bluuebunny/crossref_metadata_2025_split huggingface dataset:
Derivatographic Studies on Transition Metal Complexes. I. Deaquation-Anation Reaction of Aquopentaamminechromium(III) Complexes
Authors: Tsuchiya Ryokichi , Kaji Yoriko , Uehara Akira , Kyuno Eishin 
Published: July 2006

Abstract
By using a Derivatograph, the simultaneous analyses in TGA, DTA and DTG on the several aquopentaamminechromium(III) complexes were attempted. The enthalpy changes, ΔH, in the deaquation-anation processes of aquopentaamminechromium(III) nitrate, chloride, bromide, iodide, sulfate and sulfite were calculated as 11.9, 6.1, 9.0, 10.8, 13.8 and 12.8 kcal/mol, respectively, the activation energies, E\eweq, in the corresponding processes of the nitrate, chloride, bromide, sulfate and sulfite were obtained by the DTG curve analysis as 18, 28, 38, 36 and 33 kcal/mol, and those in the nitrate, chloride, bromide, iodide, sulfate and sulfite were obtained by the DTA curve analysis as 14, 25, 36, 19, 39 and 32 kcal/mol, respectively.
Studies on Stable Free Radicals. III. Reactions of Stable Nitroxide Radicals with S-Radicals Derived from Benzenethiols and Thiamine
Authors: Murayama Keisuke , Yoshioka Takao 
Published: July 2006

Abstract
The reaction of the extremely stable free radical, 2,2,6,6-tetramethyl-4-oxopiperidine-1-oxyl (I), was carried out with benzenethiols (IV). The formation of diphenyl disulfides (VI), benzenesulfinic acids (VII), and 1-(p-substituted benzenesulfinyl)-2,2,6,6-tetramethyl-4-oxopiperidines (X) from the above reaction shows that the radical (I) can act as a hydrogen-abstracting agent, an oxidizing agent, and a radical scavenger. Possible mechanisms for the coupling reaction of the radical (I) with the S-radicals (V) to give the sulfinamides (X) were discussed. A substituent effect was observed in the formation of the disulfides (VI). The N-oxyl radical (I) and another stable free radical, such as 2,6-di-t-butyl-4-methylphenoxyl radical (XXV), were shown to react with the S-radical (XVII) derived from thiamine (XIV) to give new types of thiamine derivatives, S-(2,2,6,6-tetramethyl-4-oxopiperidino) thiamine (XX) and S-(2,6-di-t-butyl-4-methylphenoxy)thiamine (XXVI) respectively.
Reaction of Xanthates with t-Amines. VI. The Reaction Mechanism
Authors: Yoshida Hiroshi 
Published: July 2006

Abstract
It was previously reported that xanthate reacted with t-amine to give quaternary ammonium salt at room temperature, and dithiolcarbonates at elevated temperatures. Precise study showed that these reaction products are formed by the following three reactions: the alkylation of t-amine with xanthate affords quaternary ammonium salt and the reaction of xanthate with quaternary ammonium salt yields dithiolcarbonate, while there is transesterification between thiolesters and quaternary ammonium salt. The rate constants and equilibrium constants of these reactions were calculated.
The Mechanism of the Alkaline Decomposition of Triarylsulfonium Bromide with Phenyllithium
Authors: Khim Yong He , Oae Shigeru 
Published: July 2006

Abstract
Tritolylsulfonium bromide was subjected to alkaline decomposition in order to clarify the mechanism of the reaction of triarylsulfonium bromide with phenyllithium in ether. Diaryl sulfides, diaryls, and other aryl derivatives were obtained and the combined yield was nearly quantitative. On the basis of the ratio of the products formed in the reaction, the alkaline decomposition is considered to proceed through two mechanistic routes, i. e., one involving the nucleophilic attack of phenyl anion on the sulfur atom (about 70%) and the other the “benzyne” route (about 20%).
Diffusion Coefficients of Xylose and Maltose in Aqueous Solution
Authors: Ueadaira Hisashi , Uedaira Hatsuho 
Published: July 2006

Abstract
Diffusion coefficients for the systems aqueous xylose solution and aqueous malotse solution at 25°C were measured by the Rayleigh interference method. Viscosities of these systems were also determined. The concentration dependence of diffusion coefficient for maltose solution is well described by the Gordon relation. For xylose solution, however, a small deviation from this relation is observed. The translational frictional coefficient of maltose was calculated by the shell model of Bloomfield et al. If the effect of the local viscosity around a molecule of the solute is corrected, the agreement between the calculated and the observed values is satifsactory.
ESR and Optical Absorption Studies of the Copper(II) Complexes of Ethylenediamine and Its Alkyl Derivatives
Authors: Yokoi Hiroshi , Isobe Taro 
Published: July 2006

Abstract
The ESR and the optical absorption of the copper(II) complexes of ethylenediamine and a series of alkylated ethylenediamines have been investigated in order to estimate the character of the chemical bonding in the copper(II) complex. The covalency of the bonding of the copper atom to the ligand nitrogen atoms in the complexes has been discussed in connection with the chemical and physical properties of the complexes or of their ligand molecules themselves. The ESR results indicate that the σ bonding of the complexes becomes more covalent as the number of alkyl groups in their ligand molecules increases; furthermore, the tendency toward the σ bonding becomes more pronounced when the alkyl groups are ethyl rather than methyl and when they are N-substituted alkyl groups rather than C-substituted ones. It is also indicated that there is a linear relationship between the energies of the ultraviolet absorption band for the complexes and the relative ionization potentials estimated for their ligand molecules, and that absorption band can be assigned to an electron transfer from a ligand σ orbital to an antibonding orbital associated with the copper atom. From these results, it may be concluded that, as the σ bonding becomes more covalent, this charge transfer band shifts to a longer wavelength.
Deprotonation of Oxime Complexes: Dimethylglyoxime-Cobalt(III) Complexes
Authors: Masuda Isao , Sakano Mitsuhiro , Shinra Koichiro 
Published: July 2006

Abstract
Dimethylglyoxime-Co(III) complexes with the formula [Co(dmgH)2A2]n (I), where dmgH is dimethylglyoximato mono-anion, A is an axial ligand such as aniline, p-anisidine, pyridine, γ-picoline, imidazole, NH3, CN−, and NO2−, and n is −1, 0, or +1, were found to change their electronic absorption spectra reversibly depending on the pH of the solution. These changes have been attributed to the dissociation of the proton from the intramolecular hydrogen bridges of the complex; the changes are accompanied by the formation of the complex [Co(dmgH)(dmg)A2]n−1, where dmg represents the dimethylglyoximato di-anion. The proton dissociation constants (pKa) obtained by the spectrophotometric method indicated that the complex I is generally a weak acid of pKa=7.7–12.6. With the exception of the pyridine and the γ-picoline ligand, axial ligands do not appreciably affect the pKa values. However, axial pyridine and the γ-picoline ligand increase the tendency of the hydrogen bridges to dissociate the proton.
Studies on Stable Free Radicals. IV. Decomposition of Stable Nitroxide Radicals
Authors: Murayama Keisuke , Yoshioka Takao 
Published: July 2006

Abstract
Decomposition studies of extremely stable free radicals such as 2,2,6,6-tetramethyl-4-oxopiperidine-1-oxyl (I), 2,2,6,6-tetramethylpiperidine-1-oxyl (VIII) and 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl (IX) were carried out: although radical I decomposed to give 1-hydroxy-2,2,6,6-tetramethyl-4-oxopiperidine (IV) both in the light and dark, radicals VIII and IX were more stable under these reaction conditions. Therefore it was confirmed that i) a source of hydrogen was the ketonic α-methyene hydrogens, ii) a radical which could give a thermodynamically stable conjugated product by a cycloelimination was easily decomposed and iii) the decomposition of radical I was only accelerated by heating and was independent of the action of light.
Studies of the N-Oxides of N,N-Dialkylamino Acids. II. The Syntheses of N,N-Dialkylglycine and Corresponding N-Oxides
Authors: Ikutani Yoshikazu 
Published: July 2006

Abstract
The reductive condensations of glycine with various aliphatic straight-chain aldehydes, such as acetaldehyde, propionaldehyde, and n-butyraldehyde, give the corresponding N,N-dialkyl derivatives. The N-monoalkyl derivative has not been obtained in any case. In another type of reactions, those with aliphatic branched-chain aldehydes, such as isobutyraldehyde and isovaleraldehyde, considerable N-monoalkylation takes place besides the dialkylation. The oxidations of N,N-dialkylglycine to the corresponding N-oxides have been successfully performed using an aqueous mixture of hydrogen peroxide and acetic acid except in the case of N,N-diisobutylglycine. Similar reductive condensations of sarcosine with various aliphatic aldehydes, such as acetaldehyde, propionaldehyde, n- and iso-butyraldehyde, and isovaleraldehyde, gave the corresponding N-alkylsarcosines. N-Isobutyl and N-isoamyl sarcosine were also obtained by the methylation of the corresponding N-monoalkylglycine. The N-oxides of N-alkylsarcosine were synthesized by a procedure similar to that described above.
The Acidic Nature of Synthetic Zeolites: Acid Strength and Its Correlation with the Catalytic Activity
Authors: Otouma Hiroshi , Arai Yoshimasa , Ukihashi Hiroshi 
Published: July 2006

Abstract
The acidic characters of the X and Y zeolites exchanged by hydrogen, calcium, and lanthanum ions were investigated. Very characteristic features of the acid sites were found as compared with those of an amorphous silica-alumina cracking catalyst. The acidity is generally larger in the zeolites (2–3 meq/g) than in a silica-alumina (0.5 meq/g). The acid strength is more widely distributed in the zeolites (H0=+3.3−&lt;−8.2) than in a silica-alumina (H0&lt;−8.2). Very important is the fact that the acid site increases not only in number but also in strength with an increase in the degree of ion exchange. The results on cumene cracking are in line with these results.
Vacuum-ultraviolet Absorption Spectra of Aliphatic Ketones
Authors: Ito Hiroyuki , Nogata Yoshihiko , Matsuzaki Sanae , Kuboyama Akira 
Published: July 2006

Abstract
The molar-absorptivity curves of various aliphatic ketones, mainly methyl alkyl ketones, in the gaseous state in the region from 1650 to 2000 Å have been obtained. In these ketones the absorption bands near 1950 Å and 1700 Å are denoted as A and B bands respectively. Di-n-propyl and diisopropyl ketones show, besides the A and B bands, an absorption band near 1650 Å (C band). The relations between the obtained spectra and the molecular structures of these ketones have been studied. On the basis of this study, the characteristics of the electronic transitions of A, B, and C bands have been discussed.
Determination of S*-T Transition Probabilities of Some Xanthene and Thiazine Dyes on the Basis of T-Energy Transfer. II. Results in the Aqueous Solution
Authors: Nemoto Masae , Kokubun Hiroshi , Koizumi Masao 
Published: July 2006

Abstract
Intersystem crossing probability \varphiSTA for fluorescein, eosin, erythrosin, methylene blue and thionine in the aqueous solution of pH 7.2 (only for fluorescein 0.05n NaOH solution) has been determined by comparing the quantum yield of the nonsensitized (Φ) and the sensitized photo-reduction (ΦS) on the basis of the relations
Φ=\varphiSTAβA ΦS=\varphiSTDβγA,
where βA is the fraction of triplet dye molecules that undergo reduction, \varphiSTA and \varphiSTD are respectively for acceptor (dye) and donor (sensitizer), and γ is the energy transfer efficiency. This was assumed as unity. ATU and EDTA were used as a reducing agent. 1,5-Naphthalenedisulfonic acid and 1-anthracenesulfonic acid were used as sensitizers. The above relations and assumption have been found to hold satisfactorily. The \varphiSTD values for two sensitizers were determined using erythrosin as a reference substances for which \varphiSTA was assumed to be unity. \varphiSTD obtained was 0.88 for 1,5-naphthalenedisulfonic acid, and 0.82 for 1-anthracenesulfonic acid. \varphiSTA values for dyes obtained were: fluorescein (0.021) eosin (0.64) erythrosin (1.0) methylene blue (0.52) thionine (0.55). Using these \varphiSTA values, the rate constants for the following elementary reactions have been evaluated (A, dye: RH2 reducing agent): AT+RH2→reaction, AT+RH2→deactivation, AT+A→reaction or deactivation.
Role of the Solvent in the Distribution of the Zinc-TTA Chelate and the Adduct Formation with TBP
Authors: Akiba Kenichi , Suzuki Nobuo , Kanno Takuji 
Published: July 2006

Abstract
The distributions of the zinc chelate with thenoyltrifluoroacetone (TTA) between an aqueous solution and twelve inert organic solvents were investigated. After it had been confirmed that the distributed species were ZnA2, the distribution coefficients of the chelate (PM) and those of TTA (PHA) were compared; it was found that there is a correlation which can be expressed as logPM=nlogPHA+const. When TTA and TBP are in the extraction system, the adduct formation constants of chelate were obtained. The activities of all the species which take part in the adduct formation were evaluated on the basis of the regular solution theory. It was found that the adduct formation constant in terms of activity (Ks°) is constant in all the organic solvents; namely, logKs° was found to be 4.05. Finally, the role of the solvent in the synergistic extraction system is explained systematically by a combination of the regularity in the distribution and that in the adduct formation.
A New Acidity Function, T0, in Acid-catalyzed Reactions
Authors: Takaya Haruo , Todo Naoyuki , Hosoya Tadasuke 
Published: July 2006

Abstract
In acid-catalyzed reaction systems a new acidity function, T0, which is related to the first-order rate constant, k1 by the equation log k1=C−T0 was defined by T0=−log (aH+/awh5−h1f\eweq) and was theoretically calculated in much the same manner as in Glueckauf’s treatments on a salt solution but with the additional assumption that the character of a hydrated univalent activated complex is represented by that of a hydrated alkali metal cation. The calculated results show that T0 in hydrochloric acid can be represented by:
T 0=2.4(3.9−h1+h5)logaw−logma.
This equation shows that if the hydration number (the water molecules bound with an activated complex) of an activated complex, h1, increases by one, the corresponding increment of T0 becomes −2.4logaw. It was also shown that the value of fAH+fB⁄fAfBH+ is not always constant, but depends on the hydration numbers of the AH+ and BH+ species as well as on the acid concentrations. The factors affecting the acidity function, T0, were compared with those affecting the activity of water. The applicability of the T0 was examined by means of the observed logk1 value reported by Bunnett.
Effects of Substitution on the Phosphorescence Process of Aromatic Carbonyl Compounds
Authors: Takemura Takeshi , Baba Hiroaki 
Published: July 2006

Abstract
Phosphorescence and absorption spectra, phosphorescence- and excitation-polarization, spectra and phosphorescence lifetimes were measured at 77°K for benzaldehyde, acetophenone and their eight derivatives with a halogen atom, or a hydroxyl, methoxyl or amino group as a substituent at the para position. In chloro- and bromo-derivatives, the phosphorescent triplet state is of the (n,π*) type, and is mixed with the 1La(π,π*) state by direct spin-orbit interaction, as in the case of the parent carbonyls. In addition, owing to the heavy-atom effect, it gains its singlet character by the mechanism
(Remark: Graphics omitted.)
which accounts for the observation that the phosphorescence spectrum involves out-of-plane-polarized vibrational bands. Substitution of a more electron-donating hydroxyl, methoxyl, or amino group brings about a change of the phosphorescent state from the 3(n,π*) state to the; 3La(π,π*). The following mechanisms are shown to be important to the 3La(π,π*) state:
(Remark: Graphics omitted.)
These account for two progressions with mutually perpendicular polarizations observed in the phosphorescence spectrum. The lifetimes for the transitions from the 3La(π,π*) state to the ground state of the substituted carbonyls were found to be substantially shorter than the corresponding lifetimes in aromatic hydrocarbons. This fact is quantitatively interpreted as due to the presence of a low-lying 1(n,π*) state.
Concentration Polarization Phenomena in Ion-exchange Membrane Electrodialysis. I. Studies of the Diffusion Boundary Layer by Means of Six Different Measurements
Authors: Sata Toshikatsu , Yamane Reiichi , Mizutani Yukio 
Published: July 2006

Abstract
The behavior of the diffusion boundary layer in the electrodialysis using ion-exchange membranes, mainly a cation-exchange membrane, was studied by means of six different measurements: 1) the determination of the current-voltage curve or the current-(voltage/current) curve; 2) the relation of the pH change of the solution to the current density; 3) the relation of the charge retention, i.e., the sum of the diffusion potential and the membrane potential generated from the concentration gradient across the membrane immediately after the current is shut off, to the current density; 4) the time required to reach a constant current value, namely, to obtain a stationary diffusion boundary layer, when a constant voltage is supplied to the system, versus the current density; 5) the change in the transport number of the counterion in the membrane with the current density, and 6) the relation of the permselectivity between sodium ions and potassium ions to the current density. The interrelation among these results was also examined. The quantity of hydrogen ions or hydroxide ions passing through the membrane increases abruptly at a current density lower than that at which the concentration at the membrane-solution interface in the desalting side attains its minimum. It was newly observed that the results of all the measurements, except for the pH change of the solution, show abnormal phenomena at a current density about twice the limiting current density.
Vapor Pressure of Carbon Monoxide in Condensed Phases
Authors: Shinoda Takako 
Published: July 2006

Abstract
A theoretical vapor pressure equation of the form logP+(3⁄2)logT=a+b⁄T for a diatomic molecule was applied to carbon monoxide in condensed phases. The two parameters in the equation determined from experimental vapor pressure data were used to obtain values of the static lattice energy E0, the zero point energy Ez, the geometric mean frequency ωg and the mean frequency of molecular rotation ωR in the respective phases by the information of lattice vibrations at low temperatures. From the mean values of molecular rotation frequencies, the hights of the potential barrier for hindered rotations were estimated to be 360, 230±10 and 110 cal/mol respectively.
Separation and Identification of Chlorocomplexes of Technetium(IV) formed in Hydrochloric Acid Solutions
Authors: Kanchiku Yoshihiko 
Published: July 2006

Abstract
The chemical behavior of TcCl62− in HCl solutions of different concentrations has been investigated. It was confirmed that TcCl62− is sensitive to ultraviolet and visual light, giving a series of aquated species the quantities of which depend on the HCl concentration. Those technetium(IV) chlorocomplexes were isolated by means of ion-exchange and paper electro-phoresis, and the composition of each species was determined by measuring the Cl/Tc ratio and the charge per species. The absorption spectra of isolated species were also measured.
The Mechanism of the Base-Promoted Rearrangement of N,N-Dichlorocyclohexylamine to 2-Aminocyclohexanone and the Deaminative Diazotization of 2-Aminocyclohexanone
Authors: Nakai Mamoru , Furukawa Naomichi , Oae Shigeru 
Published: July 2006

Abstract
N,N-Dichlorocyclohexylamine-1-14C has been treated with sodium methoxide in methanol and then with hydrochloric acid to yield 14C-labeled 2-aminocyclohexanone hydrochloride. Successive degradations have revealed that practically all the 14C activity was found in the carbonyl carbon of the original aminoketone. From the 14C distribution, it has been concluded that the reaction is essentially the same as that proposed for the Neber rearrangement. As a part of the degradation of 2-aminocyclohexanone, deaminative diazotization was employed to obtain cyclopentanecarboxylic acid together with other minor products. The 14C tracer work revealed that the carbonyl group of the acid is originated from the carbonyl group of the 2-amino-ketone.
Studies on s-Triazines. I. Cotrimerization of Trichloroacetonitrile with Other Nitriles
Authors: Wakabayashi Ko , Tsunoda Masaru , Suzuki Yasushi 
Published: July 2006

Abstract
2-Substituted 4,6-bis(trichloromethyl)-s-triazines have been prepared by the cotrimerization of CCl3CN with some nitriles. The reaction proceeds, in general, smoothly at ordinary pressure in the presence of hydrogen halide or Friedel-Crafts catalyst-hydrogen halide complex. An improved method was developed for the nitriles such as propionitrile with which CCl3CN did not easily cotrimerize under above mentioned conditions.
The Intensity of the n–π* Absorption Bands of Several Aliphatic Carbonyl Compounds
Authors: Ozeki Kayoko , Inagaki Masaji , Tanaka Jiro 
Published: July 2006

Abstract
The mechanism of the intensity gain of the n–π* transition has been investigated in several carbonyl compounds; (1) cyclohexane-1,4-dione, (2) d-α-bromocamphor, (3) bromonoranisatinone, (4) d-α-cyanocamphor, and (5) spiradine A methiodide. The results on the polarized absorption spectra of single crystals at room temperature have revealed that several mechanisms are involved in the appearance of the carbonyl n–π* band. These mechanisms, (1) the vibronic coupling, (2) the lowering of the symmetry properties of the n and π orbitals by the substituent perturbations, and (3) the charge transfer from the substituents, are discussed theoretically and compared with the experimental results. It is shown that the in-plane components, either parallel or perpendicular to the carbonyl axis, are predominant as the source of the band intensity. The ratio of intensities parallel and perpendicular to the carbonyl axis is estimated by the use of the polarization results.
The Crystal and Molecular Structure of the Sodium Salt of Xanthine
Authors: Mizuno Hiroshi , Fujiwara Takaji , Tomita Ken-ichi 
Published: July 2006

Abstract
The crystals of sodium salt of xanthine, C5H3N4O2Na·4H2O, are monoclinic with four molecules in a unit cell of dimensions; a=7.31, b=19.52, c=7.17 Å, β=100.0°, space group P21⁄c. The structure has been determined by application of the sign relationship S(hkl)S(h′k′l′)∼S(h+h′,k+k′,l+l′) from (hk0) intensity data and refined by three-dimensional least-squares methods. The positions of the hydrogen atoms were determined by a three-dimensional difference Fourier analysis, and it was confirmed that deprotonation took place at the position of the imino N(3)H of the xanthine molecule. Each Na+ cation is surrounded by six water molecules and each xanthine anion participates in ten hydrogen bonds, forming a close-packed system.
Total Syntheses of Tanshinone-I, Tanshinone-II and Cryptotanshinone
Authors: Inouye Yoshinobu , Kakisawa Hiroshi 
Published: July 2006

Abstract
Total syntheses of tanshinone-II (II) and cryptotanshinone (III) from 3-methylbenzofuran-4, 7-quinone (X) and 6,6-dimethyl-l-vinylcyclohexene (IX), and of tanshinone-I (I) from quinone X and o-methylstyrene (XVIII) are described. Preliminary accounts for the Diels-Alder reaction of methoxybenzoquinone revealed that the effect of substituents for orientation phenomena can be considered to be of electronic nature.