bluuebunny/crossref_metadata_2025 huggingface dataset:
Restricted Rotation Involving the Tetrahedral Carbon. XIV. Conformational Equilibria and Attractive Interactions in Substituted 9-Benzyltriptycenes
Authors: Suzuki Fumio , Oki Michinori
Published: July 2006

Several 9-benzyltriptycene derivatives were prepared by addition of benzynes to 9-benzylanthracenes. Rotation about the C9–Cbenzyl bond of compounds with a substituent at a peri-position to the benzyl group was found to be frozen at low temperatures on the NMR time scale but not at room temperature. In contrast, compounds with two substituents at two peri-positions to the benzyl group showed a frozen rotation about the C9–Cbenzyl bond at room temperature. Distribution of the conformers, as judged from the PMR intensities, showed preference to the dl-isomers in spite of the fact that they are the ones which are highly disfavored by steric effects. Interpretation of the phenomenon was based on the fact that attractive interactions, mainly charge-transfer type, exist between the substituted benzo group in the triptycene skeleton and the benzene ring in the benzyl group.
An MO-Theoretical Treatment of the Cationic Ring-Opening Polymerisation. I. Ethylene Oxide
Authors: Frenking Gernot , Kato Hiroshi , Fukui Kenichi
Published: July 2006

The stereochemical course of the acid-catalyzed ring-opening polymerisation of ethylene oxide (e.o.) has been investigated on the basis of the CNDO/2 method. By the calculation of the total energy of the interacting system of e.o. and protonated e.o. the most favored reaction path is indicated. The activation energy is found to consist only of the desolvation process. The effect of the deformation of the molecular geometry upon the net charge, the total energy, and the shape of particular MO’s is discussed. It is concluded that the ring strain does not influence the rate. By means of configuration analysis, the dominance of the HOMO–LUMO interaction in the later stage of the reaction has been established. The initiation and propagation reactions follow the same reaction mechanism.
Electronic Spectra and Electric Properties of Poly(1-methyl-4-vinylpyridinium)–TCNQ Salt
Authors: Nakatani Kenji , Sakata Tadayoshi , Tsubomura Hiroshi
Published: July 2006

Electronic spectra and conductivities of poly(1-methyl-4-vinylpyridinium)–TCNQ anion radical salts and complex salts which contain additional neutral TCNQ were studied. By addition of neutral TCNQ, a new electronic absorption band appears at 3500 cm−1 and the charge-transfer band between TCNQ anion radicals disappears. It was concluded that this new absorption band is the charge-resonance band between a TCNQ, anion radical and neutral TCNQ molecule from the dependence of its absorption intensity on the amount of added neutral TCNQ. The conductivity of the salt changed from 7×10−8 to 8×10−3Ω−1 cm−1 by inclusion of the neutral TCNQ. This change of conductivity was explained in relation with the change of the absorption spectra of these polymer salts.
Molecular Structure of Molybdenum Oxide Tetrachloride Studied by Gas Electron Diffraction
Authors: Iijima Kinya , Shibata Shuzo
Published: July 2006

The molecular structure of molybdenum oxide tetrachloride was determined to be a square pyramid by a sector-microphotometer method of gas electron diffraction. The following molecular parameters were obtained by a least-squares method: rg(Mo–Cl)=2.279±0.003 Å, rg(Mo–O)=1.658±0.005 Å, and rg(Cl···Cl(s))=3.142±0.008 Å. The structure of gaseous MoOCl4 is similar to that of gaseous WOCl4. The infrared spectra of MoOCl4 were also measured in solutions.
Proton Magnetic Resonance Spectra of l- or d-Aspartato (l-2,4-diaminobutyrato)cobalt(III) Complexes
Authors: Watabe Masatoshi , Onuki Kenji , Yoshikawa Sadao
Published: July 2006

Three diastereomeric isomers of the l-aspartato(l-2,4-diaminobutyrato)cobalt(III) and two of the d-aspartato (l-2,4-diaminobutyrato)cobalt(III), Co(N)3(O)3 type were prepared and isolated. The isomers were characterized by their electronic absorption and proton magnetic resonance spectra. Their PMR spectra indicate that the carbon proton adjacent to the coordinated N atom resonates at a higher magnetic field when O atom occupies the site trans to the N atom than when N atom occupies the same place.
Kinetic Studies of Oxygen Chemisorption on the Rutile Single-crystal Surface by Means of Electrical Conductivity
Authors: Komuro Masayoshi
Published: July 2006

The reaction of oxygen with the surface of a rutile single crystal was studied in the temperature range from 212 to 362°C and in the pressure range from 10−1 to 102 Torr. The process of the surface oxidation was examined by monitoring the electrical conductance change due to oxygen chemisorption. Two types of chemisorption kinetics were found for the rutile which had been reduced to different extents in vacuo before the introduction of oxygen. For the low-reduced rutile, the kinetics obeyed the parabolic rate law; this was interpreted by the diffusion-controlled reaction theory. On the other hand, it was found for the high-reduced rutile that the kinetics obeyed the Elovich equation; this could be explained by the boundary layer theory. The apparent activation energy for the former was 14.2 kcal/mol. For the latter, it was 4 kcal/mol and increased with an increase in the chemisorbed surface-charge density. In addition, the rate of oxygen chemisorption in the latter case was proportional to the pressure at a constant density of the chemisorbed surface charge.
Apparent Molal Volumes and Adiabatic Compressibilities of n-Alkanols and α,ω-Alkane Diols in Dilute Aqueous Solutions at 5, 25, and 45°C. II. Apparent Molal Adiabatic Compressibilities
Authors: Nakajima Toshio , Komatsu Tsuyoshi , Nakagawa Tsurutaro
Published: July 2006

Ultrasonic velocity measurements have been made on a series of dilute aqueous solutions of n-alkanols and α,ω-alkane diols by means of the sing-around method. The apparent molal adiabatic compressibilities, φK have been derived, and the φ°K at an infinite dilution has been estimated. The φ°K values per CH2 and CH3 groups were estimated from the additivity of the φ°K value for each group. The values are negative at low temperatures and markedly decrease with a decrease in the temperature. This fact suggests that the iceberg formation makes a negative contribution to the φ°K.
Magnetic Susceptibility of the Solid Oxygen-Fluorine Mixture
Authors: Sakakibara Akira , Mori Yoshihiro , Inokuchi Hiroo
Published: July 2006

The magnetic susceptibility of an oxygen-fluorine solid mixture with a 20–75% oxygen content was measured from 12 K to each melting point. The small susceptibility found below 45 K with a 20–60% oxygen content is interpreted in terms of direct- and super-exchange interaction. The supercooling of the cubic phase is suggested in the case of a 75% oxygen content.
Positron Lifetimes in γ-Irradiated Eicosane and Polyethylene
Authors: Ito Yasuo , Tabata Yoneho
Published: July 2006

The positron lifetimes in a γ-irradiated single crystal of n-eicosane and amorphous polyethylene have been measured at −78°C in a vacuum. The lifetime, τ2, of the long-lived component decreases upon irradiation in both systems, and the increase in the annihilation rate, λ2, is proportional to the concentration of free radicals. Assuming that the decrease in τ2 is entirely due to the reaction of orthopositronium (o-Ps) with free radicals, the diffusion constant of o-Ps has been estimated to be D=0.58–1.75×105 cm2 s−1. The intensity, I2, of the longlived component decreases markedly in n-eicosane, levelling off at about 20%. I2 in polyethylene does not decrease upon irradiation. Some possible explanations are given.
The Magnetic Properties of Verdazyl Free Radicals. VIII. The Crystal Structure of 1,3,5-Tri-p-tolylverdazyl Radical
Authors: Azuma Nagao , Deguchi Yasuo , Marumo Fumiyuki , Saito Yoshihiko
Published: July 2006

The crystal structure of 1,3,5-tri-p-tolylverdazyl has been determined by X-ray diffraction. The crystals are monoclinic, with the space group of P21/m and with a=8.173(3), b=20.23(1), c=6.075(2) Å, β=105.4(1)°, and Z=2. The structure was deduced from the sharpened Patterson synthesis and refined by the block-diagonal least-squares method to the final R value of 0.048 for the 1212 non-zero reflections collected by the counter-method. The sym-tetrazinyl ring has an asymmetrical boat form. The molecules are arranged approximately parallel to the (20\bar1) plane. The maximum intermolecular overlap is observed between the sym-tetrazinyl and C-tolyl groups, suggesting a weak exchange interaction between unpaired electrons.
Theoretical Calculation of 13C Chemical Shielding Anisotropy in Some Organic Compounds. II.
Authors: Ando Isao , Nishioka Atsuo
Published: July 2006

The 13C chemical shielding anisotropies of acetic acid and its related compounds were calculated theoretically by the LCGI–MO theory, using the MINDO/2 method; the results were found to agree with the experimental data measured by Pines et al. As for acetic acid, a dimer structure was suggested to be preferable to the monomer structure on the basis of the calculated and experimental results.
The Role of Anion in the Demethylation Reaction of Methylcobalamin with Mercuric Salts
Authors: Yamamoto Haruhiko , Yokoyama Takashi , Chen Ju-Ling , Kwan Takao
Published: July 2006

The demethylation of methylcobalamin with mercuric salts containing ClO4−, AcO−, Cl−, Br−, SCN−, or CN− was kinetically investigated by a conventional spectroscopic technique. The rates of reaction for mercuric chloride were proportional to [CH3–Co] and [HgCl2] while those for acetate depended little on [Hg(AcO)2], but increased in proportion with [AcO−]. The rates of reaction varied depending on the concentration and species - of anion, and the following sequence was obtained: AcO−>>Cl−≥SCN−≥Br−>>CN−. The sequence was reversely correlated with the stability constant of the equilibrium reaction, HgLn−1+L\ightleftarrowsHgLn(n=1 or 2), so that it was considered that HgL+ is an attacking electrophile in the cleavage of cobalt-carbon bond by the mercuric salts. The activity of HgCl42− for the reaction was somewhat lower than that of HgCl2 while that of HgClCN was lower to a greater extent.
Catalytic Activity of Metal Polyphthalocyanines in Autoxidation Reactions
Authors: Hara Takao , Ohkatsu Yasukazu , Osa Tetsuo
Published: July 2006

The oxidation of cumene and acrolein was carried out using metal polyphthalocyanines as a catalyst. The catalyst activated an oxygen molecule to form a phthalocyanine–O2 complex, which then abstracted the hydrogen atom of a reactant to initiate the oxidation. The catalyst had no effects on the decomposition of cumene hydroperoxide, formed selectively in the oxidation of cumene. The addition of a small amount of pyridine induced a drastic shortening of the induction period as well as a considerable increase in the oxidation rate. The initiation mechanism assumed on the basis of findings on the desorption of oxygen from the catalyst and on the effect of pyridine was confirmed by a kinetic study of the homogeneous liquid-phase oxidation of acrolein.
Metal Complexes of EDTA and Its Related Compounds. I. Geometric Isomers of [Co(X)(N-methyl-trimethylenediamine-N,N′,N′-triacetate)] Complexes with X=H2O, NH3, Cl− or CN−
Authors: Doh Myung-Ki , Fujita Junnosuke , Ogino Hiroshi , Saito Kazuo
Published: July 2006

Two isomers of the complexes of the type, [Co(X)(N-Me-trdtra)] (N-Me-trdtra=N-methyl-trimethylenediamine-N,N′,N′-triacetate) have been isolated for each X=H2O, NH3, and Cl−. The structures have been assigned from their PMR and absorption spectra and from the results of kinetic studies. The isomers have equatorialskew and polar-chair structures and no indication of the formation of polar-skew isomer was observed. Isomerization reaction of the aqua complex in an aqueous solution indicated that the polar-chair isomer is more stable than the equatorial-skew isomer. Only the polar-chair isomer of H[Co(CN)(N-Me-trdtra)] has been obtained.
Electrical Properties of 1,1-Diphenyl-2-picrylhydrazine and 2,2-Diphenyl-1-picrylhydrazyl Disks
Authors: Sakai Yoshiro , Sadaoka Yoshihiko
Published: July 2006

The electrical properties of 2,2-diphenyl-1-picrylhydrazyl (DPPH) disk were studied in the temperature range 18–60°C over frequencies 3×10–3×106 Hz in comparison with those of 1,1-diphenyl-2-picrylhydrazine (DPPHn). The frequency dependence of conductance (σac) for both DPPH and DPPHn can be explained in terms of the hopping conduction caused by localized states and/or shallow traps. At low frequencies, the strong dispersion of the capacitance of DPPH was observed while conductivity remained constant. This was accounted for by hyperelectronic polarization. The difference in electrical properties between DPPH and DPPHn indicates that the unpaired electrons in DPPH play an important role in the frequency independent conductance (σdc), but not in the frequency dependent conductance (σac).
Infrared Study of Aniline Adsorbed on Aluminum Halides and on Gallium Chloride
Authors: Sato Hiroyasu , Arase Shin-ichi
Published: July 2006

Infrared study was made on aniline adsorbed on aluminum chloride, bromide and iodide. Aniline-d0 (C6H5NH2), aniline-N,N-d2, aniline-d5 (C6D5NH2) and aniline-d7 were used. Aniline-d0–gallium chloride system was studied for comparison. Only the bands associated with amino group showed large frequency shifts on complex formation. The structures of adsorbed molecules were discussed in terms of the frequency shift of bands, especially of those assigned to C–N stretching and ND2 bending modes. The interaction of adsorbed aniline with aluminum chloride is rather weak and predominantly ionic. A strong chemisorption with the formation of an essentially covalent N···Al bond can be deduced for aniline adsorbed on aluminum bromide, iodide and gallium chloride. Such an ionic adsorption on aluminum chloride can be understood by considering the ionic structure of solid aluminum chloride. Some of the observed bands for aniline-d5 are (cm−1); 3424, 3350, 3312 (NH str.), 1620 (NH2 bend.) and 1300 (CN str.).
Studies on Mixed Chelates. V. Mixed Nickel(II) Chelates with N,N,N′,N′-Tetraethylethylenediamine and β-Diketones
Authors: Fukuda Yutaka , Morishita (nèe Fukushima) Reiko , Sone Kozo
Published: July 2006

Fourteen mixed nickel(II) chelates with the general formula, Ni teen(β-dik)X, were newly obtained. Here teen is N,N,N′,N′-tetraethylethylenediamine, i.e., a sterically hindered ligand with four bulky ethyl groups on the donor N atoms, β-dik is a β-diketonate ion, and X is an anion such as B(C6H5)4−, ClO4−, NO3− or β-dik. According to the coordination ability of the anion X, the structure of the mixed chelate changes from square planar to octahedral, remarkable solvent effects being observed on the absorption spectra of these chelates. The steric influence of the ligand “teen” was compared with that of the ligand “tmen”, i.e., its tetramethyl analog.
The Participation of Solvents in the Reaction of Alkenes with Manganese(III) Acetate
Authors: Okano Masayoshi
Published: July 2006

1-Hexene and 2-methyl-2-pentene were heated with manganese(III) acetate at 100 °C in two mixed solvents of glacial acetic acid and acetic anhydride and of propionic acid and propionic anhydride in a nitrogen flow. γ-Acyloxy carboxylic acids, γ-lactones and saturated and unsaturated carboxylic acids were obtained, these oxidative products being considered to be adducts of acetic and propionic acids. Additional investigations were carried out on a mutual reaction of the oxidant and the solvents and on the thermal analysis of manganese(III) acetate. The reaction was explained by a solvent-participating free-radical mechanism.
The Crystal Structure of Ammonium Pentamolybdodisulfate(IV) (4-) Trihydrate (NH4)4[SIV2Mo5O2l]·3H2O
Authors: Matsumoto Kazuko Y , Kato Masao , Sasaki Yukiyoshi
Published: July 2006

The crystal of (NH4)4S2Mo5O21·3H2O contains a discrete polyanion, S2Mo5O214−, formed by reactions in an aqueous solution:

5Mo7O246−+14SO2+2H+\ightleftarrows7S2Mo5O214−+H2O

or 5MoO42−+2SO2+6H+\ightleftarrowsS2Mo5O214−+3H2O

It is orthorhombic, with the space group Pbcn and with a=15.096(9), b=13.375(8), c=23.734(7) Å, Dm=2.79, and Dx=2.79g cm−3 for Z=8. The crystal consists of S2Mo5O214− anions connected with each other by hydrogen bonds, with intervening water molecules and ammonium cations. In the polyanion, five MoO6 octahedra are connected by edge sharing, and the two octahedra at the two ends are connected by corner sharing to complete the Mo5O21 ring; the two SO3 trigonal pyramids are attached to the ring from above and below the ring.
Studies of the Hydrous Titanium Oxide Ion Exchanger. II. The Equivalence of the Exchange Adsorption of Cations and the Dissociation Constant
Authors: Inoue Yasushi , Tsuji Masamichi
Published: July 2006

In order to elucidate the fundamental properties of hydrous titanium oxide as a cation exchanger, the authors examined the stoichiometry of cation exchange and the acid-base property of the exchanger by means of titration curves. The results may be summarized as follows: 1. The equivalent exchange between the hydrogen ion and either the sodium or strontium ion holds over a wide range of conditions, such as the pH, the ionic strength, and the particle size of the exchanger. 2. The method of conditioning for obtaining the exchanger in the pure hydrogen form has been established. 3. The water content in the exchanger depends on the ionic composition. 4. This hydrous titanium oxide is a four-functional, weakly acidic cation exchanger and has the following apparent pK values: pK1 6.7±0.1, pK2 10.3±0.2, pK3 12.3±0.2, and pK4 13.2±0.2. The corresponding apparent ion exchange capacities are 2.2±0.1, 1.2±0.2, 0.7±0.3, and 0.2±0.3 meq. Na+/g respectively.
Pyridoxal Model Compounds. II. The Diels-Alder Reaction of 9-Substituted 2-Methoxyanthracenes
Authors: Iwata Masaaki , Emoto Sakae
Published: July 2006

The Diels-Alder reactions of several 2-methoxyanthracenes with tetracyanoethylene (TCNE), dimethyl acetylenedicarboxylate (DMAD), and maleic anhydride (MA) were examined. TCNE gave charge-transfer complexes, but not an addition product in every case. MA gave one-to-one adducts with anthracenes, while DMAD afforded no adduct.
An Improved Synthesis of Dibenzoxanthene
Authors: Ota Koki , Kito Taketoshi
Published: July 2006

14H-Dibenzo[a,j]xanthene was easily synthesized by heating alkali (K or Na) 2-naphthyloxide under CO and CO2 pressure.
Hydrates of Organic Compounds. II. The Effect of Alkyl Groups on the Formation of Quaternary Ammonium Fluoride Hydrates
Authors: Nakayama Haruo , Watanabe Kazuichi
Published: July 2006

The solid-liquid phase diagrams for the binary mixtures of water with various quaternary ammonium fluorides, (n-C4H9)3RNF (R=H, CH3, C2H5, n-C3H7, i-C3H7, n-C4H9, i-C4H9, n-C5H11, i-C5H11, n-C6H13, n-C7H15, and C6H5CH2), have been determined in order to see the effect of alkyl groups on the formation of clathrate hydrates. It has been found that, among these compounds, not only (n-C4H9)4NF, which has been known as a clathrate hydrate-forming salt, but also several other compounds with R=C2H5, n-C3H7, i-C3H7, i-C4H9, n-C5H11, and iC5H11 can form hydrate type. These hydrates are believed to be of the clathrate hydrates since they have almost the same hydration numbers as that of (n-C4H9)4NF hydrate. From the melting points of these hydrates, it has been concluded that the most suitable alkyl chain length of quaternary ammonium salts for their clathrate-hydrate formation is C4-chain (butyl or isopentyl). In the cases of R=CH3 and C6H5CH2, hydrates having lower melting points and smaller hydration numbers than those of the above group of hydrates have been detected. No hydrates have been observed for the salts with R=H, n-C6H13 and n-C7H15.
The Crystal Structure of 1-(2-Thiazolylazo)-2-naphtholato diaquacopper(II) Perchlorate
Authors: Kurahashi Masayasu , Kawase Akira
Published: July 2006

The crystal structure of 1-(2-thiazolylazo)-2-naphtholatodiaquacopper(II) perchlorate, [CuII(TAN)(H2O)2]-ClO4, has been determined from three-dimensional X-ray data collected by counter methods. The crystals are monoclinic, with the space group P21/c; a=13.481(4), b=8.060(4), c=15.307(7) Å, β=95.58(4)°, and Z=4. The structure was refined to an R value of 0.086 for 952 non-zero reflections. The copper atom is five-coordinated and has a distorted square-pyramidal environment. The 1-(2-thiazolylazo)-2-naphtholato group (TAN) acts as a terdentate ligand, the phenolic oxygen, the azo nitrogen and the thiazole nitrogen atoms being coordinated to the copper atom to give two five-membered chelate rings. The remaining two positions are occupied by water molecules.
On the Solvent-Induced Changes of Electronic Structures of Intramolecular Exciplexes
Authors: Masaki Shinzaburo , Okada Tadashi , Mataga Noboru , Sakata Yoshiteru , Misumi Soichi
Published: July 2006

Effects cf solvent polarity upon the electron donor-acceptor interactions in the excited state of p-(CH3)2N C6H4(CH2)n-(9-anthryl) (n=0, 1, 2, 3) and p-(CH3)2NC6H4-(CH2)n-(1-pyrenyl) (n=1, 2, 3) have been investigated by means of fluorescence spectral measurements and theoretical calculations based on some simplified models. The solvent-induced electronic structural changes during the excited state lifetime have been demonstrated for some of the above intramolecular exciplexes.
Effects of Additives on Solid State Reaction. III. Effects of Halide Additives on the Formation of MgFe2O4
Authors: Shimada Shiro , Furuichi Ryusaburo , Ishii Tadao
Published: July 2006

The promoting effects of halide additives on the formation of MgFe2O4 have been studied on the basis of both kinetic and thermoanalytical data. A mixture of MgO and α-Fe2O3 powder containing 10 mol% additive (LiF, NaF, MgF2, BaF2, NaCl, or KCl) and that without additive were isothermally heated in a vacuum (Po2=100–101 mmHg) in the temperature range 666–1018 °C. High temperature X-ray analysis on MgO–Fe2O3 and MgO–Fe2O3–additive systems was carried out at a heating rate of 3 °C/min in vacuo, (Po2=1−1 mmHg). In the case of fluoride, it seems that the reactions between the fluoride and the reactants, α-Fe2O3 or MgO, promote MgFe2O4 formation in the initial stage and that compounds produced by the initial reaction accelerate diffusion in the later stage. The same promoting mechanism seems to be applicable to the case of chloride additives. The interaction between solids of NaCl and α-Fe2O3 occurring just before the melting of NaCl seems to initiate MgFe2O4 formation.
The Crystal Structure and Magnetic Property of the Alkoxo-Oxygen Bridged Tetranuclear Copper(II) Complex, Cu4{(n-C3H7)2N(CH2)2O}4Cl4
Authors: Matsumoto Naohide , Ueda Ikuhiko , Nishida Yuzo , Kida Sigeo
Published: July 2006

The crystal structure of the alkoxo-oxygen bridged tetranuclear copper(II) complex, Cu4{(n-C3H7)2N(CH2)2O}4Cl4, has been determined from the three-dimensional X-ray diffraction method. The crystals are orthorhombic with the space group Pbcn. The cell dimensions are α=15.965 (4), b=14.941 (1), c=19.305 (2) Å. The structure has been determined from the heavy atom method and refined by the block-diagonal least-squares method to give R=7.52%. The complex is of a cubane type structure formed by four copper and four alkoxide oxygen atoms. Each copper atom has a distorted square pyramidal environment. The correlation between the magnetic property and the structure was discussed on some homologous compounds of cubane structure.
The Oxidation Activity and Acid-base Properties of Mixed Oxide Catalysts Containing Titania. I. The TiO2–MoO3 and TiO2–V2O5 Systems
Authors: Ai Mamoru
Published: July 2006

The amounts of both the acidic and basic sites of two series of catalysts, TiO2–MoO3 and TiO2–V2O5, with different compositions were measured by studying the adsorption of the basic and acidic molecules in the gas phase, using both the static and pulse methods. The acidity of TiO2–MoO3 catalysts is very high at Mo=40–60 atom%, though those of the TiO2-rich (Mo<30 atom%) and MoO3-rich (Mo>80 atom%) catalysts are fairly low. The acidity of the TiO2–V2O5 increases steadily with the V2O5 content. The basicity of the catalysts is remarkably enhanced by the introduction of a small amount of MoO3 or V2O5. It can be said that the catalysts are basic at Mo<20 atom% or V<10 atom%, while the MoO3-rich or V2O5-rich catalysts are acidic. The vapor-phase oxidation of 1-butene, butadiene,and acetic acid, the dehydration and dehydrogenation of isopropyl alcohol (IRA), and the isomerization of 1-butene were carried out in the presence of an excess of air, and the relationship between the catalytic behavior and the acid-base properties was investigated. It was concluded that the activities and selectivities can be relatively well explained by the acid-base properties between the catalyst and the reactant.
Aldol Condensation of Aldehydes with Ketones Promoted by the Copper(II) Ion. Orientation to the Chemical Model for Metalloaldolases
Authors: Iwata Masaaki , Emoto Sakae
Published: July 2006

The aldol condensation reactions of aromatic aldehydes such as 1 through 4 and 7 through 13, and aliphatic aldehydes such as 5 and 6, with a number of ketones promoted by the copper(II) ion were examined. The reactions were specifically promoted by the copper(II) ion, while such metal ions as zinc, cobalt(II), manganese(II), and magnesium were quite inactive as catalysts. All the aldehydes but 7 and 8 reacted with all the aliphatic ketones except ethyl acetoacetate, acetonitrile, and nitromethane to varying degrees in the Claisen-Schmidt type of reaction. Acetylacetone gave a condensation product of the Knoevenagel type. In the reaction of aldehydes with 2-butanone, aldehydes regiospecifically attacked the methylene group at C3 of 2-butanone. Amines inhibited the reaction, while the coexistence effect of zinc or cobalt(II) was observed. It was shown that there existed a substrate selectivity depending greatly on the kinds of ketones in the reaction promoted by the copper(II) ion. As a consequence, possible intermediates in the reaction were proposed and the relationship of the aldol condensation reaction promoted by the copper(II) ion with the metalloaldolases was discussed, particularly in the light of the role of the metal ions in both catalytic mechanisms.
The Reductive N-Methylation of Amines with Tetracarbonyl-hydridoferrate-Formaldehyde
Authors: Watanabe Yoshihisa , Shim Sang Chul , Mitsudo Take-aki , Yamashita Masakazu , Takegami Yoshinobu
Published: July 2006

Alcoholic tetracarbonylhydridoferrate combined with formaldehyde is an excellent reagent for reductive N-methylation of amines. The effects of reaction conditions such as temperature, atmosphere, and molar ratio (ferrate/formaldehyde/amine) on the reaction have been examined. The optimum condition for N,N-dimethylation of aniline is at 60 °C, under carbon monoxide, and at 1.0/2.2/1.0 for the molar ratio.
A MINDO/2′-MO Study of the Inversion Barriers of Some Molecules Involving First-Row Atoms
Authors: Ohkubo Katsutoshi , Azuma Yutaka , Okada Masahide
Published: July 2006

The inversion barriers of CH3−, NH3, CH3NH2, (CH3)2NH, (CH3)3N, NH2OH, NH2CHO, and OH3+ were investigated by means of the MINDO/2′ method. Although the calculated bond lengths are in satisfactory agreement with the experimental values, the calculated bond angles are too large and resulted in relatively low inversion barriers in comparison with the observed values.
N-Allylprazole as a Ligand. III. The Crystal and Molecular Structure of (1-Allyl-3,5-dimethylpyrazole)copper(I) Chloride
Authors: Fukushima Kazuo , Kobayashi Akiko , Miyamoto Takeshi , Sasaki Yukiyoshi
Published: July 2006

The crystal structure of (1-allyl-3,5-dimethylpyrazole) copper (I) chloride, CuCl(C8H12N2), has been determined by the three-dimensional X-ray analysis. The crystal is triclinic, space group P\bar1; a=8.442(4), b=8.873(6), c=8.112(3) Å, α=103.44(3), β=116.42(3), γ=63.37(3)° and Z=2. The structure was refined to an R value of 0.056 for 1196 collected reflections. The complex has a dimeric structure in which the copper(I) ion is surrounded quasi-tetrahedrally by two bridging chlorines, a pyrazole-nitrogen and the olefinic part of the allyl group. The C=C bond distance (1.34 Å) scarcely shows any increase upon coordination to the metal. The olefin plane is almost perpendicular to the Cu-olefin bond axis and shows no significant bendings of the olefinic atoms out of the plane.
Reduction and Oxidation Potentials of Metal-free and Cobalt Tetra(p-substituted phenyl)porphyrins
Authors: Tezuka Meguru , Ohkatsu Yasukazu , Osa Tetsuo
Published: July 2006

Both reduction and oxidation potentials of metal-free and cobalt tetra(p-substituted phenyl)porphyrins were determined by means of cyclic voltammetry. They are correlated with Hammett σ values of the substituents when the electron transfer occurs at the porphin ring, but not in the electron transfer step in which the cobalt atom participates.
The Chlorination of 1,3- and 1,5-Cyclooctadienes with Various Chlorinating Agents
Authors: Uemura Sakae , Onoe Akira , Okazaki Hajime , Okano Masaya , Ichikawa Katsuhiko
Published: July 2006

The chlorination of 1,3-cyclooctadiene with various chlorinating agents gave an isomeric mixture of trans-3,4-, cis-3,4-, trans-3,8-, and cis-3,8-dichlorocyclooctene. From 1,5-cyclooctadiene an isomeric mixture of trans- and cis-5,6-dichlorocyclooctene was obtained. The isomer distribution depended a great deal on chlorinating agents in both cases.
Catalytic Oxidation of Mercaptans by Iodine-Hydrogen Iodide System in Dimethyl Sulfoxide
Authors: Aida Tetsuo , Akasaka Takeshi , Furukawa Naomichi , Oae Shigeru
Published: July 2006

Mercaptans were oxidized readily by a catalytic amount of iodine or hydrogen iodide (i.e., aq. HI-solution) in the presence of dimethyl sulfoxide to afford the corresponding disulfides nearly quantitatively.
Extrinsic Carrier Photogeneration in Poly(N-vinylcarbazole) Films Doped with Dimethyl Terephthalate
Authors: Yokoyama Masaaki , Endo Yoshihiro , Mikawa Hiroshi
Published: July 2006

Based upon the previously reported experimental results that the exciplex fluorescence of poly (N-vinylcarbazole) films doped with dimethyl terephthalate is partly quenched by an electric field, a model is proposed for the extrinsic carrier photogeneration mechanism. Interaction between a migrating singlet exciton and an electron acceptor (“encounter complex”) produces an electron-hole ion pair having a rather large separation through a charge-transfer process between the components and a thermalization process of the excess energy. This ion pair dissociates into free carriers with Onsager’s probability of escaping the geminate recombination which gives a “relaxed fluorescent exciplex state”. The field dependence of the initial separation of the ion pair is also discussed.
Kinetics of the Proton-Transfer Reactions of Some ortho-Hydroxy Derivatives of Azo and Azomethine Compounds in Dioxane-Water Medium
Authors: Yoshida Noboru , Fujimoto Masatoshi
Published: July 2006

The kinetics of the proton-transfer reactions between hydroxide ion and o-hydroxy azo and o-hydroxy azomethine compounds having a strong O–H···N or an O–H···π intramolecular hydrogen-bond are studied in 50% (v/v) dioxane-water by means of temperature-jump method. The forward and the backward rate constant kf and kr for the overall reactions OH−+HA\oversetkf\undersetkr\ightleftharpoonsH2O+A− are evaluated to be in the range between 4.4×104 and 6.1×108 M−1 s−1 and between 1.5×103 and 6.2×104 s−1 respectively. The values of the kf for the azomethines are by several orders of magnitude higher than those of the corresponding azo compounds. The values of kf and kr in dioxane-water are found to be smaller than those in aqueous medium.
Circular Dichroism of Cobalt(III) Complexes of the Type cis-[CoN2O4] and cis-[CoN4O2] Containing Acetylacetonate Ion, 2,2′-Bipyridine and 1,10-Phenanthroline
Authors: Kashiwabara (nee Konya) Kazuo , Igi Kozo , Douglas Bodie E
Published: July 2006

Two new cobalt(III) complexes, [Co(acac)(bpy)2]2+ and [Co(acac)(phen)2]2+ (acac=acetylacetonate ion, bpy=2,2′-bipyridine and phen=1,10-phenanthroline) were prepared from the reaction of [Co(CO3)(bpy)2]+ and [Co(CO3)(phen)2]+, respectively, with acetylacetone, and converted to the partially resolved optically active forms using a SP-Sephadex ion-exchange column. [Co(acac)2(bpy)]+ was also resolved partially with a SP-Sephadex column. [Co(acac)2(phen)]+ was resolved with a combination of silver dibenzoyl-d-tartrate and dibenzoyl-d-tartaric acid. The circular dichroism (CD) spectra for these four complexes and for [Co(acac)2(en)]+ and [Co(acac)2(tn)]+ (en=ethylenediamine, tn=trimethylenediamine) were measured. A marked solvent effect was observed in the d-d transition region for the CD spectra of the [Co(acac)2L]+ complexes. The absolute configurations for all these complexes were assigned on the basis of their CD spectra.
Spectral Properties of Mixed Ligand Copper(II) Complexes Containing l-α-Amino Acids
Authors: Sakurai Takeshi , Yamauchi Osamu , Nakahara Akitsugu
Published: July 2006

Absorption and circular dichroism (CD) spectral behaviors of ternary copper(II) complexes containing two l-α-amino acids or an l-α-amino acid and iminodiacetate (ida), 2,2′-bipyridine (bpy), 2-pyridinecarboxylate (pea), or 2,6-pyridinedicarboxylate (pdea), have been studied comparatively, and synthetic studies have given as crystals the mixed ligand complexes, [Cu(ida)(l-arg)]·2H2O, [Cu(ida)(l-orn)]·2H2O, [Cu(ida)(l-lys)]·1/4H2O, [Cu(pdca)(l-arg)]·H2O, and [Cu(pdca)(l-orn)]·2.5H2O, where l-arg, l-orn, and l-lys denote l-arginine, l-ornithine, and l-lysine, respectively. The CD magnitudes of the systems Cu(ida)(l-arg), Cu(ida)(l-orn), and Cu(ida)(l-lys) were found to be enhanced appreciably as compared with the magnitudes estimated from the values for the corresponding binary systems. These ternary systems showed further magnitude enhancements in 50% aqueous ethanol. The enhanced magnitudes observed for Cu(l-glu)(l-arg), where l-glu is l-glutamate, were also intensified in 10, 20, and 50% aqueous ethanol, whereas they were weakened nearly to the estimated values in aqueous solutions with higher ionic strengths (μ=0.1 and 0.5(NaClO4)). These observations support the view that the pairs of ligands constituting the above ternary complexes are fixed around copper(II) by electrostatic ligand-ligand interactions between the oppositely charged side chains. Pyridine-containing ligands, bpy, pea, and pdea, in the ternary systems with l-α-amino acids affected the signs and the magnitudes of the CD spectra.
Syntheses and Reactions of Fluorine-containing Aromatic Ketones
Authors: Kimoto Hiroshi , Muramatsu Hiroshige , Inukai Kan
Published: July 2006

Phenyl 1,1,2,3,3,3-hexafluoropropyl ketone(I) and 2,2,3-trifluoro-3-(trifluoromethyl)indanone(II) were synthesized by the radical-addition reaction of benzaldehyde to hexafluoropropene. The reduction with NaBH4 and the Grignard reaction with methylmagnesium iodide of these ketones gave the corresponding secondary and tertiary alcohols respectively. A Clemmensen reduction, alkaline hydrolyses, and reactions with hydroxylamine and with diazomethane were also carried out.
A Facile Method for the Oxidation of Alcohols
Authors: Saigo Kazuhiko , Morikawa Anri , Mukaiyama Teruaki
Published: July 2006

Trialkyltin alkoxides, prepared from alcohols and trialkyltin methoxide by azeotropical removal of methanol, are easily oxidized by bromine in the presence of trialkyltin methoxide, a hydrogen bromide captor, to give the corresponding aldehydes or ketones in good yields. Alcohols are oxidized directly in one step to the corresponding carbonyl compounds by utilizing bis(tributyltin) oxide and bromine.
Branched-chain Sugars. VIII. On the Configuration of Branched-chain Sugars from Methyl 3-O-Benzoyl-4,6-O-benzylidene-α-d-arabino-hexopyranosid-2-ulose
Authors: Yoshimura Juji , Mikami Kazutoshi , Sato Ken-ichi , Shin Chung-gi
Published: July 2006

Stereoselectivities in the Grignard, diazomethane and nitromethane reaction of methyl 3-O-benzoyl-4,6-O-benzylidene-α-d-arabino-hexopyranosid-2-ulose (1) were examined. In contrast to the Grignard reaction of 1 using methylmagnesium iodide to give a single 2-C-methyl derivative (4), the diazomethane reaction followed by reduction afforded another epimer (6). The nitromethan condensation product (10) of 1 was converted into the corresponding 2-C-acetaminomethyl derivative (13). The NMR spectrum of 2-O-acetate of 4 and comparison of the optical rotations of 4, 6, 10 and 13 in cupraramonium solution indicated that 4 and others have d-gluco-and d-manno-configuration, respectively. Discussions were made on the stereoselectivties of these reactions.
A Study of the Removal of Oily Soil by Rolling up in Detergency
Authors: Ogino Keizo , Agui Wataru
Published: July 2006

The removal of simply constituted oily soil from a low-energy surface such as polypropylene (PP) has been examined in aqueous solutions of sodium dodecylbenzenesulfonate and its builders. Oleic acid, olive oil, lauryl alcohol, oleyl alcohol, and liquid paraffin were used as model oily soils. Rolling-up was observed in all the soils except oleyl alcohol and liquid paraffin. The rolling-up of the soil occurred in the contact angle range of 0°<θ<90°(θ is contact angle) when the soil was removed incompletely from PP. Apparent activation energies for rolling-up were derived, i.e., 8 kcal/mol for oleic acid and 11.9 kcal/mol for olive oil. Complexes were formed for oleic acid, lauryl alcohol, and oleyl alcohol. The effects of the surfactant in various concentrations at various temperature, and with various builders were studied in view of the interfacial tension and the contact angle.
The Estimation of the G-Values for Ionization and Excitation of Ten-Electron Molecules: Methane, Ammonia, and Water Irradiated by 100 keV Electrons
Authors: Okazaki Kiyoshi , Sato Shin , Ohno Shin-ichi
Published: July 2006

The binary-encounter collision theory is applied to calculate the G-values for the ionization and excitation of methane, ammonia, and water irradiated by 100 keV electrons. Double collision of the incident electron in a molecule is also taken into account. On the assumption of the occurrence of certain reactions in the systems, the G-values for electrons, various radicals, and several final products were estimated. Some of the results are as follows: the G-values for electrons were 3.60 for methane, 3.56 for ammonia, and 3.00 for water. These values are in fair agreement with the experimental values: 3.6 for methane, 3.8 for ammonia, and 3.3 for water. The calculated G-value for hot hydrogen atoms was about 1.0 for all three compounds. The ratios of the G-value for excitation to that for electrons are 1.1 for methane, 1.5 for ammonia, and 1.7 for water. An estimation was also made of the G-value for the emission of highly-excited hydrogen atoms using reported cross sections. The G-values are 0.1 for methane and ammonia, and 0.2 for water.
Chromium(III) Complexes with Amino Acids. I. Chromium(III) Complexes with Glycine and dl-α-Amino Acids
Authors: Oki Hisaya , Otsuka Kiyoe
Published: July 2006

A comparison has been made between the synthesis carried out by the isothermal matrix method in solid state and that by the usual method in solution for chromium(III) complexes with glycine and dl-α-amino acids (alanine, aminobutyric acid, norvaline, norleucine, valine, isoleucine and leucine). The effect of the length of the skeletal carbon chain or the presence of the side chain in α-amino acids on the formation of complexes was investigated. The complexes with α-amino acids which have a normal chain were obtained in fac-structure except for norleucine complexes, whereas the complexes with α-amino acids which have a side chain were obtained only in dimertype by the matrix method in solid state. The chromium(III) complexes with dl-α-amino acids were all prepared as tris-type structure, except for α-aminobutyric acid and valine, whereas all the complexes of dimer-type structure were prepared in solution, except for alanine and norleucine.
Chemistry of Nitrosoimines. XV. Reactions of 3-Substituted 2-Nitrosoimino-2,3-dihydrobenzothiazoles with Lithium Aluminum Hydride and Diazo Compounds
Authors: Akiba Kin-ya , Kawamura Takayuki , Ochiumi Masahide , Inamoto Naoki
Published: July 2006

3-Substituted 2-nitrosoimino-2,3-dihydrobenzothiazoles (1) were reduced with lithium aluminum hydride to give the corresponding thiazolone azines and bis[o-(N-substituted N-formylamino)phenyl] disulfides as major products. Reactions of 1 with some substituted diazomethanes gave the corresponding unsymmetrical azine N-monoxides (16) or azines (17) depending on the structure of the diazomethane.
Nickel-Phosphine Complex-Catalyzed Grignard Coupling. I. Cross-Coupling of Alkyl, Aryl, and Alkenyl Grignard Reagents with Aryl and Alkenyl Halides: General Scope and Limitations
Authors: Tamao Kohei , Sumitani Koji , Kiso Yoshihisa , Zembayashi Michio , Fujioka Akira , Kodama Shun-ichi , Nakajima Isao , Minato Akio , Kumada Makoto
Published: July 2006

It has been established that dihalodiphosphinenickel(II) complexes exhibit extremely high catalytic activity for selective cross-coupling of Grignard reagents with aryl and alkenyl halides. This catalytic reaction can be employed in synthetic practice for reasons of simple procedures, mild reaction conditions, high yields and high purity of the coupling products, and the wide applicability to reactions involving primary and secondary alkyl (regardless of the presence or absence of β-hydrogen (s)), aryl, and alkenyl Grignard reagents and nonfused, fused, and substituted aromatic halides and haloolefins. Limitations lie in sluggish reactions between alkyl Grignard reagents and dihaloethylenes. The most effective catalysts are [Ni{(C6H5)2P(CH2)3P(C6H5)2}Cl2] for alkyl and simple aryl Grignard reagents, [Ni{(CH3)2P(CH2)2P(CH3)2}Cl2] for alkenyl and allylic Grignard reagents and [Ni{P(C6H5)3}2-Cl2] for sterically hindered aryl Grignard reagents and halides. Great stabilizing effects of phosphine ligands on the catalytic species are demonstrated by no effect observed after aging the catalyst. Organic chlorides are generally the most suitable halide in view of the reasonable reactivities and limited side reactions. Ether is favored over tetrahydrofuran as solvent. About sixty experimental results are presented and several features are discussed.
The Electronic Spectra of α,ω-Di-1-anthrylpolyenes in Solution and in Solid State
Authors: Mandal Krishnagopal , Misra T N
Published: July 2006

The electronic absorption spectra of a number of α,ω-Di-1-anthrylpolyenes have been studied in solution and in crystals. Three intense and two weak band systems have been observed. The plots of λ2–n and ε–n result in a good straight line in lower members. These results suggest that long anthrylpolyenes are not in all-trans form. Highest energy emission and lowest energy absorption bands show good overlap and identical solvent behavior. It has been concluded that in anthrylpolyenes the lowest excited state is an allowed 1Bu type. The terminal anthrylgroup interaction effect is such that 1Ag is not lowered relative to 1Bu in these polyenes. The absorption bands of anthrylpolyenes in the crystalline state could be explained in terms of factor group split components.
Ionization of Hydroxamic Acids in Aqueous Solutions
Authors: Abbasi Shahid Abbas , Ahmed Jameel
Published: July 2006

Thermodynamic ionization constants of sixteen hydroxamic acids at 25 °C and 35 °C in aqueous solution and the corresponding ΔH° (standard enthalpy change) are presented.
Infrared Studies of the Isocyanate Species Formed in the Reaction of NO with CO over Pt and Rh
Authors: Niiyama Hiroo , Tanaka Motoo , Iida Hiroshi , Echigoya Etsuro
Published: July 2006

The behavior of isocyanates formed on the surface of Rh and Pt in the reaction of nitrogen oxide with carbon monoxide was studied by means of IR spectroscopy using a flow reactor. The isocyanate species readily reacted with N2O or H2O, however, it did not decompose when dosed with NO or CO. The catalytic activity of Pt–Al2O3 in the reaction of NO+CO declined quickly with an increase in the amount of the surface isocyanate (–NCO). Accordingly, it is concluded that –NCO is not a reaction intermediate but an inhibitor of the reaction.
Emission Spectra of the Vinyl Polymers with Pendant Carbazolyl Groups
Authors: Itaya Akira , Okamoto Ken-ichi , Kusabayashi Shigekazu
Published: July 2006

The emission properties of poly(N-vinylcarbazole) (PVCz) prepared by radical and cationic polymerization (PVCz(r) and PVCz(c) respectively), the oligomers of N-vinylcarbazole, and poly[2-(N-carbazolyl)ethyl vinyl ether] (PCzEVE) were investigated in solutions. The fluorescence spectrum of PVCz(r) was different from that of PVCz(c). This seems to be attributable to the difference in the tacticity between them. On the basis of this result, the structure of the second excimer site is discussed. PCzEVE, in which the carbazolyl chromophores are widely spaced on the skeletal chains by –O–CH2–CH2– bonds, showed an interesting, new, structureless emission band with a peak at 27000 cm−1. This was different from both the monomeric structured fluorescence and the sandwich-like excimer one which were observed for the model compounds and the polymers. The emission properties of PCzEVE were unique among the vinyl polymers with aromatic chromophores widely spaced on the skeletal chain.
Synthesis and Characterization of Aluminium(III) Complexes with Schiff Bases Obtained from Salicylaldehyde Derivatives and Alkylamines
Authors: Kuma Hiro , Yamada Shoichiro
Published: July 2006

Aluminium(III) complexes with Schiff bases (abbreviated as X–sal–R) obtained from salicylaldehyde derivatives and amines (RNH2) have been synthesized by a method starting from aluminium(III) isopropoxide. Complexes of the type Al(X–sal–n-alkyl)3 have been isolated, but any attempt to obtain complexes of the types Al(X–sal–i-C3H7)3 and Al(X–sal–aryl)3 has not been successful. The tris-complexes obtained show similar electronic absorption spectra, regardless of R. Proton magnetic resonance spectra indicate that the aluminium(III) complexes may have a fac-configuration.
The Reaction of Singlet Methylene with Methane
Authors: Shibuya Kazuhiko , Obi Kin-ichi , Tanaka Ikuzo
Published: July 2006

Cyclopropane in an excess of methane was photolyzed at 1470 and 1634 Å. The decomposition rate constants of the resultant vibrationally excited ethane into methyl radicals were found to be 6.0×109 s−1 and 5.0×109 s−1 at 1470 and 1634 Å respectively. The following procedure was used in treating the results obtained in our and the other researchers’ systems. The statistical calculation was made to estimate the internal energy of singlet methylene, \barεi which is initially acquired in the primary decomposition process. The RRKM theory was then used to estimate the internal energy of the excited ethane. According to these calculations, the fraction of excess photon energy carried into ethane decreases as the energy, \barεi increases.
An External Heavy Atom Effect upon the Photoreaction of N-Acetyldiphenylmethyleneamine in Toluene
Authors: Asao Shuichiro , Toshima Naoki , Hirai Hidefumi
Published: July 2006

The photochemical conversion of N-acetyldiphenylmethyleneamine (I) in toluene to produce an addition product N-(1,1,2-triphenylethyl)acetamide and a hydrogenation product N-(diphenylmethyl)acetamide has been found to increase remarkably by displacement of para-hydrogen of toluene with a halogen (chlorine or bromine). A number of halogenated solvents, especially brominated solvents such as dibromomethane and bromobenzene, also promoted the photoreaction of the imine I with toluene. The extent of the promotion depends on the kind of a halogen atom of the solvent molecule. The reaction rate was accelerated with the number of halogen atoms of the solvent molecule. The conversion rate increased very remarkably when the concentration of bromobenzene increased from 0 to 1 mol/l. The reaction via chemical sensitization by benzophenone, a contaminant in imine I, was shown to be insensitive to the heavy atom solvent. The heavy atom effect can be attributed to an increase in the rate of intersystem crossing from the excited singlet state to the triplet state of the imine I. Imine I in the excited state was confirmed to have a hydrogen abstracting character.