bluuebunny/crossref_metadata_2025 huggingface dataset:
Derivatographic Studies on Transition Metal Complexes. VI. Thermal, cis, trans-to-cis, cis Exchange-Isomerization of [CoCl2(NH3)2en]SCN·H2O in Solid Phase
Authors: Tsuchiya Ryokichi , Suzuki Masatatsu , Kyuno Eishin
Published: July 2006

The exchange-isomerization of the complex, cis(dichloro), trans(diammine)-[CoCl2(NH3)2en]SCN·H2O to cis(chloro isothiocyanato), cis(diammine)-[CoCl(NCS)(NH3)2en]Cl, was investigated by means of both derivatographic and isothermal methods. The reaction took place immediately after the liberation of crystalline water. The thermochemical functions were obtained to be ΔH=(5.5±1.0) kcal/mol and E≠=(22.8±2.0) kcal/mol for the dehydration, while those for the exchange-isomerization were ΔH=(4.8±1.0) kcal/mol and E≠=(62.3±3.0) kcal/mol, respectively. As a probable reaction mechanism for the exchange-isomerization, a certain seven coordinated intermediate in the reaction pathway was introduced.
The Chemical Structures of Glasses of the NaPO3-Sb2O3-Na2O System
Authors: Watanabe Makoto , Tanabe Kazuo , Takahara Tomoyoshi , Yamada Tamotsu
Published: July 2006

Glassy and crystalline substances of the NaPO3-Sb2O3-Na2O system with P/Sb ratios in the range from 1.0 to 300 were prepared by heating NaPO3Sb2O3, and Na2CO3 at 1000°C and by then quenching the melts of the mixtures. Samples with P/Sb ratios smaller than 5.0 were obtained as crystalline substances containing amorphous substances. The chemical compositions of these crystalline substances were estimated from the data obtained by X-ray diffractometry and paper chromatography. Samples with P/Sb ratios larger than 7.0 were obtained as glassy substances. Condensed phosphates were separated by paper-chromatographic analysis, and the average degree of the polymerization of the phosphates was measured by the pH-titration method. It has been found that the crystalline substances in the samples with P/Sb ratios in the range from 1.0 to 5.0 were Sb2O5, NaSbO3, and an unknown crystalline substance. Assuming that the glasses have the P-O-P, P-O−, P-O-Sb, and Sb-O− linkages, a theoretical treatment of the degree of polymerization of condensed phosphates has been made and compared with the experimental data. It has been concluded that the glasses with P/Sb ratios larger than 7.0 have P-O-P, P-O−, and P-O-Sb linkages.
Structure and Intramolecular Motions in Triethylenediamine as Studied by Gas Electron Diffraction
Authors: Yokozeki Akimichi , Kuchitsu Kozo
Published: July 2006

The structure and intramolecular motions in triethylenediamine have been investigated by gas electron diffraction with a parallel study of bicyclo[2.2.2]octane in our previous paper. The structural parameters determined by a least-squares analysis on molecular intensities, with estimated limits of error, are as follows: rg(C–N)=1.472±0.007 Å, rg(C–C)=1.562±0.009 Å, ∠C–C–N=110.2±0.4°, ∠C–N–C=108.7±0.4°, rg(C–H)=1.110±0.012 Å and ∠H–C–H=111.5±5.6°. The gas-phase structure is in good correspondence with that in the crystal phase determined by Weiss et al. by X-ray diffraction. The potential function with regard to the twisting motion around the C3 symmetry axis is shown to have a broad minimum around the D3h conformation, being quite analogous to that for bicyclo[2.2.2]octane; in terms of the torsional angle φ about the C–C axis, it probably has a small hump of the order of 100 cal/mol at φ=0° and a double minimum around φ=10°. The above study was made with a new nozzle assembly, by which the sample can be heated to about 200°C. The detail of the design and operation is described.
The Synthesis of Nitro, Amino, and Acetamino Derivatives of 2,3-Dimethylbenzofuran
Authors: Kawase Yoshiyuki , Takata Setsuko , Hikishima Etsuko
Published: July 2006

Another route to the synthesis of nitro, amino, and acetamino derivatives of 2,3-dimethylbenzofuran was explored. The cyclo-dehydration of 3-(m- and p-nitrophenoxy)butanones by means of polyphosphoric acid or sulfuric acid afforded 2,3-dimethyl-4- and -5-nitrobenzofurans, which were then converted by reduction to the corresponding 4- and 5-aminobenzofurans. The 4-, 5-, 6-, and 7-aminobenzofurans were prepared by the Hofmann reaction of the corresponding carboxylic amides. The amines thus obtained were converted to 4-, 5-, and 6-acetaminobenzofurans by acetylation. The 5-, 6-,-and 7-acetaminobenzofurans were also prepared by the cycliza-tion of 3-(p-, m-, and o-acetaminophenoxy)butanones. The 7-nitrobenzofuran was prepared by the Sandmeyer reaction of 7-aminobenzofuran. The four aryloxybutanones, 2,3-dimethyl-4- and -7-nitrobenzofurans, 4-amino-2,3-dimethylbenzofuran, and 2,3-dimethyl-4-, -5-, -6-, and -7-benzofurancarboxylic amides are new compounds.
Isomerization of Gomberg’s Trityl by Protonic Acids in Benzene
Authors: Takeuchi Hiroshi , Nagai Toshikazu , Tokura Niichiro
Published: July 2006

Gomberg’s trityl (1-diphenylmethylene-4-trityl-2,5-cyclohexadiene) (I) was isomerized by protonic acids such as HCl and phenol in benzene to form p-benzhydryltetraphenylmethane(II). p-(Benzhydryl-α-d)-tetraphenylmethane (III) was formed by the treatment of I with phenol-d. Ph3CH and Ph3CCl were treated under the same conditions, but II was not obtained. It was not formed either by the reaction of phenylazotriphenylmethane with phenol. This observation indicates that H+ adds to the terminal methylene of I to form the cyclohexadienyl cation followed by deprotonation to give II. Similarly, treatment of 1-(phenyl-p-tolymethylene)-4-(diphenyl-p-tolylmethyl)-2,5-cyclohexadiene (IV) with HCl in benzene afforded α,α,α′-triphenyl-α,α′-(di-p-tolyl)-p-xylene (V). The results support the view that Gomberg’s trityl is not hexaphenylethane but 1-diphenylmethylene-4-trityl-2,5-cyclohexadiene as suggested by Lankamp et al. (Tetrahedron Lett., 1968, 249). 1,1,2,2-Tetraphenylethane and 1,1,2,2-tetra-o-tolylethane not having the cyclohexadiene structure could not be isomerized by protonic acids (HCl and PhOH) in benzene. Thus, isomerization of this type is characteristic of the cyclohexadiene structure such as that of Gomberg’s trityl.
Studies of the Synthesis of Furan Compounds. XXIII. Cyclization Derivatives of 5-Nitro-2-furimidoylhydrazine
Authors: Hirao Ichiro , Kato Yasuhiko , Hayakawa Tsunetoshi , Tateishi Hiromichi
Published: July 2006

The reaction of 5-nitro-2-furimidoylhydrazine (I) with diacetyl or furil gave 3-(5-nitro-2-furyl)-5,6-disubstituted-1,2,4-triazine derivatives (IIa, b). Refluxing I in a large excess of ethyl orthoformate afforded 3-(5-nitro-2-furyl)-5-ethoxy-1,2,4-triazoline (III) and bis[3-(5-nitro-2-furyl)-1,2,4-triazolyl]methyl ethyl ether (IV). By heating with ethyl orthoformate, III was converted to IV. When III or IV was heated in diluted sulfuric acid, 3-(5-nitro-2-furyl)-1,2,4-triazole (V) was produced. The reactions of I with cyanogen bromide in refluxing methanol and with nitrous acid in diluted hydrochloric acid gave the corresponding 3-(5-nitro-2-furyl)-5-amino-1,2,4-triazole (VI) or -1,2,4,5-tetrazole (VIII) respectively. When heated in acetic anhydride, the VI afforded monoacetyl compound (VII), while the VIII yielded 5-(5-nitro-2-furyl)-2-methyl-1,3,4-oxadiazole (X). The structures of these compounds were discussed on the basis of their IR and NMR spectra.
Infrared Spectroscopic Study of Enol and Enol Derivatives Coordinated to Platinum(II) and Palladmm(II)
Authors: Wakatsuki Yasuo , Nozakura Shun-ichi , Murahashi hunsuke
Published: July 2006

The infrared spectra of [Cl2M Olefin]2 (olefin=vinyl alcohol, vinyl ethers, and their derivatives, M=Pt and Pd) have been studied in the 4000–100 cm−1 frequency region. A normal coordinate analysis of the coordinated vinyl alcohol indicated that the lone-pair electrons of oxygen conjugated with π-electrons of the double bond to some extent, even in the coordinated state. The coordination strengths of vinyl alcohol, vinyl ethers, and their derivatives have been examined by comparing the metal-olefin streching vibrations.
Derivatives of Ditriazinylamine
Authors: Fukushima Yoshiaki , Nohara Noboru , Hashida Y\={o}ji , Sekiguchi Shizen , Matsui Kohji
Published: July 2006

Various substituted ditriazinylamines were synthesized by the reaction of N,N-bis(4,6-dichloro-s-triazin-2-yl)amine, N,N-bis(4-chloro-6-phenyl-s-triazin-2-yl)amine, or 2-chloro-4-phenyl-s-triazin-2-yl-2′,4′-dichloro-s-triazin-2′-ylamine with nucleophilic reagents. The reaction of N,N,N-tris(4,6-dichloro-s-triazin-2-yl)amine with sodium methoxide was also examined. In this case, various products were obtained, depending upon the amount of sodium methoxide used. A Hammett plot of the substituent constants (∑σm) vs. the pKa′ or the imino proton shifts of the above-mentioned ditriazinylamines gives a linear relationship.
Reactions of Haloferrocenes. IV. The Condensation of Haloferrocenes with Various Carboxylic Acids in the Presence of Copper(I) Oxide
Authors: Sato Masaru , Lam Yau Ping , Motoyama Izumi , Hata Kazuo
Published: July 2006

The condensation reaction of haloferrocenes with various carboxylic acids in the presence of copper(I) oxide was studied extensively. The reaction generally afforded the corresponding ferrocenyl carboxylates, along with a comparable amount of ferrocene. The change in the distribution of the reaction products was examined under various conditions in the reaction of bromoferrence with benzoic acid. From the discussion of the reaction mechanism, it was concluded that the ferrocenyl ester and ferrocene are produced through different active species. The reaction under proper conditions was found to be useful for the preparation of ferrocenyl esters.
Reactions of Haloferrocenes. V. The Formation of Ferrocenyl-triphenylphosphonium Perchlorate
Authors: Sato Masaru , Motoyama Izumi , Hata Kazuo
Published: July 2006

The reaction of haloferrocene with tetrakis(acetonitrilo)copper(I) perchlorate in nitromethane gave a 35% yield of biferrocenyl. The addition of triphenylphosphine to the reaction system causes a remarkable change in the reaction and gives ferrocenyltriphenylphosphonium perchlorate in a good yield. The scope of the formation of the quaternary salt was investigated in comparison with the corresponding reactions in the benzene series. It was found that the ligands coordinated in the intermediate copper(I) complex strongly affect the reaction. The mechanism of the formation of ferrocenyltriphenylphosphonium salt is also discussed.
Formation and Properties of Phenylthiomethyl Radical. Anodic Oxidation of Sodium Phenylthioacetate and Thermal Decomposition of t-Butyl Phenylthioperacetate
Authors: Uneyama Kenji , Torii Sigeru , Oae Shigeru
Published: July 2006

Phenylthiomethyl radical 1 was generated both from anodic oxidation of sodium phenylthioacetate 4 in sodium methoxide-methanol solution and from thermal decomposition of t-butyl phenylthioperacetate 5 in benzene. Both reactions afforded a similar trend of product ratios, phenyl disulfide 7 in 31–32% yield as a major product and 1,2-diphenylthioethane 6, the dimer of radical 1 in 1–2% yield. A chemical and electrochemical reaction process of 1 along with a plausible mechanism for α-elimination of 1 is discussed.
The Catalytic Reaction of Alcohols with Reduced Copper
Authors: Kawamoto Kazuaki , Nishimura Yoshiharu
Published: July 2006

The catalytic properties of a reduced copper catalyst in reaction to ethyl alcohol, n-propyl alcohol, n-butyl alcohol, 2-phenylethanol, 1-phenylethanol, 3-phenyl-1-propanol, cinnamyl alcohol, propionaldehyde, n-propyl propionate, and a mixture of ethyl alcohol and propionaldehyde were studied. The present investigation has been undertaken in order to find out whether or not the activity and the selectivity of reduced copper are affected by the method of the preparation of catalysts and the structure of alcohols used as the reactants, and to clarify the mechanism of the formation of the esters and ketones obtained from aliphatic alcohols. It has been found that, over reduced copper, saturated aliphatic alcohol gives considerable amounts of the corresponding aldehyde and ester. The formation of the ester may be explained by a hemiacetal mechanism. The hydroxyl group of aliphatic alcohol is very resistant to hydrogenolysis. However, with the phenyl-substituted alcohols the carbon-to-oxygen bond is easily broken.
The Reaction of α-Carbonyl Sulfides with Bases. I. The Reaction between α-Carbonyl Sulfides with Thiolates
Authors: Oki Michinori , Funakoshi Wataru , Nakamura Atsuko
Published: July 2006

It is found that carbonyl compounds, such as ketones and esters, bearing an alkyl(or aryl)thio group at the α-position, are smoothly reduced to the parent carbonyl compounds by the action of the thiolate anion. α-Halo or α,α-dihalo ketones are similarly reduced with the thiolate, probably via the corresponding sulfides. The mechanism of the reaction is discussed.
p-Toluenesulfonylation of 1,2-O-Cyclohexylidene-myo-inositol
Authors: Suami Tetsuo , Ogawa Seiichiro , Tanaka Takatoshi , Otake Toshiki
Published: July 2006

p-Toluenesulfonylation of 1,2-O-cyclohexylidene-myo-inositol (la) afforded one mono (1), three di (1,4, 1,5, and 1,6), three tri (1,4,5, 1,4,6, and 1,5,6), and one tetra (1,4,5,6)-O-p-toluenesulfonyl derivatives of myo-inositol, and all the structures have been established by way of their proton magnetic resonance (PMR) spectra and the reaction sequences.
Iminodithiocarbonates. IV. Pyrolyses of N-Acyl Immonium Salts of Iminodithiocarbonates
Authors: Ueno Yoshio , Nakai Takeshi , Okawara Makoto
Published: July 2006

The pyrolyses of N-acyl immonium salts of S,S′-dimethyl N-methyl- (II) and N-phenyl-iminodithiocarbonates (III) were studied. N-Methyl-immonium salt II gave S-methyl N-acyl-N-methyl-dithiocarbamate (V) at 100°C, but N-phenyl derivatives (III) gave phenyl isothiocyanate and S-methyl thiolbenzoate (VI) at 140°C. On the other hand, cyclic immonium salt, 2-(N-benzoyl-N-methyl)-1,3-dithiolanylium chloride (IV) gave 2-benzoylimino-1,3-dithiolane(VII) with elimination of N-methyl group at 200°C. It was found that N-acyldithiocarbamate V isolated was further decomposed to methyl isothiocyanate and thiolbenzoate at 200°C. Independent syntheses of N-acyldithiocarbamates V were performed on the reaction of N-monosubstituted dithiocarbamates and acyl chloride.
Dissociation Constants of the Oxalato-Titanium(III) Complex as Determined from Spectrophotometric Measurements
Authors: Pan Kuan , Lai Chin Chan , Huang Teh-Shoon
Published: July 2006

The dissociation constant of Ti(C2O4)2− ions in hydrochloric acid media was evaluated from the data obtained by spectrophotometric measurements at 25°C. The average value of pK for the reaction, Ti(C2O4)2−=Ti(III)+2C2O42−, at an infinite dilution was estimated as 9.0, while that for the Ti(C2O4)2−=Ti3++2C2O42− reaction was evaluated as 8.74.
Effect of Phase on Excitation Transfer in the Radiolysis of Isobutane
Authors: Miyazaki Tetsuo , Yamada Takahisa , Wakayama Terunobu , Fueki Kenji , Kuri Zen-ichiro
Published: July 2006

The effects of CCl4 on the formation of H2 and C4H9 radicals in the radiolysis of i-C4H10 have been studied in glass at 77°K and the liquid at 195°K. The yield of H2, which is not affected by the addition of N2O or SF6, decreases sharply upon the addition of CCl4 in the glass, as in the crystal (This Bulletin, 42, 1164 (1969); 43, 1017 (1970).), while it does not so sharply decrease in the liquid as in the solid. The effects of CCl4 on the yields of H2 correspond fairly well to those on the yields of the C4H9 radicals. The effects of CCl4 in the glass are explained by the excitation transfer from the excited butane molecule to CCl4, as in the radiolysis of i-C4H10 in the crystal. A kinetic treatment suggests that its mechanism may be the exciton transfer. Some remarks on the primary process of ionization in the radiolysis of solid hydrocarbons are given from the viewpoint of exciton transfer.
The Hydrogenation of Butadiene Catalyzed by Pentacyanocobaltate(II) in Aqueous and Non-aqueous Solvents
Authors: Funabiki Takuzo , Tarama Kimio
Published: July 2006

The hydrogenation of butadiene catalyzed by pentacyanocobaltate(II) was studied in water and in glycerol-methanol-water and ethylene glycol-methanol solutions. The amount of hydrogen absorbed, and the rate of hydrogen absorption, in the water solvent were much greater than in the other solvents. The composition of the butenes produced by the hydrogenation in the water solution was trans-2->>1->cis-2-butene at CN/Co<5.1, and 1->>trans-2->cis-2-butene at CN/Co>5.1; this composition was affected by the concentration of the complex. The composition of the butenes produced in the glycerol-methanol solution was trans-2->>1–>cis-2-butene at CN/Co<5.4 and 1->cis-2->>trans-2-butene at CN/Co>5.4; a concentration effect similar to that in the water solution was observed. The composition of butenes in the glycerol-methanol-water solution at CN/Co=6.0 was remarkably affected by the composition of the solvent. In the ethylene glycol-methanol solution, cis-2-butene was much more producible than in the glycerol-methanol solution. The mechanism of the hydrogenation of butadiene by pentacyanocobaltate(II) was discussed on the basis of these solvent effects on the composition of products, and on the basis of the kinetical behavior of this hydrogenation reaction.
Average Values of Bond Angles
Authors: Kuchitsu Kozo
Published: July 2006

A number of definitions with clear physical significance regarding the “average bond angles” (nonlinear case) are presented. Simple expressions of the average angles in terms of the linear and quadratic mean values of the displacements in the internuclear distances are given. The differences in the various average angles for H2O, D2O, CH4, CD4 and SO2 are estimated by means of a normal-coordinate analysis. The differences are shown to be small fractions of one degree. The root-mean-square angles for linear molecules (HCN, DCN, CO2 and CS2) are also calculated.
An MO-theoretical Interpretation of the Origin of the Orienting Effect in Aliphatic Systems
Authors: Fujimoto Hiroshi , Yamabe Shinichi , Fukui Kenichi
Published: July 2006

The importance of the charge-transfer interaction from the highest occupied (HO) molecular orbital (MO) of a donor to the lowest unoccupied (LU) MO of an acceptor molecule has been stressed on the basis of the numerical results of the calculation on a model of the SN2 reaction of methyl chloride. The effect of a counter ion on the frontier orbitals has been discussed. For the E2 reaction of ethyl chloride, it has been discussed how the orienting effect of the leaving nucleophile is transmitted to the trans-β-hydrogen by means of the frontier electron density. The influence of the rotation about the Cα–Cβ bond upon the reactivity of β-hydrogen has also been discussed.
Dielectric Relaxation and Molecular Structure. V. Application of the Single Frequency Method to Systems with two Debye Dispersions
Authors: Higasi Keniti , Koga Yoshinori , Nakamura Masahiko
Published: July 2006

There are four Debye equations for dilute solutions which can be used to determine the relaxation time of a polar solute molecule. This paper offers a critical examination of these equations, especially two representative formulas which are mutually independent. If the solute molecule has a non-rigid configuration and has two relaxation times, τ1 and τ2, for overall and internal rotations, respectively, average relaxation times will be obtained from these equations based on measurements at a single frequency. However, the analysis of this paper shows that under a certain condition (if a proper frequency for the measurement and a suitable equation for the calculation are employed) one may make a crude estimate regarding one of the two relaxation times. Further, the ratio of two relaxation times seems to afford a clue for investigating the mechanism of internal rotation. In addition, Cole-Cole dispersion and atomic polarization problems are also discussed.
A Remark on the Dipole Moment of Cyclohexane-1,4-dione in Relation to Its Flexible Molecular Conformation
Authors: Aihara Ariyuki , Kitazawa Chikazu
Published: July 2006

A critical remark on the interpretation of the polarity of cyclohexane-1,4-dione molecule has been made taking into consideration a possible contribution of atomic polarization estimated from the electric permittivity of the compound in the solid state. The value 9.6 cc has been assigned as the minimum for atomic polarization which gives dipole moments, 1.16D (28.6°C), 1.20D (42.9°C), and 1.22D (60.8°C) obtained in benzene solutions. A theoretical calculation of the dipole moment has been made also with an assumed potential barrier of the form, V(θ)=V0. [(π–θ)−2β]⁄2α, in relation to a flexing intramolecular movement of the molecule, where θ is the angle between two carbonyl groups substituted at the opposite sites of the molecule, V0 is the potential for a boat form A (with two carbonyl groups at the bow and the stern), and α, β are constants to be determined by applying boundary conditions: V(θ)=0 for θ=180°–137°, and V(91°)=V0. By taking 2.46D as the bond moment of carbonyl group, the best fit has been realized between the theoretical and experimental dipole moments when V0 is assumed to be close to 6000 cal/mol, i. e., twice as large as the hindering potential for the internal rotation of ethane molecule. Mention has also been made of the mechanism of dielectric absorption by this molecule in benzene solution with particular reference to the flexing motion suggested above.
ESR Studies of the Conformational Interconversion of the 9,10-Dihydrophenanthrene Radical Anion and Its Related Compounds
Authors: Iwaizumi Masamoto , Matsuzaki Takashi , Isobe Taro
Published: July 2006

The ESR spectra of the 9,10-dihydrophenanthrene radical anion change drastically with the temperature, and at temperatures around −30°C the spectra show a marked line-width alternation effect. These temperature-dependent ESR spectra and the line-width alternation effect have been interpreted in terms of the conformational interconversion of the 9,10-dihydrophenanthrene radical anion molecule. From an analysis of the spectra, the activation energy of the inversion has been estimated to be 6.3±0.6 kcal/mol. It has also been estimated, from the ratio of the axial and equatorial proton splittings, that the dihedral angle of the axial protons is about 11°. These data are compared with those of the 4,5,9,10-tetrahydropyrene radical anion. The ESR of the 4,5-dihydropyrene radical anion is also presented.
Molecular Vibrations and Force Fields of Alkyl Sulfides. II. Infrared Spectra of CH3S(CH2S)nCH3 (n=0–3)
Authors: Ohsaku Masaru , Shiro Yuji , Murata Hiromu
Published: July 2006

Infrared spectra recorded in the liquid and solid states of dimethyl sulfide, CH3SCH3, bis(methylthio)methane, CH3SCH2SCH3, bis(methylthiomethyl) sulfide, CH3SCH2SCH2SCH3, and bis[(methylthio)methylthio]methane, CH3SCH2SCH2SCH2SCH3, are reported. For the CH3SCH2SCH3 species, the gaseous spectra were also recorded. For these molecules, the observed bands were assigned to the fundamental modes of the vibrations with reference to those of reported analogous-structure molecules. The existence of the rotational isomers of the last three compounds was postulated. The regularity of the wave number of the fundamentals obtained and the intensity change in some of the bands for this series of compounds were discussed. The frequency shift in the liquid-solid phase transition was also described for a few bands.
Study on Oxidation of Chalcones with Lead Tetraacetate and Manganic Acetate
Authors: Kurosawa Kazu , Higuchi Junko
Published: July 2006

2′-Hydroxychalcones were oxidized with lead tetraacetate and manganic acetate to give trans- and cis-aurones, together with substituted benzoic acids and cinnamic acid. In the oxidation, 2′-benzyloxy-4,4′-dimethoxychal-cone gave 2-acetoxy-l-(2′-benzyloxy-4′-methoxy)phenyl-3-(4′-methoxy)phenylpropane-1,3-dione and erythro-2,3-diacetoxy-1-(2′-benzyloxy-4′-methoxy)phenyl-3-(4′-methoxy)phenylpropan-l-one. Structures of the products were elucidated spectrometrically and confirmed by syntheses.
Studies on Hydroxy Amino Acids. IV. Syntheses of Several Peptides Containing Aziridinecarboxylic Acid Derived from the Corresponding Hydroxy Amino Acid Derivatives
Authors: Nakagawa Yasuo , Tsuno Takashi , Nakajima Kiichiro , Iwai Michio , Kawai Haruki , Okawa Kenji
Published: July 2006

The β-elimination reaction of the O-tosyl β-hiydroxy amino acid peptide derivative was thoroughly investigated. The N-tosyl-l-serylglycine ester and the N-tosyl-l-threonylglycine ester gave the N-tosyl-l-aziridinecarbonyl-glycine ester and the N-tosyl-3-methyl-l-aziridinecarbonylglycine ester as the resulting products respectively by the elimination reaction. On the other hand, the N-carbobenzoxyglycyl-l-serylglycine ester was not converted into the aziridine peptide derivative; only the dehydroalanine peptide was obtained. However, the N-tosyl-l-phenylalanyl-l-threonylglycine ester and the N-carbobenzoxyglycyl-l-threonylglycine ester were converted into the corresponding aziridine peptide, and the N-tosyl-l-phenylalanyl-3-methyl-l-aziridinecarbonylglycine ester and the N-carbobenzoxyglycyl-3-methyl-l-aziridinecarbonylglycine ester were obtained respectively. It was concluded that the peptides containing threonine were easily converted into the aziridine peptides and not the serine peptides by the β-elimination reaction.
Heat Capacity of Ammonium Chloride between 8 and 300 K
Authors: Chihara Hideaki , Nakamura Minoru
Published: July 2006

Heat capacity of NH4Cl was measured between 8 and 300 K with an adiabatic calorimeter. The low-temperature limit of the Debye temperature is 352 K and its high-temperature limit in the harmonic approximation is 285 K. The λ transition point Tλ is 242.502±0.004 K with the heat of transition 1168 J mol−1 and the entropy of transition 5.00 JK−1 mol−1. It is very close to the first-order transition. From the analysis of the heat capacity between 242 and 300 K, an extra contribution to the heat capacity that amounts to 11.5 JK−1 mol−1 at 300 K is extracted and explained by a simple model which assumes an additional type of order-disorder in the arrangment of NH4 ions above Tλ. The energy difference between the parallel and the antiparallel pairs of NH4 ions is estimated to be 1.46 kj mol−1 from the low-temperature tail of the heat capacity anomaly near Tλ.
Fluorometric Determination of Aluminum and Gallium with Superchrome Garnet Y
Authors: Hiraki Keizo
Published: July 2006

A sensitive fluorometric determination of aluminum and gallium with Superchrome Garnet Y was described. The reagent reacts with aluminum and gallium to form complexes with reddish yellow fluorescence of emission maximum at 562 and 565 nm respectively. Several conditions for the determination, such as the pH of the solution, the reagent concentration, the time of standing etc. were investigated, and the composition of the complexes was determined. The maximum fluorescence intensity of the aluminum complex was found at pH 5 (heated for 10 min at 50°C), and that of the gallium complex, at pH 3. The fluorescence were stable at least for 2 hr. By using Superchrome Garnet Y, 0.02–4 μg of aluminum and 0.5–30 μg of gallium in 25 ml solution could be determined. Scandium and indium also formed fluorescent complexes. Iron(III), cobalt(II), copper(II), zirconium(IV), vanadate(V), and chromate(VI) ions interfered with the determination.
Trace Analysis of Metals by ESR. II. Indirect Microdetermination of Mercury(II) with Tetraethylthiuram disulfide Copper(II) Complex
Authors: Yamamoto Daijiro , Ikawa Noriaki
Published: July 2006

A method was devised for the indirect microdetermination of mercury by means of ESR. Tetraethylthiuram disulfide(TET)-Cu(II) complex dissolved in benzene showed a characteristic ESR spectrum. Quantitative determination of a small amount of mercury(II) was made by application of the replacement reaction of TET-Cu(II) by mercury(II)-ion in a benzene solution:

TET-Cu+Hg2+→TET-Hg+Cu2

The ratio of metal to ligand was considered to be 1 : 1 in the complex. 1.0–0.1 γ/ml and 0.1–0.01 γ/ml of mercury was determined rapidly in the presence of Mg2+, Fe2+, Ba2+, Mn2+, Zn2+, Co2+, Pb2+, Ni2+, I−, Br−, NO3−, and Cl− ions. CN− interfered with the determination. From a comparison of this and photometric methods a very small amount of mercury(II) ion can be determined with a very small amount of sample.
Dimerization and Isotopic Mixing of Ethylene by a Palladium Complex Catalyst
Authors: Kitamura Taketsugu , Maruya Ken-ichi , Moro-Oka Yoshihiko , Ozaki Atsumu
Published: July 2006

Dimerization and accompanied isotopic exchange of ethylene were studied with dichlorobis(benzonitrile)-palladium(II) complex in benzene solution. Dimerization as well as isotopic exchange take place simultaneously after an induction period, the extent of which is reduced by the presence of hydrogen releasing olefin such as 3-methyl-1-butene. Kinetics of dimerization is of first order in ethylene, but the dimerization rate does not immediately respond to the change in ethylene pressure. The results are interpreted in terms of a preformed palladium hydride complex.
Structures of Three Isomeric Dimers of 2,4,5-Triphenylimidazolyl
Authors: Tanino Hideo , Kondo Tadao , Okada Kunisuke , Goto Toshio
Published: July 2006

In addition of the piezochromic and the photochromic (dimer A) dimers of 2,4,5-triphenylimidazolyl, two new isomeric dimers were prepared; one (dimer B) being photochromic and the other (dimer C) non-photochromic. Several p-substituted derivatives of the dimers were also prepared. By comparison of their NMR and IR spectra, structures (a), (b), and (c) were assigned to the dimers A, B, and C, respectively. On treatment with hydrochloric acid in ethanol, dimer A underwent heterolytic cleavage and gave a mixture of 2-ethoxy-2H- and 4-ethoxy-4H-2,4,5-triphenylisoimidazole, and 2,4,5-triphenylimidazole.
The Biosynthesis of Linalool in Cinnamomum Camphora Sieb. var. linalooliferum Fujita
Authors: Suga Takayuki , Shishibori Tsuyoshi , Bukeo Michie
Published: July 2006

The labelling pattern in linalool biosynthesized from [2-14C] mevalonic acid in Cinnamomum Camphora Sieb. var. linalooliferum Fujita was found to be consistent with the predicted biosynthetic pathway involving the condensation of isopentenyl pyrophosphate with 3,3-dimethylallyl pyrophosphate. The radioactivities at C-4 and C-8 (and/or C-10) were about equal, in contrast to the asymmetric pattern of labelling observed for bicyclic monoterpenes, which contained a tracer predominantly in one position of the skeleton derived from isopentenyl pyrophosphate. The efficiency of the incorporation of the tracer into linalool was almost independent of the season of the examination, although a slight increase was observed in the season of the active growth of the plant.
Hydrogen Transfer Polymerization of Malononitrile
Authors: Kawabata Nariyoshi , Chen Chung Kuang , Yamashita Shinzo
Published: July 2006

Treatment of malononitrile with a catalytic amount of cuprous chloride and triethylamine under a nitrogen atmosphere resulted in the formation of solid polymer in high yield. The polymer was soluble in dimethyl sulfoxide, pyridine and hexamethylphosphoramide but insoluble in other organic solvents. The polymer was characterized by elemental analyses and IR and NMR spectra to have a mixed structure of an enamine form, (Remark: Graphics omitted.), and a ketimine form, (Remark: Graphics omitted.).
Intramolecular Hydrogen Bonding of ortho-Substituted Benzenethiols
Authors: Kobayashi Takahiro , Yamashita Akihiko , Furuya Yoshihiro , Horie Rumiko , Hirota Minoru
Published: July 2006

From the infrared, NMR, and dipole moment measurements on several substituted benzenethiols, the intramolecular hydrogen bonding in o-halo, o-methoxy, o-nitro, and o-carbomethoxybenzenethiols is verified. Fivemembered S–H···X hydrogen bonds cause remarkable enhancements of their S–H stretching absorptions without considerable frequency shifts. The favorable s-cis conformations in these thiols are also proved by comparing their experimental dipole moments with theoretical values. By far stronger hydrogen bond is observed in o-carbomethoxybenzenethiols which can form six-membered chelate ring by the intramolecular hydrogen bonding.
Measurements of the Vapor and Dissociation Pressures of Potassium Sulfate and Carbonate at High Temperatures
Authors: Kosugi Tetsuo
Published: July 2006

The dissociation reactions of potassium sulfate and potassium carbonate were determined using a quadrupoletype mass spectrometer with a Knudsen-cell-type ion source. The vapor and dissociation pressures of potassium sulfate and the dissociation pressure of potassium carbonate were obtained, by the use of the Knudsen effusion method at temperatures from 900 to 1700°K, as follows:

logP=−1.253×104\left(\frac1T\ight)+7.724(K2SO4)

logPd=−3.275×104\left(\frac1T\ight)+20.83(K2SO4)

logPd=−1.135×104\left(\frac1T\ight)+9.257(K2CO3)

The equilibrium constants of the dissociation reaction were estimated from the above data and from those of Kröger and Stratmann:

logKp=−6.94×104\left(\frac1T\ight)+38.8(K2SO4)

logKp=−1.38×104\left(\frac1T\ight)+9.80(K2CO3)
An Interstitial-Electron Model for the Structure of Metals and Alloys I. Description of Model for Metallic Binding
Authors: Johnson Oliver
Published: July 2006

Application of the Hellmann-Feynman Theorem to Metals has led to an interstitial-electron model in which there is some localization of itinerant electron density in octahedral or tetrahedral interstices of close-packed metal ion cores. A flat maximum of electron density at centers of interstices is proposed as well as preferential occupancy of either octahedral or tetrahedral interstices. Such occupancy is rather precisely determined by the requirements of minimum electron-electron repulsion and of opposite spins for electrons in adjacent interstices. Writing the interstitial-electron structure of a metal in terms of interstice occupancy thus includes electron correlation effects. The interstitial-electron structures are instantaneous pictures of electron density which are representative of the highly dynamic situation of electrons in metals. The model leads to localization of d-electrons on the metal-ion core when interstices are fully occupied by itinerant electrons, i.e. at M6+. The presence of vacant interstices is required for metallic properties. On the basis of the model, chemical binding in metals differs from that in polyhedral molecules or metal cluster compounds only in the greater delocalization of electron density in metals. The concepts of the interstitial-electron model are closer to those of the method of pseudopotentials than to the Bloch Band Theory although all of these descriptions of metals can be considered equivalent.
The Solvent Extraction of Iron(III) in Perchlorate Solutions Containing Chloride or Bromide Ions with 2-Thenoyltrifluoroacetone and Trioctylphosphine Oxide
Authors: Sekine Tatsuya , Tetsuka Toshihiro
Published: July 2006

Iron(III) in aqueous solutions, in which [H+]=1.0m, [Na+]=3.0m, and [L−]+[ClO4−]=4.0m, where L− is a chloride or bromide ion, was extracted with thenoyltrifluoroacetone (TTA) in carbon tetrachloride or with trioctylphosphine oxide (TOPO) in hexane. From the TTA extraction, it was concluded that iron(III) formed the first and the second complexes with both chloride (β1=100.88 and β2=100.80) andbromide (β1=10−0.10 and β2=100.00) ions in the aqueous phase. The distribution data of iron(III) with TOPO were then explained in terms of the extraction of the ion-pairs, Fe(ClO4)3, FeL(ClO4)2, and FeL2(ClO4), by using these stability constants. When the aqueous phase contained only chloride or bromide ions, and no perchlorate ion, the increase in the extraction with the increase in the halide ion concentration was much larger than that observed when the aqueous phase contained both halide and perchlorate ions. From the determination of the extraction of hydrogen ions and halide ions with TOPO, the extracted species in the absence of a perchlorate ion were identified as FeL3 and/or HFeL4. It was concluded that the difference in the extraction of iron(III) when a perchlorate ion was present and when it was absent is mainly caused by (i) the extraction of perchloric acid, which combines with TOPO in the organic phase and interferes with the extraction of the iron(III) halide complexes, and (ii) the extraction of iron(III) species containing one or more perchlorate ions which are large enough to be extractable with TOPO in the organic phase.
Liquid Crystalline Properties of Terminally Substituted Benzylideneanilines
Authors: Murase Kei
Published: July 2006

The preparation and mesomorphic characteristics of certain anils (p-alkoxybenzylidene-p′-alkylanilines and p-alkoxybenzylidene-p′-alkoxyanilines) are described. Fifteen new compounds were found to exhibit nematic behavior below 100°C. The structural effects of the terminal substituents on nematic temperature range are discussed. It has been found that the anils containing n-alkyl substituents in the p-position of the aniline moiety exhibit mesophases in a much lower temperature range than those containing n-alkoxy substituents. Among p-isoalkoxybenzylideneanilines, all compounds except one are non-mesomorphic.
On the Configuration of Branched-Chain Derivatives of 1,2 : 5,6-Di-O-isopropylidene-α-d-ribo-hexofuranos-3-ulose
Authors: Yoshimura Juji , Kobayashi Kazuhiko , Sato Ken-ichi , Funabashi Masuo
Published: July 2006

In order to obtain a 3-C-hydroxymethyl-d-glucose derivative some nucleophilic reactions of 1,2 : 5,6-di-O-isopropylidene-α-d-ribo-hexofuranos-3-ulose (1) and the configurations of products have been examined. Gluco-and allo-configurations of known 3-C-nitromethyl derivatives of 1 were confirmed by the fact that 3-C-acetaminomethyl-1,2-O-isopropylidene-α-d-xylo- and ribo-pentodialdofuranoses, derived by four successive transformations, showed the absence and presence of the aminal-ring formation between the aldehyde and acetamino groups, respectively. A 3-C-carbethoxymethyl derivative obtained by the Reformatsky reaction of 1 with ethyl bromoacetate was proved to be of allo-configuration by the lactone-formation between C5-hydroxyl and carboxyl groups. The configuration of 3-C-hydroxymethyl derivative (15) obtained by treatment of known 3-C-methylene derivative of 1 with permanganate was proved to be of gluco-typc by comparison of the corresponding 3-C-aminomethyl derivative (5), derived by three-step conversions, with that obtained from 3-C-nitromethyl derivatives. 15 was also obtained by epoxidation of 1 with diazomethane followed by ring-opening with alkali. Treatment of 5 and its allo-epimer with nitrous acid gave, respectively, a ring-expanded product and the 3′,5-anhydride, the former being also recognized in the epoxidation products. Structures of new compounds were examined by NMR spectra and stereoselectivity of reactions discussed.
Layered Compounds. V. Synthesis and Properties of [m.n]Paracyclophadiynes
Authors: Matsuoka Takahiro , Negi Taichi , Otsubo Tetsuo , Sakata Yoshiteru , Misumi Soichi
Published: July 2006

A series of bisethynyl compounds, IX and XII, were prepared by a modified ethynylation using N-methyl-2-pyrrolidone in good yields. Intramolecular oxidative coupling of the bisethynyl compounds has been achieved with high-dilution technique to give relatively good yields of highly strained or strainless [m.n]paracyclophadiynes I and cyclic diacetylenes XIII. From the comparison of the electronic spectra of these diacetylenic compounds, it is concluded that abnormal spectra of Ic and Id are attributed to the transannular π-electronic interaction between benzene nucleus and diacetylenic unit rather than the ring strain in the molecules. In addition, a marked down-field shift of aromatic protons in Ic compared with the other paracyclophadiynes is explained in terms of the transannular shielding effect of diacetylenic linkage.
The Preparation and General Properties of Ion-exchange Carbon Fiber
Authors: Otani Sugio , Tamura Masao , Yoshida Yatsuo , Tsuji Yoshio
Published: July 2006

Cation-exchange carbon fibers were prepared from pitch-based carbon fiber by oxidizing treatment with a mixture of K2Cr2O7, HNO3, and water. Their most characteristic properties were a large electric conductivity, a large thermal stability, and their shape. Their exchanging properties varied with the composition of the mixture and the treating conditions. The following composition and the conditions were adopted as standard.

Composition of the mixture: K2Cr2O7, 10 g; HNO3, 20 ml; H2O, 80 ml

Condition of the treatment: temperature, 104°C; period, 2.5 hr

Amount of carbon fiber: carbon fiber prepared at 1000°C 1 g

The cation-exchange capacity obtained by the standard procedure was 2.0±0.1 mequiv/g. Carbon fiber prepared at 1000°C was a better material than that prepared at 2000°C. Even after the exchangers were heated at 220°C in air, no change was observed in the capacity measured at room temperature. The electric resistivity increased from 7×10−3 ohm-cm to 8×102 ohm-cm with an increase in the capacity, and no difference was obserbed between exchangers of the acidic form and the sodium form. The tensile strength of the filament(1.9 mequiv/g in the capacity) was 6.7×106 g/cm2, and the breaking load of the spinning yarn of 1300 den. (2.0 mequiv./ g) was 3.0 kg.
Substituent Effect of Dipole and Dipolarophile in the Reaction of Nitrones with N-(Substituted phenyl)maleimides
Authors: Iwakura Yosio , Uno Keikichi , Hong Suck-Ju , Hongu Tatsuhiko
Published: July 2006

The reactions of C-(p-substituted phenyl)-N-(p-substituted phenyl) nitrones with N-(p-substituted phenyl)maleimides were carried out in THF to give both trans- and cis-isoxazolidines. The formation ratios of trans- to cis-isoxazolidines (IT⁄Ic) were determined by the NMR spectra of the cycloadduct mixtures. Though the values of IT⁄Ic varied with the electronic characters of the substituents, R1, R2, and R3, they were always found to be larger than unity.
Photo-decoloration Process of the Reverse Photochromic Spirans
Authors: Inoue Eiichi , Kokado Hiroshi , Shimizu Isamu , Kobayashi Hajime , Takahashi Yohnosuke
Published: July 2006

The unstable colorless form (A′) of the reverse photochromic spiran (SP-3) (1,3,3-trimethyl-5-methoxyspiro[indoline-2,2′-benzopyran]-8′-carboxylic acid) was obtained in a stable state by vacuum evaporation (10−5 Torr) on a KBr substrate. It was confirmed by IR spectral analysis that reverse photochromism occurred between the colored (B′; merocyanine-like structure) and the colorless forms (A′; spiropyran). A colorless transient intermediate (X) was observed in the photo-decoloration process of the (SP-3). X was transformed into both A′ and B′. Thus the photo-decoloration efficiency (φB′→A′) depends on the ratio of the conversion from X to A′. State (B′) is stabilized in a polar or proton donative solvent. The life time of X is greatly influenced by the solvent as well as the stability of B′. The photo-decoloration efficiency (φB′→A′) of the spirans is effectively improved by substituting SP-2 with (methoxyl group) at 5-position. Whether X is observable or not depends on the substituent and its position. The reversibility of photochromic cycle of the spirans was restricted by the photobleaching of B′ by UV irradiation. It was observed that the photo-bleaching of B′ is accelerated in a degassed solution.
Calorimetric Study of the Glassy State. VII. Phase Changes between the Crystalline Phases of Cycloheptanol with Various Degrees of Stability
Authors: Adachi Keiichiro , Suga Hiroshi , Seki Syûzô
Published: July 2006

The heat capacities of 8 kinds of stable and meta-stable crystalline phases including the glassy crystal of cycloheptanol were measured at temperatures from 13 to 300 K. The crystalline phases have been named crystals I, II, II′, III, III′, III″, Iβ, and glassy crystal. Transition temperatures between crystals II and I, III and II, II′ and II, III′ and III, III″ and III were determined to be 258.45, 227.26, 172.23, 152.30, and 128.2 K, respectively. The melting point and glass transition point of the glassy crystal were determined to be 280.30 and 140 K, respectively. The heats of transition between crystals II and I, III and II, III′ and III and the heat of melting were determined to be 876, 554, 58.1, and 1604Jmol−1, respectively. The residual entropy of the glassy crystal was found to be 0.7 JK−1mol−1 assuming that of crystal III′ to be zero. The stabilization phenomenon in the glassy crystalline state was also studied from the measurements of enthalpy relaxation. The stability of the various phases was determined by calculating their free energies. The degree of freedom which is frozen in the glassy crystalline state was discussed from molecular viewpoints. Classification of various phase transitions found in this material was also made from the viewpoint of thermodynamical stability.
An Electron Spin Resonance Study of the Tropone Anion Radical
Authors: Ikegami Yusaku , Watanabe Hidetoshi , Seto Shuichi
Published: July 2006

The ESR spectrum of the tropone anion radical has been examined. The radical was generated from the neutral species by the electrolytic reduction in N,N-dimethylformamide. Splitting constants are satisfactorily explained in terms of the calculated spin densities by the McLachlan procedure, confirming that the unpaired spin orbital belongs to an a2 symmetrical species. The complete delocalization of the π-electrons was assumed for the anion radical.
Generation and Cycloaddition of 8,8-Dimethylisobenzofulvene
Authors: Tanida Hiroshi , Irie Tadashi , Tori Kazuo
Published: July 2006

Transient 8,8-dimethylisobenzofulvene (5) was generated by thermal decomposition of two materials; one is formally an adduct of cyclopentadienone with 9-isopropylidenebenzonorbornadiene (6), and the other an adduct of 3,6-di(2′-pyridyl)-S-tetrazine with 6. The former was prepared by cycloaddition of 6 to tetrachlorodimethoxycyclopentadiene followed by dechlorination giving a ketal, then hydrolysis of the ketal function. Generation without any trapping reagent instantaneously yielded one kind of dimer of a stereospecific structure. In the presence of dimethyl maleate, dimethyl 9-isopropylidenebenzonorbornene-exo,cis-2,3-dicarboxylate and its endo-cis isomer were formed. In the presence of dimethyl fumarate, the trans isomer was obtained. Trapping with tropone led to a 1 : 1 adduct resulting from participation of the exocyclic C2–C8 double bond in 5. All attempts to isolate 5 or prepare a stable metal complex of 5 by conventional means were unsuccessful.
Studies of Rare Earth Oxyfluorides in the High-temperature Region
Authors: Niihara Koichi , Yajima Seishi
Published: July 2006

The behavior of the rhombohedral LnOF and the tetragonal Ln4O3F6 at high temperatures was investigated by differential thermal analysis and the high-temperature X-ray diffraction technique. In the case of the rare earth oxyfluorides, LnOF (Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y), the high-temperature transition rhombohedral\ightleftarrowscubic was observed by means of DTA and a high-temperature X-ray camera. The heat of transformation from rhombohedral to cubic was obtained by means of DTA. The transition temperatures and the heat of transformation, ΔH, shift to higher temperatures and to greater values respectively as the atomic numbers of the rare earth elements increase, although there are some anomalies. One endothermic peak was observed for the rare earth oxyfluorides, Ln4O3F6, from Sm to Lu. On the other hand, no peak was observed up to 1300°C for La, Pr, Nd, and Y. The behavior of the peak temperature of DTA against the atomic number for Ln4O3F6 is similar to that for LnF3; this indicates a transformation from an orthorhombic to a hexagonal structure.
Kinetic Study on Homolysis of Aryl Arylazo Sulfones
Authors: Kojima Minoru , Minato Hiroshi , Kobayashi Michio
Published: July 2006

Aryl arylazo sulfones were prepared, and the rates of homolyses in chlorobenzene were determined in the presence of a base for suppression of acid catalysis at 80–118°C. An isokinetic relationship was found to hold between ΔH\eweq and ΔS\eweq (β=101.0°C). The substituents on the benzenesulfonyl group influenced the rates very little, whereas the substituents on the phenylazo group decreased the rates (especially the electron-releasing substituents).