bluuebunny/crossref_metadata_2025 huggingface dataset:
Polarized Absorption Spectra of Crystals of Indole and Its Related Compounds
Authors: Yamamoto Yukio , Tanaka Jiro
Published: July 2006

The polarized absorption spectra of crystals of indole derivatives have been measured in order to confirm the presence of two types of electronic transitions, 1Lb and 1La, in the long-wavelength absorption region, and in order to determine the direction of their transition moments. The polarization spectra show that the 1A–1Lb electronic transition forms a sharp absroption band with vibrational structures lying below a broader absorption band of the 1A—1La transition. The transition memont direction of the 1Lb makes an angle of 54° to the long axis of the molecule, while that of the 1La lies at an angle of −38° to the same axis. These results were compared with the results of theoretical calculations of the P–P–P SCF MO–CI method.
Ultraviolet and Infrared Spectra of Cupferron and Neocupferron
Authors: Yoshimura Tetsuhiko , Miyake Chie , Imoto Shosuke
Published: July 2006

N-nitroso-N-phenylhydroxylamine, N-nitroso-α-naphthylhydroxylamine, and their sodium salts have been prepared from the ammonium salt of N-nitroso-N-phenylhydroxylamine (cupferron) and the ammonium salt of N-nitroso-α-naphthylhydroxylamine (neocupferron) respectively. The measurements of the UV spectra in solution and the IR spectra with Nujol mull have been carried out on these compounds, including their ammonium salts. The solvent effect and the deuteration effect on the IR spectra have also been examined for the compounds with a hydroxyl group. The formation of a rather strong hydrogen bonding in these aromatic nitrosohydroxyl-amines has been confirmed from the deuteration effect on the IR spectra and from the solvent effect on the UV and IR spectra. These compounds and their salts have shown the absorption band considered to be a chargetransfer band in the UV spectra, and they have also shown the N=O stretching mode between 1450 and 1468 cm−1 corresponding to those of nitrosamines in the IR spectra with the HCB mull.
Photooxidation of 1,4-Dihyropyridines
Authors: Mitsunobu Oyo , Matsumoto Shozo , Wada Makoto , Masuda Hiroaki
Published: July 2006

1,4-Dihydropyridines were successfully photooxidized to corresponding pyridines under suitable conditions. The substituents of the dihydropyridines, reaction mediums, and atmospheres affect the course of the reactions. When diethyl 2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate (1a), diethyl 1,4-dihydropyridine-3,5-dicar-boxylate (1b), 2,6-dimethyl-3,5-diacetyl-1,4-dihydropyridine (1c), and 3,5-diacetyl-1,4-dihydropyridine (1d) were irradiated by a super high pressure mercury lamp with filter in ethanol under air or oxygen, corresponding pyridines, diethyl 2,6-dimethylpyridine-3,5-dicarboxylate (2a), diethyl pyridine-3,5-dicarboxylate (2b), 2,6-dimethyl-3,5-diacethylpyridine (2c), and 3,5-diacetylpyridine (2d) were formed in good yields. Irradiation of 1a, 1c, and 1d in acetonitrile afforded 2a, 2c, and 2d irrespective of their atomosphere, oxygen or nitrogen. On the other hand, photolysis of 1b by the same lamp and filter in ethanol or acetonitrile in an atmosphere of nitrogen resulted in the formation of photodimer (3) which on irradiation by low pressure mercury lamp in acetonitrile dissociated to 1b followed by photooxidation giving 2b. Diethyl l-acetyl-1,4-dihydropyridine-3,5-dicarbolxyate (4e) and 1,3,5-triacetyl-1,4-dihydropyridine (4f) afforded 2b and 2d in fairly good yields when the photolyses were carried out in an atmosphere of air in ethanol or acetonitrile.
Intersystem Crossing Quantum Yields of Phthalazine and Pyridazine
Authors: Takemura Takeshi , Yamamoto Kohzaburo , Yamazaki Iwao , Baba Hiroaki
Published: July 2006

The quantum yields of S1→T1 intersystem crossing have been determined for phthalazine and pyridazine in EPA at 77°K by using the technique of T–T energy transfer. Phthalazine and pyridazine were used as the energy donor, and naphthalene-h8 and naphthalene-d8 as energy acceptor. The intersystem crossing quantum yields were found to be 0.49 for phthalazine and 0.24 for pyridazine. These values lead to the conclusion that the weakness or lack of phosphorescence in the compounds is due to an anomalously high rate of the radiationless transition from their phosphorescent triplet state as compared with the rate of the corresponding radiative transition.
Rapid Solvent Extraction and Direct Spectrophotometric Determination of Lead(II) with 1,1,1-Trifluoro-4-(2-thienyl)-4-mercaptobut-3-en-2-one
Authors: Akki S B , Khopkar S M
Published: July 2006

The thio derivative of 2-thenoyltrifluoroacetone 1,1,1-trifluoro-4-(2-thienyl)-4-mercaptobut-3-en-2-one (STTA) is used for the simultaneous extraction and direct colorimetric determination of lead. About 100 μg of lead is quantitatively extracted, at pH 6.5, with 10 ml of 0.0020m STTA-CCl4 as a bright orange colored complex, which can be measured spectrophotometrically at 480 nm. The system conforms to Beer’s law over the concentration range of 1–40 μ/ml of lead(II). The color of the complex is stable for 60 hr. Lead can be quantitatively extracted and determined in the presence of a number of ions. The method is made selective by using some sequestering agents and carrying out selective extractions with mesityl oxide. The procedure is found to be suitable for the analysis of lead in gun metal and solder.
Dielectric Dispersion at Meter Waves of 1-Hexanol and 1-Octanol in Cyclohexane Solutions
Authors: Komooka Hitoshi
Published: July 2006

The dielectric constants and losses of 1-hexanol and 1-octanol in cyclohexane solutions were measured in the frequency range 60–480 MHz at various temperatures. The values ε0−ε∞ deviate widely from the linear dependence on concentration. The curve of (ε0−ε∞)⁄c plotted against concentration c falls rapidly as c decreases. Its value seems to be zero at the concentration of 1 mol/l. A comparison with the values of higher alcohols given in literature shows that the curve is almost uniquely determined for each temperature as a function of the concentration of hydroxyl group alone, irrespective of the length of C–C chain in alkyl group of alcohols. As shown by Ibbitson and Moore, there exist considerable amounts of dimers, trimers and cyclic polymers in the dilute solutions of 1% by weight. The cause for the large values of dielectric constant cannot be merely attributed to the formation of hydrogen-bonded aggregates of molecules. A possible structure of the aggregates is discussed.
The Dissolution of Olivine in Aqueous Solutions of Inorganic Acids
Authors: Sanemasa Isao , Yoshida Minoru , Ozawa Takejiro
Published: July 2006

The dissolution of olivine was studied in aqueous solutions of inorganic acids at temperatures of 35, 50, and 65°C in order to obtain basic information about the alteration and leaching processes in acid hot spring regions. The rates of dissolution have been determined by measuring the change in the concentrations of silica, magnesium, and the total iron leached in the solutions as a function of the time. Olivine dissolved in stirred aqueous solutions of 0.05–2n perchloric, hydrochloric, and sulphuric acids without any selective dissolution of components in the mineral. The rate at which olivine dissolved was found to be two-thirds of the reaction order with respect to the sample-powder (10–20 μ in diameter) weight (i.e., first order with respect to the surface area) and to decrease in the order of H2SO4>>HCl>HClO4. HSO4− enchanced the rate remarkably. The complexing affinity of the anions did not play an important part in the reaction with olivine powder.
The Crystal Structure of (−)589-Dinitrobis(ethylenediamine)cobalt(III) (+)589-Bis(malonato)ethylenediaminecobaltate(III)
Authors: Matsumoto Keiji , Kuroya Hisao
Published: July 2006

The crystal structure of (−)589-[Co(NO2)2en2] (+)589-[Co mal2 en] has been investigated by the X-ray method. Crystal data: triclinic, space group P1; a=10.58(2)Å, b=7.98(1)Å, c=7.99(1)Å, α=122.8(2)°, β=105.3(2)°, γ=74.6(2)°; Z=1. The crystal structure was determined by the Fourier technique and was refined by the leastsquares method to an R factor of 0.101. The Δ configuration has been assigned to both the complex cation and anion, (−)589-[Co(NO2)2en2]+ and (+)589-[Co mal2en]−. The two Co-mal chelate rings are nearly planar. The O–Co–O angle in this ring is 96°, slightly larger than the N–Co–N angle observed in the cobalt(III)-trimethylenediamine chelate ring. All the ethylenediamine ligands in the two complex ions have the ob-conformation.
Binuclear Metal Complexes. III. Preparation and Properties of Mononuclear and Binuclear Copper(II) and Nickel(II) Complexes of New Macrocycles and Their Related Ligands
Authors: Okawa Hisashi , Kida Sigeo
Published: July 2006

The syntheses and properties of copper(II) and nickel(II) complexes of N,N′-alkylenebis(3-formyl-5-methylsalicylaldimine (alkylene=ethylene, propylene, or trimethylene) are described. By the reaction of these complexes with other alkylenediamines (ethylenediamine or trimethylenediamine), mononuclear copper(II) and nickel(II) complexes of new N4O2-type macrocycles have been synthesized. These complexes react with additional copper(II) or nickel(II) ions to form binuclear copper(II) or nickel(II) complexes. The geometries and properties of these new complexes are discussed.
Propiolamidines I. Syntheses of N,N′-Disubstituted Phenylpropiolamidines and New Routes to 5-N-Substituted Amino-3-phenylisoxazoles and 5-N-Substituted Amino-1,3-diphenylpyrazoles
Authors: Fujita Hiroshi , Endo Rokuro , Aoyama Akira , Ichii Takeshi
Published: July 2006

N,N′-Disubstituted phenylpropiolamidines were synthesized from phenylacetylene and carbodiimides. They were inert toward nucleophiles in a neutral or basic medium, but reactive in an acidic one. They reacted in the presence of hydrogen chloride with hydroxylamine, hydrazine, and arylhydrazines to give 5-N-substituted amino-3-phenylisoxazoles, 5-N-substituted amino-3-phenylpyrazole and 5-N-substituted amino-1-aryl-3-phenylpyrazoles, respectively, by nucleophilic addition followed by cyclization. The reaction mechanism is discussed on the basis of the structures of these heterocyclic compounds.
The Analytical Application of Sulfur Analogues of β-Diketones. I. The Extraction Spectrophotometric Determination of Cobalt(II) with 1,1,1-trifluoro-4-(2-thienyl)-4-mercaptobut-3-en-2-one (STTA)
Authors: Honjyo Takaharu , Kiba Toshiyasu
Published: July 2006

The solvent extraction of cobalt(II) with 1,1,1-trifluoro-4-(2-thienyl)-4-mercaptobut-3-en-2-one (abbreviated as STTA) in cyclohexane has been investigated, and a new spectrophotometric method for the determination of minute amounts of cobalt has been developed on the basis of the results obtained in the extraction study. When a sample solution the pH of which had been adjusted to 6.0–6.5 with hydrochloric acid or sodium hydroxide solution was shaken with a 10−3m STTA organic solution, the extraction of cobalt(II) proceeded rapidly and quantitatively. The amount of cobalt up to 8 ppm in the final organic phase could be determined by measuring the absorbance at 480 or 490 nm against the reagent blank. All other interferring ions, such as Hg(II), Cu(II), Ni(II), Pb(II), Zn(II), and Fe(III), extractable together with cobalt(II) could be stripped out of the organic phase by shaking it with 1–12m hydrochloric acid, while cobalt remained in the organic phase as it was. After this treatment, the organic phase was shaken with an aqueous buffer solution of pH 9–11; thereby, the excess of the reagent was released to a great extent from the organic phase into the aqueous solution. The cobalt-STTA chelate was then the only one existing in the organic phase; therefore, the sensitivity and the selectivity of the method increased so much that a few ppb of cobalt(II) could be determined precisely by measuring the absorbance of the final organic phase at 360 nm against the reagent blank. In this work, the apparent mole ratio of STTA to cobalt in the complex formation was estimated to be 4:1, and the molar absorption coefficients of the chelate in cyclohexane were found to be 4970000 (at 360 nm), 13200 (at 450 nm), 6500 (at 480 nm), and 5500 (at 490 nm) respectively. Anions, such as oxalate and citrate, as well as EDTA interfered with this extraction. By the recommended procedure, cobalt of a few ppb in an analytical-grade reagent of nickel nitrate hexahydrate could be determined.
Studies on Stable Free Radicals. XIII. Synthesis and ESR Spectral Properties of Hindered Piperazine N-Oxyls
Authors: Yoshioka Takao , Mori Eiko , Murayama Keisuke
Published: July 2006

New hindered 3,5-dioxopiperazines (VII, IX), hindered piperazines (VIII, X), and the corresponding N-oxyls (XI, XIII, XII, and XIV) were synthesized. The substituent and solvent effects of the nitrogen coupling constants (aN) in the N-oxyls were measured and compared with each other; the introduction of carbonyl groups at the C-3 and C-5 ring positions decreased these values, which increased in a protic polar solvent.
Steric Effect in the Nucleophilic Attack of Bromide Anion on Diaryl- and Aryl-2-thienyliodonium Ions
Authors: Yamada Yorinobu , Okawara Makoto
Published: July 2006

Duryl-, mesityl-, and o-tolyl-phenyl- and 2-thienyliodonium bromides have been synthesized. When these substances were allowed to decompose in molten (235°C) and solution (100°C) states, the nucleophile (bromide anion) preferentially attacked the substituted phenyl ring. Steric and electronic effects of phenomena have been discussed.
Chemistry of Nitrosoimines. II. Photolysis of 2-Nitrosoimino-2,3-dihydrothiazoles
Authors: Akiba Kin-ya , Fukawa Isaburo , Nomura Noboru , Inamoto Naoki
Published: July 2006

Irradiation of 3-substituted 2-nitrosoimino-2,3-dihydrobenzothiazoles (I) with a medium pressure mercury lamp gave bis[o-(N-substituted cyanamino)phenyl] disulfides (III) in high yields. Irradiation of 4,5-diphenyl-2-nitrosoimino-2,3-dihydrothiazole (VI) gave bis[(2-phenyl-2-N-phenylcyanamino)vinyl] disulfide (VIII).

The photolysis was shown to be due to the π-π* excitation from the results of specific irradiation to π-π* and π-π* bands. The relative rates of photolysis of 2-nitrosoimino-3-phenyl-2,3-dihydrobenzothiazole (Ia) were measured in several solvents. The mechanism has been discussed in connection with that in alkyl nitrites and nitrosamines.
Automatic Problem Solving Applied to Synthetic Chemistry
Authors: Bersohn Malcolm
Published: July 2006

The first computer program that plans multi-step organic syntheses has been written. In the course of its operation the program generates partially complete synthetic pathways and ranks them as to efficiency. At each stage the program develops that partially complete route which it judges to be the most efficient, and extends it by one step. Partially complete routes which lose too much material are discarded. After each tolerably efficient pathway from available starting materials to the goal molecule is completed, the entire pathway is printed, together with the yield of each step and the overall yield.
Studies on Stable Free Radicals. IX. Peroxy Acid Oxidation of Hindered Secondary Amines to Nitroxide Radicals
Authors: Toda Toshimasa , Mori Eiko , Murayama Keisuke
Published: July 2006

The hindered secondary amines, 2,2,6,6-tetramethyl-4-oxopiperidine (II) and 1,9-diaza-2,2,8,8,10,10-hexamethyl-4-oxo-spiro[5.5]undecane (VI), were oxidized with m-chloroperbenzoic acid, and the corresponding hydroxylamine (III) and N-oxyl-hydroxylamine (VIII), respectively, were isolated. The further oxidation of III and VIII with the peracid afforded the corresponding nitroxide radical IV and IX, in good yields respectively. The stoichiometry of the oxidation reaction of the hydroxylamine III to the nitroxide radical IV was elucidated on the basis of the ESR signal intensities of oxidation products at various molar ratios with the peracid and III. An ESR study of the 1-15N-labelled N-oxyl-hydroxylamine (XII) indicated that there was an intramolecular hydrogen transfer between >N–OH and >N–O · groups in the N-oxyl-hydroxylamines VIII and XII.
Dimerization and Electronic Absorption Spectra of Tetracyanoethylene Anion in Solution and in Solid
Authors: Itoh Michiya
Published: July 2006

The 2-methyltetrahydrofuran solutions of several alkali tetracyanoethylenides (M+, TCNE−, where M=Na, K, Rb, and Cs) show strong visible absorption spectra at low temperature which might be considered to be charge-transfer bands between two TCNE anions. Temperature dependence of the electronic absorption and ESR spectra of TCNE− in solution yields the monomer-dimer equilibrium of the TCNE anion. The heat of dimer formation of the anion was found to decrease in the order Na+>K+>Rb+>Cs+ with the size of the counter ions. The heat of dimer formation in Na+(TCNE)− also depends considerably on the solvent system. The absorption spectra of the solid TCNE anions were found to resemble the spectrum of the TCNE anion dimer (TCNE−)2 in solution to a great extent. A comparison of the electronic absorption and ESR spectra of M+(TCNE)− in solution and in solid demonstrates that the solid TCNE− is almost diamagnetic, and the anion dimer can be the unit of structure in the solid salts.
Exciton-Exciton Interaction and Exciton Migration in Anthracene, Pyrene, and Perylene Crystals
Authors: Inoue Akinori , Yoshihara Keitaro , Nagakura Saburo
Published: July 2006

The bimolecular annihilation of singlet excitons in pyrene, perylene, and anthracene crystals was studied by the aid of a nitrogen gas laser. The rate constant, γ, for bimolecular annihilation was estimated at 293°K to be 9×10−15 and 8×10−14 cm3 sec−1 for pyrene and perylene, respectively. The temperature dependence of γ was measured with the result that it increases with the increasing temperature for the pyrene and perylene crystals, while it is almost independent of temperature for anthracene between 77°K and 293°K. The difference in the temperature dependence of γ was attributed to the difference in the mechanism of the exciton migration of the crystals. The method developed by the present authors for studying the exciton migration based on the exciton bimolecular annihilation was compared with that obtained previously by the use of mixed crystals.
Kinetics of the Acid Hydrolysis of Carboxylatopentammineruthenium(III) Complexes
Authors: Ohyoshi Akira , Jyo Akinori , Shin Noriaki
Published: July 2006

The kinetics of the hydrolysis of pentammineruthenium(III) complexes containing carboxylates and α-substituted acetates (glycolate and glycinate) have been studied. The experiments were carried out in a solution of [H+]=0.025–0.1m, at 40–70°C. For each complex, the rate law was found to be: rate=[complex](kH2O+kH[H+]). The kH2O and kH values for the formato, acetato, propionato, isobutyrato, glycolato, and glycinato complexes are, respectively (at μ=0.10, 59–61°C): kH2O, 5.37×10−5, 11.8×10−5, 14×10−5, 13.7×10−5, 5.7×10−5, and 6.75×10−5sec−1; kH, 3.3×10−3, 2.3×10−3, 2.5×10−3, 1.7×10−3, 0.75×10−3, and 3.1×10−3M−1sec−1. The mechanisms of acid hydrolysis are discussed for the two reaction paths.
Syntheses of Formato-, Acetato-, Benzoato-, and Chlorosubstituted Acetatoruthenium Complexes, and Their Properties
Authors: Mukaida Masao , Nomura Terunosuke , Ishimori Tatsujiro
Published: July 2006

Complexes with the general formula of [Ru2(RCOO)4X], where R=H, X=Cl, or Br; R=Me, X=Cl, Br, I, SCN, NO3, or MeCOO; R=ph, X=Cl, or Br, were prepared. The magnetic properties, conductivities, polarographic behavior, and infrared spectra of these complexes were investigated. All the complexes show magnetic moments of 2.84–2.96 B.M., and their susceptibilities, at from about 300 to 100°K, can be fitted to the Curie-Weiss law with negative values of the Weiss constant (θ=−30–−60°K). These complexes seem to be isostructural. Monochloroacetato-, and trichloroacetatoruthenium complexes ([Ru2(CH2ClCOO)4Cl]·2H2O and [Ru(OH)(CCl3COO)2(H2O)]) were also prepared.
Studies of Ethylenediamine-N,N′-diacetatocobalt(III) Complexes. The Preparation and Identification of Ethylenediamine-N,N′-diacetatocobalt(III) Complexes with Ammonia, Pyridine, or Alkylamines as the Additional Ligand
Authors: Kuroda Kashiro
Published: July 2006

A group of cobalt(III) complexes containing the tetradentate ethylenediamine-N,N′-diacetate anion (EDDA) and ammonia, pyridine, or alkylamines have been derived from ethylenediamine-N,N′-diacetato(diaquo)cobalt-(III) perchlorate. Three different series among the complexes—(1) the aquo(amine) series, [Co(EDDA)(H2O)-(am)]ClO4, (2) the α-cis-bis(amine) series, α-cis-[Co(EDDA)(am)2]ClO4, and (3) β-cis-[Co(EDDA)(NH3)2]ClO4 as well as β-cis-[Co(EDDA)(en)]ClO4, have been obtained, depending on the conditions of the reaction between the starting diaquo complex and the amines. Some properties of the complexes have been examined, and the geometrical configuration of each complex has been identified on the basis of the electronic absorption spectra and the proton NMR spectra. The coordination tendency of EDDA and the amines have also been discussed.
The Crystal and Molecular Structure of Butein Monohydrate, Isolated from Dahlia variabilis
Authors: Saito Norio , Ueno Katsuhiko , Sasada Yoshio
Published: July 2006

The crystals of butein monohydrate isolated from Dahlia variabilis are monoclinic. The unit cell, with dimensions of a=10.89, b=28.88, c=4.29 Å, and β=96.7°, contains four molecules, and the space group is P21/n. An approximate structure was obtained by applying the symbolic addition procedure. The structural parameters were refined by the block-diagonal least-squares method, and the final R factor for 1063 observed reflexions was 0.171. In the molecule, the C(7)–C(8) double bond and the C(9)–O(3) carbonyl group take the s-cis conformation with respect to the C(8)–C(9) single bond. The A phenyl group and the exocyclic atoms (C(7)∼O(3)) are nearly coplanar, and this plane makes a dihedral angle of 15.6° with that of the B phenyl group. The molecules build up a three-dimensional net through the hydrogen bonds. There is also an intramolecular hydrogen bond between O(3) and O(4).
The Normal Magneto-Optical Rotatory Dispersion and the Magnetic Moment of Benzene
Authors: Takenoshita Yoshiya
Published: July 2006

The magneto-optical rotatory dispersion in the absorptionless region has been investigated with liquid benzene, and the related magnetic moment has been discussed theoretically. It has been concluded that the main contribution to the magneto-optical rotatory dispersion consists of an A term through the 1A1g→1E1u transition and that the contribution from σ -electrons is never negligible. The magnetic moment in the excited state, 1E1u, of benzene has been obtained as −1.72 β (Bohr magneton), which is about 2 or 4 times greater than the value of −1.0 β calculated with the FEN-model or the value of −0.396 β calculated by the LCAO-MO method.
The Vibrational Spectra of Water of Crystallization in Barium Chlorate Monohydrate, Calcium Sulfate Dihydrate and Copper Chloride Dihydrate Crystals
Authors: Fukushima Kunio , Yanagida Tsutomu
Published: July 2006

Infrared spectra of water of crystallization and heavy water of crystallization were mesasured for Ba(ClO3)2·H2O, CaSO4·2H2O, CuCl2·2H2O, Ba(ClO3)2·D2O, CaSO4·2D2O, and CuCl2·2D2O, in which the divalent metal ion lies on the bisector line of H–O–H angle or D–O–D angle. From a comparison of the spectra, assignment of the infrared absorption bands was made for the rotational and the translational vibrations of the water of crystallization.
Palladium-catalyzed Exchange of Allylic Groups of Ethers and Esters with Active Hydrogen Compounds. II.
Authors: Takahashi Kuniyuki , Miyake Akihisa , Hata Go
Published: July 2006

The allylic compounds (I), R1–O–R (R=allylic groups, R1=Ph, Me, PhCH2, MeCO), react with active-hydrogen compounds such as phenols, alcohols, carboxylic acids, primary and secondary amines and active methylene compounds, to give allylic derivatives of the active-hydrogen compounds by an intermolecular exchange of the allylic groups of I with the atom to which the active hydrogens are bonded in the presence of palladium catalysts. Allyl and substituted-allyl ethers are more reactive than the corresponding carboxylates. In the reactions of methyl and benzyl ethers, it is necessary to add phenol to obtain the exchange products in fairly good yields. Bis(triphenylphosphine) palladium chloride plus sodium phenoxide, palladium acetate plus triphenylphosphine, and zerovalent palladium complexes such as tetrakis (triphenylphosphine) palladium and (maleic anhydride)bis(triphenylphosphine)palladium are effective catalysts.
Origin of the Fine Structure of the Electronic Spectra of Pyrazine in Benzene Crystals
Authors: Suzuka Isamu , Ito Mitsuo
Published: July 2006

The absorption, fluorescence, and phosphorescence spectra of pyrazine doped in benzene crystal have been observed at 4.2°K. It was found that the 0-0 band and the main vibronic bands are accompanied by the fine structures consisting of several very sharp bands and few broad bands. A detailed examination of the fine structures has suggested that the sharp bands arise from the differently oriented guest molecules in the host crystal, and the broad bands come from coupling of the host crystal phonon with the guest molecule.
The Formation of Metallic Silver in Silver-Form Zeolites
Authors: Tsutsumi Kazuo , Takahashi Hiroshi
Published: July 2006

The formation of silver crystallites in silver-form zeolites was investigated, mainly by means of X-ray diffraction analysis. Silver ions were reduced to the zero-valent state; they aggregated to metals in three cases in this study—first, when silver-form zeolites were heated in a helium flow at above 600°C; secondly, when they were reduced by hydrogen, and lastly, when they were treated with the alkyl benzenes or alcohols above 300°C. The silver crystallites had sizes of 150–400, 150–200, and 200–300Å respectively when Ag(31.6%)–Na–Y4.6 was rereduced in the three cases mentioned above. If the silver ions are reduced, the zeolite becomes decationated-form, in which metallic silver is dispersed. The silver metals formed in the zeolite have peculiar interactions with oxygen.
Calculation of the Reduced Partition Function Ratios of α-, β-Quartzs and Calcite
Authors: Shiro Yuji , Sakai Hitoshi
Published: July 2006

The reduced partition function ratios (r.p.f.r.) of α,β-quartz and calcite were calculated for oxygen isotopic substitution, using the force fields. Optical vibrations are represented by factor group mode (k=0) and acoustic contributions were approximated by the Debye mode of vibration. The theoretical calculation predicts that the r.p.f.r. of quartz could have a discrete gap of about 0.8% at the α-β-transition temperature (573°C), the r.p.f.r. of α-quartz being larger in magnitude and in temperature-dependency. This implies that the isotopic fractionation factors between quartz and other materials such as water, could be significantly affected by the transition. A comparison of the calculated r.p.f.r. of quartz and calcite with the experimental fractionation factors between these minerals and water yields a fairly consistent value of the r.p.f.r. of water, supporting the force field models used for calculations. The comparison also revealed that the r.p.f.r. of water in the temperature interval 300–800°C and under a hydrostatic pressure of 2 Kb should deviate from those of ideal water vapor at the same temperatures by as much as 1% due to the non-ideality of the compressed water fluid.
Steady-Light Irradiation and Flash Photolysis Studies of [2.2]Metacyclophane-Iodine Systems. Mechanistic Implications of Transannular Dehydrogenation Reaction
Authors: Hayashi Shigenari , Sato Takeo
Published: July 2006

Irradiation of cyclohexane solutions of [2.2]metacyclophane in the presence of iodine is shown to yield 4,5,-9,10-tetrahydropyrene as the initial product. In order to clarify the mechanism of the cyclodehydrogenation reaction, steady-light irradiation, and flash photolysis experiments have been carried out. The rate of formation of 4,5,9,10-tetrahydropyrene is followed by UV spectra measurements using a characteristic band maximum at 292 nm. The rate of appearance of 4,5,9,10-tetrahydropyrene is found to be proportional to the absorption of light. The reaction is a one photon process. The reaction rate is almost constant when the concentration of iodine is less than 7×10−4 mol/l, but decreases gradually with higher concentrations. A long-lived species, whether radical or excited triplet, can not be detected by flash techniques. It is most likely that the first step involves the excited singlet. Involvement of CT-complex is proposed.
The Primary Photochemical Process of 4-Nitropyridine N-Oxide II. Decay Kinetics of the Photochemical Intermediates
Authors: Hata Norisuke , Ono Isao , Tsuchiya Tamio
Published: July 2006

In order to clarify the primary photochemical process of 4–nitropyridine N–oxide in solution, kinetic flash spectrophotometric studies were carried out under various conditions. The flash excitation of 4–nitropyridine N–oxide in alcoholic solution resulted in three transient species in the spectral region between 360 nm and 580 nm; one of them was a weak absorption at about 530 nm (transient species A and A′), and the other, a stronger one around 380 nm (transient species B). The experiments on the decay kinetics of these transients revealed that the photochemical reaction of 4–nitropyridine N–oxide in an alcoholic solution proceeded through these intermediate species originating from the excited singlet state; Process I (the photochemical formation of 4-hydroxypyridine N-oxide nitrate) involved the bimolecular interaction between an intermediate A′ and unexcited molecule, while Process II (the photochemical formation of 4-hydroxylaminopyridine N-oxide) was initiated by a hydrogen-atom abstraction from a solvent molecule by an intermediate B which was produced from another intermediate A. The two intermediates A and A′ were reasonably assumed to be formed concurrently from the excited singlet state of 4-nitropyridine N-oxide.
Peptides Containing Aminophosphonic Acids. II. The Synthesis of Tripeptide Analogs
Authors: Yamauchi Kiyoshi , Kinoshita Masayoshi , Imoto Minoru
Published: July 2006

The synthesis of tripeptides containing aminophosphonic acid was attempted as follows. Diethyl phthalylimidomethyl phosphonate (I) was chlorinated with phosphorus pentachloride to the phosphonomonochloridate (II), which was then coupled with amino acid ethyl esters to give the corresponding dipeptides (IIIa—c). The phthalyl groups of III were removed with hydrazine, and the resulting free amines were subsequently combined with phthalyl-amino acids by means of dicyclohexylcarbodiimide to produce the tripeptide analogs (IVa—c) in good yields.
Decarboxylative Alkylation in the Photolysis of Benzhydryl Esters
Authors: Fujita Shinsaku , Ozaki Yoshimi , Nozaki Hitosi
Published: July 2006

The photolysis of benzhydryl esters (1a—1b) results in decarboxylation, thus affording 1,1-diphenylalkanes, diphenylmethane, and 1,1,2,2-tetraphenylethane. The photochemistry of trityl and benzyl esters is also examined. The photochemical solvent incorporation proceeds in both radical and ionic senses. Most characteristically, the irradiation of 1a in toluene gives 1,1,2-triphenylethane, whereas that of 1a in methanol produces benzhydryl methyl ether. Such a dual nature of the photolysis is explained in terms of the intimate ion-radical pair hypothesis proposed by Walling.
Study of Across-Space Intramolecular Charge-Transfer Interaction by Absorption and Fluorescence Spectroscopy
Authors: Mutai Kiyoshi
Published: July 2006

Across-space (through-space) intramolecular charge-transfer (CT) interaction has been observed in homologous series of p-O2NC6H4(CH2)nNHAr (I) and p-O2NC6H4(CH2)nNRAr (II). Introduction of an alkyl group to the amino nitrogen of I, thus producing II, generally increases the intensity of the CT absorption band. It also induces the red-shift of the band position in most cases owing to the increase of the basicity of the donor, while the blue-shift is observed in ortho substituted derivatives. The latter effect is explained by the steric inhibition of the delocalization of nitrogen lone-pair electrons. The CT fluorescence has been observed at room temperature in the lower homologs (n=1,2, and rarely 3) of I and II. Higher intensity of the fluorescence is generally observed in n=1. The increase of intensity is observed when a small amount of benzene is added to a cyclohexane solution. The excitation spectrum shows two peaks; one at the 1Lb transition wavelength of the amine moiety and the other at the CT absorption. The former suggests the possibility that an excited donor collides intramolecularly with a ground state acceptor part (p-nitrophenyl group) to form an excited CT state, and the latter presents a strong evidence for the origin of the fluorescence being the excited CT state.
Modified Clemmensen Reductions of Keto Groups to Methylene Groups
Authors: Toda Masaaki , Hayashi Mikio , Hirata Yoshimasa , Yamamura Shosuke
Published: July 2006

A modified Clemmensen reduction is described for the conversion of keto-groups into methylene groups by using active zinc powder in common organic solvents and acetic anhydride saturated with hydrogen chloride; the scope and limitations of these new reduction systems are also discussed.
Mechanism of Charge-transfer Polymerization. III. Flash Photolysis of N-Vinylcarbazole–Chloranil System
Authors: Shirota Yasuhiko , Kawai Kiyoshi , Yamamoto Naoto , Tada Kazuhiro , Shida Tadamasa , Mikawa Hiroshi , Tsubomura Hiroshi
Published: July 2006

Photochemical formation of transient N-vinylcarbazole cation and chloranil anion-radicals has been demonstrated by means of flash spectroscopy for the N-vinylcarbazole–chloranil–solvent systems. Identification and decay of the species formed by flash illumination are described.
Infrared Spectrum and Normal Vibrations of N,N-Dimethylthioacetamide
Authors: Ray Arabinda , Sathyanarayana D N
Published: July 2006

Infrared spectrum of N,N-dimethylthioacetamide (DMTA) has been recorded in the region 250–4000 cm−1. Normal vibration analysis has been carried out employing Urey-Bradley force field and assignments are made and supported by comparison with related molecules. The complexes of DMTA with cobalt (II), copper (I), and mercury(II) chlorides have been prepared and their infrared spectra recorded. The frequency shifts in metal complexes are in accord with the assignments of C=S and C–N frequencies.
Photolyses of Alkyl Sulfinates and Sulfites
Authors: Kobayashi Michio , Minato Hiroshi , Miyaji Yoshiko , Yoshioka Takuji , Tanaka Koji , Honda Koichi
Published: July 2006

Methyl, ethyl, n-butyl, n-octyl, benzyl, and allyl p-toluenesulfinates were photolyzed in n-hexane or without solvent. The products analyses indicate that the photolyses of these esters involve the fission of ArSO–OR bond, producing a sulfinyl radical and an alkoxy radical. In the case of the allyl ester, isomerization to the corresponding sulfone took place to some extent. When optically active l-menthyl l-p toluenesulfinate was irradiated, its optical activity decreased fairly quickly while very little photolysis was observed. This photo-racemization was ascribed to the reversible formation of sulfinyl radical and menthyloxy radical. When di-n-butyl sulfite was photolyzed, the products found were explained by assuming the initial formation of n-butoxysulfinyl radical and n-butoxy radical. When n-butyl chlorosulfite was photolyzed, the products found indicate the initial fission of the S–Cl bond instead of the S–O bond.
The Structure and Synthesis of Rishitinol. A Sesquiterpene Alcohol from Diseased Potato Tubers
Authors: Katsui Nobukatsu , Matsunaga Akira , Imaizumi Kenji , Masamune Tadashi , Tomiyama Kohei
Published: July 2006

The structure and configuration of rishitinol (2), isolated from tuber tissues of white potatoes (Solanum tuberlosum × S. demissum) infected by an incompatible race of Phytophtora infestans, were deduced from spectral and chemical data and confirmed by the synthesis of its recemate. 5,8-Dimethyl-1-tetralone-3-carboxylic acid (13) prepared from 2,5-dimethylbenzyl chloride was esterified, reduced, and then dehydrated to the dihydronaphthalene derivative (20), which was converted into the oxyisopropyl derivative (21). The hydroboration of 21 followed by hydrogen peroxide oxidation afforded a multi-component mixture, from which dl-rishitinol (25=dl-2) was isolated along with isomeric glycols (22–24).
Constituents and Properties of Ammoniated Slurry From Wet-process Phosphoric Acid
Authors: Akiyama Takashi , Ando Jumpei
Published: July 2006

A large amount of gel-like substance is formed during the ammoniation of wet-process phosphoric acid and affects the production of phosphate fertilizers. The authors have found that the main constituent of the gel-like substance is a compound “S” whose composition has been determined to be (Al,Fe)NH4HF2PO4. Several other compounds, Fe3NH4H8(PO4)6·6H2O, (Fe,Al)NH4H2(PO4)2·1/2H2O, Fe(NH4)2H2F(PO4)2·xH2O, (NH4)3AlF6, gelatinous silica, etc., are also formed during the ammoniation and curing of the ammoniated slurry, depending upon pH, atomic ratio of F/(Al+Fe) and temperature. Tests also were made on the properties of the ammoniated slurry; solubility, viscosity, filterability, and the rate of sedimentation. It has been found that the properties vary with the formation of the above compounds. A high-temperature modification of (NH4)2HPO4 which is stable above 155°C has been newly found during the tests.
Vibronic Bands of Phosphorescence Spectra of Quinoxaline in Host Crystals
Authors: Ikegami Kasumi , Ito Mitsuo
Published: July 2006

The polarized phosphorescence spectra of quinoxaline in durene and p-dimethoxybenzene host crystals were observed at 4.2°K, and the vibronic bands of the phosphorescence spectrum were assigned. It was found that the intensity of vibronic bands polarized along long molecular axis arises from the vibronic spin-orbit coupling routes

(Remark: Graphics omitted.)

and the intensity of vibronic bands polarized along short molecular axis from the routes

(Remark: Graphics omitted.)

It was concluded that all the vibronic phosphorescence bands of quinoxaline originate from the Tz zero-field sublevel. This is in line with the results of El-Sayed and Brewer deduced from the magnetic field effect on the phosphorescence spectrum.
Absorption Band Shapes and Molecular Reorientation of Liquid Methyl Cyanide
Authors: Kakimoto Masao , Fujiyama Tsunetake
Published: July 2006

The shapes and intensities of the fundamental bands of liquid methyl cyanide were observed by conventional transmittance method. Using the refractive indices observed by the ATR method, the observed absorption indices were corrected for the dielectric-field effect. The band shapes were analyzed from the point of view of moment analysis or correlation-function analysis. The results indicate that the shapes of a1-type vibrations are good Lorentzian shapes, while those of the e-type can be explained as superpositions of Lorentzian and Gaussian functions. It is also found that the band-widths of the e-type vibrations were quite different from each other. Taking into account the effect of vibration-rotation interaction on the band-widths, the disagreement could be explained well. From the analyses of the band shapes of ν7 and nu8, the life-time function, ψ(t), was obtained; it represents the decay of the fraction of freely-rotating molecules.
CNDO Calculations on the Electronic Spectra of Several Saturated Compounds
Authors: Ohmichi Naoto , Tajiri Akio , Nakajima Takeshi
Published: July 2006

CNDO calculations of the excited states were performed on the first three members of paraffinic hydrocarbons—methane, ethane, and propane, and on three compounds of saturated three-membered rings—cyclopropane, ethylenimine, and ethylene oxide. The method gives a reasonable interpretation of the electronic spectra of both kinds of compounds.
The Isomerization of Propylene Oxide on Zeolite Catalysts
Authors: Imanaka Toshinobu , Okamoto Yasuaki , Teranishi Shiichiro
Published: July 2006

The selectivity and activity of propylene oxide isomerization have been investigated over zeolite catalysts at 100°C. It has been found that the acid strength of a catalyst is a dominant factor in the selectivity and activity. The stronger the acid strength, the larger the ratio of acetone to propionaldehyde. The reaction intermediates are deduced to be a propylene oxide protonated or that adsorbed on a Lewis-acid site. It has also been found that, in the cases of HY, Silnex (SiO2), and HY treated with pyridine, the selectivity and activity correlate with the strength of the interaction between the propylene oxide and the surface hydroxyl group. Moreover, it has been clarified that the H0 value of the surface hydroxyl group observed at 3660 cm−1 on HY is −8.2–−5.6, while that found at 3540 cm−1 is +4.0–+4.8.
Studies of the Sodium Salts of Homologues of Alkyl Sulfates in Aqueous Solutions in Relation to the Water Structure
Authors: Endo Harumi
Published: July 2006

The adiabatic compressibility (β) and the partial molar volume at an infinite dilution (\barV0) were obtained for aqueous solutions of the sodium alkylsulfates (SAS) of homologues. The sound velocity (U) and the density (ρ) were determined by the use of an ultrasonic interferometer and the float-balance method respectively. The results indicate that the slope at an infinite dilution (dβ⁄dC)0 of β vs. the concentration (C) diagram is in a linear relation with the carbon number (φ) of SAS. A similar relation was obtained between \barV0 and φ. We have derived these two relations by a statistical thermodynamical treatment based on the interstitial model of water, consisting of two species, one constituting the framework of an extended ice-1 structure with many cavities, and the other species, non-hydrogen-bonded water, occupying part of these cavities. The occupancy of the cavity with alkyl radical leads to a decrease in the structural compressibility, while the hydration of the ionic parts of the solute leads to a decrease in the compressibility due to the electrostriction. According to the calculations, the theoretical dependency of (dβ⁄dC)0 on φ is about three times larger than the experimental value. The theoretical dependency of \barV0 on φ is nearly in agreement with the experimental value, while the constant-addivite term is different.
Electrical Conduction in TCNQ Anion Radical Salts
Authors: Sakai Nobuko , Shirotani Ichimin , Minomura Shigeru
Published: July 2006

The temperature dependence of the electrical resistivity of single crystals of TCNQ anion radical salts with alkali metal, quinolinium, and triethylammonium cations has been investigated at temperatures between 300 and 540°K. It has been observed in these salts that the activation energy increases in the region of higher temperatures. In the cases of Na- and K(TCNQ) crystals, the reversal of the sign of the thermo-e.m.f. from the p-type to the n-type has been observed around the temperatures at which the activation energy increases. An interpretation of the experimental results is presented.
Phase Transition of Alkali Metal Cation-TCNQ Anion Radical Simple Salts
Authors: Sakai Nobuko , Shirotani Ichimin , Minomura Shigeru
Published: July 2006

The phase transition at 1 bar has been observed in alkali metal cation-TCNQ anion radical simple salts by means of measurements of the electrical resistivity of their single crystals. The temperature dependence of the resistivity under high hydrostatic pressures has been studied in order to investigate the effect of the pressure on this phase transition. The nature of this phase transition has been discussed. The pressure-induced new phase has also been found in these TCNQ salts at room temperature; thus, more than three phases (α, β, γ···) are considered to exist in the solid phase of these TCNQ, salts.
The Estimation of the Surface Properties of Metal Oxides by the Use of TCNQ Adsorption. II. The Electron-donor Property of Silica-Alumina, Silica-Titania, and Alumina-Titania System Surfaces
Authors: Hosaka Hiroshi , Kawashima Norimichi , Meguro Kenjiro
Published: July 2006

The electron-donor property of silica-alumina, silica-titania, and alumina-titania system surfaces was investigated by means of TCNQ adsorption. When TCNQ was adsorbed on the surfaces of the metal oxide systems from its acetonitrile solution, the surfaces of the metal oxides acquired the coloration characteristic of each oxide. The coloration was caused by the formation of TCNQ anion radicals on the metal oxide surfaces. The presence of the TCNQ anion radicals was confirmed by studying the ESR absorption and the electronic spectrum. The silica-alumina, silica-titania, and alumina-titania systems showed lower radical-ion-forming activity (electrondonating power) than the parent oxides-silica, alumina, and titania. The change in the activity with the composition was characteristic of each metal oxide system.
The Preparation and Some Reactions of Platinum(II) and Palladium(II) Complexes of Vinyl Ethers
Authors: Wakatsuki Yasuo , Nozakura Shun-ichi , Murahashi Shunsuke
Published: July 2006

Stable complexes with the general formula [Cl2ML]2 (M=Pt, Pd; L=vinyl ethers, propenyl ethers, 1,2-dimethoxyethylene) have been prepared. The IR spectra of [Cl2Pt(trans-CH3CH=CHOCH3)]2 showed a change which was attributed to the trans—cis isomerization of the coordinated olefin. A similar cis—trans isomerization was also suggested for the other propenyl ether and 1,2-dimethoxyethylene complexes. The palladium complex of vinyl t-butyl ether was found to react with aqueous NaOH in a way similar to the Wacker process.
Strain Gauge Electromicrobalance for Surface Tension Measurement
Authors: Koshinuma Masakatsu , Nakamura Akio , Seimiya Tsutomu , Sasaki Tsunetaka
Published: July 2006

Two types of apparatus using an unbonded strain gauge of a cantilever type for the measurement of surface tension were constructed. One is a sensitive electromicrobalance equipped with an extended arm attached to the cantilever of the strain gauge. The apparatus proved suitable as a surface balance in a completely closed system. By this apparatus, the measurement of surface tension ranging from 0 to 74 dyn/cm is possible with the accuracy of ±0.10 dyn/cm. The other type was constructed by connecting the sensing lever of strain gauge to the arm of a torsion balance with a strip of phosphor bronze. This device together with a counterbalance on the opposite side of the arm also proved to be useful as a tensiometer. Accuracy of this apparatus was a little better than that of the extended arm type balance, although a larger space is required. Both apparatus are inexpensive, easy to construct and simple to operate, and are suitable for the self-recording of time dependence of surface tension or weight change in general with sufficient accuracy. Equations proposed for the time dependence of surface tension of surfactant solution were checked by using the strain gauge tensiometer of the extended arm type.
A Consideration of Orbital Interaction in the Reaction of 1Δg Molecular Oxygen with Ethylene Derivatives
Authors: Inagaki Satoshi , Yamabe Shinichi , Fujimoto Hiroshi , Fukui Kenichi
Published: July 2006

The stereochemical path of the reaction between the 1Δg oxygen molecule and ethylene was examined in terms of orbital interaction. The results here obtained suggest that a path via the perepoxide intermediate or via a perepoxide-like transition state should be carefully examined in discussing not only the steric path to dioxetane, but also the mechanism of hydroperoxide formation.