bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stereochemical Aspects of the Photo-Beckmann Rearrangement. Stereochemical Integrity of the Terminus of the Migrating Carbon in the Photo-Beckmann Rearrangements of 5α- and 5β-Cholestan-6-one Oximes
Authors: Suginome Hiroshi , Takahashi Hajime 
Published: July 2006

Abstract
The Beckmann rearrangement of either syn-5β-cholestan-6-one oxime or anti-5β-cholestan-6-one oxime with polyphosphoric acid at 90° takes place prior to the syn-anti equilibration of these isomers. In the photo-Beckmann rearrangement a pair of lactams, in both of which the original configurations of Cα with respect to the oximino-group of the starting oximes were retained, was produced irrespective of the configuration of the oximino-group of the starting oxime. The difference of the amounts between two isomeric lactams formed in each photolysis is small but the lactams due to the migration of the more substituted carbon are produced always in a slightly larger amount than those due to the migration of the less substituted carbon. Oxygen does not affect the formation of lactams. All these results indicate a concerted reorganization of an excited singlet oxaziridine intermediate, hydrogen-bonded with protic solvent molecule (s), into the corresponding lactams. During these studies, the photochemical epimerization of 5β-steroid-6-one into the 5α-isomer by α-cleavage-recombination sequence was observed.
Restricted Rotation Involving the Tetrahedral Carbon. XIV. Conformational Equilibria and Attractive Interactions in Substituted 9-Benzyltriptycenes
Authors: Suzuki Fumio , Oki Michinori 
Published: July 2006

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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−&gt;&gt;Cl−≥SCN−≥Br−&gt;&gt;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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.