrolysis of the glasses, which resulted in the removal of sodium ions. It was proposed that the internal friction increased because the removal of sodium ions was promoted by torsional oscillation under an electric field and that the deformation of the network took place around holes which were left behind by the removal of the sodium ions.
The Hydrolysis of Ferric Complexes. Magnetic and Spectrophotometric Studies of Aqueous Solutions of Ferric Salts
Authors: Kiyama Masao , Takada Toshio
Published: July 2006

Ferric chloro, ferric aquo, and ferric sulfato complexes in acidic solutions have been hydrolyzed at temperatures below 70°C to form polynuclear complexes of iron(III). Magnetic and spectrophotometric studies have then been carried out in order to clarify the nature of the polynuclear complexes. From these studies, their empirical formulas are presumed to be Fe2(OH)2Cl2O, Fe2(OH)3(NO3)3, Fe2(OH)3(SO4)3⁄2, and Fe3(OH)2(SO4)7⁄2. The iron ions in these polynuclear complexes are in a high spin state, as are those in the ferric complexes, iron oxides, and oxyhydrates. It is proposed that, in all these polynuclear complexes except Fe3(OH)2(SO4)7⁄2, edge-shared octahedral dimer units are antiferromagnetically linked with one another by hydroxy or oxo bridging. When the hydrolysis temperature is raised, these polynuclear complexes are further hydrolyzed to form precipitates. The complexes of Fe2(OH)2Cl2O, Fe2(OH)3(SO4)3⁄2, and Fe3(OH)2(SO4)7⁄2 give β-FeOOH, α-FeOOH, and RFe3(OH)6(SO4)2 (R=Na, K or NH4) respectively, whereas the complex of Fe2(OH)3(NO3)3 gives α-FeOOH or α-Fe2O3, depending on the temperature.
Isomerism of the Metal Complexes Containing Multidentate Ligands. III. Geometric and Optical Isomers of the Tris(2-methyl-1,2-propanediamine)cobalt(III) Ion
Authors: Kojima Masaaki , Yoshikawa Yuzo , Yamasaki Kazuo
Published: July 2006

The tris(2-methyl-1,2-propanediamine)cobalt(III) complex was prepared, and four possible isomers, geometrical and optical, were isolated by column chromatography on SP-Sephadex. Their configurations were assigned on the basis of the formation ratio and electronic, infrared, circular dichroism and PMR spectra: they were later confirmed by X-ray analysis.
The Analytical Application of Sulfur Analogues of β-Diketones. II. The Separation of Mercury(II), Cobalt(II), and Zinc(II) as Their STTA (1,1,1-Trifluoro-4-(2-thienyl)-4-mercaptobut-3-en-2-one) Complexes by Extraction Chromatography
Authors: Honjo Takaharu , Kiba Toshiyasu
Published: July 2006

The behavior of trace amounts of mercury(II), cobalt(II), and zinc(II) in liquid-liquid extraction have been investigated with 1,1,1-trifluoro-4-(2-thienyl)-4-mercaptobut-3-en-2-one in cyclohexane, and the results applied to the separation of the three metals as their STTA complexes by extraction chromatography. A chromatographic column in which 10−3 M STTA in cyclohexane supported on Kel-F(poly-trifluorochloroethylene) powder was the stationary phase has been employed throughout this work. After the metal ions had been retained on the column by passing a sample solution of pH 5.5–6.0 through the column, the zinc(II) was eluted with an aqueous solution of pH 5.0 and then the mercury(II) was eluted with 1M hydrochloric acid. Last of all, since the cobalt had been caught so tightly on the column that it could not be removed even with concentrated hydrochloric acid, acetone was poured down the column in order to wash down all the organic phase together with the cobalt. The relation between the extraction chromatography and the liquid-liquid extraction in batches has been discussed with regard to the metal–STTA system under the same conditions.
Trinuclear Intermediates Isolated in the Reactions of Bis(acetylacetonato)-nickel(II) with Dry Hydrogen Bromide
Authors: Isobe Kiyoshi , Noda Kenichiro , Nakamura Yukio , Kawaguchi Shinichi
Published: July 2006

The reactions of bis(acetylacetonato)nickel(II) with restricted amounts of dry hydrogen bromide have been performed in appropriate mixtures of dichloromethane and petroleum ether at room temperature or lower in order to isolate the intermediary products, Ni3Br(acac)5, Ni3Br2(acac)4, and Ni3Br4(acac)2. The essentially octahedral trinuclear structure of Ni3Br(acac)5 was established on the basis of elemental analysis, by molecular-weight and magnetic-moment determinations, and by studying the electronic and IR spectra. Ni3Br2(acac)4 and Ni3Br4(acac)2 were characterized less satisfactorily because of their lower solubilities. The reactions of these mixed complexes with pyridine have also been examined; a new complex NiBr(acac)(py)3 was thus obtained in addition to the known compound, Ni(acac)2(py)2.
Dielectric Relaxation and Molecular Structure. III. Dielectric Relaxation Study of Some Anilines in Benzene Solutions at Different Temperatures
Authors: Vij J K , Krishan Iqbal , Srivastava K K
Published: July 2006

Measurements of relative permittivity at 1 MHz and at 9.46 GHz, the refractive index for the Sodium D-line, have been made for (a) N,N-dimethylaniline, (b) N,N-diethylaniline, (c) o-chloroaniline, (d) m-chloroaniline and (e) p-chloroaniline at temperatures of 15, 25, 35, and 45°C in dilute solutions of benzene. Dielectric relaxation times τ(1) and τ(2) have been calculated by the method recently suggested by Higasi, Koga, and Nakamura in terms of the slopes a0, a′, a″, and aD. It is remarked that τ(2) at the experimental frequency of 9.46 GHz leads to τ1 the relaxation time for overall rotation, whereas τ(1) becomes an explicit function of τ1 and τ2- These determinations suggest the presence of both molecular and intramolecular rotations in the molecules. The results for τ(2) show a systematic decrease with increase in temperature whereas for τ(1) there seems to be no observable trend. The enthalpy and entropy of activation for molecular dielectric relaxation process has been determined. The enthalpy of activation for (a) and (b) is of the same order of magnitude (i.e., 3 kcal/mol), and the same is true for the case of (d) and (e) (1.8 kcal/mol) but 6.8 kcal/mol for (c). It appears that in o-chloroaniline, there is a finite probability of H–Cl bond formation between one of the amino hydrogens and the neighbouring chlorine atom.
Pyrolysis-Gas Chromatographic Studies of Ionically-chlorinated Poly-α-methylstyrenes
Authors: Okumoto Tadaoki , Takeuchi Tsugio
Published: July 2006

The microstructure of ionically-chlorinated poly-α-methylstyrene with or without a catalyst and the distribution of chlorine in the aromatic nucleus of the polymers were studied by means of pyrolysis-gas chromatography. The degradation products, such as α-methylstyrene, p-chloro-α-methylstyrene, and 3,4-dichloro-α-methylstyrene, gave good information about substitution reactions on the aromatic nucleus in original poly-α-methylstyrene. The differences between two series of ionically-chlorinated poly-α-methylstyrene were also discussed on the basis of yield of α-methylstyrene and p-chloro-α-methylstyrene.
Solvolysis of Organic Phosphates. VIII. γ-Elimination in the Spontaneous Hydrolysis of 2-Chloro-3-pyridylmethyl Phosphate
Authors: Murakami Yukito , Sunamoto Junzo , Kanamoto Naomi
Published: July 2006

2-Chloro-3-pyridylmethyl phosphate was hydrolyzed in aqueous media. All runs were carried out in a pH range 1–3 where the reactive species are essentially of neutral and monoanion forms. The main reaction product was 3-hydroxymethyl-2-pyridone, the reaction following an apparent first-order kinetics with respect to both pyridone formation and liberation of inorganic phosphate. The hydrolytic elimination of the 2-chlorine atom was catalyzed to a great extent by the phosphate group. The dephosphorylation was effected by the presence of the 2-chlorine atom as well. The hydrolysis of the neutral phosphate species, which is in general inert to hydrolysis, was much accelerated in the present hydrolysis. A plausible mechanism was presented in terms of the concerted elimination of both 2-chlorine atom and phosphate moiety by their mutual catalytic participation. Besides the main reaction process, a normal hydrolysis affording 2-chloro-3-pyridylmethanol was also detected to proceed to a minor extent.
Oxygen-18 Scrambling Reaction of Aroyl Alkyl Carbonates
Authors: Oae Shigeru , Uchida Yuzuru , Fujimori Ken , Kozuka Seizi
Published: July 2006

Specifically 18O-labeled p-substituted benzoyl cyclohexyl carbonates (1) were prepared and heated at 45, 70 and 75°C, and novel stepwise oxygen scrambling was found to take place in 1. On being heated at 45°C, the carbonic carbonyl oxygen atom and the oxygen atom sandwiched between the two carbonyl carbon atoms of 1 were found to scramble. The 18O-scrambling among the above two and carboxylic carbonyl oxygen atoms of 1 was found to take place at 70 or 75°C. A good first order kinetic dependence was observed for the first step of the scrambling at 45°C but no substituent effect. An intramolecular mechanism involving two steps of equilibration is proposed.
Poly(vinyl alcohol) with Pending 5-Substituted Uracils
Authors: Seita Toru , Kinoshita Masayoshi , Imoto Minoru
Published: July 2006

5-Chloro-, bromo-, iodo-, N-ethylamino-, and N,N′-diethylamino-1-[(2′-dihydrogenphosphato)-ethyl]-uracil were synthesized from 1-(2′-hydroxyethyl)-uracil through the combination of halogenation, phosphorylation, and subsequent amination. These compounds were coupled with poly (vinyl alcohol) using N,N′-dicyclohexylcarbodiimide as a dehydrating agent to give polymers having 5-substituted uracils as pending groups.
Studies of Azo Colors. XI. The Diazo-coupling Reaction of Pyrroles
Authors: Mitsumura Kazuo , Hashida Y\={o}ji , Sekiguchi Shizen , Matsui Kohji
Published: July 2006

Kinetic studies have been made of the coupling reaction of several diazonium salts with pyrrole, N-methylpyrrole, and N-ethoxycarbonylpyrrole. In the case of pyrrole, it was found, from the dependence of the apparent rate constant on the pH values, that the undissociated pyrrole reacted with diazonium salts in the pH range from 4.7 to 8.2, whereas in the pH region higher than 10.0 the reactive species was the conjugate base of pyrrole. The reactivity of the pyrrole anion was higher by a factor of 8 powers of ten than that of the undissociated pyrrole. The effects of the substituents of diazonium salts on the reaction rates were also investigated. The ρ-values (4.3–4.6) obtained in the Hammett plots were practically the same as those of diazo-coupling reactions which involve ordinary aromatic amines as coupling components.
The Nickel-catalyzed Cyclodimerization of Butadiene. The Synthesis of 2-Methylenevinylcyclopentane and the Isomerization of 1,3,7-Octatriene
Authors: Kiji Jitsuo , Yamamoto Kazuyoshi , Mitani Shin-ichi , Yoshikawa Susumu , Furukawa Junji
Published: July 2006

A catalyst system of NiX2(R3P)2–NaBH4 or –R′ONa (X=halogen, R and R′=alkyl) was found to yield 2-methylenevinylcyclopentane (MVCP) and n-octatrienes (OT), depending on the amount of NaBH4 or R′ONa, which act as a reducing agent for the nickel halide. Less than an equimolar amount of the reducing agent provides a catalyst for MVCP, whereas an excess amount provides that for n-octatrienes. In the latter case, the nickel halide is reduced to zero-valent nickel, which then reacts with hydrogen halide to give a catalyst for MVCP again. The catalyst (<2:1 ratio of reducing agent: Ni) was also effective in the isomerization of 1,3,7-octatriene to MVP.
Solvolysis of cis- and trans-4-t-Butylcyclohexyl Tosylates in N-Methylacetamide. Rates and Products Distribution
Authors: Saitô Seiki , Yabuki Tatsumi , Moriwake Toshio , Okamoto Kunio
Published: July 2006

Solvolysis of cis- and trans-4-t-butylcyclohexyl tosylates (RX) in wet N-methylacetamide (H2O content: 0.06–0.94 wt%) was carried out to give olefins (77–93%), 4- and 3-t-butylcyclohexyl acetates (ROAc) (6–22%), and 4- and 3-t-butylcyclohexanols (ROH) (2–4%). In N-methylacetamide with water (0.06%, wt) trans-4-RX gave cis-4-ROAc containing 18% trans-4-ROAc whereas cis-4-RX yielded trans-4-ROAc containing only 3% of cis-4-ROAc. In the course of solvolysis (75% completion) trans-4-RX was isomerized to cis-4-RX (5.9%), whereas cis-4-RX gave only 0.3% trans-4-RX. These results are characteristic of solvolysis in this amide solvent when compared with those in other hydroxylic solvents. Stereochemical results obtained from the present studies on the solvolysis in N-methylacetamide can not be explained by the hypothetical hydrogen-bridged carbonium ion intermediate proposed for the solvolysis of cis-4-RX. The nature of N-methylacetamide as a solvolytic solvent is discussed especially with regard to the effect of its polymeric structure on the steric course of solvolysis.
Synthesis and Reactions of α-Bromoaroylacetarylamides
Authors: Shawali Ahmad S , Ali Mohammed I , Fahmi Abdelgawad A
Published: July 2006

Benzoylacetanilide and fourteen of its substituted derivatives were brominated to give α-bromobenzoylacetanilides (I). The spectral data of I indicate that they exist mainly in the keto form. Reaction of I with phenylhydrazine yielded 4-phenylazo-1,3-diaryl-2-pyrazolin-5-ones (IV). Treatment of I with thiourea and thioacetamide gave 2-amino-4-arylthiazole-5-carboxanilides (XII) and 2-methyl-4-arylthiazole-5-carboxanilides (XIII), respectively. With excess of concentrated sulfuric acid or polyphosphoric acid, α-bromobenzoylacetanilides (I) were converted into 3-bromo-4-aryl-2-quinolones (XVI). Structural assignments were based on the elemental and spectral analyses.
Synthesis and Halochromism of 4- and 6-Styryl-2-aminotropones
Authors: Imafuku Kimiaki , Matsumura Hisashi
Published: July 2006

The methylation of 4-styryltropolones with diazomethane afforded two isomers, 2-methoxy-4-styryltropones and 2-methoxy-6-styryltropones. Their reactions with ammonia gave the corresponding 2-amino-4-styryltropones and 2-amino-6-styryltropones, respectively, by normal nucleophilic substitution. Infrared and ultraviolet absorption spectra were measured. The halochromism of 2-aminotropones was also examined, the halochromic shifts being found to be linearly correlated with the Hammett substituent constants.
Peptide Synthesis via N-Acylated Aziridinone. I. The Synthesis of 3-Substituted-1-benzyloxycarbonylaziridin-2-ones and Related Compounds
Authors: Miyoshi Muneji
Published: July 2006

Optically-active 3-substituted-1-benzyloxycarbonylaziridin-2-ones were synthesized from the corresponding benzyloxycarbonyl l-amino acids by the use of a dehydrating agent, such as phosgene, thionyl chloride, or phosphorus oxychloride. The reaction was carried out in THF at −20–−30°C using triethylamine to neutralize the reaction solution exactly. Among the other N-protecting groups used in peptide chemistry, p-bromobenzyloxycarbonyl and p-chlorobenzyloxycarbonyl amino acids also gave the corresponding aziridinones quantitatively. Some of these N-acylated aziridinones were obtained in the crystalline form. A reaction mechanism was also described.
The Molecular and Crystal Structure of the Cyclic Pentamer of Formaldehyde, 1,3,5,7,9-Pentoxecane
Authors: Chatani Yozo , Kitahama Katsuki
Published: July 2006

The crystal structure of the cyclic pentamer of formaldehyde, 1,3,5,7,9-pentoxecane, has been determined by the X-ray diffraction method. The unit cell is orthorhombic, with a=8.154 Å, b=10.673 Å, c=7.666 Å. The space group is Pbcn, and there are four molecules per unit cell. The structure was refined by the blockdiagonal least-squares method to a final discrepancy factor, R, of 0.049, using 712 reflections observed with an automatic four-circle single-crystal diffractometer. The molecules in the crystals are ten-membered rings with an exact C2–2 symmetry; the torsion angles of the five independent C–O bonds are 72.9°, −118.7°, 84.2°, −123.4°, and 69.8°, and the two halves of the molecule are related by a twofold rotation axis. The averaged C–O bond length is 1.410 Å, and the averaged C–O–C and O–C–O bond angles are 115.6° and 111.8° respectively. The close intramolecular H···H distances are 2.17 Å and 2.20 Å.
A New Method for the Precise Measurement of the Polarographic Current and Its Application in Digital Polarography
Authors: Sakurai Sadato , Shirai Hideko , Niki Eiji
Published: July 2006

In order to increase polarographic precision and sensitivity, the oscillopolarographic current was digitized and stored in a 100-channel pulse-height analyzer (PHA) operated in the multi-sealer mode (MS mode). An oscillopolarograph which could sweep the DC potential rapidly was combined with the PHA. The digitized oscillopolarographic current was repeatedly stored in the PHA, so that the statistical noise was reduced and the signal-to-noise ratio of the oscillopolarographic current was increased. Also, the drift due to the change in the experimental conditions was removed effectively by shortening the measurement time. Therefore, precision was efficiently improved by means of accumulation. The relative deviation was 0.25% at the concentration of the 5×10−7 M cadmium ion. As an example of the application, trace amounts of copper, lead, and cadimum in 99.99% indium metal were analyzed.
Kinetic Studies of Thermal Decomposition Reactions of Amminechromium(III) Complexes in Solid State
Authors: Nagase Kenzo , Tanaka Nobuyuki
Published: July 2006

Kinetics of the thermal decomposition reactions of [Cr(NH3)6]X3 (X=Br, I and NCS) and [Cr(NCS)(NH3)5](NCS)2 in solid state were studied by the manometric method. The rate constants, activation energies and activation entropies of the substitution reactions of outer-sphere anions for coordinated ammonia molecules were presented, and possible reaction mechanisms were discussed.
Studies of Organosulfur Compounds. IX. The Preparation of Organometal IVb Esters of Aromatic Thio Acid
Authors: Kato Shinzi , Akada Wataru , Mizuta Masateru , Ishii Yoshio
Published: July 2006

It was found that the reactions of potassium salts of aromatic thio acid with chlorotrimethylsilane gave the corresponding thionoacyloxysilanes [ArC(S)OSi(CH3)3]. On the other hand, the reactions with chlorotrimethylgermanes or -stannane gave the corresponding thiol esters [ArC(O)SM(CH3)3, M: Ge, or Sn] containing the sulfur-metal (IVb) linkage in almost quantitative yields.
Kinetic Studies of the Nickel Phthalate Complex Formation in Solution by the Pressure-jump Method
Authors: Harada Shoji , Tanabe Hideyuki , Yasunaga Tatsuya
Published: July 2006

The rate constants of the complex formation and the dissociation of the nickel phthalate (o-phthalate) complex have been determined by the pressure-jump method. The thermodynamic parameters of the reaction were obtained from studies at various temperatures between 10 and 30°C. Upon a comparison of the data on the nickel complexes of the succinate, adipate, maleate, and phthalate, no systematic relationship between the nature of the ligands and the kinetic values has been found; this can be ascribed to the monodentated form of these complexes. The rate-determining step is the loss of the water molecule from the inner-coordination sphere of the nickel ion when the monodentated complex is formed.
The Chemical Structure of Glass of the NaPO3–Sb2O4 System
Authors: Watanabe Makoto
Published: July 2006

Glassy substances of the NaPO3–Sb2O4 system with P/Sb ratios in the range from 5.0 to 300 were prepared by heating a mixture of NaPO3 glass and Sb2O4 at 1000 °C and by then rapidly quenching the melt of the mixture. From the results of the colorimetric determination and the average degree of polymerization of the condensed phosphates, it has been found that the chain length of the phosphates increases with an increase in the P/Sb ratio. When the glass was treated with water, antimony trioxide was deposited. By using these results, a theoretical treatment for the average degree of polymerization of condensed phosphates has been made and it has been concluded that there are P–O–Sb linkages in the glass of the NaPO3–Sb2O4 system.
Electrochemical Fluorination of Diols and Heterocyclic Compounds
Authors: Abe Takashi , Nagase Shunji , Baba Hajime
Published: July 2006

Electrochemical fluorination of diols (HO–CH2–CH2–)2X (X=CH2, O, S, NH, NCH3, NC2H5) afforded the corresponding perfluoro-heterocyclic compounds together with the cleaved products as a result of cyclization. Perfluoro-p-dioxane, a new compound having boiling point at 22.5–23.0 °C, was obtained from diethylene glycol. Electrochemical fluorination of heterocyclic compounds such as tetrahydropyran, p-dioxane, p-thioxane and morpholine was carried out and the results were compared with those obtained with diols.
Intramolecular Interaction between the Phenol and the Indole Chromophores
Authors: Tamaki Takashi
Published: July 2006

The singlet-energy transfer from the phenol to the indole chromophores occurs intramolecularly, with a high efficiency, in the compounds containing these chromophores joined by the methylene and the amide groups. The total emission spectra of the compounds consisted only of those from the indole chromophore, neither the fluorescence nor the phosphorescence of the phenol chromophore contributing to them, and the excitation spectra of the fluorescence were similar to the absorption spectra. The quantitative analysis of the fluorescence-polarization spectra suggested that the 1Lb transition of the indole chromophore was excited in the energy transfer. The intramolecular interactions between these chromophores in the ground and excited states are discussed.
The Reaction Mechanism of 2-Dimethoxymethyl-3-methoxypropiononitrile with Acetamidine. III. The Reaction with Benzamidine
Authors: Nishino Takenori , Kiyokawa Masumi , Miichi Yoshiyuki , Tokuyama Kanji
Published: July 2006

In order to elucidate the effect of basicities of amidines on their reactions with 2-dimethoxymethyl-3-methoxypropiononitrile (1), the reaction of 1 with benzamidine was studied. Products are similar to those from the reaction of 1 with acetamidine. The minor pathway in the reaction with acetamidine (Route B in Chart 1) was the major one in the reaction with benzamidine. This remarkable difference could be explained in terms of the electronic effect of 2-substituents of the intermediates (4a and 4b) in both reactions and of basicities of acetamidine and benzamidine.
Anodic Ring Opening Reaction of 2-Methoxy-1-cyclopentene-1-carboxylic Acids
Authors: Torii Sigeru , Tanaka Hideo , Fukuoka Tokio , Hirai Shukuo
Published: July 2006

Electrolysis of 2-methoxy-1-cyclopentene-1-carboxylic acids 2 and 12a gave α,β- or β,γ-ring opening products 4, 5a, 7a, and 15. Electrolysis of 2 without separation of anode and cathode compartments gave 6a in a notable yield. 6a is expected to be formed by the reduction of a key intermediate 8, which can be rationalized by leading to 4 and 5. The results from the anodic oxidation of 12 suggest that the C=C double bond function of 12 was initially oxidized giving 14 followed by discharge of the carboxylate anion to afford 15. A possible mechanism for the anodic reaction of 2 and 12 has been discussed.
Synthetic Studies of Carbohydrate Derivatives with Photochemical Reactions. IX. The Photochemical Addition of 1,3-Dioxolane to Several Enoses
Authors: Matsuura Kazuo , Nishiyama Kazunari , Yamada Koh , Araki Younosuke , Ishido Yoshiharu
Published: July 2006

The photochemical addition reactions of 1,3-dioxolane to enoses with an endocyclic or exocyclic double bond, such as 3,4,6-tri-O-acetyl-d-glucal, 2,3,4,6-tetra-O-acetyl-2-hydroxy-d-glucal, methyl 4,6-di-O-acetyl-2,3-dideoxy-α-d-erythro-hex-2-enopyranoside, and methyl 5-deoxy-2,3-O-isopropylidene-β-d-erythro-pent-4-enofuranoside, were studied. It was found that the addition of 1,3-dioxolane to the enoses proceeds with great ease, thus affording the corresponding l,3-dioxolan-2-yl derivatives in excellent yields, and with a considerable regiospeciflcity and stereoselectivity. The reactions of tetrahydrofuran with the enoses were also studied.