bluuebunny/crossref_metadata_2025 huggingface dataset:
The Dianion of 9,9′-Bixanthenylidene and Its Reaction with Oxygen. A Contribution to Photochromism
Authors: Hoshino Mikio , Matsui Masao , Imamura Masashi
Published: July 2006

The anion produced by the reduction of 9,9′-bixanthenylidene with sodium or potassium metal was identified with the dianion by pulse radiolysis. It appears that the dianion is twisted around the central ethylenic bond. The dianion reacts with oxygen at 100 K to produce a colored form, the spectrum of which is in accord with that of the transient species observed in the flash photolysis of 9,9′-bixanthenylidene. The colored form is expected to be produced via a twisted 9,9′-bixanthenylidene, because the oxygen is considered to remove electrons from the twisted dianion. This twisted intermediate may also participate in the photochromic or thermochromic reaction in which the same-colored form is produced.
Calorimetric Study of Glassy State. IX. Thermodynamic Properties of Stannous Chloride Dihydrate and Dideuterate Crystals
Authors: Matsuo Takasuke , Oguni Masaharu , Suga Hiroshi , Seki S\^{y}uzô , Nagle Johan F
Published: July 2006

The heat capacity of SnCl2·2H2O and SnCl2·2D2O crystals, substances with layer structure, was measured from 13 to 300 K. Anomalies due to ordering of the hydrogen (deuterium) position were observed at TC(H2O)=217.94 K and at Tc(D2O)=234.47±0.05 K. The total entropy change of the transition was estimated to be 4.6 J K−1 mol−1 for both compounds. An exact calculation of the high temperature entropy based on the two-dimensional lattice model gave 3.13 J K−1 mol−1. The critical indices α± of the divergent heat capacity anomalies are as follows: α+(H2O)=0.53, α−H2O)=0.48, α+(D2O)=0.57, α−(D2O)=0.54. Another heat capacity anomaly was found at 140–160 K where the heat capacity values depended on the thermal history of the specimen. The enthalpy relaxation observed at the temperature region was analysed by use of the first-order rate equation, giving the activation enthalpies ΔHa(H2O)=49.9 kJ mol−1 and ΔHa(D2O)=49.8 kJ mol−1. The concept of long-range-ordered glassy state was introduced for description of the non-equilibrium state of the present substances below 140 K. A general consideration of the relation between molecular relaxation and phase change in terms of the Deborah number is presented.
The Molecular and Crystal Structure of the Cyclic Tetramer of Formaldehyde, 1,3,5,7-Tetroxocane
Authors: Chatani Yozo , Yamauchi Tadafumi , Miyake Yasuhiko
Published: July 2006

The crystal structure of the cyclic tetramer of formaldehyde, 1,3,5,7-tetroxocane, has been determined by the X-ray diffraction method. The unit cell is monoclinic, with a=11.455, b=4.160, c=12.232 Å, and β=108.4°. The space group is C2/c, and there are four molecules per unit cell. The structure was solved by using a molecular transform method and was refined by the block-diagonal least-squares method to a final R factor of 0.051, using 728 reflections measured with an automated four-circle diffractometer. The molecules in the crystal are of the so-called crown form, with an approximate C4v symmetry but an exact C2 symmetry. The torsion angles about the four independent C–O bonds appear in two distinguishable values: two bonds with 83.7 and −83.6°, and the other two bonds with 93.6 and −94.1°. The average C–O bond length is 1.403 Å, while the average C–O–C and O–C–O bond angles are 116.6 and 113.8° respectively. The deformation from a regular crown form by taking the two distinguishable torsion angles and the increase in bond angles is favorable to compensating for the intramolecular H···H repulsions; the close H···H distances in the deformed crown form are 2.16 and 2.20 Å.
A New Method for Determination of Self-diffusion Coefficients in Solid Solutions
Authors: Kurihara Seiichi , Fueki Kazuo , Mukaibo Takashi
Published: July 2006

A new method for obtaining the self-diffusion coefficients of A in the AY–BY solid solution has been proposed. In this method, the tracer diffusion of A* and the interdiffusion between AY and BY are carried out simultaneously, and the self-diffusion coefficients are determined as a function of composition over the whole range of composition in a similar way as the Boltzmann-Matano analysis. Since this method employs a diffusion couple consisting of single crystals of AY and BY, one can avoid troubles and errors due to segregation and/or phase separation which are often encountered in experiments using solid solutions as specimens. In order to confirm the validity of the proposed method, Dcl* in the TlCl–TlBr system and DAg* and DNa* in the AgBr–NaBr system have been determined at 400 °C by this method and compared with the results obtained by the conventional method. A good agreement has been found between them.
The Triplet States of 1,3,5-Tricyanobenzene Complexes with Methyl Substituted Benzenes
Authors: Matsumoto Satoru , Nagakura Saburo , Shimozato Yasuyuki , Hayashi Hisaharu , Nakamura Junko
Published: July 2006

Triplet-triplet absorption, phosphorescence, and ESR spectra have been measured on the 1,3,5-tricyanobenzene complexes with toluene, mesitylene, durene, and hexamethylbenzene. Four triplet-triplet absorption bands were commonly observed in the wave number region of 10000–30000 cm−1 for all the complexes. The observed phosphorescence and T-T absorption spectra could be understood systematically by considering the interaction among zero-order charge-transfer triplet states and zero-order locally (within the acceptor) excited triplet states. From an analysis of the zero-field splitting values obtained from the observed ESR spectra, the contribution of the zero-order charge-transfer triplet state to the lowest triplet state was determined to be 76,65,25, and 9% for the 1,3,5-tricyanobenzene complexes with hexamethylbenzene, durene, mesitylene, and toluene, respectively. From the consideration on the results obtained for various polycyanobenzene complexes, the phosphorescence lifetime was found to decrease remarkably for the complexes with the charge-transfer character higher than 50% in their lowest triplet states.
Metachromasy. II. Interaction between Sodium Polyphosphates and Crystal Violet with Special Emphasis on the Effect of Chain Lengths of the Polymer on the Metachromasy Band
Authors: Yamaoka Kiwamu , Takatsuki Mineo , Yaguchi Kunio , Miura Masaji
Published: July 2006

The interaction of crystal violet with sodium polyphosphate in aqueous solutions at neutral pH has been investigated by means of visible absorption spectroscopy and electric conductivity. The mixing ratio of polymer residue to dye was varied from 0.1 to 10000. The metachromasy band at 506 nm was found to fully develop between 3 and 10, whereas conductometric titration showed that crystal violet saturates the polymer site. Emphasis was placed on the effect of the polymer chain length on the metachromasy band. To study this effect, 17 fractionated and 13 refractionated polymer samples with degrees of polymerization extending from 4 to 300 were utilized. A critical range of the degree of polymerization from the metachromasy band exists between 7 and 20. The effect of small ions on metachromasy was also studied using sodium phosphates. An increase in Na+ ions tends to suppress the metachromasy band. This effect is more pronounced with shorter polymer lengths. In order to explain the observed metachromasy phenomena, two mechanisms were postulated; one attributes metachromasy to the flexibility of the polymer backbone when dye is present, and the other deals with specific interaction of dye and polymer site.
Dielectric Relaxation and Molecular Structure. X. Dielectric Behavior of 2-Propanol, 2-Methylpropanol, and 2-Butanol in a Variety of Solvents
Authors: Koshii Taro , Arie Eiji , Nakamura Masahiko , Takahashi Hiroaki , Higasi Keniti
Published: July 2006

The dielectric constants and losses of 2-propanol and its mixtures with benzene, chlorobenzene, 1,4-dioxane or pyridine and 2-methylpropanol or 2-butanol and their mixtures with benzene or pyridine have been measured in the frequency range of 0.35–2.1 GHz at 25.0 °C. Concentrations of alcohols are 1–0.6 mol fractions of the mixtures. The principal relaxation times and the Kirkwood correlation factor g were evaluated. Variation of the principal relaxation times against the concentrations of these branched alcohol mixtures is not much different from that of normal alcohol mixtures. The g factor decreases almost monotonously with increasing amount of solvent exception being found in case for propanol–benzene mixtures.
Vibrational Structures in the He(I) Photoelectron Spectra of Carboxylic Acids
Authors: Watanabe Iwao , Yokoyama Yu , Ikeda Shigero
Published: July 2006

The first and the second bands of the photoelectron spectra of acetic, propionic, and isobutyric acids were recorded, and the vibrational structures in the spectra were studied by comparing with the results of formic acid. The first band exhibits a νc=o, a δOH, and a ρCOOH vibrational progression, and this implies that an oxygen lone pair orbital, from which the first band of the spectra originates, contributes not only to a C=O bonding and the bonding between carbonyl oxygen and hydroxyl hydrogen, but to the settling of carboxyl group in the molecular plane. The second band exhibits a νc=o, a νc-o vibrational progression with very high frequency for the νc=o as observed in the case of formic acid. Thus the vibrational features of the second band are consistent with the ionization of an antisymmetric π orbital localized mainly on carbonyl and hydroxyl oxygen atoms. Since the 0-0 vibrational transitions for the second ionization are out of the Franck-Condon region, the second adiabatic ionization potential was estimated by comparing the vibrational fine structures of the spectra with that of formic acid. The second adiabatic ionization potential of acetic acid so determined is 11.63 eV.
Molecular Structure of Formamide as Studied by Gas Electron Diffraction
Authors: Kitano Mitsuo , Kuchitsu Kozo
Published: July 2006

The structure of formamide HCONH2 has been determined by gas electron diffraction. The rotational constants determined in previous microwave studies have also been used for determining the hydrogen parameters. From a joint least-squares analysis of the diffraction intensity and the rotational constants, where the out-of-plane vibrations are treated as finite-amplitude motions in the corrections for vibrational effects, the following rg bond distances and rz angles have been derived: C–N=1.368±0.003 Å, C=O=1.212±0.003 Å, ∠N–C=O=125.0±0.4°, N–H(average)=1.027±0.006Å, C–H=1.125±0.012 Å, ∠C–N–H(cis to C=O)=118.7±1.0°C, and ∠C–N–H (trans to C=O)=119.7±1.0°, where the uncertainties represent estimated limits of experimental error. The C–N bond is about 0.07 Å longer, whereas the C=O bond is about 0.04 Å shorter, in the free molecule than in the crystal studied by X-ray diffraction. The C–N and C=O bonds are about 0.01 Å or more shorter, and the N–C=O angle is about 3°C larger than the corresponding parameters in acetamide and N-methylacetamide.
Some Electrophilic Substitution Reactions of 2-Hydroxyazulene Derivatives
Authors: Nozoe Tetsuo , Asao Toyonobu , Oda Masaji
Published: July 2006

The bromination, chlorination, and nitration of 1,3-disubstituted 2-hydroxyazulenes were investigated. Bromination by bromine or NBS afforded 1-bromoazulan-2-one derivatives as kinetically-controlled products and 6-bromo-2-hydroxyazulene derivatives as thermodynamically-controlled products. Ghlorination by NCS gave 1-chloroazulan-2-one derivatives, while that by chlorine afforded further chlorine addition products. Nitration afforded a mixture of 1-nitroazulan-2-one and 6-nitro-2-hydroxyazulene derivatives. The ultraviolet, infrared, and NMR spectra of the products were discussed.
Studies of Peptide Antibiotics. XXX. Syntheses of Gramicidin S Analogs Containing N-Methylleucine in Place of Leucine
Authors: Sugano Hiroshi , Abe Hayao , Miyoshi Muneji , Kato Tetsuo , Izumiya Nobuo
Published: July 2006

Two analogs of gramicidin S, cyclo(–Val–Orn–Leu–d-Phe–Pro–Val–Orn–MeLeu–d-Phe–Pro–), i.e., [3-N-Methylleucine]–gramicidin S, and cyclo(–Val–Orn–MeLeu–d-Phe–Pro–Val–Orn–MeLeu–d-Phe–Pro–), i.e., [3,3′-di-N-Methylleucine]–gramicidin S, were prepared in an attempt to investigate the contribution of the NH group of the leucine residue with regard to antibacterial activity. These analogs were almost as active as gramicidin S in the antibacterial test in reaction to microorganisms. The optical rotatory dispersions of these two analogs and of gramicidin S were measured in solvents of ethanol and 8 M aqueous urea. These studies suggested that both of the analogs containing N-methylleucine have a molecular conformation very similar to that of gramicidin S, and that the NH group of the leucine residues is not necessary for stabilizing the conformation in order to exhibit the biological properties.
Effect of Pressure on the Rate of Solvolysis. Formolysis of 1-(p-Substituted benzyl)ethyl Tosylates
Authors: Sera Akira , Yamagami Chisako , Maruyama Kazuhiro
Published: July 2006

The effect of pressure on the formolysis of 1-(P-substituted benzyl) ethyl tosylates was investigated, and the activation volumes, ΔVo\eweq were estimated. The apparent values of activation volume were found to correlate nicely with σ*. Because the present substrates were believed to be formolyzed through two separate processes, anchimerically assisted (kΔ) and unassisted (ks), the apparent values of activation volume were partitioned into the corresponding activation volumes, ΔVΔ\eweq and ΔVs\eweq. The dependence of ΔVΔ\eweq and ΔVs\eweq on the substituents was examined, and the correlation between the mechanisms of solvolysis and ΔVΔ\eweq and ΔVs\eweq was discussed.
Carbon-13 Nuclear Magnetic Resonance Studies of Biphenyl Derivatives II. FT–NMR of Halobiphenyls
Authors: Imanari Mamoru , Kohno Masahiro , Ohuchi Muneki , Ishizu Kazuhiko
Published: July 2006

The natural-abundance 13C NMR spectra of the ortho- or the para-halobiphenyls were obtained by the pulse Fourier transform NMR (FT-NMR). For the para-derivatives, the observed chemical shifts of the C1 C2, and C3-positions gave an excellent linear dependence on the electronegativity of the substituents. The dependence for the C4-position, which showed a deviation from the linear plot, may be due to the heavy atom effects. The additivity of the chemical shifts holds also for the ortho-derivatives except for the cases of the bridgehead carbons, the C1 and C1′-positions. In particular, the observed chemical shifts of the C2, C3, and C4 positions for 2,2′,6,6′-tetrachlorobiphenyl showed a good agreement with the predicted values, whereas a large discrepancy can be seen between the observed and the assumed values for the C1 and C1′ positions. The effects on the chemical shifts due to the steric hindrance are discussed by comparison with the results of the hindered alkylbiphenyls. The temperature dependence of the spin-lattice relaxation time was investigated for 4,4′- and 2,2′-dichlorobiphenyls. The activation energies of the molecular reorientation are negligibly small at the C1 and C4-positions for the para-derivative, but the ortho-derivatives have higher values at these positions, indicating anisotropy for the molecular motion.
The Effect of Copper(II) on the Formation and Thermal Change of Synthetic β-FeOOH
Authors: Inouye Katsuya , Imamura Hiroyuki , Kaneko Katsumi , Ishikawa Tatsuo
Published: July 2006

The effect of Cu(II) added to β-FeOOH in various ratios up to 6% Cu/Fe was examined by X-ray diffraction, electron microscope, BET surface area, DTA, TGA and chemical analyses. Differing from other cases reported previously, Cu(II) showed no effect, but thermal changes of the Cu-doped samples indicated a reinforcement of bonding by Cu.
Studies on Preparation of High Purity Sulfur. II. Removal of Trace Amounts of Selenium and Tellurium in Sulfur by Means of Distillation with Silver
Authors: Suzuki Hiroshi , Osumi Yasuaki , Nakane Masanori , Miyake Yoshizo
Published: July 2006

In the distillation without silver, most of the selenium and tellurium in crude sulfur appeared in the distillate. However, these impurities were removed by distillation using a column which was filled with silver and heated at 600–700 °C. The removal of them in the process was confirmed in a tracer experiment.
Resonance Raman Spectra of Acid-Base Indicators. I. p-Aminoazobenzene Derivatives
Authors: Machida Katsunosuke , Kim Bak-Kwang , Saito Yutaka , Igarashi Kyoko , Uno Toyozo
Published: July 2006

Resonance Raman spectra between 1800 and 1000 cm−1 of methyl orange and a few other p-aminoazobenzene-type acid-base indicators have been investigated at various pH, and a marked spectral change has been observed on the transformation between the acid and the base forms of these indicators. The characteristic Raman frequencies have been assigned by referring to the spectra of related compounds and the deuteration effects. The spectra of the acid form are well elucidated on the basis of the quinoid-type structure.
The Relative Determination of the Soret Coefficients of Electrolytes. IV
Authors: Ikeda Toshio , Yamamoto Yasuki
Published: July 2006

The relative values of the Soret coefficients of 0.01 M aqueous solutions of symmetric tetraalkylammonium chlorides (R4NCl, R=Me, Et, n-Pr, n-Bu, and n-Am) were determined by measuring the initial thermoelectric power of “combined thermocells” made up of AgCl electrode systems, taking LiCl as a reference. The results obtained were found to be rather high, higher by about 20% than those previously found on the combined thermocells made up of calomel-electrode systems.
Dielectric Relaxation and Molecular Structure. VIII. Dielectric Relaxation of Alkyl Acetates in Benzene Solution
Authors: Koga Yoshinori , Takahashi Hiroaki , Higasi Keniti
Published: July 2006

Dielectric constants and losses at the microwave frequency of 96.52 GHz have been measured at 25°C for methyl, ethyl, n-butyl, isobutyl, s-butyl, t-butyl, n-amyl, isoamyl, n-hexyl, and n-octyl acetates in benzene solutions. Static dielectric constants, refractive indices and densities have also been measured. The effective mean relaxation times of normal alkyl acetates increase with increasing chain length of the alkyl radical, eventually approaching a steady value. The distribution parameters α of all these molecules seem to have appreciable values which may be due to various segment orientations by internal rotation.
Thermal Decomposition Reaction of Halogenoammineruthenium(III) Halide Complexes
Authors: Ohyoshi Akira , Hiraki Shunichi , Kawasaki Hideo
Published: July 2006

The thermal decomposition of halogenopentaammine- and cis-dmalogenotetraammineruthenium(III) complexes was studied by the techniques of thermogravimetry(TG), differential thermal analysis(DTA), and evolved gas analysis (EGA). The stoichiometry of the decomposition reaction was determined by the analysis of the reaction intermediates and products. The order of decreasing thermal stability, as well as order of temperature of massloss initiation, seems to be: [RuCl(NH3)5]Cl2>[RuBr(NH3)5]Br2>[RuI(NH3)5]I2 for monohalogeno complexes, and cis-[RuCl2(NH3)4]Cl>cis-[RuBr2(NH3)4]Br>cis-[RuI2(NH3)4]I for dihalogeno complexes. Trihalogenotriammine complexes were observed as intermediates for the cases of dichloro and bromo complexes, a simple decomposition reaction was found for the iodo complexes, and then the activation energy for the following reaction was determined: [RuI(NH3)5]I2→RuI3+5NH3, Ea=41.9 kcal/mol and cis-[RuI2(NH3)4]I→RuI3+4NH3, Ea=27.8 kcal/mol. The reaction mechanisms may be summarized as follows: (a) an electron-transfer mechanism, in which the ruthenium(III) was reduced by the ammonia molecule or the halide ion, (b) the thermal splitting of the ruthenium-ammine bond, and (c) the bond formation between the ruthenium(III) and the halide ion after the ion migration from the outersphere to the innersphere of the complex. The predominant factors which control these mechanisms may be the coordinate bond strength of the ruthenium(III) and various ligand species, the relative potential of electron transfer from the ligand to the ruthenium(III), and the ease of halide-ion migration from the outersphere to the innersphere of the complex.
Kinetic Studies of the Electron Transfer Reaction in Iron(II) and Iron(III) Systems. VI. Reaction in N,N-Dimethylformamide
Authors: Wada Goro , Sahira Yoshiko , Ohsaki Kyoko , Shinoda Fusako
Published: July 2006

The electron transfer reaction between Fe(II) and Fe(III) in N,N-dimethylformamide (DMF) was found to be influenced by the presence of perchloric acid, chloride ion, and water in the reaction system. This suggests that the reaction involves chemical species such as partially hydrated iron, its deprotonated iron, and FeCl2+ and FeCl2+. The individual rate constants in DMF, containing a small amount of water, are k0=33.6 M−1s−1 for Fe2+–Fe3+, k1=1.2×102 M−1s-−1 for Fe2+–FeCl2+, and k2=∼103 M−1s−1 for Fe2+–FeCl2+ at μ=0.20 M and 25°C. The formation constant for FeCl2+ was determined to be K1=(2.0±0.3)×104 M−1 at μ=0.20 M and 25°C. In the mixed solvents of DMF and water, the apparent rate constant exhibited a minimum at a certain water concentration. The activation parameters for the reactions Fe2+–Fe3+ and Fe2+–FeCl2+ are ΔH0\eweq=8.3 kcal/mol, ΔS0\eweq=−24 cal/deg·mol, ΔH1\eweq=4.5 kcal/mol, and ΔS1\eweq=−34 cal/deg·mol, respectively. The results are compared with those in H2O, D2O, and DMSO.
Photoreactions of N-Vinylcarbazole Induced by Metal Salts. VI. Cyclodimerization Catalyzed by Copper(II) Perchlorate in Aprotic Solvents
Authors: Asai Michihiko , Matsui Hiroshi , Tazuke Shigeo
Published: July 2006

Photocyclodimerization of N-vinylcarbazole(VCZ) catalyzed by Cu(ClO4)2·6H2O(Cu(II)) in tetrahydrofuran was investigated under irradiation at 365 nm. At [Cu(II)]0=10−2 M in air, when [VCZ]0 was less than 0.4 M, only 1,2-trans-dicarbazylcyclobutane(D) was formed, but when [VCZ]0 was higher than 0.5 M, rapid cationic polymerization commenced after about 0.3 M of VCZ had been converted to D. Any consumption of Cu(II) could not be detected in the course of reaction. The change of reaction course from dimerization into polymerization in the midway of reaction was presumably brought about by the consumption of oxygen. Kinetic expression for dimerization rate(Rd) was obtained as follows:

R_d∞I_0^I.0[VCZ]_0^I.0[Cu(II)]_0^0

The quantum yield for D production was much larger than 1, indicating production of D via chain mechanism.
A Study of the Interaction of Diethylcadmium with Lewis Bases as Solvents
Authors: Nakasugi Osami , Ishimori Michihiro , Tsuruta Teiji
Published: July 2006

The infrared spectra of diethylcadmium(CdEt2) in a variety of different solvents were measured. The affinity of CdEt2 toward oxygen and sulfur bases was studied by infrared frequency shifts of CdEt2. Linear relationships were observed for the plots of the two frequency shifts Δνa(C–Cd–C) of CdEt2  vs.  Δνa(C–Zn–C) of ZnEt2 and Δνa(C–Cd–C) vs.  Δν(O–D) of CH3OD. The deviation of the plots for the systems of CdEt2 with cyclic sulfides from the linear behavior was interpreted in terms of dative back-bonding from CdEt2 to sulfides. The enhanced reactivity of the Cd–S compound toward propylene oxide compared to that of the Cd–O compound was considered to result from a harder acid character of the Cd atom in the Cd–S compound caused by its back-bonding nature.
Effect of Pressure on the Rate of Solvolysis. Volume Parameters and Solvolysis Mechanism
Authors: Yamagami Chisako , Sera Akira , Maruyama Kazuhiro
Published: July 2006

The effect of pressure on the solvolysis rates of representative primary, secondary, and tertiary tosylates was investigated in three representative solvents—formic acid, aqueous acetone, and methanol. The calculated activation volumes for these reactions were found to depend on the substrate structure and on the nature of solvent in a systematic manner. The activation volumes for kc-like reactions were less negative than those for ks-like reactions. In the case of the nearly ks-like reactions, the activation volume was found to be governed by the partial molal volume of the initial state.
Kinetic Studies on the Hydrolysis of Ethyl Benzenesulfinates
Authors: Kobayashi Michio , Nishi Ritsuko , Minato Hiroshi
Published: July 2006

The rates of hydrolysis of ethyl p-substituted benzenesulfinates were determined in acidic and alkaline media; the rates were greater in the former with the sulfinates containing electron-releasing substituents, ρ=−0.54 (20°C); and in the latter with the sulfinates containing electron-withdrawing substituents, ρ=1.60. The mechanisms of the hydrolysis are discussed.
Hydrogen Exchange Reactions of Sulfilimines and Sulfoximines
Authors: Kobayashi Michio , Mori Akira , Minato Hiroshi
Published: July 2006

Alkyl phenyl sulfilimines, benzyl phenyl sulfilimine and the corresponding sulfoximines were found to exchange their α-hydrogens with deuteriums in heavy water when the medium was alkaline. No exchange was observed when the medium was acidic or neutral. The rates of exchange in a sulfilimine were greater than those of the corresponding sulfoximine. The kinetics of these H-D exchange reactions were investigated by use of pyridine as a catalyst, and the reaction mechanism was discussed.
Cationic Arylation. VII. Cationic Phenylation and Benzoyloxylation of Aromatic Compounds with Benzoyl Peroxide in Trifluoroacetic Acid
Authors: Kamigata Nobumasa , Minato Hiroshi , Kobayashi Michio
Published: July 2006

Benzoyl peroxide (BPO) was decomposed in benzene in the presence of trifluoroacetic acid. The thermal reaction is first order in BPO, and the activation energy and activation entropy are 18.7 kcal/mol and −26.3 e. u., respectively. The isomer distributions in the phenylation and benzoyloxylation of substituted benzenes determined indicate that the phenylation and benzoyloxylation are electrophilic substitution reactions. The reaction mechanisms are discussed.
The Action of Alkali on Inosine. The Formation of 5-Amino-1-β-d-ribofuranosyl-4-imidazolecarboxamide and 9-β-d-Ribopyranosyl Hypoxanthine
Authors: Suzuki Yoshihisa
Published: July 2006

On treating inosine with aqueous dilute alkali hydroxide (pH 10) over 100°C, three types of reactions have been found to occur in competition with one another: (1) the hydrolysis of the glycosidic bond to give hypoxanthine and d-ribose, (2) the opening of the pyrimidine ring at C-2 to give 5-amino-1-β-d-ribofuranosyl-4-imidazolecarboxamide, and (3) the isomerization of the ribose moiety to give mainly 9-β-d-ribopyranosyl hypoxanthine. The last two are newly-found reactions, and the products were isolated through column chromatography using Dowex 50W. The products are obtainable in yields of 30 and 10% respectively under optimum conditions. Hypoxanthine was cleaved in an alkaline solution to give 5-amino-4-imidazolecarboxamide, and 5′-inosinic acid was supposed to give 5-amino-1-β-d-ribofuranosyl-4-imidazolecarboxamide-5′-monophosphate. The ring-opening reaction at C-2 was not observed for adenosine or guanosine.
Synthesis of Alkoxythallium(III) Compounds of Olefins and Their Reaction with Copper Halides and Pseudohalides
Authors: Uemura Sakae , Zushi Kazuo , Tabata Akira , Toshimitsu Akio , Okano Masaya
Published: July 2006

Some new alkoxythallium(III) compounds of olefins, C6H5C(R1)(OR3)CH2Tl(OCOR2)2 [I], are prepared from styrene and α-methylstyrene with thallium(III) acetate and isobutyrate in various alcohols. I(R1=H) reacts with copper(I) iodide, bromide, chloride, cyanide and thiocyanate to afford the corresponding alkyl halides and pseudohalides, C6H5CH(OR3)CH2X [II], in various organic solvents, acetonitrile being the solvent of choice for the purpose of preparing II. The addition of potassium salt has a remarkable effect in improving the yield of II. The halo- and pseudohalodethallation occur at the position where thallium is attached previously to alkyl carbon. An ionic concerted intermolecular scheme is proposed as a reaction mechanism for the preparation of II. The data of NMR and IR spectra of I are briefly discussed.
The Reduction of Methyl Acetate with Several Hydrosilanes under γ Irradiation
Authors: Nakao Ren , Fukumoto Tsugio , Tsurugi Jitsuo
Published: July 2006

The reduction of methyl acetate with chlorinated hydrosilanes, HSiCl3−nRn(R=CH3 or OCH3, n=0–2), and triethylsilane under γ irradiation has been studied. The hydrosilanes other than triethylsilane reduce the ester to ethyl methyl ether. The reaction rate is proportional to the hydrosilane concentration and is independent of the methyl acetate concentration. The results indicate that the rate-determining step in the reduction reaction is the hydrogen abstraction from the hydrosilanes. The reactivities of the chlorinated hydrosilanes in the reaction increase with the progressive chlorine substitution on the silicon atom and may be due to the susceptibility of each H–Si bond toward free radicals, (Remark: Graphics omitted.).
Chemistry of Nitrosoimines. VI. Attempted Syntheses of Some Resonance Stabilized Nitrosoimines and Their UV Spectra
Authors: Akiba Kin-ya , Matsunami Satoru , Eguchi Chikahiko , Inamoto Naoki
Published: July 2006

1,1,3,3-Tetrasubstituted 2-nitrosoguanidines, the attempted syntheses and UV spectra of which are reported, are unstable, and decomposed into the corresponding ureas and nitrogen, only 2-nitroso-1,1,3,3-tetraphenylguanidine (1f) being obtained as a pure compound. The reaction of 1f with phenyl isocyanate gave pentaphenylguanidine, probably through 1,4-cycloaddition.
Mechanisms for the Reaction of Phenol with Methanol over the ZnO–Fe2O3 Catalyst
Authors: Kotanigawa Takeshi
Published: July 2006

It was confirmed from the infrared spectra of phenol chemisorbed on ZnO–Fe2O3 that the surface species were characterized by a loss of O–H stretching (3250 cm−1) and by in-plane bending vibration (1370 cm−1) as well as by a phenol ring vibration (1472 cm−1) and a shift of the C–O stretching mode from 1230 cm−1 to 1248 cm−1. From these data, phenoxide surface species were proposed. Furthermore, the dissociative adsorption of phenol was discussed by taking account of the acidity and basicity of the catalyst. That is, in the case of the adsorption, phenol was thought to sit on the acid and the base site. Based on the above discussion, a mechanism for the selective methylation at the ortho position of phenol was proposed. On the other hand, it was found from the infrared spectrum that a surface species similar to zinc formate appears on the chemisorption of methanol. Therefore, it may be possible to consider that methanol adsorbed on the base site decomposes via formate-like surface species to form carbon dioxide, carbon monoxide, and hydrogen.
The Pore Structure of the ZnO–Fe2O3 Catalyst
Authors: Kotanigawa Takeshi , Yamamoto Mitsuyoshi
Published: July 2006

With regard to the ZnO–Fe2O3 catalyst used for the selective methylation at the ortho position of phenol, the pore structures of the catalysts prepared by five processes were studied. The pore structures of these catalysts were determined by converting the detailed nitrogen desorption isotherm data to the pore-volume distribution. These catalysts had two types of pores, a micropore at about 20 Å and a macropore at 80 Å or more. These pores were sensitive to the sintering conditions. The micropore sizes were independent of the calcination temperature, but the macropore sizes were made proportionally larger with a rise in the calcination temperature. The macropore sizes were related to the particle sizes of the zinc ferrite formed by the solid reaction of ZnO with Fe2O3.
The Electronic States of 2,5-Dibromo-3,6-dichloro-1,4-benzo-quinone and Its Anion Radical as Studied Means of Their Infrared Spectra
Authors: Iida Yoichi
Published: July 2006

The infrared spectra (400–4000 cm−1) of neutral 2,5-dibromo-3,6-dichloro-1,4-benzoquinone and its anion radical were measured in order to observe the appreciable frequency differences between their corresponding bands. The vibrational assignments were made and the simple Urey-Bradley force fields were determined for both the neutral 2,5-dibromo-3,6-dichloro-1,4-benzoquinone and its anion radical. The differences in the molecular and electronic structures between these two molecules were investigated on the basis of these experimental and theoretical results. The half-occupied molecular orbital of the anion radical was found to belong to the bg irreducible representation.
Radiation Synthesis of Ethylamine from Ethane–Ammonia Systems. Effect of Nitric Oxide Addition
Authors: Shimizu Saburo , Ikezoe Yasumasa , Sato Shoichi
Published: July 2006

Formation of ethylamine was observed in the γ-radiolysis of the ethane–ammonia system: the maximum G value was 0.5. Using oxygen as a radical scavenger, it was found that the ethylamine was formed via radical and ion intermediates. Addition of excess nitric oxide suppressed the ethylamine yield, but G(C2H5NH2) increased to 1.2 on addition of an optimum amount. This was attributed to the reduction of acetaldoxime by hydrogen atoms or alkyl radicals, after acetaldoxime had been formed by the reaction between ethyl radicals and the nitric oxide added as a scavenger.
Molten-state Absorption Spectra of Weakly Interacting Donor-Acceptor Mixtures
Authors: Aihara Jun-ichi
Published: July 2006

Absorption spectra of equimolecular mixutres of bulky electron donors, such as triphenylamine, and typical electron acceptors, such as sym-trinitrobenzene (TNB) and chloranil, in the molten state are reported. Though the components do not interact in the solid, the melts display distinct charge-transfer absorption bands in the visible region.
An EMF Study of Certain Orthoferrites: YFeO3, GdFeO3 and SmFeO3
Authors: Yamauchi Shigeru , Fueki Kazuo , Mukaibo Takashi , Nakayama Chiaki
Published: July 2006

The EMF of a solid electrolyte galvanic cell on the formation of orthoferrites, LnFeO3, was measured for Ln=Y, Gd and Sm at 1200–1400 K. The free energy change of the (1/2)Fe2O3+(1/2)Ln2O3→LnFeO3 reaction was calculated.
A New Optically Active Co(II) (salen) Type Complex Containing a Pentadentate Schiff-Base Ligand
Authors: Aoi Haruhiko , Yoshikawa Sadao
Published: July 2006

A new optically active square-pyramidal cobalt(II) complex, N,N′-bis(salicylaldehyde)-2-(S)4-S-methyl-4-thio-1,2-butanediiminatocobalt(II), was synthesized. The structure of this complex was examined.
Tetracyanoethylene Complexes of Ni(0) and Co(−1) Containing Isocyanides and Nitrosyl
Authors: Kawakami Katsuhiko , Ishii Kazuhiro , Tanaka Toshio
Published: July 2006

The magnetic equivalence of the isocyanides in Ni(RNC)3(TCNE) and Co(NO)(RNC)2(TCNE) is more likely to be due to the free rotation of TCNE in solution than to the dissociative exchange of ligands.
A Convenient Method for the Preparation of Aminoethyliminodiacetatocobalt(III) Complexes
Authors: Kuroda Kashiro , Ohtsuka Shuji , Matsumoto Noriko
Published: July 2006

Sodium dinitro(aminoethyliminodiacetato)-cobaltate(III) has been obtained by the oxidation of an aqueous mixture of cobalt(II) chloride, sodium nitrite, and a reaction product between ethylenediamine and sodium monochloroacetate. Several other complexes with the tetradentate ligand have also been derived from the dinitro complex.
Catalytic Function of Metal Salts on the Reduction of Pyridine-2-carbaldehyde by 1-Benzyl-1,4-dihydronicotinamide
Authors: Shirai Masamitsu , Chishina Taizo , Tanaka Makoto
Published: July 2006

A catalytic function of metal salts on the reduction of pyridine-2-carbaldehyde by 1-benzyl-1,4-dihydronicotinamide was discussed kinetically. The reduction rate was affected not only by the nature of metal cation but by that of counter anion.
Magneto-chemistry and Infrared Spectra of Ammonia and Primary Aliphatic Amine Complexes of Copper(II) Chromate
Authors: Sengar Babu Ram S , Narain Gopal
Published: July 2006

Complexes of divalent copper of the type CuCrO4·4Am and CuCrO4·2Am·2H2O with Am=ammonia or primary aliphatic amine, have been prepared and characterized. All the compounds reported are paramagnetic and values of μeff in the range 1.77–1.86 B.M. The assignment of the vibrational bands of the ligands and their shifts in frequency on co-ordination with copper(II) ion are discussed.
Amperometric Titration of Lead with Potassium Dithiotrihydroxymethyl Aminomethane and Its Determination in Presence of Mercury and Silver
Authors: Deshmukh G S , Chaudhuri H , Mahanti H S
Published: July 2006

Amperometric titration of lead with potassium dithiotrihydroxymethyl aminomethane at −0.2 V (vs. SCE) in ammoniacal ammonium tartrate-potassium nitrate base electrolyte (pH 8.0) has been carried out with a dropping mercury electrode. Lead has also been estimated in binary solutions with silver and mercury. The accuracy of the procedure is comparable to that obtained with classical methods.
A Novel Route to Menthyldiphenylphosphine
Authors: Tanaka Masato , Ogata Ikuei
Published: July 2006

As evidence of a novel, configurationallystable Grignard reagent, menthyldiphenylphosphine (MDPP) has been obtained by the reaction of diphenylphosphinous chloride with the Grignard reagent derived from menthyl chloride.
Epoxide Rearrangement II. Isomerization of 1-Methylcyclohexene Oxide over Solid Acids and Bases
Authors: Arata Kazushi , Akutagawa Susumu , Tanabe Kozo
Published: July 2006

The reaction of 1-methylcyclohexene oxide over solid acids and bases at 108 °C was found to give five main products, 2-methylcyclohexanone (III), 1-methylcyclohexanol (IV), 2-methyl-2-cyclohexene-1-one (V), 2-methyl-enecyclohexanol (VIa), and 2-methyl-2-cyclohexene-1-ol (VIb), with a small amount of 1-methylcyclohexene (I) and unidentified compound (II). The ketone (III) was formed predominantly over zeolite, SiO2–Al2O3, H2SO4/SiO2, AlCl3, and BBr3, while the allyl alcohol (VI) was given by Al2O3 and TiO2. HCl/SiO2 and solid H3PO4 calcined at 400–900°C gave both products, III and VI, in the same amounts, though the latter calcined at 200–300°C formed almost 100% ketone. Solid lithium perchlorate was surprisingly active for the formation of ketone, but other metal per chlorates and lithium salts were quite inactive. Alkaline earth metal oxides and NaOH/SiO2 were almost inactive. The catalytic activity and selectivity as well as the reaction path and mechanism are briefly discussed mainly in connection with acid-base property of solid catalysts.
Electron Scavenging Study on the Photobleaching of Trapped Electrons in 3-Methylhexane Matrices at 77 K
Authors: Oka Koichi , Yamazaki Hideo , Hatano Yoshihiko
Published: July 2006

The effect of addition of sulfur hexafluoride as an electron scavenger on quantum efficiency was investigated for the decay of trapped electrons in 3-methylhexane matrices at 77 K during photobleaching in the wavelength range 700–1900 nm. Since the quantum efficiency for the decay of trapped electrons in pure matrices is independent of the initial concentration, almost all the recombination of liberated electrons with the cations is geminate. The increase in quantum efficiency for the decay of trapped electrons by the addition of the electron scavenger SF6 was analyzed quantitatively. The quantum efficiency for the photoliberation of trapped electrons from the trapping sites may be about unity. The liberated electrons in the absence of the electron scavenger are retrapped or neutralized. The ratio of the former process to the latter at a wavelength greater than 1500 nm is much larger than that at a shorter wavelength. The wavelength dependence of the ratios of the electron scavenging process to these processes has also been discussed.
Some Remarks on the Reaction Mechanism and Kinetic Rate Constants for the Pentacyanocobaltate(II)-catalyzed Hydrogenation of Olefins Using the Iterative Simulation Technique
Authors: Ohkubo Katsutoshi , Tsughihashi Kohji , Ikebe Hiromichi , Sakamoto Hiroyuki
Published: July 2006

The reaction mechanism and kinetic-rate constants of the pentacyanocobaltate(II)-catalyzed hydrogenation of olefins were investigated. The present study with an iterative simulation technique supported the Co(CN)53−+H2→Co(CN)5H3−+H· and Co(CN)53−+H·→Co(CN)5H3− reactions for the uptake of H2 by the cobaltate(II) during the initial stage of the reaction. An examination was also made of the stationary-state approximation used for the kinetic analysis of the reaction.
Electronic Structures of Excited States of Benzoquinolines
Authors: Yamaguchi Hiroyuki , Ikeda Teruki , Mametsuka Hiroaki
Published: July 2006

Measurements of the dipole moments and acidity constants in the lowest excited singlet states for benzo[c]quinoline, benzo[f]quinoline, and benzo[h]quinoline have been carried out by spectrophotometry. The electronic structures of excited states have been calculated by using the semi-empirical SCF–π–MO CI method, which allows for a bond order-bond length relationship at each iteration. The experimentally-determined dipole moments and acidity constants can not be correlated to the calculated electronic structures of the Franck-Condon states, but they can be correlated to the calculated structures of the equilibrium states for the lowest excited singlet states of three isomeric benzoquinolines.
The Absorption and Fluorescence Spectra of 2-Methyl-1-aceanthrenone and Its Cation. A Comparison with 9-Anthracenecarboxaldehyde
Authors: Hirayama Satoshi
Published: July 2006

The fluorescence and absorption spectra of 2-methyl-1-aceanthrenone (I) and its cation were investigated. The spectra showed well-defined vibrational structures in a wide variety of solvents, but not in ethyl alcohol and acetic acid. The existence of the 1Lb absorption band on the shorter-wavelength side of the 1La band was strongly supported by the different solvent effects of these bands. In non-polar solvents, (I) formed a strongly fluorescent, 1:1, hydrogen-bonded complex with a trichloroacetic acid molecule. The formation constant in n-hexane was determined spectrophotometrically as 3.1×10−2 M−1 at 20 °C. In acidic solutions, pKa and pKa*, were determined as −5.1 and 1.3 for the ground and first excited singlet states respectively. These values are the same as the corresponding values of 9-anthracenecarboxaldehyde (9-CHO-A), reflecting a marked resemblance in the electronic nature of the carbonyl groups of the two compounds. The broad absorption spectra of 9-CHO-A, in contrast to the highly structured spectra of (I), are due to a feasible torsional motion of the carbonyl group of the former compound.
Photoemission from Pyrene and its Derivatives
Authors: Hino Shojun , Hirooka Tomohiko , Inokuchi Hiroo
Published: July 2006

Photoemissions from pyrene and its derivatives, 1,3,6,8-tetrachloropyrene(TClP), 1,3,6,8-tetrabromopyrene(TBrP), 1,6-dicyanopyrene(CDNP), 1,3,6,8-tetracyanopyrene(TCNP), and 1,3,6,8-tetranitropyrene (TNO2P), were measured. Their photoelectron energy distribution curves(EDCs) were thus obtained; the peaks or shoulder appearing on the EDCs correspond to the ionization potentials of the pyrene molecule. Further, the spectral dependences of their quantum yields(SDQYs) were measured. The ionization potentials obtained from their threshold values were 5.8 eV(pyrene), 6.3 eV(TClP), 6.0 eV (TBrP), 6.3 eV(DCNP), 6.2 eV(TCNP), and 6.6 eV(TNO2P).
The Analysis of the Molecular Vibration by the Molecular Orbital Method. I. Application to HCN
Authors: Miyazaki Tomoo , Ikeda Masaru , Shibata Masayuki
Published: July 2006

The approximate self-consistent molecular orbital method has been applied to the analysis of the vibrational spectrum of HCN. The frequencies of the fundamental, overtone, and combination bands in the region from about 700 to 12000 cm−1 have been calculated, and their absolute infrared absorption intensities have been estimated, the variational method being used in this calculation. Also, the frequencies and absorption intensities of hot bands, referring to the bending vibration, have been calculated. In comparison with the experimental results, the calculated frequencies were not always appropriate. However, it was found that these results are effective in the analysis of the molecular vibration if the calculated frequencies are discussed along with their infrared absorption intensities.
Effects of Anionic and Cationic Surfactants on the Ion Flotation of Cu2+
Authors: Kobayashi Koichi
Published: July 2006

The effects of several anionic surfactants—sodium α-sulfolaurate, sodium laurate, sodium dodecylsulfate, and cationic surfactants, dodecylpyridinium chloride, and dodecyltrimethylammonium chloride—on the bubble flotation of Cu2+ ions were studied. Sodium α-sulfolaurate was found to be most effective for the flotation of Cu2+ ions. The flotation rate (percent removed) increased sharply from zero at about pH 6, and a rate larger than 95% was attained in the pH region of about 7 to 11. Cationic surfactants alone could float Cu2+ ions only slightly. They floated most of the Cu2+ ions upon the addition of bentonite, however. A flotation rate of about 90% was attained in the pH region larger than about 6. This was explained by the Cu2+ ions being removed as polynuclear species, which combined directly with an anionic surfactant or a cationic surfactant with the aid of bentonite.
The Role of the Promoting Mode in Nonradiative Transitions in Large Molecules
Authors: Fujimura Yuichi , Nakajima Takeshi
Published: July 2006

A rate expression for the intramolecular nonradiative transition where a promoting mode acts also as an accepting mode at the same time has been derived within the statistical limit. The dependence of the nonradiative transition rate on the shift of the equilibrium point of the promoting mode in the relevant electronic states, Δp, has been examined for two cases, i) excited \ightsquigarrow ground states and ii) excited \ightsquigarrow excited states, in aromatic hydrocarbons which satisfy the above condition.
Diffusion and Adsorption of a Model Cationic Dye, m-Nitrobenzylamine, in Polyacrylonitrile
Authors: Morita Zenzo , Hossain T M Abul , Iijima Toshiro
Published: July 2006

A model cationic dye, m-nitrobenzylamine (NBA), was synthesized, and the diffusion and adsorption behavior in polyacrylonitrile was investigated by the cylindrical film roll method. pKa of NBA was determined spectroscopically to be 9.2 at 25 °C. The diffusion was concentration dependent and was described by the chemical potential gradient model. The temperature dependence of the diffusion coefficients above Tg, which was found to be 65 °C from the inflection point of Arrhenius plot, could be described by WLF equation, where C1g and C2g are 1.64 and 17.09 (deg.) at pH 4.2, and 2.41 and 33.11 (deg.) at pH 6.8, respectively. Adsorption isotherm of NBA was obtained at 95 °C and pH 1.5, 4.2 and 6.8. The adsorption of NBA, bis(m-nitrobenzyl)amine and Malachite Green at pH 4.2 and those of NBA and bis(m-nitrobenzyl)amine at pH 6.8 were more or less the same. It is concluded that the adsorption of cationic compounds on polyacrylonitrile is virtually dependent upon the ion exchange mechanism. But the presence of sodium chloride in the dye bath did not change the adsorption of NBA at pH 4.2 and 95 °C. The surface concentration of NBA was gradually increased with rise of temperature at pH 1.5, 4.2 and 6.8.
Laser Photochemistry. II. Determination of the ORD and CD Spectra of Some Chromium(III) β-Diketonates
Authors: Yoneda Hayami , Sakaguchi Ushio , Nakashima Yoshiaki
Published: July 2006

An argon ion laser has been used to partially photoresolve the following tris(β-diketonato)chromium(III) complexes; Cr(acac)3, Cr(3-X-acac)3 (X=Cl−, Br−, I−, and NO2−), Cr(tfac)3, and Cr(bzac)3, where the abbreviations are acac=acetylacetonate ion, 3-X-acac=γ-substituted acetylacetonate ion, tfac=trifluoroacetylacetonate ion, and bzac=benzoylacetonate ion. From the wavelength dependence of the steady state resolution yield, the method of photoresolution has been confirmed to allow the determination of the ORD and CD spectra of optically pure enantiomers. The ORD and CD spectra of the above-mentioned compounds are given.