bluuebunny/crossref_metadata_2025 huggingface dataset:
Calorimetric and Magnetic Studies of Crystalline and Glassy Bis[N-(3-methoxysalicylidene)isopropylamine]nickel(II)
Authors: Arai Naoto , Sorai Michio , Seki Syûzô
Published: July 2006

Thermal and magnetic properties of Ni(3-CH3O-SAL·iso-C3H7)2 were investigated by measuring thermograms, infrared and electronic spectra, heats of solution, magneitc susceptibilities, and heat capacities around glass transition temperature. In addition to the known paramagnetic crystalline phase III and the diamagnetic crystalline phase IV, two new crystalline phases (I and II) were discovered. Phase I was found to be paramagnetic, its molecular geometry being of a tetrahedral four-coordinated form like that of phase III, while phase II, similar to phase IV, is diamagnetic and has a square-planar four-coordinated form. Although the order of thermodynamic stability of these four crystalline phases was not determined, they were isolated stably at room temperature. The supercooled liquid and glassy states of this compound were realized for the first time by quenching the sample in the molten state. Unusual magnetic behaviors of these two states were satisfactorily accounted for by assuming an equilibrium between the diamagnetic and the paramagnetic species. In the supercooled liquid state, the paramagnetic species was partially converted into the diamagnetic one with decreasing temperature. Below the glass transition temperature Tg, however, this conversion process was prevented and the magnetic susceptibility obeyed apparently Curie’s law with a 26% paramagnetic content. The heat capacity measurement revealed a typical glass transition phenomenon at 297.5 K and the heat capacity jump at Tg was determined to be 172 JK−1mol−1. Detailed discussions were given for the relationship between molecular geometry and its associated magnetic property and also for the phase relationship between various phases.
A Molecular Orbital Calculation of Chemically Interacting Systems. Addition of Singlet Methylene to Ethylene
Authors: Fujimoto Hiroshi , Yamabe Shinichi , Fukui Kenichi
Published: July 2006

A semi-empirical self-consistent-field molecular orbital calculation of the addition of singlet methylene to ethylene was carried out on the basis of an isolated molecule approximation. The calculation was made with respect to two modes of approaches of methylene to ethylene which were proposed by Hoffmann. A calculation of the electron populations by use of the configuration interaction wave function showed that singlet methylene added to ethylene double bond in an electrophilic fashion with a quasi-synchronous formation of two σ bonds to yield cyclopropane. The present calculation revealed the important roles of the interaction between the highest occupied molecular orbital of ethylene and the lowest unoccupied molecular orbital of methylene and of the interaction between the highest occupied molecular orbital of methylene and the lowest unoccupied molecular orbital of ethylene, in interpreting the formation of new σ bonds between ethylene and methylene and the disappearance of the π bond of ethylene.
Photochemical Reactions of p-Benzoquinone Complexes with Aromatic Molecules
Authors: Arimitsu Satoshi , Tsubomura Hiroshi
Published: July 2006

Electronic absorption spectra and ESR spectra have been measured for the photolyzed charge transfer complexes between p-benzoquinone and aromatic donors in low temperature matrices. When the p-benzoquinone complex with toluene or p-xylene was irradiated at 77°K, an electronic absorption spectrum attributable to the semiquinone radical was obtained together with that of the benzyl-type radical. The spectral shape and position of the former are somewhat different from those of the semiquinone radicals obtained by the photolysis of p-benzoquinone or hydroquinone. These differences indicate the presence of interaction between semiquinone and benzyl-type radicals. The ESR spectra obtained from these systems show that these radicals form pairs in the triplet (S=1) state. It is concluded that the radical pairs are produced as a result of intermolecular hydrogen atom transfer from the aromatic donor molecule to p-benzoquinone in the excited states of the CT complexes formed between them. The irradiations of various p-benzoquinone complexes were carried out in the wavelength regions corresponding to the lowest CT absorption bands at 77°K, and the reactivities were discussed in relation to the electronic structures and geometrical configurations of the CT complexes in the excited states. From the analysis of ESR spectra, the fine structure constant was evaluated for each of the radical pairs, from which the average distance between interacting unpaired electrons was calculated.
Photochemical Reaction of 9-Chloroacridine in Aerated and Deaerated Ethanol. II. Studies by Means of a Flash Technique
Authors: Nakamaru Katsumi , Niizuma Shigeya , Koizumi Masao
Published: July 2006

Studies were made on the transient species produced when the aerated and deaerated ethanol solutions of 9-Cl-acridine (9-Cl-A) are flashed. In the deaerated solution, triplet state of 9-Cl-A and a long-lived radical species of unknown structure were detected. It was established that the latter is produced by a reaction in the singlet excited state of 9-Cl-A (and possibly in the higher triplet (Tn−π*)) and that it produces biacridyl by a bimolecular reaction. In the aerated solution, another radical species of a long life of which structure is still unknown, was detected. It was established that this radical species reacts bimolecularly and produces acridone.
Binuclear Metal Complexes. IV. The Preparation and Properties of Binuclear Copper(II) Complexes of Schiff Bases Derived from 2,6-Diformyl-4-methylphenol and Glycine or Alanine
Authors: Okawa Hisashi , Kida Sigeo , Muto Yoneichiro , Tokii Tadashi
Published: July 2006

A new series of binuclear copper(II) complexes with different bridging groups, Fsal(=gly)2Cu2X (X=OH, Cl, Br) and Fsal(=ala)2Cu2X (X=Cl), were synthesized, Fsal(=gly)2 and Fsal(=ala)2 being the Schiff bases prepared by condensation of 2,6-diformyl-4-methylphenol with glycine and alanine, respectively. The copper(II) ions are bridged by the phenolic oxygen in the organic moiety and also the X. The properties of the complexes were studied by IR spectra, visible spectra, and magnetic susceptibility measurements at various temperatures. From the cryomagnetic data it was concluded that the effect of the bridging group X upon magnetic exchange interaction decreases in the order: OH>Cl∼Br.
Studies on New Derivatives of 8-Quinolinol as Chelating Agents. II. Chelate Formation of Some Aminomethyl Derivatives Derived from 8-Hydroxyquinoline-2-carbaldehyde with Metal Ions
Authors: Hata Takehisa , Uno Toyozo
Published: July 2006

The reactions of new oxine derivatives with additional coordinative sites, 8-hydroxyquinoline-2-carbaldehyde, 2-(p-chlorophenylaminomethyl)-, 2-(naphthylaminomethyl)-, 2-(p-tolylaminomethyl)-, and 2-(o-hydroxyphenylaminomethyl)-8-hydroxyquinoline, and N,N′-bis(8-hydroxy-2-quinolylmethyl)ethylenedianiine (abbreviated as HQA, CAMHQ, NAMHQ, TAMHQ, PAMHQ, and BHQED respectively), with Cu2+, Co2+, Ni2+, Zn2+, Cd2+, Mn2+, Mg2+, and Ca2+ were investigated by potentiometric and spectrophotometric methods. The stability constants of the metal chelates were determined in a 50 v/v % aqueous dioxane solution at 25°C. The stability constants of metal chelates of HQA, NAMHQ, CAMHQ, and TAMHQ with a ligand-to-metal ratio of 2:1 are lower than those of oxine. In these ligands, steric hindrance due to the aminomethyl group results in lower stability constants of the metal chelates. PAMHQ reacts as a terdentate ligand with Cu2+, Mn2+, Mg2+, and Ca2+to form 1:1 chelates by coordination with quinoline nitrogen and two phenolate oxygens. BHQED reacts with Cu2+, Co2+, Ni2+, Cd2+, and Mn2+ to form a protonated chelate, MHL+, in the acid region, while, in the neutral region, one proton is released from the protonated chelate to form a deprotonated chelate, ML, by coordination with six donor groups, namely, two imino and hydroxyl groups, and two quinoline nitrogens. BHQED acts as a sexadentate ligand to form the most stable chelates among these oxine derivatives.
Spectra and Keto-Enol Equilibrium of Benzoylacetanilides
Authors: Shawali Ahmad Sami A S , Naoum Magdi M , Ibrahim Saad A
Published: July 2006

A series of twelve monosubstituted benzoylacetanilides have been prepared by condensation of acetoacetanilide with substituted benzoylchlorides. IR and UV spectral data are presented and discussed. The benzoyl CO stretching frequencies were correlated with σ+ (\barv=34.97σ++1705; r=0.983). The effect of substituents in the benzoyl moiety on the keto-enol equilibrium, has also been investigated. The data were correlated by the equation: logK=0.865σ+−0.615; r=0.988.
Studies on Benzoquinolines [f] and [h]. Part I
Authors: Tiagi Rameshwar P , Joshi Bhuwan C
Published: July 2006

2-Chloro-4-methyl and 2-methyl-4-chloro-benzo[h]quinolines, 1-chloro-3-methyl- and 1-methyl-3-chlorobenzo[f]quinolines were converted into corresponding hydrazino derivatives. Structural studies of the hydrazino compounds and their derivatives were carried out. Chlorine atom in a position adjacent to nitrogen of the ring was found to be more reactive than in that away from nitrogen in benzo[f] and [h]quinolines. Cyclisation of hydrazino derivatives by nitrous and formic acids occurred at position 2 in 1-methyl-3-hydrazinobenzo[f]quinoline and at position 3 in the case of 2-hydrazino-4-methylbenzo[h]quinoline, respectively, while in the case of 1-hydrazino-3-methylbenzo[f]quinoline, at position 10 and in 4-hydrazino-2-methylbenzo[h]quinoline, at position 5, respectively.
The CNDO/2 Study of Barbararyl Cation and Its Isomeric C9H9+ Systems
Authors: Yoneda Shigeo , Winstein Saul , Yoshida Zen-ichi
Published: July 2006

The geometrical and electronic structures of C9H9+ systems have been studied applying CNDO-2 method. The calculated results are used to discuss the stabilities of the structures for C9H9+ system and their electronic states. It is suggested that the carbonium ion which has a D3h symmetry (IV) enjoys much stabilization energy, whereas bicyclo[3.2.2]nonatrienyl cation (I) is less stable than IV. The stability of IV can be explained by unusual delocalization of its electrons over the molecule.
Bromine Addition to Cyanonorbornene Derivatives
Authors: Kikkawa Sh\={o}ichi , Nomura Masakatsu , Uno Y\={o}ichir\={o} , Matsubara Masaaki , Yanagida Y\={u}ji
Published: July 2006

The addition reactions of endo-5-cyanonorbornene, trans-endo,exo-5,6-dicyanonorhornene, cis-endo-5,6-dicyanonorbornene, and cis-exo-5,6-dicyanonorbornene with bromine have been studied. The assignments of the configurations of bromine adducts were determined mainly on the basis of the NMR spectra. As to trans-endo,exo-5,6-dicyanonorbornene, reaction mixtures have been found to contain trans and exo-cis adducts. The reaction conditions involving the proportions of these isomers and a rationale for the formation of the exo-cis adduct are discussed. cis-endo-5,6-Dicyanonorbornene and cis-endo-5,6-dicyanonorbornene gave the exo-cis adduct and the trans adduct respectively. The stereochemistry of bromine atoms may be explained in terms of a steric factor. A kinetic study showed that these addition reactions in solution in acetic acid obey the second-order rate law and that the magnitudes of the rate constants are in the order; cis-exo-5,6-dicyanonorborne>trans-endo,exo-5,6-dicyanonorbornene>cis-endo-dicyanonorbornene.
Asymmetric Hydrogenation of C=O Double Bond with Modified Raney Nickel. XXI. The Effect of Water on the Asymmetric Activity of the Catalyst
Authors: Ninomiya Toshio
Published: July 2006

The effect of water added to the hydrogenation system of methyl acetoacetate was investigated on catalysts modified with l-amino acids, their derivatives, and d- or l-hydroxy acids. In the absence of water, catalysts modified with all l-amino acids except l-serine and l-proline gave methyl ds(−)-3-hydroxybutyrate, and in the presence of water all the catalysts modified with l-amino acids gave methyl ls(+)-3-hydroxybutyrate. On the other hand, the catalysts modified with l- or d-hydroxy acids were not affected by the addition of water and gave an ls(+) or ds(−) hydrogenation product respectively. In the presence of water, the catalyst modified with the l-valine methyl ester gave an ls(+) product, while the catalysts modified with N-acetyl l-amino acids were not affected by water. As a whole, it was concluded that water added to the hydrogenation system affected the amino group of the modifying reagent on the catalyst surface, which might play an important role in the asymmetric control of the substrate approaching the catalyst surface. The water in the hydrogenation system also promoted the hydrogenation rate, regardless of the modifying reagents.
Asymmetric Hydrogenation of C=O Double Bond with Modified Raney Nickel. XXII
Authors: Ninomiya Toshio
Published: July 2006

The state of the amino acid molecule used as a modifying reagent on a catalyst surface was investigated. From the relationship between the asymmetric activities of the catalysts modified with l-valine and its derivatives and the stability constants of the nickel chelates of l-valine and its derivatives, it was concluded that l-valine adsorbs like a ligand of the chelate on the catalyst surface. This conclusion was also supported by the finding that the asymmetric activity of the catalyst modified with the nickel l-valine chelate was higher than those of the catalysts modified with l-valine and its derivatives. Also, the asymmetric activities of the catalysts modified with l-histidine, l-serine, and l-proline, and with the nickel chelates of the above three l-amino acids were discussed on the basis of the stability constants of the nickel chelates of the above three l-amino acids, it was concluded that two conditions at least are necessary for the modifying reagent to be effective; it must adsorb stably on the catalyst surface, and it must have a structure affording effective asymmetric control of the substrate.
Structure and Reactivity of Organic Ions in Gas-Phase Radiolysis. III. The Benzenonium Ions Formed by the Reactions of CH5+ and C2H5+ Ions from Methane with o-Xylene
Authors: Yamamoto Yukio , Takamuku Setsuo , Sakurai Hiroshi
Published: July 2006

The gas-phase radiolysis of mixtures of o-xylene and excess methane has been studied at room temperature as a function of methane pressure and the added NO and NH3 in order to investigate the reactions of CH5+ and C2H5+ ions from methane with o-xylene. It has been suggested that the proton transfers from these ions to o-xylene result in the isomerization to m-xylene via an intermediate σ complex, dimethylbenzenonium ion, and that a part of the C2H5+ ions is added to o-xylene leading to the formation of two isomers of dimethylethylbenzene. The proposed mechanism of the methane-sensitized isomerization of o-xylene to meta isomer has been supported by the observation that both m-xylene-d0 and m-xylene-d1 were formed in the radiolysis of a mixture of o-xylene and methane-d4. The isotope effect (kH/kD) on the proton loss from the dimethylbenzenonium ion was roughly estimated to be 1.8±0.4. Group migration of intermediate a complexes was discussed.
Asymmetric Hydrogenation of C=O Double Bond with Modified Raney Nickel Catalyst. XXIII
Authors: Ninomiya Toshio
Published: July 2006

The ultraviolet spectra of acetylacetone and methyl acetoacetate adsorbed on evaporated nickel film modified with amino or hydroxy acid were measured. The spectroscopic data suggested that the adsorbed species of acetylacetone was affected by the modifying pH, that the interaction between acetylacetone and the hydroxy acid was different from that between acetylacetone and the amino acid, and also that methyl acetoacetate, similar to acetylacetone, chemisorbed with a pseudo aromatic ring on the nickel surface. Consequently, the above results strongly support the theory that in the asymmetic hydrogenation, the substrate, acetylacetone or methyl acetoacetate, approaches the catalyst surface in a form like a pseudo aromatic ring, that it is asymmetrically controlled by the modifying reagent adsorbed on the catalyst surface, and, further, that the ease of the adsorption of the substrate onto the catalyst determines the rate of asymmetric hydrogenation.
Thermolysis and Photolysis of Benzopinacol Dicarboxylates
Authors: Shirafuji Tamio , Yamamoto Yasusi , Nozaki Hitosi
Published: July 2006

Thermal decomposition of benzopinacol dicarboxylates (I) results in the cleavage of the central carbon-carbon bond to afford benzhydryl esters (II) and benzophenone (III). Benzopinacol diacetate (Ia) in benzyl alcohol-benzene solution produces benzyl acetate via ionic reaction path, whereas Ia in THF-benzene or in toluene gives radical products such as 2-diphenylmethylenetetrahydrofuran and bibenzyl, respectively. Photolysis of I proceeds in the similar manner as thermolysis to afford II and III. The ester II is further decarboxylated photo-chemically to give 1,1-diphenylalkane, diphenylmethane, and 1,1,2,2-tetraphenylethane. The photochemical solvent incorporation of II proceeds in both radical and ionic sense. Such dual nature of the reaction products in thermolysis and photolysis of I and of the photodecarboxylation of II is explained in terms of the intimate ion-radical pair hypothesis proposed by Walling.
Synthesis of Some Nucleoside Analogs of Substituted 1,2,3-Triazole
Authors: Makabe Osamu , Fukatsu Shunzo , Umezawa Sumio
Published: July 2006

1-(β-d-Ribofuranosyl)-1,2,3-triazole-4-carboxamide (4) and 4-amino-1-(β-d-ribofuranosyl)-1,2,3-triazole-5-carboxamide (7) have been synthesized as an approach to obtain bioisosteres of pyrazomycin, an antiviral agent. The synthesis has been accomplished by condensation of blocked triazoles with tri-O-benzoyl-d-ribofuranosyl chloride in the presence of mercuric cyanide in nitromethane. UV spectral studies revealed the orientation of N-glycosidation in the substituted triazoles.
A Salt Effect on the Reaction of Zinc Carbenoid
Authors: Kawabata Nariyoshi , Noda Shigeyoshi , Yamashita Shinzo
Published: July 2006

Bicyclo[4.1.0]heptane (norcarane) was obtained as the major product of the reaction of cyclohexene with diethylzinc and methylene iodide. In the presence of lithium halide or magnesium halide, however, the yield of norcarane considerably decreased. Large amounts of n-propyl and n-butyl iodides were formed which was interpreted in terms of an insertion mechanism, viz., insertion of zinc carbenoid into the carbon-iodine bond of ethyl and n-propyl iodides.
N,N,N′,N′-Tetramethylethylenediamine-Copper Salt-catalysed Coupling of Aryl Grignard Reagents with Alkyl and Aralkyl Halides
Authors: Onuma Kazuhiko , Hashimoto Harukichi
Published: July 2006

In the presence of N,N,N′,N′-tetramethylethylenediamine (TMEDA) and a small amount of copper salt, phenyl- and p-tolylmagnesium bromides react with alkyl or benzyl halide to give cross-coupling products in benzene or in a benzene-diethyl ether solvent. Among the alkyl iodides, normal iodides are most reactive, while secondary iodides do not react under our conditions. As copper salts, CuCl, CuCl2, CuCl2(TMEDA), and CuBr are all efficient for catalysis. This newly-developed catalytic system of TMEDA-copper salt is thought to be useful for the syntheses of polyalkyl-substituted aromatic hydrocarbons. As the reaction mechanism, the intermediate formation of TMEDA-coordinated organocopper(I) species and the nucleophilic displacement is proposed.
The Synthesis and Reaction of Monohalogeno-t-butyloxycarbonylamino Acids
Authors: Ohnishi Takanobu , Sugano Hiroshi , Miyoshi Muneji
Published: July 2006

Monohalogeno-t-butyloxycarbonylamino acids (XBOC-amino acids) were synthesized by the use of the corresponding chloroformates in a basic aqueous solution. Several dipeptides containing XBOC-amino acid were also prepared. The cleavage of the XBOC group was successfully carried out not only under some acidic conditions, but also by heating in methanol or ethanol. In order to demonstrate the usefulness of this group in peptide synthesis, Z–Gly–Lys(Z)–Gly–OEt was synthesized via BrBOC–Lys(Z)–Gly–OEt, which had been treated by hot ethanol. Side reaction during the synthesis of XBOC-amino acids will also be described.
A Simple Protecting Group Protection-Purification “Handle” for Polynucleotide Synthesis. II.
Authors: Tajima Kiyohiko , Hata Tsujiaki
Published: July 2006

A new method for the synthesis of oligonucleotides by employing a protecting group protection-purification “handle” was investigated. It was found that 3′-O-acetylthymidylyl(5′→3′)thymidine 5′-phosphor[p-N,N-dimethylamino]anilidate (NpTpTOAc) was prepared in 65% yield from thymidine 5′-phosphor[p-N,N-dimethylamino]anilidate (NpT) and 3′-O-acetylthymidine 5′-phosphate (pTOAc) in the presence of triisopropylbenzenesulfonyl chloride (TPS). The NpTpTOAc was selectively isolated by the use of Dowex 50W-X2 and Amberlite IR-45 resins. After treatment of NpTpTOAc with 80% acetic acid, pTpTOAc was obtained in 60% yield based on pTOAc. Similarly, trinucleotide derivative, pTpTpTOAc, was isolated in 31% yield based on pTpTOAc.
Total Syntheses of Carbohydrates. I. Dihydroxyacetone and Dl-Erythrulose
Authors: Ando Takashi , Shioi Sachiko , Nakagawa Masazumi
Published: July 2006

An improved method of preparation of halopropargyl alcohol is described. Hydration of halopropargyl alcohol followed by hydrolysis gave dihydroxyacetone which was identified as its dibenzoate. 2-Butyne-1,4-diol was converted into acetoxymethyl vinyl ketone. 1,4-Diacetoxy-3-bromobutan-2-one obtained by the addition of acetyl hypobromite to the vinyl ketone was treated with silver acetate to yield tri-O-acetyl-Dl-erythrulose. Hydrolysis of the triacetate afforded Dl-erythrulose which was identified as phenylhydrazone.
The Nuclear Magnetic Resonance Spectra of 2-Formylaminopyridine and 2-Formylamino-γ-picoline
Authors: Enomoto Nobuko , Kondo Michio
Published: July 2006

The NMR spectra of 2-formylaminopyridine and 2-formylamino-γ-picoline have been recorded under various conditions. At low temperatures, these compounds were found to exist in two forms. In these two forms, the chemical shifts of the ring proton-3 differ much from each other because of the difference in the orientation of the formylamino group, which has a large magnetic anisotropy. The difference in the chemical shifts of the formyl protons in the two forms are too large to be explained by the anisotropic shielding effect of the pyridine-ring currents. At higher temperatures, the signal coalescence of these protons in two forms have been observed. The molecular structures of these compounds have been concluded to be planar.
The Self-diffusion of Chloride Ions in Nickel Dichoride Crystallites and an Isotopic Exchange Reaction between Chlorine Gas and the Crystallites
Authors: Sensui Yoshihiro
Published: July 2006

The self-diffusion of chloride ions in the bulk of nickel dichloride crystallites was studied in the temperature range of 180–340°C in a carefully-evacuated vacuum system; the isotopic exchange reaction between gaseous chlorine and the crystallites was also studied. The activation energy for the migration of chloride ions was determined to be 1.01 eV (=23.3 kcal/mol). The exchange reaction proceeded with activation energies of 3.6 and 9 kcal/mol for the active and the less-active part of the surface first layer, 13 and 16 kcal/mol for the active and the less-active one of the second layer, and 21 kcal/mol for the third layer. (These activation energies converge to the value of the self-diffusion in the bulk.) The Θ-rule nearly holds good in the present case.
Oxygen Vacancies in the Perovskite-type Ferrites. II. Mössbauer Effect in the SrFeO2.5 -LaFeO3 Solid-solution System
Authors: Yamamura Hiroshi , Kiriyama Ryôiti
Published: July 2006

The Mössbauer effect was studied for the solid-solution Sr1−xLaFeO2.5+x⁄2 system, prepared by firing in a vacuum. The intensity of the characteristic six absorption lines of the tetrahedral-iron site in the brownmilleritetype phase (0.0≤x≤0.02) was weakened with an increase in the La content because of an increasing incorporation of oxygen, while the Mössbauer parameters remained constant. SrFeO2.5 with a brownmillerite-type structure, completely changed into a cubic perovskite-type structure at the composition with x=0.30; however, the original absorption peaks for the tetrahedral-iron site still exist even if the intensity is considerably decreased. Moreover, new peaks came out, with Mössbauer parameters different from those for the octahedral- or the tetrahedraliron sites. On the basis of the values of their Mössbauer parameters, the origin of the new peak can be assigned to the presence of a five-coordinated iron site surrounded by a trigonal bipyramidal polyhedron of oxygen rather than a square pyramidal one. The three kinds of iron site lead to a single octahedral one when most of Sr is replaced with La (x≥0.50). The oxygen-deficient, perovskite-type phase with a cubic symmetry may be stabilized by the presence of the mixed-coordination scheme of Fe3+, i.e., the octahedral, trigonal bipyramidal, and tetrahedral sites.
Ultrasonic Study of Solute-Solvent Interaction in Aqueous Solutions of Tetraalkylammonium Salts
Authors: Hirata Fumio , Arakawa Kiyoshi
Published: July 2006

Ultrasonic velocity of aqueous solutions of tetraalkylammonium chlorides was measured over wide ranges of concentration and temperature in order to study the nature of solute-solvent interactions. Adiabatic compressibility was obtained from the data of sound velocity and density. The results were discussed in terms of the influence of solutes upon the structure of liquid water. It has been shown that Me4N+ is a structure breaker, while n-Bu4N+ forms a structure or “icebergs” around the cations evidently, and that the ability of iceberg formation begins at n-Pr4N+. It was concluded that the icebergs have a more rigid structure than the ice-like structure in bulk water.
Hydrogenation by Cyanocobaltate. II. Mechanisms of the Hydrogenations of 1,3-Butadiene and Isoprene Catalyzed by Pentacyanocobaltate(II) in Aqueous Solution
Authors: Funabiki Takuzo , Matsumoto Mitsuo , Tarama Kimio
Published: July 2006

Hydrogenations of 1,3-Butadiene and isoprene catalyzed by pentacyanocobaltate(II) have been studied by the measurements of infrared and nuclear magnetic resonance spectra on the reaction solutions and by following the time-courses of the reactions. Infrared spectroscopy has revealed: (1) The aging reaction is promoted by CN- ion and it hardly occurs at a low CN/Co ratio. (2) In the hydrogenation of butadiene the formation of a σ-but-2-enyl complex at a high CN/Co ratio is very rapid, but that of a syn-π-(1-methylallyl) complex at a low CN/Co ratio is generally slow. The rate of the formation of these complexes is affected by the relative concentration of butadiene to Co(CN)5H3−. (3) In the hydrogenation of isoprene a σ-3-methylbut-2-enyl complex is formed regardless of the CN/Co ratio. Nuclear magnetic resonance spectroscopy has confirmed the structures of these complexes and it also showed that the σ-but-2-enyl complex consists of simliar amounts of the cis- and trans-isomers. The reactions are explained by the mechanisms, in which intermediate complexes in the formation of alk-1-enes and alk-2-enes are the cis- and trans σ-but-2-enyl and the syn-π- (1-methylallyl) complexes in the case of butadiene, and the σ-2- and -3-methylbut-2-enyl and the π-(1,2-dimethylallyl) complexes in the case of isoprene. It is described that the reactivity and the selectivity in the hydrogenation of conjugated dienes are strongly controlled by the steric factor in the transition state.
The Reaction between Hydrocarbon and Hydrogen Sulfide in Silent Electrical Discharge. I. The Reaction of Ethylene or Propylene with Hydrogen Sulfide
Authors: Nishimura Yoshiharu , Kawamoto Kazuaki
Published: July 2006

In order to examine the possibility of the direct introduction of the sulf hydryl radical into ethylene or propylene and that of the telomerization by means of a silent discharge, the mixture of ethylene or propylene and hydrogen sulfide was discharged in an ozonizer. (1) With ethylene and hydrogen sulfide, the main products were ethyl mercaptan, n-butyl mercaptan, and ethylene dithioglycol. Besides these compounds, the reaction products were confirmed to be diethyl sulfide, s-butyl, n-hexyl, n-propyl, and isopropyl mercaptans, and gaseous products. (2) With propylene and hydrogen sulfide, on the other hand, n-propyl mercaptan, di-n-propyl sulfide, isopropyl mercaptan, and 1,2-propyIene dithioglycol were obtained as the main products. Besides these compounds, there were diisopropyl sulfide, ethyl and n-butyl mercaptans, 4-methyl-1-pentene, 2,3-dimethylbutane, 1,5-hexadiene, 2-methylpentane, 1-hexene, n-hexane, and gaseous products. The maximum yield of the liquid products was obtained when ethylene or propylene and hydrogen sulfide were mixed in approximately the ratio of 1:1. Judging from the relative concentration of each compound in the reaction products, it may be said that vinyl, ethyl, and sulfhydryl radicals in the reaction system of ethylene and hydrogen sulfide, and 2-methylvinyl, isopropenyl, propyl, allyl, isopropyl, and sulfhydryl radicals in the reaction system of propylene and hydrogen sulfide, are the main intermediates.
Thermal Decomposition of Ammonium Salts of Transition Metal Oxyacids. III. Thermogravimetric Analysis of Ammonium Chromate
Authors: Park Il-Hyun
Published: July 2006

Thermal decomposition of ammonium chromate (AC) and ammonium dichromate (ADC) has been studied by means of TG, DTA, and DTG. It showed four steps in thermal decomposition of AC and three steps in that of ADC. Decomposition product in each step of the thermal decomposition was examined by X-ray diffraction method. From the results of both thermogravimetric analysis and X-ray study, it was concluded that the first decomposition product of AC was ADC, the second was CrO3 and the final product was Cr2O3. The third product gave the X-ray patterns of the mixture of Cr2O3 and CrO3, and the mole ratio of O/Cr in the temperature range for the existence of the product (300–390°C) was 2.1–2.0. The kinetics in the second decomposition step for AC and in the first decomposition step for ADC were studied, giving the values of the energy of activation of 24.2 and 22.4 kcal/mol, respectively.
Thermal Decompsition of Ammonium Salts of Transition Metal Oxyacids. IV. Determination of Constituents of Gases Evolved in Decomposition of Ammonium Chromate
Authors: Park Il-Hyun
Published: July 2006

Constituents of gases evolved in thermal decomposition of ammonium chromate and ammonium dichromate have been studied by an omegatron mass spectrometer. From the data of gas analysis, the following conclusions have been obtained. The decomposition of the first step started with proton transfer mechanism and the ratio of NH3 to H2O was not 2 : 1 at the beginning. The second step corresponded to the formation of N2, N2O, and H2O through oxidation of NH3 by the chromate anion. The decomposition in the third step was accompanied by the evolution of oxygen molecules. The production of CrO3 was confirmed by comparing the dissociation pressure of CrO3 produced in AC decomposition with that of pure CrO3. The decomposition in the last step corresponded to the process from CrO2 to Cr2O3, with the evolution of O2, CO2, and CO.
Reactions of Diazoketones in the Presence of Metal Chelate. IV. Formation and Reaction of Carbonyl Ylides
Authors: Ueda Kozaburo , Ibata Toshikazu , Takebayashi Matsuji
Published: July 2006

The copper chelate-catalyzed decomposition of o-methoxycarbonyl-α-diazoacetophenone was carried out in benzene. The reaction gave a dimer of a carbonyl ylide intermediate. The intermediate was trapped with dipolarophiles such as trans-dibenzoylethylene, ethyl fumarate, isoprene and dimethyl acetylenedicarboxylate, yielding 1,3-dipolar adducts in a stereospecific and stereoselective manner. Similar results were obtained in the catalytic decomposition of o-(n-butoxycarbonyl)-α-diazoacetophenone. The configuration of adducts and the mechanism of the reaction are discussed.
Anodic Reaction of 2-Furoic Acids. II. Electrolysis of Methyl 5-Acetyl-2-furoate and Its Homologous in Protic Solvents
Authors: Torii Sigeru , Tanaka Hideo , Okamoto Tsutomu
Published: July 2006

Anodic oxidation of methyl 5-acetyl-2-furoate 4 in methanol leads to ring-opened diesters 8 and 9, and lactone 10 in addition to methyl 5-acetyl-2,5-dimethoxy-2,5-dihydro-2-furoates 7. Formation of 8, 9, and 10 can be rationalized as arising from 7. On the other hand, oxidation of methyl 5-methoxy- and 5-bromo-2-furoates, 5 and 6, also give 9 and 10. The reactions involve initial production of cationic intermediates 13 and 15, which are readily solvolized to give 8, 9, and 10. A mechanism of the formation of the intermediates 13 from 5, 6, and 7 is discussed.
Reaction of α-Halosulfoxides with Amines
Authors: Numata Tatsuo , Oae Shigeru
Published: July 2006

When optically active bromomethyl p-toly sulfoxide was treated with sodium methylmercaptide or sodium ethoxide, optically active α-substituted methyl p-toly sulfoxides were obtained in good yields. By contrast, reaction with secondary amines produced achiral p-toluenesulfenamides, methylenediamines, and amine hydrobromides in nearly quantitative yields. The reaction with an amine is presumed to proceed through the initial nucleophilic substitution at α-carbon of the sulfoxide to form aminomethyl p-toly sulfoxide, followed by rearrangement to the corresponding sulfenate, and subsequent attack of the amine at the sulfur atom of the sulfenate to form the final product. Meanwhile, a facile interconversion of alkoxymethyl p-toly sulfoxide and corresponding sulfenate was also observed.
The Photochemistry of 4,5-Disubstituted 1,3-Dioxolen-2-ones
Authors: Hiyama Tamejiro , Fujita Shinsaku , Nozaki Hitosi
Published: July 2006

The benzene-sensitized photoreaction of 4,5-dipropyl- (IIa) and 4,5-tetramethylene-1,3-dioxolen-2-one (lIb) in isopropyl alcohol gives two reduction products, cis- (V) and trans-4,5-disubstituted 1,3-dioxolan-2-one (VI). The irradiation of octa- (IId) and decamethylene-bridged vinylene carbonate (IIe) results in transannular hydrogen atom transfer from a methylene group to the olefinic bond and a subsequent recombination affording three tricyclic products, IX, X, and XIX. An examination of the stereochemistry of the products has indicated the participation of a diradical intermediate.
The Phenolysis of Tetrahydrolinalyl and 2-Octyl Systems. The Rates, Steric Courses, and Product Distributions
Authors: Okamoto Kunio , Kinoshita Tomomi
Published: July 2006

As tertiary and secondary systems with optical activity, tetrahydrolinalyl (methylethylisohexylcarbinyl) chloride or p-nitrobenzoate and 2-octyl p-toluenesulfonate have been selected, and their titrimetric and polarimetric rate constants (kt and kp) for SN1 phenolyses have been measured in the presence of triethylamine (or sodium phenoxide) in 50 wt% phenol–benzene. At higher amine (or phenoxide) concentrations, the kt and kp coincide with each other for tetrahydrolinalyl chloride (at 25.0°C) or p-nitrobenzoate (at 100.0°C), and also for 2-octyl tosylate (at 75.0°C), exhibiting the typical features of the nN1 solvolysis rate constant. In the absence of the amine (or sodium phenoxide), the kt diminishes to show a gap between the kp and the kt, indicating the occurrence of an ion-pair return in the phenolysis for both systems. Under the same reaction conditions as those of the rate measurement, tetrahydrolinalyl chloride and p-nitrobenzoate yield the phenyl ether, with a predominant racemization accompanied by some net inversion of the configuration, whereas 2-octyl tosylate gives 2-octyl phenyl ether, o-, and p-2-octylphenols, with a net inversion of the configuration accompanied by a slight racemization. These steric results indicate that phenol can be considered as a typical solvolytic solvent. The product distributions have been assessed for the reactions of 2-octyl chloride (200°C) and of tetrahydrolinalyl chloride (25.0°C) with the molecule of phenol under the SN1 phenolysis conditions, by extrapolating the product composition curves to a zero concentration of the phenoxide. For both systems, the phenol molecule is predominantly O-alkylated (74 and 99% respectively), accompanied by minor amounts of C-alkylation. In contrast to the phenol reaction, the phenoxide ion undergoes more C-alkylation (42 and 50% respectively).
Friedel-Crafts Aralkylation. II. The AlCl3·CH3NO2-catalyzed Phenethylation of Benzene and Toluene with 2-Arylethyl Chlorides in a Nitromethane Solution
Authors: Ichii Makoto
Published: July 2006

The rates of AlCl3·CH3NO2-catalyzed phenethylations of benzene (50°C) or toluene (25°C) with 2-arylethyl (ring-substituted phenethyl) chlorides were measured in homogeneous nitromethane solutions. The reactions are first-order in the aromatic component, first-order in the phenethyl chloride, and second-order in aluminum chloride. Substituent effects in the phenethyl chlorides give linear relationships with Hammett’s σ constants. A displacement mechanism involving a nucleophilic attack by the aromatic substrate on the phenethyl chloride-catalyst system is proposed for the reactions. Competitive phenethylations of benzene and toluene were also carried out at 50°C. Both the isomer distribution and the relative reactivity of toluene to benzene are affected by the ring-substituents, the effects of which are correlated closer with the substrate selectivity. These results suggest that the transition state in the rate-determining step for the phenethylations is in nature an (oriented) π complex rather than a σ complex.
The Reaction of Elemental Sulfur with Organic Compounds. IV. The Reactions of N-Arenesulfonylsulfilimine and Sulfoximine with Sulfur and Diaryl Disulfide
Authors: Oae Shigeru , Tsuchida Yoshiyuki , Tsujihara Kenji , Furukawa Naomichi
Published: July 2006

The reactions of elemental sulfur and diaryl disulfide with the compounds bearing a semipolar S→N linkage were investigated. Elemental sulfur was found to react with N-arenesulfonylsulfilimine and sulfoximine affording the corresponding sulfide and the sulfoxide respectively. Diaryl disulfide also was found to undergo similar reactions with these compounds. In the reaction of diaryl disulfide with N-arenesulfonylsulfilimine, N,N-bis-(arylthio)arenesulfonamide was obtained as a main product besides the corresponding sulfide. The mechanisms of these reactions are discussed.
Optical Resolution of Aspartic Acid by Using Copper Complexes of Optically Active Amino Acids
Authors: Harada Kaoru , Tso Wung-wai
Published: July 2006

Optical resolution of Dl-aspartic acid by using copper complexes of l-alanine, d-alanine, l-glutamic acid, d-glutamic acid, and l-proline in aqueous solution is described. In this investigation the effects of (1) the concentration of reactants and (2) the ratio of the optically active amino acid to racemic aspartic acid in the reaction mixture were studied.
Model Reactions for the Biosynthesis of Thyroxine. XIX. The Formation of a Thyroxine Precursor by Photooxidation of 4-Hydroxy-3,5-diiodophenylpyruvic Acid in Organic Solvents
Authors: Omura Kanji , Nishinaga Akira , Matsuura Teruo
Published: July 2006

Photooxidation of 4-hydroxy-3,5-diiodophenylpyruvic acid (I) in methanol was found to yield a hydroperoxide (IV). This hydroperoxide reacted anaerobically with 3,5-diiodotyrosine (II) to form thyroxine (III). A photo-product, presumably IV, apparently accelerated the oxidation of I. Methanol, among several organic solvents, was found to be the best solvent for the photooxidation. Similar oxidations with 4-hydroxy-3-iodo-5-methoxyphenylpyruvic acid (V) and 4-hydroxyphenylpyruvic acid (VI) showed that the rate of oxidation decreased in the order I>V>VI. A product of the photooxidation of I, probably the hydroperoxide IV, also acts as an accelerator in the photooxidation of the desiodo analog VI of I.
Studies of Acyl and Thioacyl Isocyanates. IX. The Cycloaddition Reactions of Benzoyl and Thiobenzoyl Isocyanates with Anils
Authors: Tsuge Otohiko , Kanemasa Shuji
Published: July 2006

Thiobenzoyl isocyanates react with benzylidenanilines, benzylidenalkylamines and dianils to yield the corresponding mono- and bis (4+2) cycloadducts. Benzoyl isocyanates do not react with benzylidenanilines, but they are easily added to benzylidenebenzylamine to give the (4+2) cycloadducts in good yields. Cycloaddition of these isocyanates to anils is dependent upon the basicity of the nitrogen atom of C=N bond. Neither benzoyl isocyanates nor thiobenzoyl isocyanates are added to the C=C bond of cinnamylidenanilines, but they react with the C=N bond to afford the (4+2) cycloadducts.
The Synthesis and Stereochemistry of 2,3-Ferrocenocyclopentenone
Authors: Shirafuji Tamio , Odaira Akio , Yamamoto Yasusi , Nozaki Hitosi
Published: July 2006

An optical isomer of 2,3-ferrocenocyclopentenone (X) has been synthesized from methyl (1S) (−)-2-hydroxy-methylferrocenecarboxylate via a six-step synthesis. The absolute configuration of (−)-X has been confirmed by a comparison of its CD and ORD curves with those of the corresponding ferrocene homologs previously recorded. The mass spectrum of X is also discussed.
Electrocatalytic Chemistry of the Transition Metal Complexes. II. Dehydrogenation of Cyclohexene Catalyzed by the Electroreduced Cobalt Complex of α,β,γ,δ-Tetraphenylporphine
Authors: Kageyama Hironori , Hidai Masanobu , Uchida Yasuzo
Published: July 2006

The metal complexes of α,β,γ,δ-tetraphenylporphine (M(TPP), M=Co(II), Ni(II), FeCl(III), Pd(II), Pt(II), Cu(II), MnCl(III), and V(IV)O) were electrolyzed at −2.0 V vs. Ag wire in the presence of cyclohexene under nitrogen atmosphere. The cobalt complex only had the catalytic activity of dehydrogenating cyclohexene to 1,3- and 1,4-cyclohexadiene and benzene. With the use of dimethylformamide, dioxane, and hexamethylphosphoric triamide as solvent, cyclohexadienes were produced, and with that of benzonitrile, and dimethyl sulfoxide, benzene was produced and cyclohexadienes were scarcely produced at all. In all cases, the current efficiency of the products was much higher than 100%, indicating that the dehydrogenation reaction is catalytic. The composition of the products also varied with the reaction temperature. When ethanol was added to the reaction solution, the amount of cyclohexadienes increased with benzonitrile used as solvent. The ESR spectrum observed at g=2.003 under electrolysis at the second wave potential is due to the anion radical of cobalt(I) tetraphenylporphine. From polarographic data and other experiments, the species is considered to be an intermediate for dehydrogenation of cyclohexene. The active sites for dehydrogenation are considered to be both the central metal atom and the conjugated ring.
Photolyses of Diaryl α-Disulfones
Authors: Kobayashi Michio , Tanaka Koji , Minato Hiroshi
Published: July 2006

Di-p-tolyl disulfone and diphenyl disulfone were decomposed in various arenes by irradiation of UV light. The products found were arenesulfonic acids, arenesulfonic anhydrides, thiolsulfonates, diaryl sulfones, biaryls, and sulfur dioxide. All the findings indicate that photolyses of α-disulfones yield a pair of arenesulfonyl radicals.
Diazotization of Tetrafluoroanthranilic Acid and Several Reactions of Related Compounds
Authors: Hayashi Sei-ichi , Ishikawa Nobuo
Published: July 2006

Diazotization of tetrafluoroanthranilic acid with nitrosylsulfuric acid in acetic acid gave a ring-hydroxylated, stable diazonium salt 4, which was isolated in high yield. Several reactions on this diazo compound were carried out. Replacement of the diazonium group with hydrogen, chlorine, or bromine was accomplished with the usual reagents. The reaction of diazo compound with diazomethane afforded a benzoxadiazine compound 13. Other related polyfluoroaromatic compounds were prepared.
The Crystal Structure of Cupric Complex with Succinimide I. Cesium Tetrakis(succinimidato)copper(II) Dihydrate
Authors: Tsukihara Tomitake , Katsube Yukiteru , Fujimori Kumiko , Ito Toshiaki
Published: July 2006

The crystal structure of cesium tetrakis(succinimidato) copper(II) dihydrate, Cs2(Cu(sucim)4)·2H2O, has been determined by means of X-ray analysis. The crystals are violet rhombic plates. Dimensions of the triclinic unit cell are a=9.19, b=15.32, c=8.39 Å, α=88.7°, β=92.0°, γ=93.8°, and z=2. The space group is C\bar1. The structure has been determined by the Patterson synthesis, a series of Fourier syntheses and the least-squares method. The coordination around the copper atom is a square planar. Two independent cesium ions have a quite different environment. Complex anions, (Cu(sucim)4)2−, are linked with each other through the hydrogen bonds between water and carboxyl oxygen atoms.
ESR Studies of the Conformation and Restricted Rotation of 4-Phenyl-1,3-dioxane Anion
Authors: Iwaizumi Masamoto , Matsuzaki Takashi , Isobe Taro
Published: July 2006

The ESR of the 4-phenyl-1,3-dioxane anion shows a line-width alternation effect which can be attributed to the restricted rotation between the 1,3-dioxane and benzene rings. From the temperature dependence of the line-width alternation effect, the activation energy was determined to be 180±110 cal·mol−1. The preferential conformation between the two rings was estimated from the hyperfine splitting constant of the proton at the 4 position in the 1,3-dioxane ring, to be that where the two rings have some angle close to 90° rather than the structure where they are parallel. It was also found that an odd electron, which mainly occupies a vacant π orbital in the benzene ring, delocalizes appreciably into a part of the 1,3-dioxane ring.
Vibration Spectra and Molecular Structures of n-Butyl Chloride and n-Butyl Bromide in Relation to Parallel (1:3) Interactions
Authors: Fujiyama Tsunetake
Published: July 2006

The vibration spectra of liquid n-butyl chloride and n-butyl bromide are observed in the region of 1500–100 cm−1. From the analyses of spectra corresponding to the skeletal deformation vibrations, the molecular configurations are determined for both molecules. All the possible rotational isomers, the TT, GT, TG, GG, and GG′ forms, are observed for n-butyl chloride, while four isomers, the TT, GT, TG, and GG forms, are observed for n-butyl bromide. The results are compared with those of the electron-diffraction methods. It is shown that unfamiliar interactions must be considered for the parallel (1:3) interaction between methyl and chlorine substituents.
Electrochemical Behaviour of the Lithiated Nickel Oxide Crystal
Authors: Yoneyama Hiroshi , Tamura Hideo
Published: July 2006

The electrochemical properties of lithiated nickel oxide were studied using a single-crystal (100) face and a sintered body. The I–V curves of the Fe2+/Fe3+ system on the single-crystal electrode were almost the same as those on the sintered-body electrode when the electric resistivities of the crystals were equal. However, a high amount of charge was obtained at the sintered-body electrode compared with the single-crystal electrode when the crystals were oxidized anodically. The effect on these reaction rates of the space charge depletion layer formed on the electrode surface will be discussed. The dependence of the reaction rates on the electric resistivity of the crystal can be understood to a certain extent through this discussion.
Normal Vibrations and Far-infrared Spectra of Ammonium Chloride and Ammonium Chloride-d4 Crystals
Authors: Fukushima Kunio , Yamamoto Hiroko
Published: July 2006

The normal coordinate treatment of optically active lattice vibrations of ammonium chloride and ammonium chloride-d4 at low temperature was made in order to elucidate the nature of the vibrations and obtain force constants in the potential in the crystals by the method of least squares. Using the constants, the optically active lattice vibrations of a crystal model for ammonium chloride and ammonium chloride-d4 at room temperature were calculated. The far-infrared spectra obtained and the Raman and infrared spectra in literature were discussed.