bluuebunny/crossref_metadata_2025 huggingface dataset:
A Chlorine NQR Study of Trichlorides of Group V Elements
Authors: Hashimoto Masao , Morie Toshiaki , Kato Yoshifumi
Published: July 2006

The NQR frequency of 35Cl has been observed in polycrystalline PCl3, POCl3, AsCl3, and SbCl3 at 77°K and above. In all cases, the resonance frequency decreases at higher temperatures. The temperature coefficient of the resonance frequency is analyzed according to a modified Bayer-type treatment. A qualitative examination of the experimental results, including Robinson’s results for BiCl3 at 83 and 299°K, reveals that the strength of the intermolecular interactions in the solids of these trichlorides decreases in this order: BiCl3>SbCl3>AsCl3>PCl3. The resonance was found to “fade-out” at temperatures below the melting point for the solids of PCl3 and POCl3, while the resonance was observed up to the melting point for the other compounds. The origin of this phenomenon is discussed.
The Catalytic Oxidation of Carbon Monoxide on Titanium Dioxide; Anatase and Rutile
Authors: Onishi Yoshito
Published: July 2006

For the purpose of examining the surface state of titanium dioxide during the catalytic oxidation of carbon monoxide, the electric conductivities of anatase and rutile at 350–800°C, the amount of active oxygen on the catalyst surface at 400–600°C, and oxygen deficiency during the reaction were measured. The temperature-dependence of electric conductivities are represented by the formula σ=A·eE⁄RT in narrow temperature ranges. The amounts of active oxygen per unit surface area of rutile were 3–5 times as much as those of anatase at same temperatures, and 1–3% of them desorbed during the reaction. When the coverage fraction of active oxygen on the catalyst, θ, is assumed to be equal to 1 in oxygen, the following equation can express the relation between the rate constant of the reduction of titanium dioxide by carbon monoxide, kCO, and that of the oxidation of reduced titanium dioxide by oxygen kO2, during the oxidation of carbon monoxide:

k CO·PCO·θ=2kO2·PO2·(1–θ)2.
An Adiabatic Calorimeter for Heat Capacity Measurements in the Temperature Range from 80 to 550 K. Heat Capacities of α-Alumina (Sapphire) and Anhydrous Magnesium Acetate
Authors: Onodera Natsuo , Kimoto Arata , Sakiyama Minoru , Seki Syûzsô
Published: July 2006

An adiabatic calorimeter for the measurements of heat capacities of solid and liquid in the temperature range 80–550 K and the automatic temperature control system are described. The working platinum resistance thermometer is calibrated against a standard thermometer. The measurements of heat capacity of α-Al2O3 prove the precision to be ±0.3% and give an accuracy of ±0.6%. By means of this calorimeter, heat capacities of anhydrous magnesium acetate have been measured for its glassy and crystalline states around the glass transition point.
Studies on s-Triazines. VII. A New Method of Preparing 2-Methyl-4,6-bis(trichloromethyl)-s-triazine
Authors: Wakabayashi Ko , Tsunoda Masaru , Suzuki Yasushi
Published: July 2006

During the liquid-phase chlorination of CH3CN, a trimerization reaction occurred to yield four s-triazine derivatives, 2-methyl-4,6-bis(trichloromethyl)-s-triazine (I), 2-chloromethyl-4,6-bis(trichloromethyl)-s-triazine (II), 2-dichloromethyl-4,6-bis(trichloromethyl)-s-triazine (III), and 2,4,6-tris(trichloromethyl)-s-triazine (IV). The structure of each s-triazine derivative has been assigned on the basis of the results of elemental analysis and the spectral (particularly Mass and NMR) data after each derivative had been separated in a pure form using the gas-liquid chromatographic (GLC) method. The product composition was seen to depend upon the rate of the chrorination of CH3CN and the presence of a catalyst. The s-triazine I was shown to be the precursor of the s-triazines II and III; the pathways for the formation of the s-triazine IV were also investigated. Then, the selective cotrimerization of CH3CN with its chlorinated compounds was investigated; this yielded the s-triazine I, a useful intermediate of pesticides and resines. The reaction was found to provide a new method of preparing s-triazine I.
Measurement of Negative Ions Formed by Electron Impact. VIII. Ionization Efficiency Curves of Negative Ions from Methyl and Ethyl Cyanides
Authors: Tsuda Satoru , Yokohata Akira , Umaba Toshikatsu
Published: July 2006

The ionization efficiency (I.E) curves of m/e 26(CN−), 27(HCN−), 38(C2N−) and 39(CHCN−) ions from methyl and ethyl cyanides, besides 40(CH2CN−) ions from methyl cyanide, and 50(C3N−) ions from ethyl cyanide were measured to the extent of about 25 eV electron energies under the pressure of ∼10−6 mmHg by a Hitachi RMU-6D mass spectrometer. Schemes of plausible reactions expected to appear at each onset value observed in the respective IE curves were sought thermochemically by using ΔHf values of the reactants and products. The estimation method of unknown ΔHf values is described also. It should be noted that for CN− ions one process (probably, R+CN−) was observed in lower energies than 2 eV; C2N− ions are expected to be formed with excess energy; also, for CN− and HCN− ions rather strange phenomena of the decrement of their signal intensities with increasing electron energies were observed in the range of higher energies. Moreover, the IE curves of C3N− ions in the higher energy region were well interpreted in terms of the overlapping phenomena of dissociative capture process with ion pair formation process. It was found from this work that EA(HCN) \gtrsim1 eV, ΔHf(CHCN−) ∼3.2 eV, EA(CHCN) \gtrsim1.1 eV and EA(CH2CN) \gtrsim1.6 eV. For the electron affinity of C2N a value \gtrsim2.3 eV is tentatively introduced on the basis of EA(C3N)=2.4 eV, EA(C5N)=2.3 eV, and EA(CN)=3.4 eV.
Test for Validity of Constant Ionic Medium Principle. Variation of the Activity Coefficient of Hydrogen Ion in Various Compositions of Medium Cations with 3 m Perchlorate Ions
Authors: Ohtaki Hitoshi , Biedermann Georg
Published: July 2006

Potential changes of cells with a glass electrode and a hydrogen electrode in combination with a reference half-cell were measured in solutions of various compositions of cations at constant concentrations of hydrogen and total perchlorate ions. Measurements were carried out for the systems LiClO4-NaClO4, LiClO4-AgClO4, NaClO4-AgClO4, NaClO4-TlClO4, LiClO4-Mg(ClO4)2, LiClO4-Ba(ClO4)2, NaClO4-Ba(ClO4)2, AgClO4-Ba-(ClO4)2, and LiClO4-La(ClO4)3. In some cases a remarkable potential change was observed. Part of the change was due to the variation of the liquid junction potential at the interface of a test solution and a solution in a salt bridge. However, the change was attributed in greater part to the electrostatic free energy change of the transfer of hydrogen ion from a (3/m  m Am+, 3m ClO4−) solution to a (xm Am+, ym Bn+, 3m ClO4−) solution (where mx+ny=3). Variation of the composition of electrolytes gives rise to a significant change of the dielectric constant of a solution, so that the activity coefficient of hydrogen ions varies in different solutions at a constant concentration of perchlorate ions. Potential changes are additive in A1(ClO4)m1-B1(ClO4)n1, A1(ClO4)m1-B2(ClO4)n2 and B2(ClO4)n2-B1(ClO4)n1 solutions for a given replacement of cations in solutions, where A1 B1 and B2 denote cations with charges of m1  n1 and n2, respectively.
ESR Measurement and Irradiation at Variable Temperatures below 77°K
Authors: Iwasaki Machio , Nunome Keichi , Ichikawa Takahisa , Toriyama Kazumi
Published: July 2006

An apparatus for irradiation and subsequent ESR measurements at variable temperatures below 77°K was constracted by combining an ESR spectrometer, and an X-ray irradiator, and a laboratory scale low temperature refrigerator operating at the temperature region between 77 and 4.2°K. A device for rotating the single crystal specimen was made to measure the angular dependence of the ESR spectra. The lowest specimen temperature achieved was estimated to be 6°K and the precision of the temperature control was less than ±0.5°K for a period of several hours. The apparatus makes it possible to irradiate samples and to measure ESR spectra at any temperature in the range between 77 and 6°K. Some applications for irradiation and ESR measurements at low temperatures are also described. An unstable radical which disappears at about 60°K was found in an irradiated single crystal of l-cystine dihydrochloride. Experimental evidence for the quantum tunnelling of the methyl group in polymethylmethacrylate radical was also found by the temperature dependence of the spectra observed at temperatures lower than 77°K.
Nature of the Acid Sites on the Surface of Silica-alumina. II. The Relation between the Acid Property of the Sites and the Photo-ionization of Polyacenes Adsorbed on the Surfaces
Authors: Takimoto Kazuto , Miura Masaji
Published: July 2006

The ESR and diffuse reflection spectra of the polyacenes adsorbed on the surfaces of silica gel, alumina, and silica-alumina were measured. The amount of the cation radicals generated on the surfaces was enhanced upon irradiation with UV light. This was interpreted in terms of the photo-ionization accomplished via a chargetransfer state by an absorption of hνCT, which was expected to vary with the strength of the Lewis-acid sites. The rate of the radical formation was not the first order, and that of the annihilation was the second order only in the initial stage. These phenomena are discussed in connection with the heterogeneity of the acid properties on the surfaces.
Spectrophotometric Determination of Benzethonium with Tetrabromophenolphthalein Ethyl Ester
Authors: Tsuboughi Masahiro
Published: July 2006

A spectrophotometric method is proposed for the determination of benzethonium. The method is based on solvent extraction of the ion-pair formed between benzethonium and colored tetrabromophenolphthalein ethyl ester, into 1,2-dichloroethane. The extract has a maximum absorbance at 615 mμ, and follows Beer’s law with good precision up to 4×10−6  m in aqueous solution. The absorbance of the extract is constant in the pH range 7–11. Organic cations interfere.
The Crystal Structure of κ′-Al2O3, the New Intermediate Phase
Authors: Okumiya Masataro , Yamaguchi Goro
Published: July 2006

A structure model of κ′-Al2O3 has been obtained by means of X-ray powder diffraction data. An hexagonal unit cell with a=5.544 and c=9.024 Å and containing 5\frac13 A2O3 was assumed. The oxygen arrangement is the same close packed structure as that of tohdite, and 10\frac23 aluminium atoms are statistically distributed over several octahedral and tetrahedral positions. The R factor for the reflection intensity is 0.13 for 115 reflections.
The Extraction of the Cesium Ion with Some Nitrophenols into Nitrobenzene. I. Distribution Studies
Authors: Koyama Mutsuo , Tochiyama Osamu , Fujinaga Taitiro
Published: July 2006

The liquid-liquid extraction of alkali-metal nitrophenolates was studied by using nitrobenzene as the extracting solvent. Nitrophenol derivatives such as o-, m-, p-nitrophenols, α-dinitrophenol, and picric acid were chosen here in order to examine the effect of their steric characters and pK values on the distribution equilibrid. It was concluded that: 1) all the cesium nitrophenolates extracted into nitrobenzene were mainly in the dissociated form; 2) the extraction of m- and p-nitrophenolates proceeds by the stepwise adduct formation with free phenols, whereas little tendency of adduct formation was observed with the pier ate system; 3) α-dinitrophenolate has a character between the other two; 4) the distribution of o-nitrophenolate is negligible. A detailed discussion is given of the phenomena in terms of ionic equilibria in both the aqueous and organic phases.
Preparation and Circular Dichroism of Six Isomers of Bis(l-alaninate-N-monoacetato)cobaltate(III) Complexes
Authors: Okamoto Ken-ichi , Hidaka Jinsai , Shimura Yoichi
Published: July 2006

Six isomers, two trans(N) and four cis(N), of bis(l-alaninate-N-monoacetato)cobaltate(III) ions have been synthesized as their sodium or potassium salts. The isomers have been separated by ion-exchange column chromatography and their geometrical and chiral configurations determined on the basis of their absorption and circular dichroism spectra in visible and near ultraviolet regions and of proton magnetic resonance spectra. The corresponding l-prolinate-N-monoacetate complex has also been studied. The asymmetry of the coordinated imino nitrogen has been discussed from the analysis of the CD curves.
The Michael Reaction of Fluoro-substituted-9,9′-Bifluorenylidenes and -Fluorenes, and the Syntheses of Some Related Compounds
Authors: Minabe Masahiro , Tanaka Akio , Wakui Masahiro , Suzuki Kazuo
Published: July 2006

The Michael reaction of fluoro-substituted 9,9′-bifluorenylidenes and fluorenes was carried out; the normal addition products, fluoro-substituted tribiphenylenepropanes, were obtained, but no abnormal product was isolated. Some new fluoro-substituted-fluorenes, -9,9′-bifluorenylidenes, -9,9′-bifluorenyls and -α,δ-dibiphenylenebutadienes, were synthesized. The structures of the fluoro-substituted tribiphenylenepropanes were confirmed by the lithium-halogen interconversion reaction of 9-lithiofluorenes and 9-bromo-9,9′-bifluorenyls. The pyrolyses of fluoro-substituted tribiphenylenepropanes afforded fluoro-substituted or nonfluoro-substituted-9,9′-bifluorenylidenes, -9,9′-bifluorenyls, -fluorenes, and -fluorenones. Differential scanning calorimetry was applied to fluoro-substituted-9,9′-bifluorenyls and -tribiphenylenepropanes.
The Hofmann Rearrangement. II. Kinetic Substituent Effects of ortho-, meta-, and para-Substituted N-Chlorobenzamides
Authors: Imamoto Tsuneo , Tsuno Yuho , Yukawa Yasuhide
Published: July 2006

The reaction rates of the Hofmann rearrangement of ortho-, meta-, and para-substituted N-chlorobenzamides were measured under the same reaction conditions as were used for the preceding N-bromo series. The rate constants of the N-chloroamides were found to be slightly larger than those of the N-bromoamides. The relative values of the activation entropy and the activation enthalpy of N-chloro- and N-bromo-derivatives were approximately −4 e.u. and −1.3 kcal/mol respectively. The LFER between the two series was excellent, indicating that the reaction mechanism was almost the same for both series. The effects of the leaving group on the reactivity of ortho-substituents were discussed in terms of the ortho/para rate ratios and the relative values of the activation parameters of ortho- and para-substituents.
The Independent Isolation of a Primary Enamine and the Tautomeric Imine
Authors: Shin Chung-gi , Masaki Mitsuo , Ohta Masaki
Published: July 2006

Isolation of a primary enamine and its tautomeric imine has been described and their dimerization discussed. Reduction of ethyl 3-methyl-2-nitro-2-butenoate with aluminum amalgam afforded ethyl 2-amino-3-methyl-2-butenoate (I) (enamine form), while treatment of ethyl 3-methyl-2-oxobutanoate with triphenylphosphinimine gave ethyl 2-imino-3-methylbutanoate (II) (imino form). The enamine and its tautomeric imine dimerized to give 3,6-diisopropylidene-2,5-dioxopiperazine (VII) and 2-ethoxycarbonyl-2,5-diisopropylimidazolid-4-one (IX), respectively. However, individual acylation of both the enamine and the imine gave the same acyl compound.
Mechanism and Reactivity of Hydrolysis of Aliphatic Sulfonate Esters
Authors: Mori Akira , Nagayama Masuzo , Mandai Hiroshi
Published: July 2006

It was shown with a five-membered sultone that the hydrolysis of aliphatic sultones in water proceeds substantially by BAL1-E1 mechanism, and that it is a nucleophilic substitution reaction caused by hydroxyl ion and water. We carried out a kinetic experiment on the hydrolysis of 1,4-butanesultone and ethyl ethanesulfonate, both in water and in water-acetone mixed solvent. It was found that these aliphatic sulfonate esters were hydrolyzed substantially by BAL1-E1 mechanism as in the case of a five-membered sultone, and in particular, ethyl ethanesulfonate was hydrolyzed by complete BAL1-E1 mechanism. The results seem to be justified by a tracer experiment with H218O. Namely, the ratios of the C–O fission to the S–O fission in 1,3-propanesultone and ethyl ethanesulfonate were 85.6:14.4 and 100:0, respectively. In strong alkaline solutions and approtic solvent-water systems, the SN2 reaction involving attack of the nucleophile on sulfur atom took place partly in sultones, but practically not in linear sulfonate esters. On the other hand, the ratio of relative reaction rates of a five-membered sultone, a six-membered sultone, and a linear sulfonate ester in water is 37:1:7. Since Ea is nearly the same for these three compounds, the contribution of strain in the molecular structure to the reactivity is small, and in consequence the above ratio seems to be attributed to ΔS\eweq.
Substituted Benzopyranopyridine and Pyrimidine Ring Syntheses by the Ternary Condensation of Ethyl Cyanoacetate, Salicylaldehyde, and Certain Aldehydes in the Presence of Ammonium Acetate
Authors: Sakurai Akio , Midorikawa Hiroshi , Hashimoto Yasuo
Published: July 2006

Various 1-substituted benzopyranopyridines were readily prepared by the condensation of ethyl cyanoacetate and salicylaldehyde (or 3-methoxysalicylaldehyde) with aliphatic aldehydes (propion, n-butyl, n- and isovaleraldehyde) in the presence of ammonium acetate. On the other hand, condensation with aromatic aldehydes such as benzaldehyde and o-, m-, or p-substituted benzaldehydes gave 2-aryl-benzopyranopyrimidines.
Nuclear Magnetic Resonance Study of the Effect of the Hydrogen Bond on the Internal Rotation of Biphenyls
Authors: Oki Michinori , Akashi Kageyasu , Yamamoto Gaku , Iwamura Hiizu
Published: July 2006

Internal rotation about the pivot bond of several biphenyl derivatives has been studied by means of the nuclear magnetic resonance technique using non-identical chemical shifts of the two methyls in the isopropyl group which is located close to the center of dissymmetry. The results with the 2-methoxy and 2-hydroxy derivatives are compared. The solvent effect is marked in 2-hydroxy derivatives. These results, together with the substituent effect, indicate that the fact that the energy of activation for rotation about the pivot bond of the 2-hydroxy derivatives is a little higher than the corresponding methyl ether may be attributed to the stabilization of the ground state resulting from the presence of intramolecular O–H···π interaction. The infrared data agree with the above conclusion.
Reactions of p-Benzoquinone Derivatives with Ethylenediamine
Authors: Asahara Teruzo , Sen\={o} Manabu , Teshirogi Takuma
Published: July 2006

From the reaction results of p-benzoquinone derivatives with various amino compounds, it becomes clear that chloranil reacts with ethylenediamine to afford an unexpected product. The spectroscopic analyses of the product show that this is an addition compound with some contribution of charge-transfer structures. Bromanil gives a similar product upon reaction with ethylenediamine.
A Synthesis of Thyrotropin-Releasing Factor
Authors: Inouye Ken , Namba Keiko , Otsuka Hideo
Published: July 2006

A procedure is given for the synthesis of thyrotropin-releasing factor (TRF), a tripeptide l-pyrogultamyl-l-histidyl-l-proline amide. Benzyloxycarbonyl(Z)-glutaminyl-histidyl-proline amide (III) is obtained as an intermediate by the coupling of Z-glutamine p-nitrophenyl ester with histidyl-proline amide which is derived from the crystalline Z-dipeptide amide. Deprotection of III and the subsequent cyclization produce TRF in a moderate yield. Compound III and the corresponding Nα-acetyl derivative have little or no TRF activity.
Cyclic Acetylenes. XI. The Syntheses of p,p′-Bridged Cyclic Tolans by the Fritsch-Buttenberg-Wiechell Rearrangement
Authors: Ando Takashi , Nakagawa Masazumi
Published: July 2006

In order to ascertain the effect of ring strain on the electronic spectra of cyclic acetylenes, a series of p,p′-bridged cyclic tolans (Vn, n=11, 12, 13, 14, and 18) has been synthesized. It was found that the increasing ring strain exerted an appreciable hypochromic effect and also caused a slight bathochromic shift of the absorption band. The bathochromic shift observed in the p,p′-bridged cyclic tolans (Vn) forms a contrast with the hypsochromic shift observed in the strained o,o′-bridged cyclic diphenyldiacetylene (VI, n=3).
The Crystal Structure of Bis(pyridine-2-acetamide)copper(II) Perchlorate
Authors: Sekizaki Masao , Marumo Fumiyuki , Yamasaki Kazuo , Saito Yoshihiko
Published: July 2006

The crystal structure of bis(pyridine-2-acetamide)copper(II) perchlorate, Cu(paaH)2(ClO4)2, was determined from three-dimensional X-ray photographic data and refined by block-diagonal least-squares methods, using 1698 independent reflections to give R=0.12. The crystals are monoclinic with a space group of C2/c. There are four formula units in a unit cell with dimensions of: a=10.957, b=12.178, c=15.566 Å, and β=108.7°. The complex is centrosymmetric and square-planar, with two ligand molecules coordinating to the copper atom in trans positions through the amide-oxygen and the ring-nitrogen atoms. Two perchlorate ions coordinate weakly to the central copper atom through one of the four oxygen atoms from the top and bottom of the plane containing copper, amide-oxygen, and ring-nitrogen atoms.
The Effect of Benzene on the Reaction of the Recoil Bromine Atom with Ethyl Bromide
Authors: Shiokawa Takanobu , Sato Toshiro , Kondo Kenjiro
Published: July 2006

An attempt was made to estimate the effect of benzene on the recombination reactions of the recoil bromine atoms activated by the 81Br(n,γ)82mBr\oversetI.T→82Br and 81Br(n,2n)80mBr reactions in ethyl bromide and benzene mixtures. It seems to be reasonable to conclude, from the consideration of the parent yield, that the reactions leading to the formation of parent molecules in the thermal and high-energy regions can be classified into two reaction types. Judging from the results of the 81Br(n,γ)82mBr\oversetI.T→82Br reaction, approximately 53% of the parent yield from the high energy reactions in the pure ethyl bromide system is formed through the de-excitation process of the excited ethyl bromide labelled by the direct substitution reaction of the energetic recoil atom, while 47% is formed by the reaction of the recoil atom with ethyl radicals in the cage. The reaction of ethylene with hydrogen bromide, which is produced by the decomposition of the labelled excited ethyl bromide, contributes about 51% of the parent yield from the thermal energy reaction; the rest is formed by the other thermal reactions. Furthermore, no essential difference was observed between the recombination reactions of the recoil 82Br and 80mBr atoms produced by the 81Br(n,γ)82mBr\oversetI.T→82Br and 81Br(n,2n)80mBr reactions respectively.
The Crystal Spectra of Molecular Compounds of 1,6-Diaminopyrene
Authors: Amano Takako , Kuroda Haruo , Akamatu Hideo
Published: July 2006

Polarized absorption spectra were observed on the single crystals of molecular compounds which involve 1,6-diaminopyrene as electron donor and p-chloranil, p-bromanil, p-iodanil, and tetracyano-p-quinodimethane as electron acceptor. It is shown that, in spite of the low ionization potential of diaminopyrene 6.56 eV, its solid molecular compounds with chloranil, bromanil, and iodanil are of non-ionic type, and their crystal spectra exhibit the general features characteristic of a typical charge-transfer molecular compound composed of neutral molecules. The diaminopyrene-TCNQ, compound was found to be of ionic type. Although the bromanil and iodanil compounds of diaminopyrene exhibit two charge-transfer bands, in the region below 10 kK and at about 20 kK respectively, the chloranil compound does not show the near-infrared charge-transfer band corresponding to the charge transfer from the highest occupied orbital of the donor to the lowest vacant orbital of the acceptor. A discussion is given for this phenomenon from the overlap between the donor and acceptor orbitals.
Cyclic Acetylenes. XII. The Syntheses of o,p′-Bridged Cyclic Tolans by the Fritsch-Buttenberg-Wiechell Rearrangement
Authors: Kataoka Mutsuo , Ando Takashi , Nakagawa Masazumi
Published: July 2006

The polymethylene ether derivatives of o,p′-dihydroxydiphenvlacetylene (VIIn, n=7,8,9,10,11 and 12) have been synthesized by the Fritsch-Buttenberg-Wiechell rearrangement. The electronic, infrared, and NMR spectra of VIIn were examined. It was observed that the increasing ring strain had a hypochromic effect, with a hypso-chromic shift of the long-wavelength band in the electronic spectra of VIn making a contrast with the bathochromic shift in the strained p,p′-bridged cyclic tolans.
The Electronic Spectra of the Anion Radical Salts Derived from 2,3-Dicyano-1,4-benzoquinone and 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone
Authors: Iida Yôichi
Published: July 2006

The anion radical salts derived from 2,3-dicyano-1,4-benzoquinone and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone were prepared. The absorption spectra in an acetonitrile solution and the solid-state spectra were examined for these anion radical salts. Unlike the absorption spectra in solution, in the solid-state spectra strong charge-transfer bands appeared and there were blue-shifts of the high-energy bands. These spectroscopic features were discussed on the basis of the charge-transfer interaction between the anion radicals. The solid-state properties of these salts were compared with those previously investigated for the anion radical salts of the halogen-substituted p-benzoquinones.
Multidentate Ligand Substitution Reactions. XII. Substitution Reactions of the Nickel(II)-nitrilotriacetate Complex with Diethylenetriaminepentaacetic Acid in the Presence of Ethylenediamine and of the Nickel(II)-N-(2-hydroxyethyl)-iminodiacetate Complex with Ethylenediaminetetraacetic Acid and Cyclohexane-1,2-diamine-N,N,N′,N′-tetraacetic Acid
Authors: Kodama Mutsuo , Karasawa Sadatsugu , Watanabe Toshiyuki
Published: July 2006

The substitution reactions of the nickel(II)-nitrilotriacetate complex with diethylenetriaminepentaacetic acid in the presence of ethylenediamine and of the nickel(II)-N-(2-hydroxyethyl)-iminodiacetate complex with ethylenediaminetetraacetic acid and cyclohexane-1,2-diamine-N,N,N′,N′-tetraacetic acid were studied by employing the polarographic method. In the presence of ethylenediamine, the reaction of the nickel(II)-nitrilotriacetate complex with diethylenetriaminepentaacetic acid was found to proceed through the following four pathways:

(Remark: Graphics omitted.)

where X3− and Z5− denote completely-deprotonated nitrilotriacetate and diethylenetriaminepentaacetate anions respectively, and A°, ethylenediamine. By comparing the rate constants of the substitution reactions of the nickel(II)-nitrilotriacetate and ethylenediamine complexes with their dissociation rate constants, the structure of the reaction intermediate was determined. From the concentration dependence of the reaction rate, the reactions of the nickel(II)-N-(2-hydroxyethyl)-iminodiacetate complex with ethylenediaminetetraacetic acid and with cyclohexane-1,2-diamine-N,N,N′,N′-tetraacetic acid were concluded to proceed through the following two reaction pathways:

(Remark: Graphics omitted.)

where X2− and Y4− mean completely-deprotonated N-(2-hydroxyethyl)-iminodiacetate and ethylenediaminetetraacetate or cyclohexane-1,2-diamine-N,N,N′,N′-tetraacetate anions. From a comparison of the rate constants for the reaction of the N-(2-hydroxyethyl)-iminodiacetate complex with those for the corresponding reaction of the iminodiacetate complex, it was found that the hydroxyethyl group in the N-(2-hydroxyethyl)-iminodiacetate anion rather accelerates the dissociation of the N-(2-hydroxyethyl)-iminodiacetate anion from the nickel(II) ion.
Studies on Heteroaromaticity. XLIV. Reactivities of Benzoyl Cyanide N-Oxide and Some Derivatives Therefrom
Authors: Sasaki Tadashi , Yoshioka Toshiyuki , Suzuki Yasuyuki
Published: July 2006

ω-Chloroisonitrosoacetophenone was treated with ethylenic and acetylenic dipolarophiles to afford 3-benzoylisoxazolinines and -isoxazoles, respectively. With m-nitrobenzaldoxime or m-nitrobenzonitrile, it yielded 3-benzoyl-5-(m-nitrophenyl)-1,2,4-oxadiazole. The phenylhydrazones of the 3-benzoylisoxazole and -oxodiazole thus produced were converted to the corresponding 1,2,3-triazoles thermally or by the treatment with a base. The photoinduced rearrangement of 3-benzoyl-5-phenylisoxazole afforded 2-benzoyl-5-phenyloxazole. Treatment of ω-chloroisonitrosoacetophenone with aziridine afforded a new type of aziridine oximes, which was converted to 2-benzoyloxazoline.
Solvolysis of Organic Phosphates. III 3-Pyridyl and 8-Quinolyl Phosphates in Spontaneous Reaction
Authors: Murakami Yukito , Sunamoto Junzo
Published: July 2006

The spontaneous hydrolysis of 3-pyridyl and 8-quinolyl phosphates was investigated at 60, 70, and 80°C over the −log[H+] range from 1 to 7 in aqueous media with an ionic strength of 0.10. The reactions followed apparent first-order kinetics with respect to the unreacted phosphate species, and the maximum rate was observed around −log[H+]=2.5. Reactive species of each phosphate in hydrolysis were the neutral zwitterion and the monoanion, the former being found to be more labile. In a moderately acidic region (−log[H+]<2.0), an apparent enhancement of the reaction rate was detected for both phosphates, which was attributed to the acid catalysis acting on the zwitterion species. The activation enthalpy for hydrolysis of the zwitterion and the monoanion falls near 30 kcal mol−1. This is consistent with the reaction mechanism expected for hydrolysis of ordinary monoalkyl or monoaryl phosphate, in which the P–O bond cleavage takes place. The activation entropy data also provide an evidence for the unimolecular nature of the transition state. The kinetic solvent isotope effect kH2o/kD2o for the hydrolysis of both phosphates falls near unity. The isotope effect in this magnitude is consistent with the intramolecular proton-transfer mechanism. The results are, therefore, consistent with a mechanism for the hydrolysis of the zwitterion species of 8-quinolyl phosphate in which the quinolinium group donates a proton intramolecularly to the leaving ester oxygen atom in the transition state.
A Novel Cyclodimerization of Butadiene. A Synthetic Route to 2-Methylenevinylcyclopentane
Authors: Kiji Jitsuo , Masui Kazuo , Furukawa Junji
Published: July 2006

In the presence of a controlled amount of alcohol, the dimerization of butadiene to produce 2-methylenevinylcyclopentane has been shown to occur by means of several nickel catalysts. The most effective nickel catalysts are: (1) (Bu3P)2NiX2 (X=Cl and Br) and organolithium, (2) (o-tolyl)NiX(PEt3)2 (X=Cl, Br, and I), and (3) π-allylnickel bromide and tri-n-butylphosphine. A detailed study of the role of alcohol during the reaction by the arylnickels is presented. In the presence of butadiene, the aryl-nickel bond of (o-tolyl)NiX(PEt3)2 is reductively cleaved by methanol to give toluene, and then the dimerization of butadiene occurs. With CH3OD as the reducing reagent, toluene is not deuterated, but with CD3OD the aromatic ligand is deuterated on the carbon originally bonded to nickel to give monodeuterotoluene.
Phosphorylation of Alcohols and Phosphates by Oxidation-Reduction Condensation
Authors: Mukaiyama Teruaki , Hashimoto Mitsunori
Published: July 2006

Phosphorylation of alcohols and phosphates forming mixed esters of phosphoric acid and pyrophosphate by the oxidation-reduction condensation with triphenylphosphine and 2,2′-dipyridyl disulfide has been investigated. n-Butyl p-nitrophenyl phosphate was obtained in 80% yield when p-nitrophenyl dihydrogen phosphate was treated with one equiv. each of triphenylphosphine and 2,2′-dipyridyl disulfide in the presence of three equiv. of anhydrous n-butyl alcohol at room temperature. It was found that P1,P2-bis(p-nitrophenyl)pyrophosphate was obtained in 91% yield when p-nitrophenyl dihydrogen phosphate was treated with 1.5 equiv. each of triphenylphosphine and 2,2′-dipyridyl disulfide.
Structure of Polynucleotide Complex with Non-Complementary Nucleosides. II. Poly I, U + Poly C
Authors: Akutsu Hideo , Tsuboi Masamichi
Published: July 2006

Three copolymers of riboinosinic acid and ribouridylic acid (poly I,U) with uridylic acid contents, 20, 32, and 44% were prepared. The ultraviolet absorption measurements were carried out with aqueous solutions of mixtures of poly I,U and polytribocytidylic acid (poly C) of various mole ratios. It has been shown that a double-helical structure is formed with an I···C type inter-base binding and with the U residue looping out of the helix. The structure was found to break on heating the solution. The process of break down was followed by means of ultraviolet absorption measurements.
Anisotropy of the Indirect Nuclear Spin-Spin Coupling Constants. III. Problems in the Structure Determination of the Molecule Dissolved in a Nematic Solvent
Authors: Nakatsuji Hiroshi , Morishima Isao , Kato Hiroshi , Yonezawa Teijiro
Published: July 2006

Anisotropy of the indirect nuclear spin-spin coupling constant was studied theoretically. All the contributions to the coupling tensors were calculated for various molecules by using the INDO molecular orbitals. As shown in part I of this series, the calculated 13C–H coupling anisotropy of 13CH3F is too small to be compared with the value obtained experimentally by Krugh and Bernheim. Thus we examined the substituent effect on the anisotropy in the 13CH3X series. It is concluded that the experimentally estimated value of the 13C–H coupling anisotropy in 13CH3F as large as 1890 Hz is erroneous and that it contains some other effects which are more important than electronic effect. We believe that the change in molecular geometry from gas state to the solute state in a nematic solvent is the most probable origin for the differences between theories and experiments. For the directly bonded C–X couplings (X is C, N or F), their anisotropies are in the same order of magnitude as their isotropic couplings. For the non-bonded C–X nuclei, they seem negligible in magnitude. For the F–F couplings, their anisotropies are exceptionally large and the orbital term is a very important source of anisotropy. Furthermore, even for the isotropic F–F couplings, the orbital and spin dipolar terms are very important and sometimes make decisive contributions exceeding the Fermi contact term.
The Interpretation of the EPR Spectra of the Amorphous State of Group VIB Hydride Radicals by Means of the Gas-phase Data
Authors: Kotake Yashige , Ono Mitsuo , Kuwata Keiji
Published: July 2006

A new procedure for the interpretation of the amorphous EPR spectra of the group VIB hydride radicals, i.e., OH, SH, SeH, and TeH, is proposed. The point of this method is to combine the observed hyperfme structure of these radicals in the gas phase and the calculation of the anisotropic hyperfine coupling constant. For this purpose, the Slater orbital and analytical Hartree-Fock orbitals were examined as unpaired electron orbitals by the comparative calculation of the hfs constants. The accuracy of this method was evaluated successfully by applying it to the OH radical. Moreover, in the case of the SH radical the newly-observed spectra in the amorphous state could be assigned to the SH radical.
Measurements of Total Cross Sections for the Scattering of Potassium Atoms by Rare Gases
Authors: Kusunoki Isao
Published: July 2006

Total cross sections for the scattering of potassium by He, Ne, Ar, Kr, and Xe have been measured in the thermal energy range. The velocity of potassium beam is selected by a velocity selector of a slotted disk type. To obtain accurate total cross sections, the pumping effect of a McLeod gauge for the pressure measurements, the fringe effect of the scattering chamber, corrections for angular resolution and for thermal motion of the target gases are taken into consideration. A new type of scattering chamber with a variable length is used to eliminate the error of the effective scattering path length. Velocity dependence of total cross sections has been obtained and glory undulations are observed for potassium-xenon systems. For argon, krypton, and xenon the van der Waals constants are calculated from the absolute total cross sections. The values of CK–Ar, CK–Kr, and CK–Xe are 237, 354, and 535×1060 erg·cm6, respectively, and are in good agreement with the theoretical ones of Dalgarno and Davison. For neon the velocity dependence of the total cross section can not be explained by the van der Waals potential, −C⁄rs, where s=6. For helium the correction factors for thermal motion of the scattering gas are large and the value of s for attractive potential can not be determined unambiguously.
Ferrocene Polymers Obtained by the Polycondensation of Ferrocene with Dicarboxylic Acid Chlorides
Authors: Asahara Teruzo , Sen\={o} Manabu , Mitsuhashi Keiryo , Ichikawa Yohsuke
Published: July 2006

The polycondensation reactions of ferrocene with terephthaloyl and adipoyl chloride were investigated in the presence of AlCl3, ZnCl2, or FeCl3 as the catalyst and in dichloromethane, n-hexane, carbon tetrachloride, or dioxane as the solvent. With terephthaloyl chloride, the highest polymer yield was obtained when AlCl3 in n-hexane was used, and the product was mainly of a polyketone structure. The polycondensation with adipoyl chloride afforded the most satisfactory result when ferrocene was treated in liquid adipoyl chloride with neither catalyst nor solvent, and a product with the expected structure was obtained. The average molecular weights of the products are in the range of 3000–7000. Polymers obtained by polycondensation with terephthaloyl and succinyl chloride are paramagnetic and show the temperature dependence characteristic of semi-conductivity.
Studies on the Interaction between Long Chain Alcohols and Alkyl Sulfates. I. Molecular Association between Long Chain Alcohols and Corresponding Alkyl Sulfates
Authors: Moroi Yoshikiyo , Motomura Kinshi , Matuura Ryohei
Published: July 2006

Molecular interaction between long chain alcohols and corresponding alkyl sulfates, such as dodecyl alcohol-sodium dodecyl sulfate, tetradecyl alcohol-sodium tetradecyl sulfate and hexadecyl alcohol-sodium hexadecyl sulfate, was studied by measurement of heat of complex formation, differential thermal analysis and infrared spectroscopy. It was found that there were two kinds of complexes, I and II, differing in the composition of alcohols and corresponding sulfates. The former is stable at temperatures below the melting point of alcohol, the molar ratio of alcohol to sulfate being 0.53–0.63. The latter is stable at temperatures above the melting point of alcohol, its molar ratio being 1.0. The heat of formation of II is 7–8 kcal/mol, which suggests that the complex is formed by a force similar to hydrogen bonding between alcohols and sulfates. The peak temperature in the DTA curve due to decomposition of the complex is about 10°C lower in I than in II and the characteristic absorption bands in IR spectrum are 3480 cm−1 and 3520 cm−1 in I and II, respectively, which correspond to hydrogen bond between two components.
The Gas-Phase Radiolysis of Cycloheptatriene
Authors: Nakamura Katsuyoshi , Takamuku Setsuo , Sakurai Hiroshi
Published: July 2006

The γ radiolysis of cycloheptatriene (CHT) in the gas phase has been investigated as a function of the pressure (2–14 mmHg) and in the presence of various additives (NO, O2, NH3, N2O, and C3H8). The G values obtained at 10.5 mmHg and at a total dose of 1.1×1019 eV are as follows: hydrogen, 0.50; methane, 0.16; acetylene, 1.52; cyclopentadiene, 0.29; benzene, 0.65; toluene, 1.68; dimers, 2.99. The yields of toluene and cyclopentadiene decrease with the pressure and are not appreciably affected by these additives; this suggests a contribution of the excited CHT molecules formed by direct excitation to their formation. The formation of dimers and benzene is affected by a radical scavenger (O2, NO), indicating the importance of the radical processes. The reaction products obtained via a C7H7+ ion, which is well known to be produced by the irradiation of CHT, have not been observed, while in the radiolysis of CHT in the presence of benzene and a radical scavenger, biphenylmethane has been produced, presumably by a reaction of the C7H7+ ion with benzene. Therefore, it was assumed that the C7H7+ ion produced from CHT does not contribute to the dimer formation, but may initiate the ionic polymerization.
Heats of Immersion of Silica-alumina in Nonaqueous Solvents
Authors: Miura Masaji , Iwaki Toru , Komuro Masayoshi , Tanaka Kusao , Ito Kenji
Published: July 2006

The heats of immersion of silica gel, alumina, and silica-aluminas in benzene, cyclohexane, and a solution of n-butylamine in benzene have been studied in connection with the acid properties of the surfaces. It was found that n-butylamine interacts more strongly with the surfaces of silica-aluminas than is the case in an aqueous system, which was previously investigated. Further, the interactions of benzene with the surfaces of silica-aluminas were discussed on the basis of the results of the adsorption isotherms of benzene on the surfaces.
Studies on Cobaloxime Compounds. V. Oxidation of Formaldehyde with Cobaloximes and Aquocobalamin
Authors: Hohokabe Yorikatsu , Yamazaki Noboru
Published: July 2006

Catalytic activities of cobaloximes in the oxidation of formaldehyde were compared with each other and with the activity of aquocobalamin (vitamin B12a). All the cobaloximes showed much less activities than B12a. Chlorocobaloximes had the highest activities. Reaction order was found to be −0.18 with respect to the concentration of hydrogen ion, 0.71 to that of formaldehyde, and 0.49 to that of chloroaquocobaloxime. In anaerobic conditions, the reduced-state B12r considered to be an intermediate in the air-oxidation reaction of aldehyde was detected spectrochemically, but not the reduced-state of cobaloxime. A much slower reaction of aldehyde with cobaloximes as compared with cobalamin was attributed to the higher reduction potentials of the former.
The Nitrosation of β-Keto Sulfoxides
Authors: Otsuji Yoshio , Tsujii Yasuhiro , Yoshida Akihiko , Imoto Eiji
Published: July 2006

β-Keto sulfoxides were prepared by the reaction of the esters with the methylsulfinyl carbanion. The nitrosation of the β-keto sulfoxides, RCOCH2SOCH3 (R=C6H5, C6H5CH2CH2, n-C3H7), with sodium nitrite and hydrochloric acid gave the corresponding α-chloro-α-isonitroso ketones, RCOC(=NOH)Cl, in high yields. However, the nitrosation of α-substituted β-keto sulfoxide, RCOCH(R′)SOCH3, in a similar manner afforded the α-isonitroso ketones, RCOC(=NOH)R′. The mechanisms of these reactions were studied.
A Facile Desulfurization Reaction with a Combination of Two Kinds of Metals in Acidic Media. The Synthesis of Hypoxanthine
Authors: Nakamizo Nobuhiro , Shiozaki Kazuo , Hirai Seiichi , Kudo Shiro
Published: July 2006

A facile desulfurization procedure has been presented for the method that synthesizes hypoxanthine in one step by heating 4,5-diamino-6-hydroxy-2-mercaptopyrimidine with a desulfurizing agent in formic acid. When Raney nickel prepared in the usual way was used as the desulfurizing agent, it was necessary for the ratio of nickel atoms to sulfur atoms (the Ni/S ratio) to be more than 2.6 : 1. On the contrary, when the Raney alloy per se was used, the amount of nickel could be diminished to a catalytic amount (Ni/S 0.2–0.3). The higher the content of aluminum in the alloy, the smaller the Ni/S ratio required for the desulfurization. In contrast with usual desulfurization reactions carried out in neutral media, most of the sulfur was released from the reaction mixture as hydrogen sulfide. Although aluminum or iron powder by itself had little desulfurizing activity, its addition to the Raney alloy was useful in diminishing the Ni/S ratio. Furthermore, combinations of nickel or cobalt salts and aluminum or iron powder were as effective as the Raney alloy as desulfurizing catalysts. In the case of a combination of nickel formate and aluminum powder, a large portion of the nickel ion was proved to be reduced to metallic nickel. The desulfurization reaction also proceeded smoothly in an aqueous solution of hydrochloric or sulfuric acid. On the basis of these facts, a mechanism was proposed with which the active nickel catalyst is regenerated by such auxiliary metals as aluminum or iron.
The Photochemistry of Heterocyclic Compounds. IV. The Mechanism of the Photodecomposition of Alloxan Monohydrate. The Effects of Solvents
Authors: Wake Shigeo , Mawatari Takeshi , Otsuji Yoshio , Imoto Eiji
Published: July 2006

The photolyses of alloxan monohydrate (1) were carried out in water, 2-propanol, and dioxane. Irradiation in water produced alloxantin dihydrate (2), glyoxal (5), oxaluric acid (6), parabanic acid (7), and oxalyl diureide (8). However, when the photolyses were conducted in 2-propanol and dioxane, 2 and 5 were isolated as the main products. A detailed examination of the changes in the product distributions in the three solvents led to the conclusion that 2 and 5 are produced through the pathways involving the radical fission of the C–OH and C–CO bonds in 1. On the other hand, 6, 7, and 8 were supposed to be produced by the pathways involving the photochemical hydrolysis of 1 to alloxanic acid (13).
Studies on Stable Free Radicals. V Reactivity of a Stable Free Radical, 2,2,6,6-Tetramethyl-4-oxopiperidine-1-oxyl
Authors: Yoshioka Takao , Higashida Susumu , Morimura Syoji , Murayama Keisuke
Published: July 2006

A stable N-oxyl radical, 2,2,6,6-tetramethyl-4-oxopiperidine-1-oxyl (I), afforded 1-hydroxy-2,2,6,6-tetramethyl-3-(2,2,6,6-tetramethyl-4-oxopiperidinoxy)-4-oxopiperidine (IX) by hydrogen-abstraction followed by the coupling reaction of the N-oxyl radical I with the C radical III derived from I. The product IX was characterized as the monoacetate (X), monobenzoate (XI), urethane (XII), semicarbazone (XIII), triol (XIV), triacetate (XV), and a new N-oxyl radical (XVI). It has been confirmed that i) the extremely stable N-oxyl radical abstracts the α-methylene-hydrogen of the ketone which affords a thermodynamically stable conjugated ketone, ii) radical I acts as a scavenger toward a C-radical intermediate and iii) the decomposition of radical I proceeds via the C-radical to give phorone (V).
The Synthesis of 1-Phenylazulene and 2-Phenylazulene from the Troponoid Compound
Authors: Nozoe Tetsuo , Takase Kahei , Fukuda Satoko
Published: July 2006

1-Phenylazulene (I) and 2-phenylazulene (II) were synthesized from the troponoid compound. 3-Phenyl-(III) and 3-benzoyl-2H-cyclohepta[b]furan-2-ones (IV) were prepared by the reaction of 2-chlorotropone with ethyl phenylacetate and with ethyl benzoylacetate respectively. The reactions of III with malononitrile or ethyl cyanoacetate gave 1-phenylazulene derivatives, from which I was derived. On the other hand, the reactions of IV with ethyl cyanoacetate or diethyl malonate gave 2-phenylazulene derivatives, from which II was derived.
Aminocyclitols. XXVI. A Synthesis of Aminocyclopentanetetrols
Authors: Suami Tetsuo , Sakota Yukio , Tadano Kinnichi , Nishiyama Shigeru
Published: July 2006

Hydrogenation of 2,3-O-cyclohexylidene-5-nitro-1,2,3,4-cyclopentanetetrol, subsequently followed by hydrolysis and acetylation, afforded (1,4/2,3,5)- and Dl-(1,2,3/4,5)-5-acetamido-1,2,3,4-tetra-O-acetyl-1,2,3,4-cyclopentanetetrol (3 and 14). Beginning with (1,4/2,3,5)-5-acetamido-1,4-di-O-acetyl-2,3-O-cyclohexylidene-1,2,3,4-cyclopentanetetrol (2), two hitherto unknown (1,2,3,4,5)- and Dl-(1/2,3,4,5)-5-acetamido-1,2,3,4-tetra-O-acetyl-1,2,3,4-cyclopentanetetrol (10 and 12) were prepared. The structures were established by proton magnetic resonance spectra.
Linear Conjugated Systems Bearing Aromatic Terminal Groups. V. Syntheses and Electronic Spectra of 2,2′-, 3,3′-, and 9,9′-Diphenanthrylpoly-ynes
Authors: Akiyama Shuzo , Nakagawa Masazumi
Published: July 2006

2,2′-, 3,3′-, and 9,9′-Diphenanthrylpoly-ynes (Vn, VIn, and VIIn, n=1–6) were synthesized and their electronic spectra were measured. It was found that the longest-wavelength absorption maxima (λmax) in the spectra of each series of the diphenanthrylpoly-ynes (Vn, VIn and VIIn) shift linearly with the xth power of the number of acetylenic bond (n), [λmax∝nx], being x=1.3 for Vn and x=1.4 for VIn and VIIn.