bluuebunny/crossref_metadata_2025 huggingface dataset:
The Photochemical Reduction of Nitrobenzene and Its Reduction Intermediates. X. The Photochemical Reduction of the Monosubstituted Nitrobenzenes in 2-Propanol
Authors: Hashimoto Shizunobu , Kano Koji
Published: July 2006

The photochemical reduction of the monosubstituted nitrobenzenes has been investigated in 2-propanol under a nitrogen atmosphere. The nitrobenzenes with electron-withdrawing groups on meta- and para-positions (p-NO2, m- and p-CN, m- and p-COOC2H5, p-COOCH(CH3)2, and m- and p-COOH) were photoreduced to the corresponding anilines, and nitrobenzene and the para-substituted nitrobenzenes with electron-donating groups (p-CH3 and p-OCH3) were photoreduced to the corresponding phenylhydroxylamines. p-Nitroaniline and p-nitrophenol were unreactive toward the photoreduction. In the experiments on the determination of the quantum yields for the nitrobenzenes’ disappearance upon irradiation with a 313- or 366-nm light, it has been found that there is a linear correlation between the log-values of the relative quantum yields of the substituted nitrobenzenes and nitrobenzene and the Hammett constants, and the ρ value was + 1.5. The results obtained suggest that the hydrogen-abstraction reaction of the photoexcited nitrobenzenes may proceed electrophilically.
Synthesis of Chelating Agents. VIII. Synthesis and Acid Dissociation of 3,3-Dimethylbutane-1,2-dinitrilo-N,N,N′,N′-tetraacetic Acid
Authors: Yanagihara Yuzo , Yano Tairoku , Kobayashi Hiroshi , Ueno Keihei
Published: July 2006

3,3-Dimethylbutane-1,2-dinitrilo-N,N,N′,N′-tetraacetic acid (BEDTA) has been synthesized by the carboxymethylation of 3,3-dimethylbutane-1,2-diamine (BEDA). The stepwise acid dissociation constants determined by the potentiometric method were found to be pKa1=6.26 and pKa2=9.78 for BEDA and pKa1=2.1, pKa2=3.62, pKa3=5.29, and pKa4=11.6 for BEDTA at 25°C and an ionic strength of 0.1 (KCl). The values were discussed in relation to molecular structures.
ESR Investigation of Copper Ions on Several Kinds of Cation Exchange Resins
Authors: Umezawa Kayoko , Yamabe Takeo
Published: July 2006

Copper ions on several kinds of cation exchange resins were investigated by means of ESR spectroscopy. It was found that the motion of copper ions is restricted in the network of the ion exchange resin, and that the mobility of copper ions is closely connected with the chemical interaction of the copper ions with the fixed ionic groups of the resins. The mobility of copper ions is in the order of; on the sulfonic group>on the phosphonic group>on the carboxylic group>on the iminodiacetate group. This sequence is the reverse of the selectivity for the copper ion. The effect of the water molecules involved in ion exchange resins is also considered, and the copper species on each ion exchange resin are assumed.
Aroyl Arenesulfonyl Peroxides. III. Thermal Decomposition of p-Chlorobenzoyl p-Toluenesulfonyl Peroxide.
Authors: Hisada Ryuki , Kobayashi Michio , Minato Hiroshi
Published: July 2006

p-Chlorobenzoyl p-toluenesulfonyl peroxide was synthesized. Its spontaneous decomposition in benzene or in carbon tetrachloride did not follow a first-order rate equation because of the rate acceleration due to p-toluenesulfonic acid produced. When powdery magnesium oxide was suspended in benzene, isomerization to p-chlorophenyl p-toluenesulfonyl carbonate was completely inhibited, and the rate followed a first-order equation. The products of decomposition (p-chlorobiphenyl, p-chlorobenzoic acid, p-toluenesulfonic acid, phenyl p-toluenesulfonate, etc) were accounted for in terms of initial formation of p-toluenesulfonyloxy and p-chlorobenzoyloxy radicals. p-Toluenesulfonyloxy radical was found to be a very effective hydrogen-abstractor with little tendency to add to benzene.
Preparation of Cyclamenaldehyde by Selective Hydrogenation in Some Cobalt Carbonyl Complex Catalysts under Oxo Conditions
Authors: Kogami Kunio , Takahashi Osamu , Kumanotani Ju
Published: July 2006

Selective hydrogenation of p-isopropyl-α-methylcinnamaldehyde to cyclamenaldehyde in some cobalt carbonyl complex catalyst systems has been investigated under several oxo conditions. The yield of the aimed aldehyde was improved as much as 84 to 86.3% under controlled conditions. Selectivity of the hydrogen increased with the decrease of temperature and the increase of partial pressure of hydrogenation in a water gas. A maximum yield (84%) was obtained with solvents such as isopropyl ether and hexane when used in 2-fold volume for the cinnamaldehyde. A tris(2-bromoethyl) phosphite-substituted cobalt carbonyl complex catalyst gave the best yield (86.3%) as compared with catalysts unsubstituted and substituted with PR3, P(OR)3, and PO(OR)3(R=alkyl, aryl).
Photodecomposition of Vinyl Iodide in Gas Phase
Authors: Yamashita Shigeru , Noguchi Shigeo , Hayakawa Teruo
Published: July 2006

Photodecomposition of vinyl iodide has been studied at 313 and 254 mμ using a high intensity light source. Because of high concentration of the radicals formed primarily due to the high intensity of the light source, only the inter-radical reactions were taken into account in considering the secondary processes.

Both molecular and free radical processes have been observed in the primary process and the ratio of the contribution of molecular process to free radical process was found to be about 1 : 6 in the wavelength range studied. A slight energy dependence of kd⁄kc, the ratio of the rate of disproportionation reaction to that of combination reaction of vinyl radicals, was found in the secondary processes.
The Calculation of the Rates of Intramolecular Nonradiative Transitions in Benzene
Authors: Shimakura Noriyuki , Fujimura Yuichi , Nakajima Takeshi
Published: July 2006

Intramolecular nonradiative transition rates for various interstates of benzene were calculated from the standpoint of the breakdown of the Born-Oppenheimer approximation. The electronic parts of the coupling matrix elements were explicitly evaluated. These parts vary in the range of 10−1–10−3 Å−1. The nonradiative transition rates for the 1E1u→1B1u,1B2u transitions were predicted to be appreciable. The rate for the 1B1u→1B2u transition vanishes as long as the geometrical structure of the 1B1u state is assumed to be of the D6h symmetry. These results are compared with the experimental nonradiative transition widths recently reported by Jortner et al.
A Chlorine NQR Study of Some Perchloro-compounds
Authors: Hashimoto Masao , Mano Koichi
Published: July 2006

The NQR frequencies of chlorines in seven perchloro-compounds were measured at 77°K and above. The assignments of the frequencies were made for each compound. It was found that the resonance frequency is considerably influenced by the electrostatic repulsion between chlorine atoms due to the close Cl···Cl distances. For several compounds, the resonance was found to fade out at rather low temperatures.
The Laser Photolysis of Methylene Blue in the Presence of p-Chlorophenylglycine
Authors: Obi Kinichi , Makino Hiroshi
Published: July 2006

The photoreduction of methylene blue by a ruby laser light has been studied. The kinetic treatment and the measurement of the apparent activation energy show that, under the high-intensity irradiation, the excited triplet state of methylene blue plays a main role in the photoreduction by p-chloro phenylglycine. The apparent activation energy of the reduction of methylene blue is reduced from 7.4 to 2.8 kcal as the laser light energy increases from 23 to 530 mJ.
The Dye-sensitized Photooxygenation of Hexamethyleneammonium Hexamethylenedithiocarbamate by Xanthene Dyes
Authors: Yamase Toshihiro , Kokado Hiroshi , Inoue Eiichi
Published: July 2006

The photoelimination of hexamethyleneammonium hexamethylenedithiocarbamate (HMTC) can be sensitized by xanthene dyes, such as rose bengal and eosine yellowish. In contrast to the direct photolysis results, the presence of HMTC in the dye-sensitized decomposition produces no carbon disulfide and consumes oxygen during the irradiation. The quantum yield of photoelimination in an aerated ethanol solution was measured. The quantum yield was almost unchanged on the variation of the xanthene dye concentration from 10−5 to 10−6m. This is different from the former observation that there was an apparent tendency for the quantum yield to decrease monotonously with an increase in the thiazine dye concentration. The singlet oxygen mechanism, in which the photochemical reaction is initiated by the interaction between the triplet dye and the ground-state oxygen molecules, has been inferred for the dye-sensitized photoelimination of HMTC. It has been explained in terms of the effect of 1,4-diazabicyclo [2.2.2] octane, β-carotene, and tetramethylethylene in reducing the quantum yield. The photooxygenation of HMTC by dyes seemed to be caused by attack of the singlet oxygen on the thiocarboxyl-ion group, which has a rate constant of 108m−1sec−1 in ethanol.
Interaction between Phenothiazine Triplet State with Several Electron Acceptors
Authors: Iwaoka Teiki , Kokubun Hiroshi , Koizumi Masao
Published: July 2006

As an extension of the previous paper (This Bulletin, 44, 341 (1971)) which proposed the formation of a certain charge transfer complex between triplet phenothiazine (PTHT) and oxygen or dimethylisophthalate, the similar donor-acceptor interaction has been studied between PTHT and several other acceptors such as dimethylterephthalate (DMTP), nitrobenzene, dinitrobenzene, and terephthalonitrile in deaerated ethanol solutions. In case of DMTP, studies have been made also in cyclohexane. It has been established that all the acceptors except nitrobenzene attack PTHT with the diffusion controlled rate constant and that in ethanol they give rise to free radical ions and/or solvent shared ion-pair. In cyclohexane, however, no transient species other than triplet has been detected.
Electronic Spectra and Structures of Organic π-Systems. VI. Electronic States of Diazomethane, Ketene, Diazocyclo-pentadiene and Benzenediazonium Ion
Authors: Yoshida Zen-ichi , Kobayashi Tsunetoshi
Published: July 2006

The electronic states of diazomethane, ketene, diazocyclopentadiene and benzenediazonium ion were studied by the semi-empirical ASMO LCAO SCF CI method. Both π- and \barπ-systems were taken into consideration. Two types of approximations, Mulliken’s formula and a new semitheoretical formula, were used in the evaluation of the core resonance integrals. The latter gives satisfactory results though it contains no arbitrary adjustable parameters. The longest wavelength singlet-singlet transition of diazomethane, ketene or diazocyclopentadiene is 1π–1\barπ, and that of benzenediazonium ion 1π–1π.
Transient Species Obtained by the Flash Photolysis of Chloranil in Various Solutions
Authors: Kawai Kiyoshi , Shirota Yasuhiko , Tsubomura Hiroshi , Mikawa Hiroshi
Published: July 2006

Transient absorption spectra have been obtained by the flash photolysis of chloranil in various organic solvents. In trichlorotrifluoroethane, two T-T′ absorption systems of chloranil were obtained with well-resolved vibrational structures. In tetrahydrofuran, on the other hand, absorption spectra mostly consist of semiquinone radical formed by the hydrogen abstraction from solvent. In benzene and in acetone, the first T-T′ absorption system was much more diffuse and was accompanied by a weak, broad absorption at longer wavelength (λ>550 nm) which might be assigned to a charge transfer absorption from triplet chloranil as acceptor and the solvent molecule as donor. In acetone and in methanol, it has also been found that there is an equilibrium between semiquinone radical and semiquinone anion.
Stereoselective Formation of Isomers of the Bis(l-aspartato)-l-(or d-)alaninatocobaltate(III) Complex
Authors: Matsuda Toshitsugu , Okumoto Tetsuro , Shibata Muraji
Published: July 2006

The reaction of racemic α-alanine, in the presence of active charcoal, on a reaction mixture of the [Co(CO3)3]3− complex with l-aspartate led to the stereoselective formation of the [Co(l-asp)n(ala)3−n]n− (n=0—3) complexes. By means of ion-exchange chromatography and a recrystallization procedure, three stereoisomers of the bis(l-aspartato)alaninato complex have been obtained; mer1-Λ-[Co(l-aspH)2(l-ala)]·H2O, mer2-Λ-[Co(l-aspH)2(l-ala)]·2H2O, and fac-Δ[Co(l-aspH)2(d-ala)]·4H2O (where the mer1 and mer2 isomers have different geometries). These isomers have been characterized by comparing their CD and PMR spectra with those of the corresponding isomers obtained using l- or d-alanine in place of racemic alanine. The fac/mer ratio has been estimated to be ca. 64/36. The Δ/Λ AIA ratio in the fac isomer has been estimated to be ca. 95/5, while the Δ/Λ ratio in both the mer1 and mer2 isomers has been estimated as ca. 25/75.
Studies on the Isomerization of 2,4-Dinitrophenylhydrazones of Some Aliphatic α-Keto Acids and the Preparation of Their Geometrical Isomers
Authors: Katsuki Hirohiko , Tanegashima Chizuko , Tokushige Masanobu , Tanaka Shozo
Published: July 2006

Cis-trans isomerization of 2,4-dinitrophenylhydrazones of some aliphatic α-keto acids takes place in water and some organic solvents by the catalysis of hydrogen ions. Trans isomer is more stable than cis isomer for lower keto acids and the reverse is the case for higher keto acids. The fraction of cis isomer in isomeric mixture at equilibrium in organic solvents such as ethyl acetate and ethyl ether, saturated with 6n hydrochloric acid, was larger than that in aqueous solution. The two isomers could be separated by means of the difference in their solubility characteristics in 1n sodium carbonate except for some keto acids with tertiary or quaternary β-carbon. Melting points of some pairs of the hydrazone isomers were found to be the same when measured by the usual method. This is due to the isomerization of one isomer to the other which takes place during the course of heating.
The Dissociation Constants of Weak Acids in a Methanol-Water Mixture
Authors: Kondo Yasuhiko , Tokura Niichiro
Published: July 2006

The theoretical expression of the Henry constant has been derived on the basis of the concept of an ideal associated mixture for the system in which a solute, M, exists as such clusters as M·(H2O)j·(MeOH)z−j, which are related to each other by the equation:

M·(H2O)j−1·(MeOH)z−j+1+H2O\oversetKj\ightleftarrowsM·(H2O)j·(MeOH)z−j+MeOH

Making use of the theoretical expression, the transfer-free energies of halogen acids from water to water-methanol mixtures and the dissociation constants of weak acids in water-methanol mixtures have been analyzed and the following equilibrium constants have been obtained for a proton, assuming that a proton is in a higher free energy state in methanol than in pure water, while a counter ion is in the same free-energy state:

K 1=210, K2\doteqdot16, K3\doteqdot2,K4\doteqdot1

The maximum phenomena observed for the dissociation constants of charged acids in the same mixture could be reproduced by the combination of the above Henry constants; emphasis has been placed on the importance of the assumption of a multi-step solvation mechanism.
A Consideration of Orbital Interaction in Nitrogen Extrusions of Cyclic Azo Compounds
Authors: Inagaki Satoshi , Fukui Kenichi
Published: July 2006

The stereochemical paths of nitrogen extrusions from cyclic azo compounds have been examined from the point of view of particular orbital interaction. The stereoselectivity of the recyclization of 1-pyrazoline derivatives and the homologues on the extrusion can be understood in terms of interaction between the frontier orbitals of the C–N–N–C σ-bond system and of N–N π-bond. Other cyclic azo compounds are found also to behave consistently with the direction of the particular orbital interaction between the relevant parts e.g., strained σ-bonds, π-bonds and lone pairs, and two weakened C–N bonds, and of the interaction between approximate p orbitals at the α carbons with respect to the nitrogen and unstrained σ-bond to be cleaved.
Studies of Thioiminocarbonates. II. The Cyanide Ioncatalyzed Addition of Alcohols to Thiocyanates
Authors: Tanaka Kazuhiko
Published: July 2006

It was found that thiocyanates reacted with methanol in the presence of a catalytic amount of cyanide ion to give thioiminocarbonates. The effects of other catalysts upon the addition of methanol to thiocyanates were examined: the azide ion and the methoxide ion were effective, while triethylamine, sodium thiocyanate, potassium iodide, triphenylphosphine, sodium acetate, and mercuric cyanide were ineffective. A plausible reaction mechanism involving the addition of the cyanide ion to thiocyanates was proposed.
Thallium(III) Chloride Tetrahydrate as a Lewis Acid Catalyst for Aromatic Alkylation and Acylation
Authors: Uemura Sakae , Sohma Kazuhiro , Okano Masaya
Published: July 2006

From a study of aromatic alkylation and acylation using TlCl3·4H2O catalyst, it was revealed that this metal chloride was a milder Lewis acid catalyst than AlCl3 and FeCl3 and was similar in activity to ZnCl2. Although the yields of the products were generally low, the characteristics of this catalyst were observed in the formation of β,β′-dimethylstyrene and benzoylacetone upon the respective methallylation and acetylation of benzene and in the fact that the hydrated chloride was more effective than the anhydrous one. In a sharp contrast to aromatic bromination, Tl(OAc)3 showed little activity in these reactions.
Studies of Peptide Antibiotics. XXVII. Synthesis of an Analog of Gramicidin S Containing a Glycine Residue in Place of a Proline
Authors: Matsuura Shuji , Waki Michinori , Izumiya Nobuo
Published: July 2006

[Gly5]-Gramicidin S in which one l-proline residue at 5-position in gramicidin S is replaced with glycine was synthesized and tested for antibacterial properties. The cyclic decapeptide obtained was as active as natural gramicidin S. It was suggested that the mode of antibacterial activity of [Gly5]-gramicidin S and its conformation are similar to those of GS.
Sulfenylation of Active Methylene Compounds with Sulfenamides
Authors: Kumamoto Takanobu , Kobayashi Susumu , Mukaiyama Teruaki
Published: July 2006

Equimolar reactions of sulfenamides derived from secondary alkylamines with active methylene compounds afforded mono-sulfenylated compounds in good yields. The reactions of 2 mol of sulfenamides derived from imides with 1 mol of active methylene compounds in the presence of a base gave di-sulfenylated compounds. It was found that α-mono-sulfenylated ketones were prepared by the reactions of enamines with sulfenamides derived from imides. α-gem-Di-sulfenylated ketones were prepared by the reactions of α-mono-sulfenylated ketones with sulfenamides derived from imides in the presence of a base. The preparation and reactions of N-phenylthiobenzamidine hydrochloride were also examined.
The Palladium-catalyzed Ferrocenylation of Olefins
Authors: Kasahara Akira , Izumi Taeko , Saito Genji , Yodono Minoru , Saito Ryu-ichi , Goto Yoshiaki
Published: July 2006

Ferrocenylpalladium chloride, prepared in situ from chloromercuriferrocene and lithium chloropalladite, reacts readily with various olefins to produce alkenylferrocene derivatives. Enol esters and allylic alcohols also react to form (2-oxoalkyl)- and (3-oxoalkyl)-ferrocene derivatives. The synthesis of 1,1′-dialkenylferrocene derivatives from 1,1′-bis(chloromercuri)ferrocene, olefins and palladium salt is also reported. The reaction may proceed by means of a catalytic amount of the metal salt and by the aid of cupric chloride; it provides an extremely convenient method for the synthesis of a wide variety of ferrocene derivatives.
Spectroscopic Studies on the Tautomers of Heptane-2,4,6-trione and Its Methylated Homologues
Authors: Sagara Fumio , Kobayashi Hiroshi , Ueno Keihei
Published: July 2006

3,5-Dimethylheptane-2,4,6-trione and 3-methylheptane-2,4,6-trione are synthesized by methylationheptane of-2,4,6-trione via alkali metal enolates or an enamine intermediate of the mother compound. In keto-enol tautomerism, the latter two compounds take triketo-, monoenol-, and bisenol forms, while the first one exists in triketo and monoenol forms, being unable to take a bisenol form. NMR spectra of the tautomers are assigned by combining with IR data. Keto-enol ratio in a range of solution phases at various temperatures are estimated by NMR method and effect of the branched methyl groups upon the keto-enol tautomerism is discussed.
The Crystal Structure of 1-Ethyl-5-bromouracil. I. The Crystal Structure of the Form I Crystal of 1-Ethyl-5-bromouracil
Authors: Mizuno Hiroshi , Fujiwara Takaji , Tomita Ken-ichi
Published: July 2006

1-Ethyl-5-bromouracil, C6H7N2O2Br, is crystallized in two forms. Crystals of the form I are monoclinic with four molecules in a unit cell of dimensions; a=7.89, b=12.01, c=9.71 Å, β=121.0°, space group P21⁄c, Three-dimensional intensity data were collected by diffractometer with Mo-Kα radiation. The structure was determined by heavy atom method and refined by the block-diagonal least-squares method. The final R-value was 0.052 for all observed reflections. The molecules are joined together in pairs around a center of symmetry with two N–H···O hydrogen bonds connecting N(3) to carbonyl oxygen O(4), and stacked with the base plane tilted each other.
The Syntheses of 1,3-Oxathiolan-5-one Derivatives
Authors: Satsumabayashi Sadayoshi , Irioka Shuichi , Kudo Hiroshi , Tsujimoto Kozo , Motoki Shinichi
Published: July 2006

The condensations of aldehydes with thioglycollic acid or α-mercaptopropionic acid were carried out; 2-substituted- or 2,4-disubstituted-1,3-oxathiolan-5-ones were thus obtained. The intermediate of the reaction was isolated only when phenylglyoxal and thioglycollic aicd were used.
The Trapping Efficiency for Electrons in Polar Glasses at 77°K
Authors: Sawai Takeshi , Shinozaki Yoshiharu , Meshitsuka Gisuke
Published: July 2006

The trapped electron yields in alcohols and methanol-water mixtures at 77°K as a function of the electron scavenger concentration have been measured. The reciprocal of the trapped electron yield increased linearly with the concentrations of phenol, acetone, and acrylamide. The relative trapping efficiency for electrons was found to increase with an increase in the dielectric constant of the matrix at room temperature. The relative travelling distance of electrons in these matrices was also estimated.
The Second CMC of an Aqueous Solution of Sodium Dodecyl Sulfate. IV. Fluorescence Depolarization
Authors: Kubota Yukio , Kodama Michiko , Miura Masaji
Published: July 2006

The depolarization of the fluorescence emitted from a dye solubilized in the micelle was measured over a wide concentration range of sodium dodecyl sulfate (SDS). The polarization of the fluorescence showed an abrupt increase at the 1st CMC and at about 70 mm of SDS; the latter agrees very closely with the 2nd CMC revealed by conductivity and viscosity measurements. This phenomenon implies that there is a certain change in the micelle structure at the 2nd CMC. The micellar size was calculated from the fluorescence depolarization data using Perrin’s equation. The results showed that: (1) the micellar volume below the 2nd CMC is in good agreement with that determined by light-scattering, (2) the micellar volume gradually increases with an increase in the concentration of SDS, and (3) the micellar volume increases abruptly at the 2nd CMC.
The Crystal Structure of d,l-1,1,4aα-Trimethyl-2α-hydroxy-8α-acetoxy-1,2,3,4,4α,5,6,7,8,9-decahydrophenanthrene
Authors: Furusaki Akio , Hamanaka Nobuyuki , Matsumoto Takeshi
Published: July 2006

The conformation of d,l-1,1,4aα-trimethyl-2α-hydroxy-8α-acetoxy-1,2,3,4,4α,5,6,7,8,9-decahydrophenanthrene has been studied by means of X-ray methods. The crystals are triclinic, with two molecules in a unit cell with the dimensions of a=11.463, b=11.509, c=7.430 Å, α=84°42′, β=102°47′, and γ=115°40′. The space group is P\bar1. The intensity data were collected on an automatic four-circle diffractometer with CuKα radiation. The structure was solved by the symbolic-addition method, and was refined by the block-diagonal-matrix leastsquares method with anisotropic temperature factors for all the non-hydrogen atoms. From a difference Fourier map, all the 28 hydrogen atoms were also found. Further least-squares refinement including these hydrogen atoms reduced the R factor to 5.4%. In the present molecule, the cyclohexene ring has the normal half-chair conformation, and does not show the unusual behavior found in the p-bromobenzoate of 1,1,4aα-trimethyl-2α-hydroxy-8β-methoxy-1,2,3,4,4α,5,6,7,8,9-decahydrophenanthrene. The 8α-acetoxyl group, like the 8β-methoxyl group in the p-bromobenzoate, takes the axial orientation notwithstanding the inversion of the configuration. Such a conformation seems to be the preferred one for a cyclohexene ring which has a methoxyl or an acetoxyl group at the allylic position.
Studies of Ionic Association. I. Alkali Halide and Sodium Nitrate in the Butyl Alcohol-Water System
Authors: Yui Norio , Kurokawa Y\={o}ichi , Nakayama Masami
Published: July 2006

It has previously been reported that the dissociation of alkali halide and sodium nitrate between butanol and water phases could be explained reasonably if they were dissociated into free ions in each phase. The present investigation was undertaken to see to what extent dissociation occurs in the butanol phase. Conductometric measurements were carried out on solutions of LiBr, NaBr, NaCl, KCl, RbCl, and NaNO3 in the n-butanol–water system and on the solution of NaCl in the t-butyl alcohol–water system at 20°C or 25°C. These data were analyzed by using the Fuoss-Onsager equation for associated electrolytes, and the association constants were calculated to be as follows: NaBr 250, NaCl 600, KCl 610, RbCl 1850, NaNO3 180, and NaI 220 in the n-butanol–water (11 wt%) system at 25°C (except NaBr), and NaCl; 590, 160, and 75 for water wt% 30, 45, and 60 in the t-butyl alcohol–water system at 25°C, respectively. The association constants of NaCl in the t-butyl alcohol–water system were explained in terms of the simple electrostatic theory. The results were discussed briefly in comparison with conductance data reported in the literature.
Low-frequency Lattice Vibrations and Intermolecular Forces of the 9,10-Anthraquinone Crystal
Authors: Miyazaki Yoshio , Ito Mitsuo
Published: July 2006

The low-frequency Raman active lattice vibrations of the 9,10-anthraquinone single crystal were measured at various temperatures from 26°C to −190°C, and the symmetry species of the observed Raman bands were determined by polarization measurements. From a comparison between the observed and calculated frequencies, it seems that Dashevsky’s potential expresses well the intermolecular potential of the 9,10-anthraquinone crystal. It was also found that the temperature dependence of lattice vibrations can be explained reasonably with this potential.
Effect of Matrix on the Formation of Solvent Radicals in the Radiolysis of Alkanes in the Solid State at 77 K
Authors: Fukaya Mitsuharu , Wakayama Terunobu , Miyazaki Tetsuo , Saitake Yoshiyuki , Kuri Zen-ichiro
Published: July 2006

The effect of the matrix on the radiolysis of 2,3-dimethylbutane, neopentane. 2,2-dimethylbutane, and isobutane in the solid state has been studied at 77 K by means of ESR spectroscopy. Though only the ·CH2CH-(CH3)CH(CH3)2 radical is formed by the γ-irradiation of 2,3-dimethylbutane in the I crystal, the CH3\overset·C(CH3)-CH(CH3)2 radical is formed by the γ-irradiation of 2,3-dimethylbutane in the II crystal. Though the t-C4H9 and neo-C5H11 radicals are formed by the γ-irradiation of pure neopentane, the formation of radicals is affected appreciably by the addition of a small amount of alkanes. When neopentane containing ethane, etc. is γ-irradiated, the solute radical is mainly formed by energy transfer form the γ-irradiated neopentane to the solute. Most of the solutes have a spherical molecular structure like that of neopentane or are smaller than neopentane. When neopentane containing 3-methylpentane, etc. is γ-irradiated, only the neopentyl radical is formed. The molecular structures of the solutes are very different from that of neopentane. The formation of the solvent radical in the radiolysis of 2,2-dimethylbutane is affected by the addition of 3-methylpentane or methylcyclphexane. The formation of the butyl radical in the radiolysis of isobutane is also changed drastically by addition of alkanes. It is concluded that the formation of solvent radicals in the radiolysis of solid alkane is appreciably affected by the conditions of the matrix.
The Proton Chemical Shift of n-Pentane
Authors: Ando Isao , Nishioka Atsuo
Published: July 2006

The temperature dependence of the proton chemical shift of n-pentane was calculated by the CNDO/2 method, taking into account the possible preferred conformations and the contributions from the diamagnetic, paramagnetic, and bond anisotropy terms. It was found that the bond anisotropy term contributes predominantly, while the diamagnetic term is not negligible, and that the paramagnetic term is negligible in comparison with these terms. The observed temperature dependence of the chemical shift can be reasonably explained by calculations using 570 cal/mol as the energy difference between the trans and gauche conformations, and also using 9.1×10−30 cm3 as the magnetic anisotropy of the C–C bond.
The Temperature Dependence of the Nuclear Quadrupole Resonance of 35Cl in KClO3, AgClO3, Ba(ClO3)2·H2O, and Cu(ClO3)2·6H2O
Authors: Suhara Masahiko
Published: July 2006

The nuclear quadrupole resonance (NQR) frequencies of 35Cl in KClO3, AgClO3, Ba(ClO3)2·H2O, and Cu(ClO3)2·6H2O have been measured as a function of the temperature in the range from 77 to 350 K at a constant (atmospheric) pressure. These data have then been analyzed by the method of Brown. The torsional frequencies of the ClO3− ion in the crystals have been determined by fitting the experimental data with the Bayer theory, modified by taking into account the anharmonicity in torsional oscillation. The low barrier height obtained in Cu salt indicates that a freer rotational motion of the chlorate ion is to be expected in this crystal.
The Photoreduction of 2-Nitronaphthalene in 2-Propanol
Authors: Obi Kinichi , Bottenheim Jan W , Tanaka Ikuzo
Published: July 2006

The photoreduction of 2-nitronaphthalene in 2-propanol has been studied at 313 nm. The photoreduction is suppressed in the presence of dissolved oxygen or a triplet quencher such as 1,3-cyclohexadiene. The results are consistent with the triplet state of 2-nitronaphthalene being the reactive species. 2-Naphthylhydroxylamine is formed as the reaction product. The quantum yield for the disappearance of 2-nitronaphthalene is estimated to be 0.037. The low quantum yield results from the slow reaction rate of hydrogen abstraction by the ππ* triplet state of 2-nitronaphthalene.
Emission Spectra of Aromatic Halides by Controlled Electron Impact
Authors: Ogawa Teiichiro , Tsuji Masaharu , Toyoda Minoru , Ishibashi Nobuhiko
Published: July 2006

Fluorobenzene, chlorobenzene, and bromobenzene were excited at a very low pressure in the vapor phase by a controlled electron beam of 60–300 V. Their emission spectra were then measured and compared with those excited by the photon. Fluorobenzene showed a characteristic photoemission of the parent molecule in the 260–320 nm region. The band was assigned to the transition from the lowest excited state to the ground state, and its shape did not vary appreciably with the energy of the electron beam. Though the spectrum had some features of “resonance fluorescence,” the vibrational structure of the band was not identical with that of any of the spectra obtained by photon impact between 4.7–4.9 eV. This seems to indicate that the molecule gave different spectra according to the excitation energy. However, the excitation by 60 V electrons and that by 300 V electrons did not produce any remarkable difference in the spectra under the resolution of the spectrometer used. Other aromatic halides failed to show any characteristic band of the parent molecules; instead, they showed weak lines due to Cl+ or Br+ and pronounced bands due to HCl+ or HBr+. This result was ascribed to the spin-orbit coupling effect and the predissociation of the excited parent molecules.
The Electronic Structure of the Electron Donor-Acceptor Complex in Its Lowest Excited Singlet State. II
Authors: Masuhara Hiroshi , Tsujino Nobuyuki , Mataga Noboru
Published: July 2006

The electronic spectra of some 1,2,4,5-tetracyanobenzene complexes in the lowest excited singlet state at 77 K were obtained by laser photolysis method. The observed spectra can be well reproduced with the superposition of the bands similar to those of acceptor anion as well as donor cation, independent of donors. Comparing the spectra with those of ionic radical salts, it is concluded that the electronic structure of these complexes is quite polar and the fluorescent state is a contact ion-pair. The electronic structures of excited electron donor-acceptor systems have been discussed, on the basis of the interaction between donor cation and acceptor anion. The chargetransfer degree in the excited complexes was found to increase in the following order; 1,2,4,5-tetracyanobenzenehexamethylbenzene complex in the phosphorescent state<hydrocarbon-amine heteroexcimers<the present complexes in the fluorescent state.
The Kinetics of Association-Dissociation Reaction in an Aqueous Solution of n-Butylamine by Means of Ultrasonic Absorption
Authors: Nishikawa Sadakatsu , Yasunaga Tatsuya
Published: July 2006

The ultrasonic absorptions of n-butylamine in aqueous solutions were measured at 25°C in the range of frequency from 15 to 220 MHz and of concentration from 0.698 to 3.00 M. The peak sound absorption was found. The mechanism of the observed peak sound absorption was attributed to the 4A\ightleftharpoonsA4 reaction where A and A4 are the monomer and tetramer of the solute respectively. The rate constants of the forward and backward reaction were determined to be 2.2×106 M−3 sec−1 and 9.0×107 sec−1 respectively, and the standard volume change between the initial and final state in the reaction was calculated to be 14 ml mol−1.
Dielectric Relaxation and Molecular Structure. IV. Dielectric Relaxation and Hydrogen Bonding in Chloroanilines
Authors: Vij J K , Srivastava K K
Published: July 2006

Measurements of relative permittivity were carried out at 30.0 °C in p-dioxane at 1 MHz and at 9.48 GHz for ortho (A), meta (B), and para (C) chloroanilines. The results are interpreted in terms of hydrogen bonding between amino hydrogens and the oxygen atoms of the dioxane molecule, the dipole moments and dielectric relaxation time values being given. The relative behaviour of chloroanilines has been discussed. It seems that a finite probability of H–Cl bond formation exists between one of the amino hydrogens and the neighbouring chlorine atom in o-chloroaniline.
Study of the Poisoning Effect on Nickel and Nickel Boride Catalysts by Means of a Flow Microcalorimeter
Authors: Imanaka Toshinobu , Nitta Yuriko , Teranishi Shiichiro
Published: July 2006

The relation between the poisoning effect on nickel and nickel boride catalysts in the liquid-phase hydrogenation of styrene and the bond strength of inhibitors on the catalysts has been studied by means of liquid-phase chromatography using a thermal detector. The results show that the sequence of poisoning effect is in agreement with that of the adsorption heat of inhibitors, and that the adsorption heat of each inhibitor on nickel boride is smaller than that on nickel. Besides, this sequence is also in agreement with that of the bond strength of the central metal ion and the coordinated ligand of some manganese complexes in a homogeneous system. These facts indicate that the adsorption energy of inhibitors on a catalyst in a heterogeneous system corresponds to the bond strength of the ligand coordinated to metal complexes in a homogeneous system.
The Crystal Data of Ternary Rare Earth Borides, RCo2B2
Authors: Niihara Koichi , Shishido Toetu , Yajima Seishi
Published: July 2006

Compounds with the composition of RCo2B2 (R=La, Nd, Sm, Gd, Tb, Dy, and Y) were prepared by arcmelting methods. Their crystal structure was investigated by means of X-ray diffraction. These ternary rare earth borides crystallize in the tetragonal lattice. The lattice parameters are a=3.616±0.003 Å and c=10.215±0.005 Å for LaCo2B2 and a=3.561±0.002 Å and c=9.358±0.005 Å for YCo2B2. The good agreement between the X-ray diffraction intensities observed and those calculated shows that the ternary borides, LaCo2B2 and YCo2-B2, crystallize in the ThCr2Si2-type structure. The crystallographic data obtained for LaCo2B2 and YCo2B2 are as follows: space group 14/mmm(D4h17); 2R in 2(a), 4Co in 4(d), and 4B in 4(e) with z∼3⁄8. The boron atoms in this structure are situated at the center of a trigonal prism formed by four rare earth atoms and two cobalt atoms. We also found the RCo2B2 compounds to be isostructural with LaCo2B2 and YCo2B2, where R=Nd, Sm, Gd, Tb, and Dy. However, efforts to prepare CeCo2B2 and ErCo2B2 by arc-melting were unsuccessful.
The Mechanism of the Lumiflavin-sensitized Photooxygenation of Tryptophan Accelerated by Adenine
Authors: Yoshimura Akio , Kato Shunji
Published: July 2006

It was found that the lumiflavin-sensitized photooxygenation of tryptophan in a dilute aqueous solution is greatly accelerated by the addition of adenine. This effect of adenine on the photosensitized oxygenation is specific for flavin dyes, and the quantum yield increases with the oxygen concentration at very low oxygen concentrations, but decreases at higher oxygen concentrations. Therefore, singlet oxygen can be excluded from the intermediates of this oxidative reaction. The oxygen adduct of the dye is considered to be a possible intermediate for the photooxygenation of tryptophan accelerated by adenine.
Radiation Synthesis of Hydrogen Cyanide from Nitrogen–Ethylene System. Effect of Temperature, Gas Density, and Reactor Wall
Authors: Ikezoe Yasumasa , Sato Shoichi , Danno Akibumi
Published: July 2006

The rate of formation of hydrogen cyanide from the nitrogen–ethylene system by 60Co gamma rays was found to depend on irradiation temperature, gas density, gas composition, and the nature of the wall surface of the reaction vessel. Above 100 °C, the G(HCN) value increased with the rise of temperature. Below 100 °C , the G(HCN) value remained constant down to −196 °C. In the temperature range from 400 °C to −196 °C, it increased with reduction of nitrogen gas density. The largest G(HCN) value obtained was 2.0. In certain cases, the wall surface influenced the suppression of hydrogen cyanide formation. As an active species responsible for hydrogen cyanide formation, excited nitrogen molecules are proposed in addition to nitrogen atoms. Excited nitrogen molecules are decomposed to nitrogen atoms with small activation energy or deactivated by collision with other molecules. They play an important role in cyanide formation at low pressures and at high irradiation temperatures.
The Atomic Absorption Spectrophotometric Determination of Bismuth in Premixed Inert Gas(Entrained Air)-Hydrogen Flames
Authors: Nakahara Taketoshi , Munemori Makoto , Musha Sôichirô
Published: July 2006

The atomic absorption spectrophotometric determination of bismuth in aqueous solutions was established in premixed inert gas(entrained air)-hydrogen flames with a “multi-flame” burner in conjunction with a Nippon Jarrell-Ash Model AA-1 atomic absorption/flame emission spectrophotometer. Under the optimum operating conditions, a straight calibration graph was obtained at 223.1 nm in the concentration range of 0-10 ppm and the bismuth sensitivity for a 1% absorption was 0.1 ppm. The effects of acids and other elements on the bismuth atomic absorption were examined. Phosphoric acid caused a considerable depressing effect on the bismuth absorption. Hydrochloric acid remarkably depressed the bismuth absorption at acid concentrations lower than 0.5 n, but it gave no interference in acid concentrations higher than 0.5 n, in which water-insoluble bismuth oxychloride was quickly dissolved in hydrochloric acid. Hydrofluoric, nitric, perchloric, and sulfuric acids had no effect on the bismuth absorption. Most of the elements examined, with the exception of aluminum, boron, cerium, silicon, and zirconium, gave no interference to the bismuth absorption. The depressing interferences due to some elements were removed in appearance by adding a large amount (2000 ppm) of magnesium (as chloride). Furthermore, it was found that most of the depressing interferences could be eliminated by adding a large amount (0.1 M) of ammonium salts (as chloride or perchlorate) to the sample solutions. Bismuth in the presence of magnesium chloride, ammonium chloride, or ammonium perchlorate could be determined without interference from various other elements. The atomic absorption spectrophotometric method was applied to the determination of bismuth in sulfide ores, aluminum-, tin-, and lead-base alloys with satisfactory results.
Determination of Titanium in Some Metallurgical Materials by Atomic Absorption Spectrophotometry
Authors: Nakahara Taketoshi , Munemori Makoto , Musha Sôichirô
Published: July 2006

The atomic absorption spectrophotometric determination of titanium was subject to interference by other elements in a nitrous oxide-acetylene flame with a Perkin-Elmer Model 303 atomic absorption spectrophotometer, fitted with a 5-cm long-path slot burner. The effects of various other elements, acids, and water-miscible organic solvents on the titanium atomic absorption were examined. Aluminum produced the greatest enhancement of the titanium absorption of all the elements examined. Both butyric acid (2.0 M) and diethylene glycol mono-butyl ether (20%) enhanced the titanium absorption by about 100% in aqueous solutions. In the presence of 5000 ppm aluminum or 20% diethylene glycol monobutyl ether, the interferences from other elements appeared to be completely removed. Furthermore, the extraction of titanium with cupferron into methyl isobutyl ketone was successful in effecting an increase in the sensitivity of titanium and in eliminating, or at least diminishing the interferences from other elements. The atomic absorption method was then applied to the determination of titanium in ferric oxides, nickel-chromium steel, nickel alloy, and steels with satisfactory results.
Formation of Zinc(II) Complexes with Several Carboxylic Acids and Their Extraction with Carbon Tetrachloride
Authors: Moriya Hiromitsu , Sekine Tatsuya
Published: July 2006

The distribution of zinc(II) was determined between 0.1 M constant-ionic-strength media containing sodium perchlorate and/or carboxylate ions, A−, and carbon tetrachloride containing a neutral ligand, quinonline, Q, or the dimer of the same carboxylic acid, (HA)2. The distribution ratio was measured as a function of the concentration of carboxylate ions in the aqueous phase or of that of one of the above neutral ligands, in the organic phase. The extraction constant of the ZnA2 species in the caproic acid system was found to be KexA=[ZnA2]org/[Zn2+][A−]2=10−0.15, while that in the valeric or butyric acid system was too small to be determined. The distribution ratio of zinc(II) increased with an increase in the concentration of the ligand in the organic phase. These increases were explained by the formation of adducts in the organic phase; in the caproate system, the species found were ZnA2Q, and ZnA2Q2, (β1(org)=[ZnA2Q]org/[ZnA2]org[Q]org=101.92, β2(org)=[ZnA2Q2]org/[ZnA2]org[Q]org2=102.84) or ZnA2(HA)4 (β2(org)=[ZnA2(HA)4]org/[ZnA2]org[(HA)2]Org2=102.92). No polynuclear species was found in these organic phases when the initial zinc(II) concentration in the aqueous phase was less than 10−3 M.
The Preparation and Spectroscopic Properties of Fumaronitrile Complexes of Palladium(0) and Platinum(0)
Authors: Suzuki Keinosuke , Okuda Hideshi
Published: July 2006

Fumaronitrile complexes, M(FMN)(AsPh3)2 (M=Pd, Pt and FMN=fumaronitrile), have been prepared. Various chelating agents replaced AsPh3 in the complexes, giving M(FMN)L (L is a chelating agent containing N, P, or As as donor atoms). The chemical shift of the methine protons of these complexes increased in the order:

Pd–As<Pd–P<Pt–As<Pt–P.

This is probably the increasing order of the π-back donation in these complexes. The UV spectra of the complexes are also described.
A Separation Scheme for the Analysis of Metal Ions Using Column Extraction Chromatography. Grouping of Nineteen Metal Ions into Six Fractions
Authors: Akaza Ikuko , Tajima Takatoshi , Kiba Toshiyasu
Published: July 2006

A new scheme for the quantitative group separation of 19 common cations by reversed-phase extraction column chromatography has been devised. The following six columns, in which the organic solvent was adsorbed on Daiflone(polytrifluorochloroethylene), were prepared: a TBP–2n HCl column for Fe(III), Hg(II), and Sn(IV); a TOA(CCl4)–2n HCl column for Ag(I), Bi(III), Zn(II), and Cd(II); a TBP–6n HCl column for Sb(III); an AcAc(CHCl3)–pH 5.0 column for Cr(III) and Al(III); a TTA(MIBK)-pH 5.0 column for Cu(II), Co(II), Ni-(II), Pb(II), Mn(II), and Mg(II), and a TTA(MIBK)-pH 7.0 column for Ca(II), Sr(II), and Ba(II). After a test solution had been passed through the six columns successively in the above order, the metal ions are grouped and entirely retained on the specified columns.
Dehydration in Liquid Sulfur Dioxide. I. Acid Amide and Acid Anhydride Synthesis in an Iodine—Pyridine—Sulfur Dioxide System
Authors: Nojima Masatomo , Hasegawa Shigeru , Tokura Niichiro
Published: July 2006

A novel dehydrating reagent consisting of the I2–pyridine–liq. SO2 system has been examined in order to obtain acid amides from carboxylic acids and amines in liq. SO2. Among the amines, aniline gave the most satisfactory results. A fairly good yield was also achieved when the SO2Cl2–Py–SO2 system was used in place of the I2–Py–SO2 system. Various amines in the absence of acids in this system gave N,N′-disubstituted diaminosulfone derivatives in good yields. Benzoic acid itself in the absence of amines gave benzoic acid anhydride in this system slowly.
The Photochemical Reaction of Diphenylacetylene with Enamines
Authors: Miyamoto Norioki , Nozaki Hitosi
Published: July 2006

The irradiation of a mixture of diphenylacetylene (I) and the enamine of the diethyl ketone (II) or of cyclopentanone (IV) gives two β,γ-unsaturated ketones, III and X respectively, in which the diphenylacetylene moiety is formally inserted into the respective enamine double bond under hydrogen migration. The reaction with the enamine of cyclohexanone (V) affords 2-(1,2-diphenylvinyl)cyclohexanone (XIII) as the major product in addition to the cycloadduct (XV). In each case, the formation of photodimers of I has been observed. The reaction is quenched by the addition of pyrene, is sensitized by triphenylene, and is supposed to proceed by way of a triplet path. The different routes of the enamine reactions can be explained by considering the geometry of the intermediate diradicals.
Studies on Aminosugars. XXXIII. Syntheses of 4-Azido-2,3,6-tri- O-benzyl-4-deoxy- and 6-Azido-2,3,4-tri-O-benzyl-6-deoxy-α-d-glucopyranosyl Chloride
Authors: Takagi Yasushi , Tsuchiya Tsutomu , Umezawa Sumio
Published: July 2006

The titled compounds (8 and 13) have been prepared as synthetic intermediates.
Quantitative Estimation of the Fehling Reaction of 1-O-Protected Uronic Acids
Authors: Yoshimura Juji , Hashimoto Jun-ichi , Ando Hiroaki
Published: July 2006

Quantitative estimation of the Fehling reaction of 1-O-protected uronic acid derivatives showed that the reducing power of 1-O-protected hexofuranuronic acid derivatives corresponds to 23–37% of that of d-glucose. The presumption that the reducing ability might be attributed to the formation of unsaturated aldehydo-sugars by removal of the 1-O-protecting group through a cupric ion-catalyzed β-elimination was supported by the fact that 2,5-dimethoxy-6-oxo-2,4-hexadienoic acid was formed by alkaline β-elimination of methyl (methyl 2,3,5-tri- O-methyl-α-d-glucofuranosid)uronate.