bluuebunny/crossref_metadata_2025 huggingface dataset:
Adsorption of Benzoic Acid on Gold in Perchlorate Solutions
Authors: Katoh Koichi , Schmid G M
Published: July 2006

The adsorption of benzoic acid from solutions of 10−2 to 10−5  m on gold electrode surface in perchlorate solutions of pH 1–4 was studied from differential capacity data obtained by a single pulse method. Strong adsorption is observed in the more acidic solutions. This points to predominant adsorption of benzoic acid molecule, rather than benzoate anions, possibly due to the π-electron interaction. At pH 1, benzoic acid replaces four water molecules. This interprets the flat adsorption of benzoic acid molecule on the gold electrode and the π-electron interaction with free electron of the metal surface. The standard free energy of adsorption Δ\barG° is −10.4 kcal/mol.
Steric Effects in Azo Compounds. The Electric Dipole Moments and the Absorption Spectra of Azobenzene Derivatives
Authors: Yamamoto Shunzo , Nishimura Norio , Hasegawa Shigeo
Published: July 2006

The electric dipole moments of trans-4-N,N-dimethylaminoazobenzene and its derivatives, and the absorption spectra of azobenzene derivatives and their conjugate acids have been measured. The dipole moment and the intensity of the π–π* band are clearly reduced by introduction of methyl groups into ortho positions to azo group. The twisting angle of the benzene rings with respect to the azo group has been estimated for 2,2′-disubstituted azobenzenes and their conjugate acids by means of the Braude equation. From the spectral intensity and transition energy, it was concluded that the conjugate acids are generally more susceptible than the bases to the steric effect.
Vibrational Analysis of the 2400–2800 Å Bands of 1,2,3- and 1,3,5-Trimethylbenzenes in Vapour Phase
Authors: Verma V N , Nair K P R , Rai D K
Published: July 2006

The near ultraviolet absorption spectra of 1,2,3- and 1,3,5-trimethylbenzenes have been photographed in vapour phase at different vapour pressures on a Q-24 Zeiss Medium Quartz Spectrograph. Assuming C2v symmetry for the 1,2,3- and D3h symmetry for the 1,3,5-isomer, tentative assignments of the observed bands have been made in terms of various ground state and excited state fundamentals. The respective vibrational modes have also been suggested.
Photomicroscopic Observation of Dispersion State of Droplets in Flowing Emulsion
Authors: Suzuki Kazushige , Watanabe Takehiko
Published: July 2006

The viscosity of dilute emulsion with disperse phase of volume fraction φ=0.005–0.06 was measured, and the dispersion state of emulsion droplets under shear was observed with a photomicroscope. Oil components used were aromatic hydrocarbons, i.e., benzene, o-xylene, and toluene, and saturated hydrocarbons, i.e., cyclohexane, decaline, n-hexane, etc. As emulsifier, Arlacel 60 or Arlacel 83 was used for W/O type emulsion and Tween 20 for O/W type one. For the W/O type emulsions of aromatic hydrocarbon of low emulsifier concentration (0.2%), Einstein’s equation could be applied to the viscosity at a high rate of shear in the range of φ below 0.02, in spite of the presence of aggregates of droplets in the flowing emulsion. When φ becomes 0.04–0.06, the deviation from Einstein’s equation was large. In the case of higher emulsifier concentration (1%), the deviation from Einstein’s equation was noticeable even for φ=0.01, when Arlacel 60 was used as stabilizer. The results may be brought about by the increase of effective volume fraction of disperse phase owing to the inclusion of continuous phase liquid in aggregates. In the case of W/O type emulsions of saturated hydrocarbon and O/W type ones, irrespective of the kind of oil phase liquid, the aggregates were completely redispersed into primary droplets at a high rate of shear, and Einstein’s equation could be applied.
Stereochemical Studies of Monoterpene Compounds. X. Intramolecular Interaction of Oxirane and Cyclopropane Rings with a Hydroxyl Group
Authors: Watanabe Satoru , Suga Takayuki , Shishibori Tsuyoshi , Matsuura Tamon
Published: July 2006

The intramolecular interaction of oxirane and cyclopropane rings with a hydroxyl group in the alicyclic α,β-epoxy-, β,γ-epoxy-, and cyclopropyl alcohols was investigated by means of the infrared spectroscopy. cis-α,β-Epoxyalcohols (II, IV and V) showed a free hydroxyl band, an interacted hydroxyl band with a C–O bond of the oxirane ring, and/or a band due to a O–H···O hydrogen bond, whereas trans-epoxyalcohols (I and III) showed only a free hydroxyl band. The interaction between the hydroxyl group and a C–C bond of the oxirane ring was likely to be absent. β,γ-Epoxyalcohols revealed a hydroxyl band interacting with lone-pair electrons of the oxirane oxygen, in addition to a free hydroxyl band. The O–H··· cyclopropane interaction was found with 2-(1-methylcyclopropyl)-5-methylcyclohexanols (VII and VIII). The correlation of the infrared spectra with the conformation of the interacting groups is also discussed.
The Protonation of Aromatic Hydrocarbon Radical Anions. II. Interpretations of the Rate Constants in Terms of HMO Calculations
Authors: Hayano Shigeo , Fujihira Masamichi
Published: July 2006

The rates of the protonation of aromatic hydrocarbon radical anions with water in dimethylformamide (DMF)-water mixtures were measured by means of the decay of the visible absorption maxima of radical anions with time. The rates were found to be greatly accelerated by the increasing water content in DMF-water mixtures. This behavior suggests that the negative charge is much more localized in the transition state than in the original radical anion. The rate constants in DMF could be obtained by extrapolation. The correlation of these rate constants to the molecular structure of radical anions was discussed on the basis of the results of HMO calculations. This correlation and the solvent effect could be interpreted by means of the charge-transfer mechanism.
Tritium Fractionation on the Crystal Growth of Sodium Sulfate Decahydrate from Its Tritiated Aqueous Solution
Authors: Tanaka Haruhiko , Negita Hisao
Published: July 2006

The fractionation of tritiated water (HTO) was examined during the crystallization of sodium sulfate decahydrate, Na2SO4·10H2O, from a slightly supersaturated solution which contained a trace amount of tritium. No appreciable fractionation of HTO was found to occur in the crystallization under both stirred and unstirred conditions. The factors which may influence the degree of the fractionation were generally considered in connection with the studies by deuterated water. It was suggested that virtually all of the water of crystallization in sodium sulfate decahydrate should come from free water in its aqueous solution, and should integrate into the crystal in accordance with the volume-diffusion model. This model was supported also by the energetical consideration of the sodium ion in the crystallization.
81Br Nuclear Quadrupole Resonance of Modifications of Titanium Tetrabromide
Authors: Okuda Tsutomu , Furukawa Yoshihiro , Negita Hisao
Published: July 2006

81Br NQR of titanium tetrabromide has been observed at temperatures between −196°C and 35.5°C, and its Zeeman effect has been measured at room temperature. The cubic form of titanium tetrabromide shows two resonance lines, as has been reported previously; their temperature coefficients change from positive to negative when the temperature is raised. The bond angles, ∠Br–Ti–Br, are in the range of 108.7° to 110.3°. The asymmetry parameters are 2.0 and 2.5%. On the other hand, the monoclinic form shows four resonance lines; 39.175, 39.184, 39.454, and 39.800 MHz at 11°C. The temperature coefficient of the lowest line is positive at the lower temperature, whereas those of the remainder are negative. The bond angles, ∠Br–Ti–Br, are found in the range of 108.8° to 110.1°. The asymmetry parameters are 1.2, 4.6, 2.1, and 3.5% for the bromine atoms in the order of increasing resonance frequencies. The ionic and double-bond characteristics of the Ti–Br bond in both forms are about 60 and 16%. These findings suggest that, in titanium tetrabromide. the crystal field has little effect on the molecular shape, the bond character, and the asymmetry parameter.
The Crystal Structure of the 2 : 3 Complex of Zinc Phthalocyanine and n-Hexylamine
Authors: Kobayashi Takashi , Ashida Tamaichi , Uyeda Natsu , Suito Eiji , Kakudo Masao
Published: July 2006

Crystals of the 2 : 3 complex of zinc-phthalocyanine and normal hexylamine were studied. They are monoclinic, space group P21⁄c, with cell dimensions a=12.40, b=15.76, c=20.05, β=93.2° and there are four phthalocyanine and six hexylamine molecules per cell. The phthalocyanine molecule is not planar and the central zinc ion is displaced from the plane by 0.48 Å toward the nitrogen atom of the amine. Zinc ion is of a square pyramidal five coordination. There are two bonding states for the amine in the complex crystal. One is weakly bonded and can be easily released from the lattice and the other is strongly bonded and coordinated directly to the zinc ion. None of the atomic parameters of these amines except those of the coordinating nitrogen were exactly determined.
Studies of Peptide Antibiotics. XXV. Synthesis of an Immediate Precursor of Gramicidin S
Authors: Makisumi Satoru , Matsuura Shuji , Waki Michinori , Izumiya Nobuo
Published: July 2006

A linear decapeptide, HCO-d-Phe-Pro-Val-Orn-Leu-d-Phe-Pro-Val-Orn-Leu-NHCH2CH2OH, which has been identified as an immediate precursor of gramicidin S was synthesized in order to define the physical and biological properties of this peptide. The synthetic product possessed practically no antibacterial activity against any of the microorganisms tested, though the optical rotatory dispersion feature of this peptide was quite similar to that of gramicidin S. Stability of the terminal blocking groups of this peptide to the action of hydrogen chloride in methanol was also discussed.
Rare-Gas-Sensitized Radiolysis of Toluene
Authors: Yamamoto Yukio , Takamuku Setsuo , Sakurai Hiroshi
Published: July 2006

The Ar-, Kr-, and Xe-sensitized radiolyses of toluene was studied at room temperature in the gas phase. The discussion was concentrated on the formation of three isomers of methyldiphenylmethane (MDPM), which, it had been suggested in a previous paper on the direct radiolysis of toluene, were formed by the ion-molecule reaction of C7H7+ ions. The sensitization effect on the MDPM formation was extremely large in the case of Ar, and decreased in the order of Ar, Kr, and Xe. These results were explained in terms of charge transfer from these rare gases to toluene, resulting in the formation of the C7H7+ ions. The isomer distribution of MDPM’s in the raregas-sensitized radiolysis was considered on the basis of the reaction mechanism proposed previously. The sensitization effect on the formation of other products was also discussed briefly.
A Simple Relation among the Energy Differences between Conformers of XH2C-CH2Y, C6H11X, C6H11Y, and trans-1,2-C6H10XY
Authors: Fujimoto Etsuko , Kozima Kunio , Takeoka Yoshiko
Published: July 2006

By measuring the infrared intensities, the energy differences between two conformers have been determined for bromocyclohexane, iodocyclohexane, trans-1-bromo-2-chlorocyclohexane, 1-bromo-2-chloroethane, ethylene bromohydrin, and ethylene iodohydrin in dilute solutions, and for cyclohexanol, trans-2-chlorocyclohexanol, ethylene chlorohydrin, and ethylene bromohydrin in vapors.

It was ascertained that the following relation holds for the energy differences:

Et−Eg=(Eaa−Eee)−(Ea−Ee)−(Ea′−Ee′).

Here Et−Eg is the energy difference between the trans and the gauche isomer of XH2C–CH2Y, Eaa−Eee is that between the aa- and the ee-isomer of trans-1,2-C6H10XY, and Ea−Ee and Ea′−Ee′ are those between the a- and the e-isomers of C6H11X and C6H11Y respectively, where X is a halogen and Y is a halogen or the O–H group.
Spectrophotometric Determination of Anions by Solvent Extraction with Metal Chelate Cations. XIV Determination of Iodide Ions with Tris(1,10-phenanthroline)iron(II)
Authors: Yamamoto Yuroku , Tarumoto Tsunehiko , Tsubouchi Masahiro
Published: July 2006

Iodide was extracted from the aqueous phase into nitrobenzene in a wide pH range of 3–9 by use of tris(1,10-phenanthroline)iron(II) chelate cations and then determined spectrophotometrically at 516 mμ. Beer’s law was effective up to 8.0×105  m of iodide in the aqueous phase. Standard deviation of the determination was 1.1% at 15°C. The color intensity of the extracted species in nitrobenzene was constant for at least 3 hr. The distribution ratio was 1.02 at 15°C and 0.83 at 26°C. No serious interferences by foreign anions were observed except for perchlorate, chlorate, and thiocyanate. Cations did not essentially interfere with the determination.
Studies of 8-Mercaptoquinoline as Chelating Agents. I. Sodium Salt of 8-Mercaptoquinoline
Authors: Mido Yoshiyuki , Sekido Eiichi
Published: July 2006

The infrared spectra of the sodium salt of 8-mercaptoquinoline and its related compounds have been measured in the region between 4000 and 400 cm−1. Some substituent-sensitive bands have been investigated in order to find a clue to further infrared studies of its metal chelates. The thermal stabilities of the sodium salt have been examined by thermal gravimetric analysis and by differential thermal analysis. It has been shown that the sodium salt can be dried at temperatures between 100° and 200°C without any thermal change, and that, at ca. 210°C in air, the abrupt increase in weight of the sodium salt may be due to the absorption of oxygen. The effect of hydration on the sodium salt is discussed on the basis of results with regard to X-ray diffraction patterns, infrared spectra, and weights. The sodium salt is proposed to crystallize with two moles of water and to combine inequivalently with two waters of crystallization.
Studies of 8-Mercaptoquinoline as Chelate Agents. II. Infrared Absorption Spectra of its Divalent Metal Chelates
Authors: Mido Yoshiyuki , Sekido Eiichi
Published: July 2006

The infrared spectra of divalent metal thiooxinates have been measured in the region between 4000 and 400 cm−1, and the relationships between these spectral bands and the characteristics of the metal-ligand bonding and the structures of the thiooxinates have been discussed. The plots of the frequencies of the metal-sensitive bands around 990 and 670 cm−1 against the atomic weight of the metal make it possible to classify these metal thiooxinates into two groups, one of which includes Cu-, Co-, Ni-, and Mn-thiooxinate, and the other, Cd-, Zn-, and Pb-thiooxinate. The deviation of the point for Zn-thiooxinate from the line belonging to thiooxinates with such metal atoms as have no available d-orbitals has been compared with the case of oxinates. Moreover, from the appearance of the 450 cm−1 band in the latter group, the structure of these thiooxinates may be tetrahedral. As for the frequencies of the two metal-sensitive bands mentioned above, those of Pd- and Pt-thiooxinate are the highest and that of Ag(I)-thiooxinate, examined for the sake of comparison, is the lowest. The possibility of the analytical application of the metal-sensitive band around 670 cm−1 has been discussed.
The Infrared Spectra and Normal Coordinate Treatments of L3Sn-Mn(CO)5 (L=Cl, Br, CH3, and C6H5)
Authors: Onaka Satoru
Published: July 2006

The infrared absorption spectra (2200–60 cm−1) have been measured for four analogous compounds, Cl3Sn–Mn(CO)5, Br3Sn–Mn(CO)5, (CH3)3Sn–Mn(CO)5, and Ph3Sn–Mn(CO)5. Normal coordinate analysis has been made for three molecules-Cl3Sn–Mn(CO)5, Br3Sn–Mn(CO)5, and (CH3)3Sn–Mn(CO)5- on the basis of a modified Urey-Bradley force-field. The calculated frequencies attain close agreement with validly-assigned frequencies. The force constant, K(Sn–Mn), for each molecule varies with the substituent on the tin atom, and increases in the order of: K(Sn–Mn) of Cl3Sn–Mn(CO)5>K(Sn–Mn) of Br3Sn–Mn(CO)5>K(Sn–Mn) of (CH3)3Sn–Mn(CO)5. The vibrational eigenvectors reveal that the Sn–Mn stretching vibrational modes are considerably coupled with other vibrational modes, especially with CMnC deformation and axial MnC stretching modes.
Studies on Cobaloxime Compounds. VI. Decomposition of Formic Acid with Cobaloximes and Cobalamins
Authors: Hohokabe Yorikatsu , Yamazaki Noboru
Published: July 2006

Catalytic activities of cobaloximes in the decomposition reaction of formic acid were compared with each other and with those of cobalamins. In the cobalamin series, the activity decreased in the order aquocobalamin (vitamin B12a)>methylcobalamin>cyanocobalamin (vitamin B12). In the cobaloxime series, the activity decreased in the order Co(OH)(DH)2(H2O)>CoCl(DH)2(H2O)>Co(CN)(DH)2(H2O)>CH3Co(DH)2(H2O). Cobalamins had much greater activities than the corresponding cobaloximes. The reaction proceeded with uptake of oxygen. No hydrogen gas was evolved in the reaction. The reaction rate slightly decreased with the increase of pH between 6.0 and 7.0. The reaction rate changes with 0.39 power of formic acid concentration less than 1×103  m (comparable to that of cobaloxime), and becomes independent of the concentration greater than 1×103  m. It changed with 0.89 power of the concentration of hydroxoaquocobaloxime. Aquocobalamin was reduced to B12r in the presence of formic acid but not hydroxoaquocobaloxime in anaerobic conditions. The catalytic activities of cobaloximes lower than the corresponding cobalamins were attributed to the higher reduction potentials of the former.
The Separation and Concentration of Acetylacetonato Chelates Using a Benzene Column
Authors: Maruyama Kazuo , Mashima Micho
Published: July 2006

This paper is concerned with the application of the zone-melting technique to metal-chelate compounds. An organic solvent which is liquid at room temperature such as benzene, and several acetylacetonato and thenoyltrifluoroacetonato chelates as solutes were prepared. The effective distribution-coefficient k dependence on the molecular weight was revealed by the normal freezing technique. In the deployment process, the acetylacetonato chelates of Fe and Th were chosen as solutes because their k values were different. The experiment was carried out at 2 cm/hr, the rate of zone travel. When a 30-cm column was used, the “removal percentages” of Fe from Th were 41 and 85% for 3 and 5 zone passes respectively. However there was a 22% loss of Th in the latter case. Furthermore, a remarkable concentration was found, and it was shown that the concentration effect may be useful for micro-analysis. At this stage, a relatively large bubble of benzene was observed at the liquid and solid interface; therefore we can call this “three-phase zone-melting.”
Organic Photochemical Reactions. XIV. The Photocycloaddition of Acetone to Cyclooctene and 1,3-Cyclooctadiene
Authors: Shima Kensuke , Sakai Yoshiki , Sakurai Hiroshi
Published: July 2006

The photocycloaddition of acetone to cyclooctene (COE) or 1,3-cyclooctadiene (COD) yields isomeric cis-and trans-oxetanes in good yields. Kinetic studies of these reactions reveal that the photoaddition of acetone to COE proceeds via the attack of the triplet acetone on the ground state COE, while the addition to COD probably occurs by the attack of the excited singlet acetone on the ground state COD.
Pd(II) Complexes with 2,2′-Diaminobiphenyl
Authors: Onaka Satoru
Published: July 2006

The new palladium (II) complexes with 2,2′-diaminobiphenyl (DABP) have been synthesized under various conditions. The hexa-coordinated palladium complex, [Pd(DABP)2Cl2], has been prepared under a high pressure. The square planar diamagnetic complexes, [Pd(DABP)2]X2 (X=Cl, Br), have been synthesized under atmospheric pressure. As to the [Pd(DABP)2]Cl2 complexes, two isomers, the yellow complex and the yellow-green complex, are obtained according to the temperature at which the complexes are synthesized. Both the complexes, the yellow and the yellow-green complexes, are similar with respect to the powder X-ray diffraction pattern and the IR spectra in the region from 4000 cm−1 to 200 cm−1, but are somewhat different with respect to the stability to air, the thermal stability, and the solubility in chloroform.
Fourier Analysis of Alternating Current Polarography: Amplitude and Phase of Fundamental and Second Harmonic AC Polarographic Waves
Authors: Kojima Hiroyuki , Fujiwara Shizuo
Published: July 2006

The Fourier analysis of the instantaneous AC polarographic current was performed with a computer on-lined to a potentiostat. From the Fourier spectra, the amplitudes and phase angles of both the fundamental and the second harmonic AC polarographic waves were obtained. In the Cd(II) system, the current amplitude DC potential curves and phase angle-DC potential curves for the fundamental and the second harmonic AC polarographic waves were compared with the theoretical curves. The method is applicable to the accurate analysis of electrode reaction kinetics.
The Reaction of Nitriles with Phosgene. V. Cyclization Reactions of N-(α-Chlorobenzylidene)carbamoyl Chloride
Authors: Yanagida Shozo , Yokoe Masaaki , Ohoka Masataka , Komori Saburo
Published: July 2006

N-(α-Chlorobenzylidene)carbamoyl chloride (1) reacts with hydrazine hydrate to give 3-phenyl-1,2,4-triazolone (2), with sodium azide in the presence of water to give 5-phenyltetrazole (3), and with aliphatic nitriles in the presence of hydrogen chloride to give 6-chloro-2-phenyl-5-substituted-4(3H)-pyrimidones (5) and 4,6-dichloro-2-phenyl-5-substituted pyrimidines (6). However, the reaction of 1 with trichloroacetonitrile or pivalonitrile in the presence of hydrogen chloride did not give the expected triazines.
Photochemical Rearrangement of N-Substituted Benzylanilines
Authors: Ogata Yoshiro , Takagi Katsuhiko
Published: July 2006

Photochemical migration of an alkyl group from nitrogen to ortho and para positions in N-substituted benzylanilines (I) has been studied. Quenching study suggests that the rearrangement proceeds via a triplet state. The rate of disappearance of N-(p-tolyl)-α-phenethylamine (III) in photolysis was found to be 3×107–3×108sec−1. Substituted benzylanilines (I) were synthesized to estimate their quantum yields of photorearrangement. A plot of the σ value for a substituent in the migrating benzyl group vs. logarithm of relative rate gives a positive ρ value with various quantum yields for intersystem crossing (0.1–1); the ρ value indicates that electron-withdrawing substituents in the benzyl group accelerate the rearrangement. A reaction scheme is presented.
The Synthesis of 7-Isopropyl-2,4-dimethylazulene (Se-Guaiazulene) from 4-Isopropyltropolone
Authors: Nozoe Tetsuo , Takase Kahei , Fukuda Satoko
Published: July 2006

7-Isopropyl-2,4-dimethylazulene (Se-guaiazulene) (I) was synthesized from 4-isopropyl-7-methyltropolone (II), which had itself been derived from 4-isopropyltropolone. The tropolone, II, was then converted to 3-acetyl-5-isopropyl-8-methyl-2H-cyclohepta[b]furan-2-one (VI) via the p-tolylsulfonyloxytropone derivative derived from II. The application of the azulene synthesis to VI gave 3-cyano-7-isopropyl-2,4-dimethylazulene-1-carboxylic acid (VII), from which I was obtained by the removal of the carboxyl and cyano groups.
The Bromination of 2-Methoxytropone and Its Bromo Derivatives
Authors: Nozoe Tetsuo , Takase Kahei , Yasunami Masafumi
Published: July 2006

The reaction of 2-methoxytropone and its bromo derivatives with bromine was examined in various solvents. The treatment of 2-methoxytropone or 5-bromo-2-methoxytropone with bromine in methanol gave an addition product, 2,6-dibromo-7,7-dimethoxy- (II) or 2,4,6-tribromo-7,7-dimethoxy-2,4-cycloheptadien-1-one (XIV) respectively, together with the substitution products. On the contrary, the treatment of 2-methoxytropone with bromine in anhydrous ethanol, chloroform, or carbon tetrachloride gave a reddish complex compound. In aqueous ethanol or acetic acid, however, it gave 3,5,7-tribromotropolone. A possible reaction mechanism involving the nucleophilic attack of a methanol molecule on 2-methoxytropones at the 2-position is presented to account for the formation of the addition products.
Linear Conjugated Systems Bearing Aromatic Terminal Groups. IV. The Syntheses of Some Diarylacetylenes
Authors: Akiyama Shuzo , Nakasuji Kazuhiro , Nakagawa Masazumi
Published: July 2006

The syntheses of 1,1′-, 9,9′-, and 1,9′-dianthryl-, 2,2′-, 3,3′-, and 9,9′-diphenanthryl-, 1,1′-and 2,2′-dipyrenyl-, and 6,6′-dichrysenylacetylenes according to the pyrolytic reactions of the corresponding β-ketoalkylidenetriphenylphosphorane derivatives (intramolecular Wittig reaction) were described.
The Reaction of Dihalotetramethylbenzenes with Fuming Nitric Acid as a New Convenient Route to Some Dihalotrimethylbenzylic Compounds
Authors: Suzuki Hitomi , Nakamura Kiyomi , Takeshima Michiko
Published: July 2006

Products obtained by the nitration of three isomeric dichloro and dibromotetramethylbenzenes with fuming nitric acid have been investigated. 3,6-Dihalo-1,2,4,5-tetramethylbenzene (dihalodurene) gave mainly 3,6-dihalo-2,4,5-trimethylbenzyl nitrate or 1,2-bis(nitrooxymethyl)-3,6-dihalo-4,5-dimethylbenzene, depending on the reaction temperature and the amount of nitrating agent. 4,6-Dihalo-1,2,3,5-tetramethylbenzene (dihaloisodurene) yielded a mixture of 3,5-dihalo-2,4,6-trimethylbenzyl nitrate and 2,6-dihalo-3,4,5-trimethylbenzyl nitrate, the latter in somewhat greater amount. 5,6-Dihalo-1,2,3,4-tetramethylbenzene (dihaloprehnitene) gave 5,6-dihalo-2,3,4-trimethylbenzyl nitrate as the sole nitrooxylation product. The reaction affords a new convenient route to precursors of various polysubstituted benzylic compounds hitherto not easily obtained by ordinary methods. Physical properties of some dihalotrimethylbenzylic compounds (chloride, nitrate, acetate, alcohol, and bisbenzyl ether) have been recorded.
Nitration of Pentamethylnitrobenzene, Pentamethylbenzoic Acid and Its Methyl Ester, Pentamethylacetanilide, and Pentamethylphenol and Its Methyl Ether. Orienting Effect of the Substituents for the Side-chain Nitrooxylation
Authors: Suzuki Hitomi , Nakamura Kiyomi
Published: July 2006

The nitration of a series of the titled pentamethylbenzene derivatives has been investigated in order to know the orienting effect of substituent groups for the side-chain nitrooxylation. The nitrooxylation was found to occur almost exclusively at the methyl groups adjacent to the electron-withdrawing substituents (NO2, COOH, and COOCH3), while with the compounds containing electron-donating groups (OH and OCH3) the main reaction led to the conversion into cyclohexadienone, with the concomitant formation of small amounts of meta-nitrooxylated product. Pentamethylacetanilide underwent side-chain nitrooxylation along with some deacetylation. The location of the nitrooxymethyl group seems to be most likely ortho and meta, the latter being predominant.
An Acoustical Study of the Kinetics of Intermolecular Hydrogen Bonding and the Applicability of the Hammett Rule
Authors: Yasunaga Tatsuya , Nishikawa Sadakatsu , Tatsumoto Nobuhide
Published: July 2006

Rate and equilibrium constants for the hydrogen-bond dimerization of benzoic acid and meta- and parasubstituted compounds in N,N-dimethylformamide have been determined by the measurement of the ultrasonic absorption in the 15–95MHz frequency range at 20°C, and the Hammett rule for the rapid monomer-dimer reaction has been examined. The forward and backward rate constants are 0.67×108 sec−1 and 2.8×107 sec−1  m−1 for para-toluic acid, 0.90×108 sec−1 and 1.9×107 sec−1  m−1 for meta-toluic acid, 1.6×108 sec−1 and 1.5×107 sec−1  m−1 for benzoic acid, 2.1×108 sec−1 and 2.4×107 sec−1m−1 for para-chlorobenzoic acid, and 3.3×108sec−1 and 1.6×107 sec−1m−1 for metachlorobenzoic acid respectively. The forward and backward activation enthalpies for benzoic acid are 8.4 kcal/mol and 3.3kcal/mol respectively. Using the substituent constants in Jaffe’s table, the reaction constants in the Hammett rule are calculated to be 1.2 and −0.33 for the forward and backward reactions respectively.
Electronic Structures of Tris(2,2′-bipyridyl) Complexes of Transition Metals in Lower Oxidation States
Authors: Hanazaki Ichiro , Nagakura Saburo
Published: July 2006

The electronic structures of various transition metal complexes with 2,2′-bipyridyl in low oxidation states are studied theoretically by the composite system method. The results show that the excess electrons are not localized on the metal ion but are transferred to some extent to the ligand antibonding π-molecular orbitals with the lower oxidation states of complex ions. The present theory can explain reasonably and systematically the observed magnetic moments and ESR spectra of the complexes, the simple one-electron treatment being inappropriate for a theoretical explanation of their magnetic properties. According to the present treatment, their electronic absorption spectra can be explained satisfactorily from a qualitative point of view as the overlapping of the π–π* transition bands in the ligands with the metal-ligand charge-transfer transition bands.
Mixed Monolayers of Poly(methyl acrylate) and Its Saponified Polymer
Authors: Hironaka Seiichiro , Kubota Takashi , Meguro Kenjiro
Published: July 2006

A film balance study of the mixed monolayers with various ratios of poly(methyl acrylate) and its saponified polymer or of the monolayers themselves was carried out on distilled water, and the mixed monolayers were compared with individual monolayers of the saponified polymers. These mixed monolayers expanded more than individual saponified polymers at the same degree of saponification, giving larger limiting areas. Their limiting areas deviated from the linearity between the limiting area and the degree of saponification, in contrast to the fact that the limiting areas of individual monolayers decreased linearly with an increase in the degree of saponification. This fact can be considered to be due to interactions between the side chains of the ploymers.
CNDO Calculations of Electronic Structures and Spectra of Nonalternant Conjugated Hydrocarbons
Authors: Tajiri Akio , Ohmichi Naoto , Nakajima Takeshi
Published: July 2006

The energetically most favorable geometrical structures with respect to C–C bond-length variation of fundamental nonalternant conjugated hydrocarbons have been examined using CNDO/2 approximation with its original parameterization. It was found that all the molecules examined should exhibit a marked bond alternation, accompanied with a molecular-symmetry reduction in the case of pentalene and heptalene. The predicted molecular dipole moments are in good agreement with the available experimental values. The electronic spectra have been calculated using a modified version of the CNDO/2 method proposed by Del Bene and Jaffe, with a new parameterization. The results are found to be in good agreement with experiment.
Magnetic and Thermal Properties of Crystals Including Isolated Clusters. II. Heat Capacity of Co3(C5H5)3S2 from 15 to 270 K and Mechanism of Phase Transition
Authors: Sorai Michio , Kosaki Akio , Suga Hiroshi , Seki Syûzô , Yoshida Toshikatsu , Otsuka Sei
Published: July 2006

Heat capacity of Co3(C5H5)3S2 was measured between 15 and 270 K. A phase transition was discovered at 192.5±0.1 K with the transition enthalpy and the entropy of 5253.4 J mol−1 and 28.894 J K−1 mol−1, respectively. The transition entropy is well described as the sum of the configurational entropy of Rln8 due to cyclopentadienyl rings and the magnetic contribution of Rln4. The transition behavior is satisfactorily accounted for in the whole temperature region investigated in terms of the cooperative coupling between the orientational motion of the rings and the electronic states of a molecule on the basis of the Chesnut exciton model modified by the present authors. The model proposed here is to take both the temperature dependences of the energy parameters and the inversion of the spin state at higher temperatures into account. The measurements of infrared spectra and proton magnetic resonance were made as a function of temperature. These results are favorable to the present model. The electron spin resonance experiment also confirmed the present model.
The Formation Constants and Composition of Tetraethylenepentamineheptaacetato Nickel(II) Complexes measured by a Potentiometric Titration Method
Authors: Masuda Yoshitaka , Hirai Yukiko , Sekido Eiichi
Published: July 2006

Stability constants for nickel(II) complexes of tetraethylenepentamineheptaacetic acid (TPHA: H7L) were determined by the pH titration method. In an aqueous solution (μ=0.1) three uninuclear complex species, NiH2L, NiHL, and NiL, and a binuclear compound, Ni2L seem to exist. The structures of uni- and bi-nuclear chelates are discussed with their visible absorption spectra. Formation of the hydroxo complex was not observed on the titration curves. In the present investigation no evidence was found for species of Ni2HL either. The formation constants of the complexes stated above have been calculated as follows, (at 25±0.1°C). logKML=16.18, logKMHL=10.00, logKMH2L=6.16, logKM2L=17.35 and logKML2=27.78.
Polarographic Study of the Rates of the Dissociation Reactions of the Cobalt(II)-Acetylacetonate Complex and of the Nickel(II)-Acetylacetonate, -Glutamate, -Aspartate, and -Iminodiacetate Complexes
Authors: Kodama Mutsuo , Nunokawa Hisao , Oyama Noboru
Published: July 2006

The cobalt(II)-acetylacetonate complex and the nickel(II)-acetylacetonate, -glutamate, -aspartate and -iminodiacetate complexes were found to give kinetic waves due to the dissociation of these complexes at the electrode surface preceding the electron-transfer step. From the experimental examination of the nature of the kinetic current and a theoretical consideration, the mechanism and the rate constants of the dissociation of these complexes at the mercury-electrode surface were determined. The dissociation reactions were found to proceed through the following mechanism:

MX22−m\ightleftharpoonsMX2−m+Xm− rapid

MX2−m\oversetkd\ightleftharpoonsM2++Xm− slow

M++2e−+Hg=M(Hg)

The rate constants, kd′s, for the dissociation reactions of cobalt(II)-acetylacetonate complex and of nickel(II)-acetylacetonate, -glutamate, -aspartate, and-iminodiacetate complexes at 25°C were estimated to be 9.30, 0.56, 0.69, 1.21×10−2, and 2.5×10−4 sec−1 respectively. From a comparison of the rate constants, the dissociation of nickel(II)-aminopolycarboxylate complexes was concluded to proceed invariably through a reaction intermediate in which the leaving aminopolycarboxylate anions is bonded to the nickel(II) ion through one nitrogen and one oxygen atoms (Glycinate intermediate). In the formation reactions of cobalt(II)- and nickel(II)-acetylacetonate complexes in a 1:1 ratio, the dissociation of coordinated water from the metal(II) ion is rate-determining (water-loss mechanism).
Mixed-ligand Complexes of Copper(II). I. An ESR Study of Coordination Bonding
Authors: Yokoi Hiroshi , Otagiri Masaki , Isobe Taro
Published: July 2006

The sample solutions were prepared by mixing equal volumes of any two of the 1.00×10−2 mol/l solutions of the 1:2 complexes of copper(II) with ethylenediamine, N,N-dimethylethylenediamine, N,N-diethylethylenediamine, 1,3-diaminopropane, l-alanine, l-serine, N,N-diethylglycine, and β-alanine, where an equivolume mixture of water and methanol was used as the solvent. The X-band ESR measurements for these sample solutions were carried out at the temperature of liquid nitrogen. The observed ESR line shapes showed that only the mixed-ligand complexes are formed almost quantitatively in all the solutions except two: equivolume mixtures of the two complex solutions of ethylenediamine and β-alanine and those of ethylenediamine and N,N-dimethylglycine, in which the coexistence of two or more complex species was clearly demonstrated. The ESR line shapes and, furthermore, the intensities of the visible absorption indicated that the symmetry of the ligand field of the mixed-ligand complexes is as axial as that of the parent complexes. The ESR experimental results showed that the g⁄⁄ value of a mixed-ligand complex almost equals the mean of the g⁄⁄ values of its two parent complexes, but that there is not such a clear correlation between their A⁄⁄ values. It was interestingly concluded from the determined g values that the covalency of the metal-ligand bonds of a mixed-ligand complex are intermediate in degree between those of its two parent complexes.
Mixed-ligand Complexes of Copper(II). II. A Study of Dismutation Constants
Authors: Yokoi Hiroshi , Otagiri Masaki , Isobe Taro
Published: July 2006

The dismutation constants for mixed-ligand complexes of copper(II) involving, as bidentate ligands, ethylenediamine, l-alanine, β-alanine, and N,N-dimethylglycine were determined at two or three temperatures by both the spectrophotometric and ESR methods, and the thermodynamic constants were then derived from those data. It was found for these systems that the entropy change plays a main role in governing the equilibrium between a mixed-ligand complex and its parent complexes, and that the differences in the dismutation constants among the mixed-ligand complexes are due to the small but different values of the enthalpy term.
Stability Constants of Alkaline Earth Metals with o-Arsono-o′-hydroxy Azo Compounds
Authors: Kina Kenyu , Tôei Kyoji
Published: July 2006

The acid dissociation constants of the o-arsono-o′-hydroxy azo compounds, and their chelate stability constants with alkaline earth metals, have been measured by the pH titration method at an ionic strength of 0.10 and at 25.0±0.1°C. These azo compounds were synthesized by the coupling reaction of diazotized o-aminophenylarsonic acid with naphthol sulfonates. As the coupling components, 1,8-dihydroxynaphthalene-3,6-disulfonic acid (chromotropic acid), 2-hydroxynaphthalene-3,6-disulfonic acid (R acid), and 1-hydroxynaphthalene-3,6-disulfonic acid were used. o-Arsonophenylazochromotropic acid (Neo-Thorin) formed the most stable chelates. It was concluded that the stabilization of the metal chelate ring of the Neo-Thorin was due to a quasi-aromaticity of the six-membered ring which was produced by the hydrogen bond between two naphtholic hydroxyl groups of chromotropic acid. The metal chelate stability order, Mg>Ca>Sr>Ba, is parallel to the reciprocal of the ionic radii of the metal ions.
Analytical Study of the Lead Ion-selective Ceramic Membrane Electrode
Authors: Hirata Hiroshi , Higashiyama Kenji
Published: July 2006

The lead(II) ion-selective ceramic membrane electrode developed by sintering a mixture of lead, silver, and cuprous sulfides showed sensitivity, selectivity, and other response characteristics well suited to analytical utilization. The Nernstian slope was obtained over a concentration range from 10−1 to 10−6m Pb2+ in activity, and the analytical range had a concentration of 10−1–10−7m when the membrane contained less than 30 wt% of cuprous sulfide and more than 1 wt% of lead sulfide. Among the common ions, silver, cupric, mercury(II), ferric, sulfide and iodide ions interfered seriously. About 10 times as many cadmium and bromide ions and more than 1000 times as many alkali metal, alkaline earth metal, zinc, aluminum, nickel, manganese(II), cobalt, and nitrate ions did not interfere with the lead ion, however. The electrode potentials did not change over a pH range from 2 to the pH at which the precipitation of lead hydroxide occurred. The electrode was safely used at temperatures from 0 to 95°C, and the potentials of the membrane satisfied the Nernstian equation within the limits of experimental error. The membrane electrode responded to activity changes very quickly: the rate of those changes was twice that in a lead sulfide-silver sulfide two-component ceramic electrode. A continuous potential measurement for 5 months promised long-term stability and accuracy. The rapid response rate and the long lifetime suggest that the continuous monitoring of some changing systems is feasible.
Functional Group Analysis by Gas Chromatography. IV. Pyrolytic Reaction of Carboxylic Acids in Sulfur Vapor
Authors: Hara Tadashi , Ito Susumu
Published: July 2006

This paper deals with a quantitative gas chromatographic analysis of the product evolved by the pyrolytic reaction between carboxylic acid and sulfur vapor. About 10 mg of carboxylic acid was mixed with 2–3 g sulfur and made to react at 1000–1100°C for 10min. The gaseous product was taken in a gas sampler and subjected to gas chromatography. Carbon dioxide was produced from the carboxyl group, carbon disulfide from carbon, hydrogen sulfide from hydrogen and nitrogen molecule from nitrogen. The peak area ratios of carbon disulfide and hydrogen sulfide to carbon dioxide were found in the gas chromatogram with glycine as a standard substance, and the other carboxylic acids were analyzed on the basis of the relation between the peak area ratio and the chemical composition of glycine. Aliphatic and aromatic carboxylic acids gave satisfactory resuls by this method, but not pyridine carboxylic acid. Weighing a definite amount of sample is not needed in this method. Information concerning the chemical composition as well as the functional group of a carboxylic acid can be obtained.
Aromatic Bromination by the Use of Organic and Inorganic Thallium Salts
Authors: Uemura Sakae , Sohma Kazuhiro , Okano Masaya , Ichikawa Katsuhiko
Published: July 2006

Using organic and inorganic Tl salts, the following aromatic brominations were carried out in a CCl4 or HOAc solvent and were found to occur very smoothly; (A) aromatic bromination with TlBr3·4H2O, (B) aromatic bromination with Br2 in the presence of Tl(III) and Tl(I) salts, and (C) the bromination of arylthallium(III) compounds. From a study of the relative rates and selectivities of benzene and toluene, it was deduced that an arylthallium(III) compound was not involved as an intermediate in the A and B reactions, that Tl(III) salts were more effective catalysts than Tl(I) salts for the B bromination, and that the A reaction was essentially identical with the B reaction with the TlBr3·4H2O catalyst. By considering the difference in the catalytic behavior of Tl(III) and Tl(I) salts in the B reaction, probable mechanisms are suggested.
A New Rearrangement Reaction of Azoxybenzene with Arenesulfonyl Chloride
Authors: Oae Shigeru , Maeda Tetsuya , Kozuka Seizi , Nakai Mamoru
Published: July 2006

Azoxybenzene was found to react with arenesulfonyl chloride to afford o- or p-arenesulfonyloxyazobenzene. This new rearrangement reaction is found in various substituted azoxybenzenes and arenesulfonyl chlorides. By the use of the 18O tracer technique, the ortho rearrangement was found to proceed via an intramolecular path, while the rearrangement to the para position was intermolecular. The yields of the rearranged products were determined by the isotopic dilution technique, while the migratory aptitude was also determined by the use of azoxybenzene-1-14C. It was found that the ratio of the sulfonyloxy migration to the phenyl ring attached to the azoxy side to that of the azo side is 1 to 2 for the ortho rearrangement. On the bases of these observations, the mechanism of this new rearrangement reaction is discussed.
Studies of Azo Colors. VIII. The Azo-coupling Reactions of Active Methylene Compounds
Authors: Hashida Y\={o}ji , Kobayashi Morio , Matsui Kohji
Published: July 2006

The kinetics of the azo-coupling reactions of various active methylene compounds with diazobenzene-4-sulfonic acid have been studied spectrophotometrically. In the reactions of all the active methylene compounds used, it was found that the reaction rate was proportional to both the concentration of the diazonium salt and the carbanion (or enolate ion) of the azo component. In the reactions of a series of β-dicarbonyl compounds, a plot of the logarithms of the rate constants against the pKa values of active methylene compounds gave a straight line. However, the correlation between the reactivity and pKa was found unsatisfactory in the case of active methylene compounds with such electron-withdrawing substituents as NO2, CN, COR, SO2R, and Cl. These results are discussed in terms of the nucleophilicity of these carbanions.
Thermal Decomposition of Benzoyl p-Toluenesulfonyl Peroxide
Authors: Hisada Ryuki , Minato Hiroshi , Kobayashi Michio
Published: July 2006

Benzoyl p-toluenesulfonyl peroxide (BTP) was synthesized by addition of barium hydroxide and water to a mixture of p-toluenesulfonyl chloride and peroxybenzoic acid in dichloromethane at −15°C. Rates of decomposition of BTP in inert solvents increased rapidly as the decomposition proceeded. This autocatalysis was prevented and the reaction followed a first-order rate equation when magnesium oxide suspension was present in the medium for removal of p-toluenesulfonic acid produced by the decomposition. The products of decomposition were analyzed. When magnesium oxide suspension was present, main products were those ascribable to homolysis (biphenyl, 44mol%, in benzene; chlorobenzene, 44 mol%, hexachloroethane, 27 mol%, in carbon tetrachloride), but products ascribable to ionic reactions were also present (phenyl p-toluenesulfonyl carbonate, 22–26mol%).
Conformation of α-Aminobutyric Acid in Aqueous Solution
Authors: Akimoto Toshio , Tsuboi Masamichi , Kainosho Masatsune , Tamura Fumihide , Nakamura Asao , Muraishi Shuichi , Kajiura Teruo
Published: July 2006

Raman spectrum of α-aminobutyric acid has been observed in its 15% aqueous solution (neutral). By comparing it with the Raman and infrared spectra of crystal A (in which 40% of the total molecules are the T-form molecules, 36% Ga-, and 24% Gb-form molecules), crystal B (which consists only of T-form molecules), and a complex crystal of this amino acid with calcium chloride (in which 85% are the Ga-form molecules), it has been shown that the Ga-form molecules are predominant in the aqueous solution. Here, T-, Ga-, and Gb-forms have respectively the amino group, the hydrogen atom, and the carboxy group in the position trans to the methyl group in the internal rotation around the Cα-Cβ bond. Proton magnetic resonance spectrum was observed of a Cγ-deuterated product (CD3CH2CH NH3+COO−) in its aqueous solution at several temperatures in the −1.5 to 91°C range. It has been indicated that the Ca-form is more stable by about 300 cal/mole than the other two forms.
Catalytic Oxidation over Molecular Sieves Ion-exchanged with Transition Metal Ions. IV. The Oxidative Dehydrogenation of Cyclohexane
Authors: Mochida Isao , Jitsumatsu Tetsuji , Kato Akio , Seiyama Tetsuro
Published: July 2006

The oxidative dehydrogenation of cyclohexane over molecular sieves ion-exchanged with cupric ion (Cu(II)–Y) was investigated by means of an ordinary flow reactor with a reactant gas composed of 1.0% cyclohexane, 50% oxygen, and 49% nitrogen. The reaction was studied at temperatures between 210–350°C; here, carbon dioxide and benzene were the main products. The Cu(II)–Y was found to be a very active catalyst for the oxidation of cyclohexane as well as for that of olefins, in comparison with an ordinary cupric oxide catalyst supported on silica gel; the selectivity for benzene formation was as high as 80% below 10% conversion. Both products were found to be formed in competitive reactions. The catalytic activities were also studied on molecular sieves ion-exchanged with other transition metal ions, such as palladium (II), silver (I), and zinc (II). The relations between the catalytic activities and the heats of formation of the corresponding metal oxides per g-atom oxygen were examined; volcano-shaped correlations were observed for both benzene and carbon-dioxide formations for these catalysts. The most active catalyst was Cu(II)–Y for benzene formation, whereas it was Pd (II)–Y for the carbon dioxide formation. The meaning of the correlations was discussed according to Balandin’s explanation, based on thermochemistry, although no satisfying explanation was found. The compensation effects were observed between the activation energies and the frequency factors in these oxidations.