bluuebunny/crossref_metadata_2025 huggingface dataset:
Compounds Related to Acridine. X. The Reaction of 9-Ethynylacridine with Active Methylene Compounds
Authors: Tsuge Otohiko , Torii Akiyoshi
Published: July 2006

In the presence of aqueous sodium hydroxide, 9-ethynylacridine (I) reacts with malononitrile and with ethyl cyanoacetate to yield the corresponding 1,1-disubstituted 3-(9-acridanylidene)propenes III. A similar reaction of I with diethyl malonate affords a 2:1 adduct VI and a 1:2 adduct VII. On the other hand, I reacts with acetylacetone to give 3-acetyl-5-(9-acridanylidene)-1-(9-acridinyl)pent-1,3-diene (IX). In this context, the reaction of 9-chloroacridine (XI) with active methylene compounds has been reinvestigated; XI reacts with malononitrile and with ethyl cyanoacetate to afford products XII with an acridane structure, while with diethyl malonate XI gives 9-di(ethoxycarbonyl)methylacridine (XIII), as has been reported previously.
Studies on Nitrile Salts. I. Dimerization of Nitriles Having α-Hydrogen in the Presence of Hydrogen Chloride
Authors: Yanagida Shozo , Fujita Tetsuo , Ohoka Masataka , Katagiri Ichiro , Komori Saburo
Published: July 2006

The compositions and structures of several stable nitrile-HCl salts previously reported were reinvestigated. Most of them have been found to have the composition of 2RC≡N·2HCl and have been identified as N-(α-chloroalkenyl)alkylamidine hydrochlorides (3) by mass and NMR spectra analyses. However, the 2:3 adduct from chloroacetonitrile was confirmed to be N-(α,α,β-trichloroethyl)chloroacetamidine hydrochloride. The scope and limitations of the dimerization reaction of nitriles having α-hydrogen with HCl were studied. Most nitriles having α-hydrogen react with HCl to give N-(α-chloroalkenyl)alkylamidine hydrochlorides (3). Their hydrolysis to diacylamines (4) was also investigated.
An MO-simulation of Elementary Reactions in Hydrocarbon Oxidation. I. A Bimolecular Coupling Reaction of the Methyl Radical and Molecular Oxygen
Authors: Ohkubo Katsutoshi , Kitagawa Futoshi
Published: July 2006

An MO-simulation of the geometrical change in the bimolecular methane oxidation, CH3+O2→CH3O2, was performed using the CNDO/2 approximation. The geometry of CH3O2 was predicted to take rOO=1.19 Å and ∠COO=111° with fixed distances of rCO=1.44 Å and rCH=1.09 Å. The coupling reaction proceeds smoothly, without any appreciable activation energy, with the geometric transformation of the momentarily-living CH3--O2, with rCO=2.36∼1.44 Å, rOO=1.132∼1.19 Å, and ∠COO=90∼111°. The magnitude of the electron migration between CH3 and O2 throughout the reaction was estimated.
Hydrates of Organic Compounds. I. Solid-Liquid Phase Equilibria in the Water+1,4-Dioxane System and Some Properties of 1,4-Dioxane Hydrate
Authors: Nakayama Haruo , Tahara Masao
Published: July 2006

The solid-liquid phase diagram for the water +1,4-dioxane system has been determined by the ordinary cooling curve method and with the aid of a differential scanning calorimeter (DSC). The diagram shows the existence of a hydrate which is stable in rather narrow ranges of temperature (−15.8∼−13.5 °C) and of composition (37.0∼46.5 wt% dioxane). From the phase relations and an analysis of the calorimetric data, the composition and the heat of formation (from the liquid states of both components) of the hydrate have been estimated to be C4H8O2·mH2O with m=36∼39 and ΔH1=−51.3 (for m=36)∼−55.6 (for m=39) kcal/mol respectively. This hydrate seems to be the same as that recently reported by Rosso et al., though the compositions and the temperature ranges are very different.
Acidic properties of Binary Metal Oxides
Authors: Shibata Katsue , Kiyoura Tadamitsu , Kitagawa Jun , Sumiyoshi Takashi , Tanabe Kozo
Published: July 2006

Eighteen binary metal oxides consisting of TiO2–MmOn, ZnO–MmOn and Al2O3–MmOn (MmOn: metal oxide) were prepared by the usual co-precipitation method, their acid amounts and strengths being determined by n-butylamine titration using various acid-base indicators. The acid strengths of fourteen of the tested binary oxides of molar ratio 1 : 1 were found to be remarkably higher than those of the component single oxides. High acid strengths were as follows: H0≤−8.2 for TiO2–SiO2, H0≤−5.6 for TiO2–Al2O3 and Al2O3–ZrO2 and H0≤−3 for TiO2–CdO, TiO2–SnO2 and ZnO–SiO2. The acid amounts of sixteen binary oxides were larger than those of the component oxides. The effect of the composition of binary oxides on acidity was examined for TiO2–Al2O3, ZnO–Al2O3 and Al2O3–ZrO2. The acidity maxima appearing for TiO2–Al2O3 and ZnO–Al2O3 were found to be of molar ratio\simeq9:1 and for Al2O3–ZrO2\simeq3:2. A fairly good correlation has been demonstrated between the observed highest acid strengths and the average electronegativities of metal ions of binary oxides.
Solvent Effect under High Pressure. Participation of Solvent in the Activated Complex in the Menschutkin Reaction
Authors: Tamura Katsuhiro , Ogo Yoshiaki , Imoto Tatsuya
Published: July 2006

Rates of the reaction between 3,5-lutidine with ethyl iodide have been measured at 50 °C over the pressure range 1–1,940 kg/cm2 in benzene-nitrobenzene mixtures. The solvation number and average pressure within the solvation-shell of activated complex have been estimated from the rates and the compression of solvent. The solvation number was almost independent of solvent composition, but not the average pressure within the solvation-shell. Estimation of the structural term of the activation volume Δ1V\eweq in the reaction has been discussed. The logarithms of the rate constants showed a linear relation with the ET-values under atmospheric pressure.
The Photoelectron Spectra of Alcohols, Mercaptans and Amines
Authors: Ogata Hitoshi , Onizuka Hatsuki , Nihei Yoshimasa , Kamada Hitoshi
Published: July 2006

The HeI photoelectron spectra of aliphatic amines, alcohols and mercaptans were measured. These spectra, especially those of methylsubstituted compounds, were interpreted in terms of the orbital energies and corresponding eigenvectors calculated by the CNDO/2 and the INDO type self-consistent field molecular orbital techniques. Modification of CNDO/2 was also performed and the results are briefly discussed.
Intermediates and Mechanism of Photo-Oxygenation Reaction of Triethylamine
Authors: Tsubomura Hiroshi , Yagishita Teruo , Toi Hiroo
Published: July 2006

The electronic absorption spectrum caused by the charge transfer interaction between oxygen and triethylamine was studied quantitatively. It is concluded that there is no particular stabilization between them due to the charge transfer interactions. The intermediate radicals produced by the excitation of triethylamine–O2 in the region of the charge transfer band were studied by the ESR method at various temperatures from 77 to 300 K. The chemical analysis of the irradiation products of the same system was also carried out. The radicals observed are methyl, ethyl, and possibly, (C2H5)2N\dotCHCH3, \dotOOH and (C2H5)2NO·. The products identified are acetaldehyde and diethylamine. Based on these results, the various reactions taking place in the overall photochemical process were speculated.
Electron-donating Strengths of Some Ketimines Intermolecular Charge Transfer Studies
Authors: Abu-Eittah R , Hamed M M
Published: July 2006

The electron-donating strengths of some ketimines have been investigated via the formation of charge transfer complexes with iodine as electron-acceptor. Two types of ketimines were chosen as electron-donors, namely, the =N– unsubstituted as well as the =N– substituted ketimines. With the first type of donors the “n” charge transfer complex was obtained whereas with the second type the “π” charge transfer complexes were obtained. The equilibrium constants were computed for the different types of complexes. An attempt is made to estimate the ionization potentials of the donors from the position of the charge transfer band characteristic of the specific complex.
Intramolecular Rotations in 1,2-Dialkoxyethanes in the Liquid State
Authors: Das Arati , Ghatak Alpana , Hasan Abul , Roy S B
Published: July 2006

Dielectric measurements have been made in 1,2-dimetboxy- and 1,2-diethoxyethane in the liquid state in 1.62, 3.17, and 3.49 cm microwave region. Both the molecules are found to relax mostly by methoxy/ethoxy group rotations.
Polarographic Study of the Substitution Reactions between Nickel(II) Ions and Copper(II) Chelates of Triethylenetetraminehexaacetic Acid
Authors: Haque Md Shamsul , Kopanica Miloslav
Published: July 2006

The mechanism of substitution reaction between nickel ion and Cu–TTHA chelate was studied by polarographic technique. During the study of the substitution reaction the existence of mixed binuclear chelate CuXNi2− was verified and the value of the stability constant was calculated on the basis of polarographic data. Formation of the mixed binuclear chelate was further verified by the amperometric tit ration of the equimolar mixture of both metal ions with TTHA. Finally the existence of mixed binuclear chelate CuXNi2− was verified by potentiometric titration method. When nickel is present in large excess the replacement of Cu2+ ions from Cu2X2− occurred directly without formation of intermediate mixed binuclear chelate. The stability constant of Cu2X2− was calculated from equilibrium study.
A UV Study of the Magnesium Haematoporphyrin Complex
Authors: Anand V D , Carper W R
Published: July 2006

The interaction between magnesium and haematoporphyrin has been studied spectrophotometricaly as a function of concentration, pH and temperature and the existence of a strong 1 : 1 complex has been established. The Benesi-Hildebrand equation was used to determine Kc’s at various wavelengths and temperatures, at pH’s of 7.4, 8.2, and 9.0. The enthalpy of complex formation is seen to change from +9.78 kcal/mol to −9.50 kcal/mol as the pH changes from 8.2 to 9.0. This change may be a reflection of the change in the various ligands which coordinate to the magnesium ion in addition to the porphyrin ring.
Some Reversible and Irreversible Electrode Processes at DME. A Study on Uranyl and Zinc Complexes of l-Hydroxyproline in Aqueous and Aqueous-Methanolic Solutions
Authors: Rawat P C , Gupta C M
Published: July 2006

Complexes of zinc and uranyl ions with l-hydroxyproline (LHP) have been investigated by polarographic method of analysis at 25±1 and 35±1 °C. At pH 4.5, formation of uranyl-LHP complex was observed with metal to ligand ratio of 1: 1 in aqueous and aqueous-methanolic solutions. The stability constant for the complex species is logKc=1.50, 1.30, 1.61, 1.87 in aqueous (25 °C), aqueous (35 °C), aqueous-methanolic (10% v/v) and aqueous-methanolic (50% v/v) media respectively. Between pH 3.0–12.0, zinc–LHP complex has been observed to be reduced irreversibly at DME. Detailed investigations have been reported on the system at 25±1 °C and 35±1 °C at pH 10.0 in varying concentrations of the ligand. Kinetic parameters—the formal rate constant Kf,h° and transfer coefficient α have been calculated.
Liquid-Liquid Extraction of Zinc with Thiothenoyltrifluoroacetone Direct Photometric Determination in the Organic Phase
Authors: Solanke K R , Khopkar S M
Published: July 2006

The thioderivative 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 photometric determination of zinc. About 68 μg of zinc was quantitatively extracted at pH 7–7.5 with 10 ml of 0.001 M STTA in carbon tetrachloride as yellow green colored complex. It was measured spectrophotometrically at 450 nm. The system conformed to Beer’s law over the concentration range of 0.4 to 30 μg of zinc per ml. The color of the complex was stable for more than 96 hr. Zinc was extracted quantitatively and was determined in the presence of large excess of (1 : 300) ions which are associated with it. The method was made selective by using sequestering agents like ascorbic, oxalic, citric acids or alkali cyanide to form unextractable negatively charged complexes. The selective extraction with mesityl oxide was used to eliminate the interferences due to iron and chromium. The procedure was found to be applicable for the analysis of zinc in gun metal and brass. The proposed method is comparable with the standard methods for the extraction of zinc.
The Thermal Properties of Gallium-bearing Allophane
Authors: Kasai Mitsuhiro , Kudo Yoshiyuki , Hamada Shuichi
Published: July 2006

The DTA patterns of synthesized coprecipitated gels, SiO2–Al2O3–Ga2O3–H2O system, resembled that of allophane, and the exothermic peak temperature in the DTA was lowered continuously from 980 to 810 °C with an increase in the gallium content, while that on mixed gels scarcely lowered. The apparent activation energy for this exothermic reaction on the coprecipitated gels decreased with an increase in the gallium content, while that on the mixed gels hardly changed. The crystallization process during the heat treatment of the gels depended on the content and on the coexistence state of the gallium. A unit cell volume of a mullite crystallized at 1200 °C in the coprecipitated gels was enlarged by forming a solid solution with the gallium ion, in contrast to the small change in that formed in the mixed gels. Further, the exothermic peak in the DTA was considered to originate not only from the formation of the mullite, but also from that of the silico-alumina spinel in the gallium-bearing gels; the exothermic reaction products seem to depend on the composition or the coexistence state of gallium in the gels.
An MO-theoretical Interpretation of the Reductive Cleavage of Organic Halides by Pentacyanocobaltate(II)
Authors: Ohkubo Katsutoshi , Kanaeda Hirokazu , Tsuchihashi Kohji
Published: July 2006

The mechanism of the reductive cleavage of organic halides (RX) by pentacyanocobaltate(II) Co(CN)53− was investigated by means of the extended Hückel MO theory. First, the molecular structure of Co(CN)53− was considered to be the square-pyramidal C4V configuration, without H2O as its sixth ligand. Secondly, the order of the observed rate constants for the Co(CN)53−+RX→Co(CN)5X3−+R. reaction was found to be in satisfactory accordance with that of the calculated binding energies of the R-X bond. Thirdly, the reductive cleavage of RX by Co(CN)53− proceeds by the aid of the predominant electron-migration from the highest-occupied, lone-pair halogen-orbital to the singly-occupied dz2 Co-orbital and from the highest-occupied dxz (or dyz) Co-orbital to the lowest-unoccupied, antibonding pσ* orbital of the R–X bond. Finally, the mode of the interaction between Co(CN)53− and RX was precisely discussed in terms of the homolytic cleavage of the R–X bond.
The Solubility of Sulfur in Na2O–SiO2 Melts under Various Oxygen Partial Pressures at 1100 °C, 1250 °C, and 1300 °C
Authors: Nagashima Shigeru , Katsura Takashi
Published: July 2006

The solubility of sulfur in Na2O–SiO2 melts with the Na2O/SiO2 molar ratios of 1/3, 1/2, and 1/1 was investigated by varying the oxygen partial pressure at 1100, 1250, and 1300 °C. The results at 1100 °C are complicated, for the equilibrium state within the gas phase is not established. From the experiments at 1250 and 1300 °C, the following conclusions are reached: (1) When the temperature and the Na2O/SiO2 ratio in the melt are constant, the solubility of sulfur increases with an increase of the total amount of sulfur in the gas phase. (2) When the temperature, the Na2O/SiO2 ratio, and the total amount of sulfur in the gas phase are constant, the solubility of sulfur shows its minimum at a specific oxygen partial pressure; at higher oxygen partial pressures, the sulfur dissolves in the melts mostly as sulfate, while at lower oxygen partial pressures, the sulfur dissolves mostly as sulfide. (3) When the temperature and the total amount of sulfur in the gas phase are constant, the solubility rises greatly with an increase in the Na2O/SiO2 ratio in the melt. (4) When the Na2O/SiO2 ratio in the melt and the total amount of sulfur in the gas phase are constant, the minimum point of the solubility shifts in the direction of higher oxygen partial pressures as the temperature increases. This corresponds to the shifts of the equilibrated gas composition as the temperature increases.
Molecular Complexes of Arenetricarbonylchromium
Authors: Kobayashi Hiroshi , Kobayashi Mitaka , Kaizu Youkoh
Published: July 2006

Arenetricarbonylchromium forms a charge-transfer molecular complex with electron acceptors such as 1,3,5-trinitrobenzene and tetracyanoethylene but not with electron donors such as N,N,N′,N′-tetramethyl-p-phenylenediamine. The ionization potentials of arenetricarbonylchromium complexes were determined from the charge-transfer transition energies in the molecular complexes. The molecular complexes are formed by a charge-transfer interaction of electron acceptor toward the π-coordinating benzene ring of arenetricarbonylchromium in the case of 1,3,5-trinitrobenzene, and by a charge-transfer toward the central chromium in the case of tetracyanoethylene.
Circular Dichroism of Copper(II) Complexes with Optically Active Tetradentate Ligands in Aqueous Solutions
Authors: Murakami Tasuku , Hatano Masahiro
Published: July 2006

The circular dichroism (CD) spectra of copper(II) complexes containing the asymmetric tetradentate ligands, such as ethylenediamine-N,N′-di-l-α-propionate, ethylenediamine-N,N′-di-l-α-isovalerate, and ethylenediamine-N,N′-di-l-α-hydrocinnamate, were measured in an aqueous solution. Each of the CD curves can be resolved into four components in the d–d region by Gaussian analysis; these components are related to the four possible d–d transitions of the copper(II) ion. The visible CD spectrum profile of the complexes varies with the variation in ligands; this implies that the conformation of the complexes is affected appreciably by the bulkiness of the side chain in the ligand.
Application of the Zone Melting Technique to Metal Chelate Systems. VII. Computer-assisted Consideration on the Solute Distribution Profiles in Zone Melting Process
Authors: Maeda Shigeru , Kobayashi Hiroshi , Ueno Keihei
Published: July 2006

A new equation is derived which gives the solute distribution along a column after a zone melting chromatography (ZMG) process, where the initial charge of a sample mixture of k<1 is placed on the upper end of the column, one zone length high. The solute distribution differs significantly from that obtained by Pfann’s equation on an infinite ingot, in the neighborhood of the upper end as expected from the difference in the initial conditions. The solute distribution is calculated numerically for the case in which the initial charge is placed by several zone lengths on the column top. The present multiple zone charge method shows little difference in solute distribution from the conventional single zone charge method, having the advantage of increasing the sample amount to be fractionated. Numerical calculation is performed to find the zone length with which the greatest amount of the solute of k<1 is concentrated into the bottom fraction of a certain length of a given column after each zone pass. A series of resulting zone lengths, showing a stepwise shortening, pass after pass, provides the optimum mode of decrease in the zone length.
The Tautomeric Equilibria of 4-(Dialkylamino)azobenzene Derivatives. II. 2- and/or 2′-Methyl-4-(dimethylamino)azobenzene Derivatives
Authors: Yamamoto Shunzo
Published: July 2006

The tautomeric equilibrium constants, Kt=[ammonium ion]/[azonium ion], of the first conjugate acids of 2- and/or 2′-methyl-4-dimethylaminoazobenzene derivatives were estimated by the spectrophotometric method. The effects of the 2- and 2′-methyl groups on the basicity of the amino and the azo nitrogens were examined in order to explain the effects on the tautomeric equilibrium. The effects of the 2- and 2′-methyl groups on the basicity of the amino nitrogen is an inductive one only, while the effects on the basicity of the azo nitrogens are both electronic and steric. The latter effect of the 2′-methyl group is very large, but that of the 2-methyl group is not significant. The order of Kt in a series of compounds is almost the same as that of the basicity of the azo nitrogens. That is to say, the magnitude of Kt is mainly governed by the basicity of the azo nitrogens.
Carbon Products Prepared from Variant Pitch Materials. VIII. The Preparation of Isotropic Pitch Carbon with a High Density
Authors: Otani Sugio , Oya Asao
Published: July 2006

The present works were undertaken in order to prepare the isotropic Pitch Carbon with a high density and with a desired degree of graphitization. The tablets were prepared by pressing some kinds of variant pitch materials and were then heat-treated below 2600°C in N2 gas. Isotropic Pitch Carbon with a high density and with a low degree of graphitization can be readily prepared by pressing the non-graphitizable variant pitch material under high pressure. On the other hand, for the purpose of preparating isotropic Pitch Carbon with a high density and with a high degree of graphitization, a graphitizable variant pitch material with a low softening point, —in other words, with a good ability of sintering— was pressed into tablets under low pressure. The typical properties of the Pitch Carbon thus obtained (H.T.T. 2600°C) were as follows: Bacon Anisotropic Factor: 1.01; Bulk density: 1.79 g/cc; d002: 3.40 Å; Lc: 210 Å.
The Reaction of Nucleophilic Reagents at the β-Position of 3-Bromo-4-nitropyridine N-Oxide
Authors: Matsumura Eizo , Ariga Masahiro
Published: July 2006

Some nucleophilic substitutions on the β-position of the pyridine nucleus were carried out. The reactions of 3-bromo-4-nitropyridine N-oxide(1) with diethyl sodiomalonate, ethyl sodiocyanoacetate, and ethyl sodioacetoacetate in diethyl carbonate or pyridine afforded 3-bis-(ethoxycarbonyl)methyl-4-nitropyridine N-oxide (2), 3-cyano(ethoxycarbonyl)methyl-4-nitropyridine N-oxide (3), and 3-acetyl(ethoxycarbonyl)methyl-4-nitropyridine N-oxide (4) respectively, and ethyl sodioacetoacetate, when treated at a higher temperature, gave 3-ethoxycarbonyl-2-methyl-furo(3,2-c)pyridine N-oxide (5). A probable mechanism of the reaction was presented.
Kinetics of Multidentate Ligand Substitution Reactions. XV. Substitution Reactions of 1,2-Cyclohexanediamine-N,N,N′,N′-tetraacetic Acid (CyDTA) with Zinc(II) Iminodiacetate (IDA), N-(2-Hydroxyethyl)iminodiacetate (HIDA), and Nitrilotriacetate (NTA) Complexes and Those with Cobalt(II)-IDA, -HIDA, NTA, -N-(2-Hydroxyethyl)ethylenediamine (EtEN), and Diethylenetriamine (Dien) Complexes
Authors: Kodama Mutsuo , Hagiya Kaoru
Published: July 2006

The kinetics of the substitution reactions of CyDTA with zinc(II)-IDA, -HIDA, and -NTA complexes and those with cobalt(II)-IDA, -HIDA, -NTA, -EtEN, and Dien complexes were studied by using the polarographic technique. All the substitution reactions studied in this paper were found to have a common reaction mechanism. They were first-order with respect to the CyDTA anion, and they were also first-order with respect to the metal(II) complex with a 1 : 1 composition; their reaction mechanism could be formulated as:

(Remark: Graphics omitted.)

From a comparison of the observed rate constants with those estimated on the basis of the proposed reaction intermediate, the detailed reaction mechanism and structures of the reaction intermediates were discussed. The steric effect of the cyclohexane ring on the rate of the substitution reaction was also discussed.
The Synthesis of Azulene Derivatives Condensed with Several Heterocycles
Authors: Nozoe Tetsuo , Asao Toyonobu , Kobayashi Masao
Published: July 2006

The reactions of ethyl 1,2-diaminoazulene-3-carboxylate with formic acid, nitrous acid, glyoxal sodium bisulfite, diacetyl, and benzil afforded the corresponding azulene derivatives condensed at the 1,2-position with nitrogen-containing heterocycles, namely, imidazole, triazole, and pyrazine rings. 2-Amino-1-formylazulene reacted with guanidine or thiourea to give 2-aminoazuleno[2,1-d]pyrimidine. The ultraviolet and visible absorption spectra of these azulenes are presented.
Synthesis of “Reversed” Nucleosides of Some Purine and Pyrimidine Bases
Authors: Fukatsu Shunzo , Takeda Yoshiro , Umezawa Sumio
Published: July 2006

The title compounds have been synthesized by condensation of terminal iodo-sugars with purine bases and pyrimidine bases in dime thy lformamide in the presence of sodium hydride or lithiu a hydride.
Formation and Reaction of Cyclohexanone Oxime Hydrogen Sulfate
Authors: Fukui Kiyoshi , Uchida Masaru , Masaki Mitsuo
Published: July 2006

Cyclohexanone oxime hydrogen sulfate, prepared by the reaction of cyclohexanone oxime with sulfur trioxide–1,4-dioxane complex under mild conditions, was isolated as stable salts with various Lewis bases. It was found that a Beckmann rearrangement of the oxime hydrogen sulfate to 3,4,5,6-tetrahydro-2H-azepin-7-ol hydrogen sulfate was retarded by the weak Lewis base 1,4-dioxane and prevented by a stronger Lewis base aniline. The rearrangement of the oxime hydrogen sulfate was also found to be promoted by Lewis acids such as sulfur trioxide, tin tetrachloride or zinc chloride. Hydrogen chloride retarded the rearrangement. Alcoholysis of the oxime hydrogen sulfate gave cyclohexanone oxime and monoalkyl sulfate quantitatively, while hydrolysis of the oxime hydrogen sulfate gave cyclohexanone, cyclohexanone oxime and ε-caprolactam.
Reaction of 3,4,5,6,-Tetrahydro-2H-azepin-7-ol Hydrogen Sulfate with Cyclohexanone Oxime–Tin Tetrachloride Complex
Authors: Masaki Mitsuo , Fukui Kiyoshi , Uchida Masaru , Yamamoto Koichi , Uchida Izuhiko
Published: July 2006

Cyclohexanone oxime hydrogen sulfate was found to undergo facile rearrangement to 3,4,5,6-tetrahydro-2H-azepin-7-ol hydrogen sulfate in the presence of ε-caprolactam–tin tetrachloride complex, while the oxime hydrogen sulfate decomposed in the presence of ε-caprolactam. Other metal halides were studied to see if the oxime hydrogen sulfate undergoes rearrangement in the presence of the lactam. Gyclohexanone oxime–tin tetrachloride complex was synthesized. Its reaction with the tetrahydroazepin-7-ol hydrogen sulfate was found to give the lactam–tin tetrachloride complex and the oxime hydrogen sulfate which regenerated the tetrahydro-azepin-7-ol hydrogen sulfate in the reaction system. Tin tetrachloride complex was prepared with several oximes.
Synthetic Studies of Bacitracin. VIII. Synthesis of Cyclohexapeptide Moiety
Authors: Munekata Eisuke , Masui Yoshihiro , Shiba Tetsuo , Kaneko Takeo
Published: July 2006

For the purpose of synthesis of antibiotic bacitracin of six amino acids-membered ring formula, the following intermediate peptides, i.e., cyclo-(Nα-benzy]oxycarbonyl-l-lysyl-Nδ-cyclopentyloxycarbonyl-d-ornithyl-l-isojeucyl-d-phenylalanyl-l-histidyl-α-methyl-l-aspartyl) (III) and Nα-benzyloxycarbonyl-Nε-t-butyloxycarbonyl-l-lysyl-Nδ-cyclopentyloxycarbonyl-d-ornithyl-l-isoleucyl-d-phenylalanyl-Nim-benzyl-l-histidyl-l-aspartyl-d-isoasparagine benzyl ester (IV) were prepared. In this synthesis, cyclopentyloxycarbonyl group was introduced to protect δ-amino group of ornithine residue and cleavability of this protecting group for hydrogen fluoride was investigated.
Kinetic Studies on the Cationic Ring-Opening Polymerization of Tetrahydrofuran Initiated by Superacid Esters
Authors: Kobayashi Shiro , Danda Hidenori , Saegusa Takeo
Published: July 2006

The present paper descibes kinetic studies on the cationic ring-opening polymerization of tetrahydrofuran (THF) initiated by superacid esters such as ethyl fluorosulfate (EtOSO2F), chlorosulfate (EtOSO2Cl), and trifluoromethanesulfonate (EtOSO2CF3). The phenoxyl end-capping method was found to de applicable to kinetic analyses of the THF polymerization initiated by superacid esters. Also, the rate constants of propagation (kp) and of initiation (ki) were determined directly by NMR spectroscopic method. Rate constants determined by these two methods were in good agreement within experimental error. As a polymerization mechanism it was established that the propagation proceeds via cyclic oxonium species. The kp values of superacid esters varied depending upon the nature of the counter anion, OSO2X−, e.g., kp at 0°C in CH2Cl2: 0.66×10−3 (X=F), 1.4×10−3 (X=Cl), and 1.7×10−3 (X=CF3) 1/mol·sec, respectively. These magnitudes, however, were at least lower than one half of those of typical Lewis acid initiators. Initiation by superacid ester is a dipole-diple reaction, and ki values were about 1/10–1/20 of the corresponding value of triethyloxonium tetrafluoroborate (Et3O+BF4−). Activation parameters were calculated for both the propagation and initiation reactions. In order to compare the present systems with those of superacid initiators, model reactions were examined by NMR spectroscopy.
Kinetic Study on the Ring-Opening Polymerization of Tetrahydrofuran by Pyrosulfuryl Chloride Initiator
Authors: Kobayashi Shiro , Saegusa Takeo , Tanaka Yoshiaki
Published: July 2006

This paper deals with a kinetic study of the ring-opening polymerization of tetrahydrofuran (THF) initiated by pyrosulfuryl chloride (PSC). The kinetic analysis was based on the determination of the concentration of propagating species, [P*], by the phenoxyl end-capping method. The rate constants of the three elementary processes, propagation (kp), initiation (ki), and termination (kt), were determined. Activation parameters for the propagation were; ΔEp\eweq=12 kcal/mol, and Ap=7.6×106 l/mol·sec. From the kp values and the NMR study of the THF–PSC reaction, it is concluded that the propagation proceeds via the bis-oxonium species 5b. The ester type species 5a may be involved at a very early stage of polymerization. However, its contribution was quite small throughout the polymerization. The THF polymerization initiated by PSC was characterized by the fast initiation. The mechanism of termination was also examined. The THF polymerization by trifluoromethanesulfonic anhydride was also studied kinetically, which was characterized by a living propagation by bis-oxonium species.
The Metalation of Fluorene by Means of the Diethylmagnesium–Hexamethylphosphoramide System
Authors: Tomoi Masao , Kakiuchi Hiroshi
Published: July 2006

The metalation of fluorene by means of the Et2Mg–HMPA system was investigated. The reaction scarcely occurred at all when the mole ratio of HMPA: Et2Mg fell below 1:1, but it proceeded easily when the ratio was over 1:1, and a solvent-separated ion pair of magnesium fluorenide was formed. When the ratio was 2:1, the order of reaction was unity in both fluorene and Et2Mg. It was demonstrated by the kinetic and NMR studies that the active species of metalation in such a case was not Et2Mg but the Et2Mg–HMPA complex, in which two molecules of HMPA are coordinated to Et2Mg.
Reactions of the Iodocarbenoid of Zinc. I. The Synthesis of Alkyl-substituted 7-Ethylcyclohepta-1,3,5-trienes via the Ring-expansion of Alkylbenzenes with Diethylzinc and Iodoform
Authors: Miyano Sotaro , Hashimoto Harukichi
Published: July 2006

By treatment with diethylzinc and iodoform, benzene gave 7-ethylcyclohepta-1,3,5-triene in a yield of 58%, along with a quantitative formation of ethyl iodide. Alkylbenzenes, including methyl-, ethyl-, isopropyl-, tert-butyl-, and o-dimethylbenzene, gave the corresponding alkyl-substituted 7-ethylcyclohepta-1,3,5-trienes in yields of 60, 45, 41, 35, and 52% respectively. The tropylium iodide resulting from the adduct of the iodocarbenoid of zinc to benzene (7-iodonorcaradiene) is suggested as an intermediate in the formation of the 7-ethylcycloheptatriene.
The Preparation and Reactions of N-Substituted Hexafluoroisopropylideneimines
Authors: Ishikawa Nobuo , Kitazume Tomoya
Published: July 2006

N-Aryl- and N-alkylhexafluoroisopropylideneimines (2) were prepared from the hexafluorothioacetone dimer (1) by treatment with either aryl- or alkylamines. These imines reacted with alcohols and thiols to give three addition products, 7, 8, and 9. Phenylhydrazone (3), semicarbazone (4), hydrazone (5), and azine (6) of hexafluoroacetone were also obtained directly from 1 and the corresponding carbonyl reagents.
The Effect of Acylamino Groups in Diazo-coupling Reactions
Authors: Hashida Yoji , Mitsumura Kazuo , Sekiguchi Shizen , Matsui Kohji
Published: July 2006

A kinetic study has been made of the coupling reactions of diazonium salts with N,N-dialkyl-N′-acyl-m-phenylenediamines, including N′-acetyl- (I,II), N′-benzoyl- (III), N′-carboethoxy- (IV), and N′-p-toluene-sulfonyl derivatives (V, VI). It was found from the pH dependence of the apparent rate constant that the reactive species of a substrate varies with the pH of the medium, from an undissociated molecule to an anion formed by the ionization of an acylamino group. In the case of I, the activating effect of the dissociated acylamino group seems to be higher than that of the undissociated acylamino group by some 8 powers of ten.
The Synthesis of 1,2-Diamino- and 1,2,3-Triaminoazulene Derivatives
Authors: Nozoe Tetsuo , Asao Toyonobu , Kobayashi Masao
Published: July 2006

The diazo coupling reaction of 2-amino- (I), 2-acetamido-, and 2-amino-1-ethoxycarbonyl-azulene with p-toluene diazonium salt gave the corresponding l-(p-tolylazo)azulene derivatives, II, V, and VIII respectively, in good yield; 2-amino-1,3-di(p-tolylazo)azulene (III) was also obtained by the reaction of I and two molar equivalents of p-toluene diazonium salt. The catalytic reduction of V and VIII afforded 2-acetamido-1-aminoazulene and ethyl 1,2-diaminoazulene-3-carboxylate as hydrochloride. The similar reduction of II and III yielded only a resinous product, and 1,2-diamino- or 1,2,3-triaminoazulene could not be isolated, not even as their salts. However, the reductive acetylation of II and III afforded the corresponding polyacetamidoazulenes. The ultraviolet and visible absorption spectra of these azulenes are indicated.
Hydrolyses of p-Nitrophenyl(Oligodeoxyribonucleotide Succinate)s by Oligodeoxyribonucleotide N-Acetylhistidates on Polycytidylic Acid
Authors: Shimidzu Takeo , Letsinger Robert L
Published: July 2006

The hydrolyses of p-nitrophenyl(oligonucleotide succinate)s, in which the oligonucleotides are dGpG, dGpT, dGpC, dGpA, and dGpGpG, by oligonucleotide N-acetylhistidates, in which the oligonucleotides are dGpG, dGpT, dGpC, dGpA, and dGpGpG, or by dGpG nicotinate were carried on polycytidylic acid (Poly C). While the hydrolysis did not occur at lower concentrations of them, it did take place at moderate concentrations, in the presence of Poly C. From the kinetics of the hydrolysis, it was concluded that the interaction between those oligonucleotide derivatives and Poly C was homogeneous at lower concentrations of them and heterogeneous at higher concentrations. The change in the viscosity of the reaction system was correlated with the kinetical results. The heterogeneity in the interaction can be explained as a contiguous stacking of the oligonucleotide derivatives on Poly C. The tendency of the contiguous stacking was great in dGpGpG N-acetylhistidate. The rate of the hydrolysis of Poly C was higher than that without Poly C. The order in magnitude of the interaction between the oligonucleotide derivatives and Poly C was dGpGpG-derivative>dGpGp-derivative>dGpC-derivative>dGpA-derivative>dGpT-derivative.
Studies on Pyrophosphates II. A New Method for the Synthesis of Nucleotide Coenzymes and Their Analogs
Authors: Nakagawa Iwao , Hata Tsujiaki
Published: July 2006

A new method for the synthesis of unsymmetrical pyrophosphates from the reaction of alkyl phosphorothioates and disilver salt of alkyl phosphates are described. Nucleotide coenzymes such as uridine diphosphate glucose, uridine diphosphate galactose, and flavin adenine dinucleotide was synthesized.
Reactions of N-Acylaminoacetamidine with 1,3-Bifunctional Compounds
Authors: Uchida Hiroaki , Iwasawa Hiroyuki , Ohta Masaki
Published: July 2006

The reactions of N-benzoylaminoacetamidine(IIIa) and N-benzyloxycarbonylaminoacetamidine(IIIb) with various 1,3-bifunctional compounds were investigated. Both IIIa and IIIb were found to react with acetylacetone to produce 2-amino-3-benzoylamino-4,6-dimethylpyridine and 2-amino-3-benzyloxycarbonylamino-4,6-dimethylpyridine, respectively. On the other hand, IIIa reacted with ethyl acetoacetate or diketene to produce 2-(N-benzoylaminomethyl)-4-hydroxy-6-methylpyrimidine. Reaction of IIIb with malononitrile gave 1-amino-2-(N-benzyloxycarbonylaminoethylidene)malononitrile.
Arrangement of Acridine Orange in the Poly-α,l-glutamic Acid-Acridine Orange Complex
Authors: Sato Yukio , Hatano Masahiro
Published: July 2006

The temperature dependencies of the absorption and circular dichroism spectra of the poly-α,l-glutamic acid-acridine orange complex were observed at the temperatures in the range of 23–95 °C. The circular dichroism spectra were resolved into several Gaussian components by means of a computer online system. Thus, the circular dichroism spectrum can be resolved to five components. The shorter-wavelength bands, consisting of one positive and one negative element, were assigned to the transitions polarized parallel to and perpendicular to the axis of the α-helix of polypeptide respectively. On the other hand, the longer-wavelength bands, having equal magnitudes but signs opposite to each other, were assigned to the transition of the acridine orange dimer bound to polymer. The fifth band, at the shortest wavelength was uncertain. On the basis of these results, the arrangement of acridine orange molecules bound to poly-α,l-glutamic acid was discussed. Thus, two kinds of arrangements of acridine orange molecules were postulated. One is a left-handed super-helix around the right-handed α-helix of the polypeptide in the acidic pH region, and the other is a right-handed super-helix around the core of the α-helix in the alkaline pH region when the molar ratio of glutamyl residues to the dye is kept around unity. In these two complexes, there are dimeric acridine orange molecules bound to the polymer; in the latter complex, the super-helix consists of dimeric acridine orange molecules. Two types of arrangements of acridine orange molecules around the polypeptide were offered for the elucidation of the circular dichroism spectra of the complex of acridine orange with poly-α,l-glutamic acid in an aqueous solution.
The Primary Photochemical Process of 4-Nitropyridine N-Oxide. III. Its Photochemical Behavior in an Aqueous Solution
Authors: Hata Norisuke , Ono Isao , Osaka Kenji
Published: July 2006

4-Nitropyridine N-oxide does not undergo photochemical changes in an aqueous solution. When small amounts of 2-propanol or tetrahydrofuran were added to a deaerated solution, however, the 4-nitropyridine N-oxide was found to be reduced photochemically to afford 4-hydroxylaminopyridine N-oxide. From the measurements of the quantum yields and from flash-spectroscopic experiments under various conditions, such a photoinduced reduction of 4-nitropyridine N-oxide in deaerated water was revealed to be initiated by a hydrogen-atom abstraction from a 2-propanol or tetrahydrofuran by the triplet species. The situation was quite different from the case of an alcoholic solution, in which some intermediate species originating from the excited singlet state was responsible for the photoreduction.
Emission Spectra of Benzonitrile, Aniline, and Nitrobenezene by Controlled Electron Impact
Authors: Tsuji Masaharu , Ogawa Teiichiro , Ishibashi Nobuhiko
Published: July 2006

The emission spectra of benzonitrile, aniline, N,N-dimethylaniline, and nitrobenzene under controlled electron-impact excitation (60–300 eV) were investigated at a very low pressure. Bands of the parent molecules were observed in the 260–410 nm region on benzonitrile and anilines, and were assigned to the S1–S0 transitions. However, no emission of the parent molecule was observed on nitrobenzene and this was attributed to the spinorbit coupling effect of the nitro group and the predissociation of the excited parent molecule. Bands of the following fragment species were observed for all four compounds: H(Balmer series, CH(A2Δ2–X2II), and CN(B2Σ–X2Σ). In addition, NH(A3II–X3II) band on aniline and NO(A2Σ–X2II, B2II–X2II), CO(b3Σ–a3II), and CO+ (A2II–X2Σ, B2Σ–X2Σ) bands on nitrobenzene were observed. The linear relationships between the electron beam current and the emission intensities of the parent molecules and the fragment species indicated that most of the excited species were produced by primary electron-molecule collision processes (CN of anilines, CO, and CO+were found to be exceptional). The mechanism of the excitation and the fragmentation of the parent molecules and the comparison of the present spectra with those by discharge and by optical excitation were discussed. It was concluded that some excited species were produced through superexcited states.
Dielectric Constant Measurement on Organic Crystalline Powder
Authors: Ishii Kikujiro , Kinoshita Minoru , Kuroda Haruo
Published: July 2006

The microwave cavity perturbation method was applied for the measurement of the dielectric constants for polycrystalline samples of ten aromatic compounds (naphthalene, anthracene, phenanthrene, pyrene, chrysene, perylene, durene, acenaphthene, biphenyl, and p-terphenyl.) The method is shown to give a reasonable result, if the effect of the second order perturbation term is properly included and if Böttcher’s equation is carefully applied in transforming an apparent dielectric constant obtained on a powder sample into the mean dielectric constant of a crystal. The nature of the ordinarily used cavity perturbation equation and of Böttcher’s transformation equation is discussed in this respect. The obtained mean dielectric constants are; naphthalene 2.87, anthracene 3.12, phenanthrene 2.96, pyrene 3.14, chrysene 3.09, perylene 3.34, durene 2.55, acenaphthene 2.94, biphenyl 2.88, and p-terphenyl 2.98. The molecular polarization calculated from these values agreed quite well with the values estimated from the bond polarization given by Le Fèvre et al.
Photoelectron Spectra and Sum Rule Consideration. Higher Alkyl Amines and Alcohols
Authors: Katsumata Shunji , Iwai Toshio , Kimura Katsumi
Published: July 2006

Photoelectron spectra of higher alkyl amines and alcohols (Me, Et, n- and i-Pr, and n-Bu) have been measured with the 584 Å line of helium. Seven photoelectron bands corresponding to p-type MO’s were identified for ethylamine and ethanol. Nine bands were observed for n- and i-propylamine and n- and i-propanol, and eleven for n-butylamine and n-butanol, in addition to the first C2s bands appearing at about 19 eV. The sum rule previously proposed by Kimura et al. has further been applied to the compounds studied here. Total sums of vertical ionization energies in the region below 18 eV have been found to be well reproduced by the sums of appropriate energies estimated for the p-type localized MO’s, using Koopmans’ theorem. Information on orbital character has also been obtained from the sum rule in each symmetry species.
Isocyanide-phosphine Complexes of Cobalt(I)
Authors: Otsuka Sei , Rossi Michele
Published: July 2006

Diamagnetic penta-coordinate Co(I) complexes of formula, [Co(p-CH3C6H4NC)4(PPh3)]X (1) and [Co-(p-CH3C6H4NC)3(PPh3)2]X (2) (X=Cl−, Br−, I−, ClO4−, BPh4−) were obtained from CoX(PPh3)3 or CoX2(PPh3)2. Their 1H NMR spectra served to deduce the trigonal bipyramidal structure. The aromatic ring proton NMR spectra and the IR CN stretching absorptions of radial modes were discussed in terms of the dπ-pπ back bonding.
The Magnetic Properties of Iron(II) Complexes with 2-(2′-Pyridyl)imidazole and Its Derivatives
Authors: Sasaki Yoshihiro , Shigematsu Tsunenobu
Published: July 2006

The magnetic susceptibilities and Mössbauer spectra of iron(II) complexes of 2-(2′-pyridyl)imidazole (PI), 2-(6′-methyl-2′-pyridyl)imidazole (6-MPI), and 2-(2′-pyridyl)benzimidazole (PBI) have been measured in the 4.2–298 K temperature range. The results show that Fe(II)(PI)3(ClO4)2H2O and Fe(II)(PBI)3(ClO4)2H2O have a spin equilibrium between 1A1 and 5T2, while Fe(II) (6-MPI)3(ClO4)2H2O does not have such an equilibrium. The temperature dependence and magnitude of the magnetic data for Fe(II)(PBI)3(ClO4)2H2O and Fe(II)(6-MPI)3(ClO4)2H2O have been calculated by using a parametric Iigand-field approximation. The results indicate that the orbital splittings of the 5T2 ground state due to trigonal distortion are −2000 and −800 cm−1 for Fe(II) (6-MPI)3(ClO4)2H2O and Fe(II)(PBI)3(ClO4)2H2O respectively.
Energetic Reactions of 80Br Activated by (I. T.) Process in C3H8-C2H6 and C3H8-CH3Br Systems
Authors: Numakura Kenshi , Tachikawa Enzo
Published: July 2006

In order to examine the relative importance of the thermal ionic process in the reactions of 80Br from the (I. T.) process with C3H8, we chose C2H6 or CH3Br as diluents. Some assumptions have made in estimating the yield-variation of products from the diluents: 1) the rate of the reduction of the yields of the products from C3H8caused by the addition of the diluent is the same for all of the products and 2) the ionic yield is zero over the whole range of concentrations of C3H8. With these assumptions, the analysis of the results shows that the contribution of the thermal ionic process in these binary systems has only minor importance; the products are, essentially, formed via energetic processes. It is also found that the ratio of n-C3H780Br/i-C3H780Br per bond basis seems to decrease from 1.1±0.1 on the addition of the diluent. This indicates that the formation of i-C3H780Br is a lower energy process, relative to that of n-C3H780Br in the present reaction system.
Syntheses and the Beckmann Fission of Cyclic α-Hydroxyimino Ketones
Authors: Kataoka Mutsuo , Ohno Masaji
Published: July 2006

A convenient method for the preparation of α-hydroxyimino cycloalkanones has been established by the reaction of cycloalkanones and nitrosyl chloride. ω-Cyanocarboxylic acids or their derivatives were obtained in good yield by the Beckmann rearrangement of these α-hydroxyimino ketones.
Reaction of 4-Picoline N-Oxide with Acetic Anhydride as Studied by Chemically Induced Dynamic 13C Polarization (CIDNP)
Authors: Iwamura Hiizu , Iwamura Michiko , Imanari Mamoru , Takeuchi Makoto
Published: July 2006

The 13C spectrum taken during the reaction of 4-picoline N-oxide with acetic anhydride at 110 °C in the NMR cavity (23.5 kG) shows a pair of emission lines at 15.8 and 154.4 ppm and enhanced absorption at 29.6 and 125.0 ppm (TMS-based). The signals are found to be due to 4-ethylpyridine formed as a minor product of the reaction and are interpreted in terms of the memory effect of the polarization induced in the precursor 4-picolyl-acetoxy radical pair.
The N→O and N→S Migrations of the s-Triazinyl Groups of N,N-Di-s-triazinyl Derivatives of o-Aminophenol and o-Aminothiophenol
Authors: Tsunoda Shigeo , Shiojima Takeo , Hashida Y\={o}ji , Sekiguchi Shizen , Matsui Kohji
Published: July 2006

N,N-Bis(dichloro-s-triazinyl)-2-aminophenol reacted with an excess of dimethylamine or methylamine to give N,O-bis(s-triazinyl)-2-aminophenol and N-s-triazinyl-2-aminophenol upon the aminodechlorination, N→O migration, and cleavage of the s-triazinyl group. However, N-(dimethoxy-s-triazinyl)-N-(dichloro-s-triazinyl)-2-aminothiophenol reacted with an excess of dimethylamine to give merely a disulfide of N-s-triazinyl-2-amino-thiophenol upon the aminodechlorination and cleavage of the dimethoxy-s-triazine nucleus. On the other hand, N,N-bis(s-triazinyl)-arylamines containing no ortho-OH or -SH group were stable to the attack by amines, while phenoxy-dimethoxy-s-triazine or phenylthio-dimethoxy-s-triazine reacted readily with dimethylamine to give dimethylamino-dimethoxy-s-triazine upon the fission of phenol or thiophenol. From these resutls, the reactions of the N,N-bis(s-triazmyl) derivatives of both o-aminophenol and o-aminothiophenol with amines to give the corresponding N-s-triazinyl derivatives are considered to proceed by means of an intramolecular nucleophilic attack by the phenoxide or thiophenoxide anion on the s-triazine ring carbon to give the N,O- or N,S-bis(s-triazinyl) derivative upon the N→O or N→S migration of the s-triazinyl group, followed by the cleavage of the O- or S-s-triazinyl group to give the final product. However, when the intermediary derivative is stable to amine, the intermediate is obtained as the major final product.