bluuebunny/crossref_metadata_2025 huggingface dataset:
Modified INDO Calculations of the Electronic Structure of Transition Metal Carbonyl Compounds
Authors: Tatsumi Kazuyuki , Fueno Takayuki
Published: July 2006

An INDO molecular-orbital method developed for the treatment of systems involving 3d orbitals have been applied to transition metal carbonyl complexes Ni(CO)4, Cr(CO)6, and Fe(CO)3(butadiene). The Koopmanstheorem values of ionization potentials are found to be in excellent agreement with the observed photoelectronspectroscopic data, except for the cases where a considerable reorganization in electronic distribution accompanies the ionization process. The INDO molecular orbital functions compare well with those reported on the basis of ab initio calculations.
Radiative Triplet Lifetimes in Benzene and Azabenzenes with Particular Reference to Phosphorescence Mechanisms in Benzene
Authors: Ito Hirotoshi , I’Haya Yasumasa J
Published: July 2006

Calculations of radiative triplet lifetimes of benzene and azabenzenes are carried out by making use of an INDO/S method in which the parametrization of the CNDO/S method is used, retaining the semi-empirical Slater-Condon parameters determined in the INDO/2 method. The calculated excitation energies, oscillator strengths, and radiative lifetimes are in reasonable agreement with experimental values. The possible phosphorescence mechanisms for the 3B1u state of benzene are discussed rather in detail, considering the first-order vibronic as well as the first-order spin-orbit and the second-order spin-vibronic couplings. It is concluded that the strong first-order vibronic coupling between the triplet manifolds, 3B1u and 3E1u, is responsible for the almost purely out-of-plane polarized phosphorescence of benzene, borrowing an intensity from the 3E1u-1A1g intercombination, and that the effects of the first-order spin-orbit and the second-order spin-vibronic couplings are small. The conclusion is in accord with the analyses of the Zeeman and MI DP spectra presented by van Egmond and van der Waals.
S2 Formation during the Pyrolysis of H2S in Shock Waves
Authors: Higashihara Tetsuo , Saito Ko , Yamamura Hitoshi
Published: July 2006

The rate of S2 formation from shock-heated H2S was measured by means of the UV absorption technique in the temperature range of 2380–3000 K. At all the temperatures measured, the S2 absorption during the reaction could be represented by (S2)t=(S2)∞{1−exp(−kt)}, where:

k=109.2exp(−72 kcal⁄RT)s−1.

The mechanism of the S2 formation was proposed, and the value of the second-order rate constant, k1, for the primary reaction, H2S+M→SH+H+M, was estimated as follows:

k 1=1013.1exp(−92 kcal⁄RT)1mol−1s−1.

The effects of the addition of NO and O2 on the rate of S2 formation were also investigated. The results showed the validity of the proposed reaction mechanism.
Study of Emulsions in Molten Salts. III. The Concentration, Stability and Particle-Size Distribution of Dispersed Lithium in Molten Lithium Chloride
Authors: Nakajima Tsuyoshi , Nakanishi Koichiro , Watanabe Nobuatsu
Published: July 2006

The concentration, stability and particle-size distribution of lithium dispersed in molten lithium chloride were investigated. The maximum content of dispersed lithium obtained by spontaneous emulsification was 4.8×10−3 mol/g at 678 °C. The concentration of dispersed lithium somewhat increased with the amounts of lithium oxide and nitride added to the molten salt by the mechanical agitation of the lithium–lithium chloride solution. The concentration was about 1.7 times that obtained by spontaneous emulsification except when a large amount of lithium nitride was added. Dispersed lithium in lithium chloride was shown to be fairly stable in the liquid state, as well as against the solidification of molten lithium chloride. The particle-size distribution of dispersed lithium was obtained by means of a scanning electron microscope. The sizes of the lithium particles dispersed in lithium chloride were shown to be mostly between 0.3 and 0.9 μ.
Reaction of Di-t-butyl Thioketone with Aryllithium. Effect of Temperature and Solvent
Authors: Ohno Atsuyoshi , Nakamura Kaoru , Shizume Yasumasa , Oka Sinzaburo
Published: July 2006

Di-t-butyl thioketone reacts with phenyllithium affording both C-phenylated and S-phenylated products. The product distribution largely depends on the reaction temperature and solvent: the lower the temperature and the more solvated the counter cation, the larger the yield of the S-phenylated product. Steric effect is also important: 2,6-dimethylphenyllithium affords only S-arylated product. The result has been interpreted in terms of the charge-transfer-intermediate—radical-combination mechanism.
Principal Axes of the EFG Tensors and Torsional Oscillations in Boron Triiodide
Authors: Okuda Tsutomu , Ishihara Hideta , Yamada Koji , Negita Hisao
Published: July 2006

The Zeeman effect of 127I NQR and the quadrupole effect of 11B NMR on a single crystal of BI3 were observed in order to investigate the principal axes of the EFG tensors. The frequencies of the torsional oscillations were determined from the temperature dependence of e2Qqii⁄h.
Mesomorphic Properties of 2-(4-n-Alkoxybenzylideneamino)anthracenes
Authors: Sakagami Sakumitsu , Nakamizo Minoru
Published: July 2006

2-(4-n-Alkoxybenzylideneamino)anthracenes were synthesized, and the phase transitions were determined using a differential scanning calorimeter and a polarizing microscope. Methoxy through propoxy derivatives exhibit the monotropic nematic state, whereas the higher members show the enantiotropic nematic state.
The Analytical Application of Oleophilic Quaternary Ammonium Salts. XI. The Extraction of the Iron(III)–Pyrocatechol Violet–Tridodecylethylammonium Ternary Complex
Authors: Shijo Yoshio
Published: July 2006

The ionic associate of the iron(III)–Pyrocatechol Violet chelate anion with tridodecylethylammonium bromide is extracted into methyl isobutyl ketone. The ternary complex has an absorption maximum at 623 nm. The optimum pH for the extraction is 5.7–6.4 The molar absorptivity of the complex is 7.76×104 cm−1·mol−1·l. Its composition is estimated to be (Remark: Graphics omitted.).
Solvent Extraction Equilibria of Acids. V. The Extraction of Hydrobromic, Hydroiodic, and Thiocyanic Acids with Trioctylphosphine Oxide in Hexane
Authors: Niitsu Masaru , Sekine Tatsuya
Published: July 2006

The solvent extraction of hydrohalogenic acids and thiocyanic acid (HX) in 1 mol dm−3 electrolyte solutions with trioctylphosphine oxide (E) has been studied at 25 °C. The extraction constant, Kex1=[HXE]org[H+]−1[X−]−1][E]org−1, for thiocyanic acid was found to be 102.5, while Kex2=[HXE2]org[H+]−1[X−]−1[E]org−2 for hydrobromic and hydroiodic acids were found to be 100.34 and 101.78 respectively.
Condensation Products of Benzanthrone Obtained Using Copper Powder and Fused Zinc Chloride
Authors: Aoki Junji , Takekawa Minoru , Fujisawa Shoji , Iwashima Satoshi
Published: July 2006

By heating benzanthrone (3) with copper powder, zinc chloride, and sodium chloride, violanthrene B (8) and isoviolanthrene B (13) were obtained in addition to the tetrabenzo[a, cd, j, lm]perylene (4) reported previously. This method may be considered to be a convenient method of synthesizing not only 4, but also 13.
Vibration Spectra and Rotational Isomerism of Chain Molecules. II. Butane, Pentane, Hexane, Pentane-d12, and Hexane-d14
Authors: Harada Issei , Takeuchi Hideo , Sakakibara Masaaki , Matsuura Hiroatsu , Shimanouchi Takehiko
Published: July 2006

The Raman spectra of butane, pentane, hexane, pentane-d12, and hexane-d14 and infrared spectra of pentane-d12 and hexane-d14 were measured for the liquid and solid states. The rotational isomerism of normal paraffins was studied on the basis of the spectral observations and the normal coordinate calculations. The spectra of the deuterated compounds were useful in the confirmation of the less stable isomers and the establishment of the local symmetry force field of normal paraffins. The enthalpy differences among the rotational isomers were studied on pentane and hexane, which yielded some important data for the study of the conformations and properties of longer hydrocarbons.
Statistical Mechanical Calculation of the Radial Distribution Function for a Water-like Fluid
Authors: Hirata Fumio
Published: July 2006

The radial distribution function (RDF) for a water-like system, which has the fundamental characteristics of water, is calculated using the graph-theoretical technique developed by Andersen and Chandler. An interaction potential devised to simulate the hydrogen bond is regarded as a perturbation of the pair interaction between the two molecules of a reference system which consists of hard spheres each having a point dipole at each center. The effect of the hydrogen bond-like potential on the distribution of the molecules is shown explicitly. The results show a tetrahedral coordination similar to that in water. The resulting RDF has qualitatively reproduced the features observed in the experimental RDF curve for water.
Violet Emission Bands of the CN Radical Produced by Photodissociation of BrCN
Authors: Tatematsu Setsuko , Kondow Tamotsu , Nakagawa Toru , Kuchitsu Kozo
Published: July 2006

The violet emission spectra of CN(B2∑−X2∑), Δv=0, were observed by the photodissociation of BrCN by Lyman-α radiation (121.6 nm). The peak intensities for the vibrational levels v′≥1 relative to v′=0 decreased with the BrCN pressure (up to 2 Torr), whereas at 0.1 Torr or lower the spectrum was essentially independent of the pressure. The relative vibrational populations (v′=0–10) and the effective rotational temperatures were estimated by a band-envelope analysis. The effective rotational temperature, estimated to be 2000±200 K for v′=0–4, was practically independent of the pressure. Within the low-pressure limit the distributions of the excess energy to vibration and rotation were estimated to be 0.50±0.08 and 0.17±0.02 eV, respectively.
2-Mercaptobenzothiazole Supported on Silica Gel for the Chromatographic Concentration of Cadmium, Copper, Lead, and Zinc in Natural Water Samples
Authors: Terada Kikuo , Inoue Akihiko , Inamura Junko , Kiba Toshiyasu
Published: July 2006

The preparation and characteristics of 2-mercaptobenzothiazole supported on silica gel (MBT–SG), and its application to the preconcentration and determination of cadmium, copper, lead, and zinc in natural water samples are described. The MBT–SG was prepared by impregnating silica gel with MBT in a dioxane–methyl acetate solvent mixture, drying, washing with deionized water, and finally drying. The chelating capacity of the material was 0.01 meq. Cu/g. Cadmium, copper, lead, and zinc were quantitatively retained on the MBT–SG at pH values of 4.8, 2.5, 4.8, and 6.5 for an aqueous solution, and at pH values of 4.8, 2.8, 4.8, and 6.5 for sea water. A column made of the material provided quantitative recovery of these metals from natural water samples at higher flow rates (2–5 1/h) than other chelating resins, e. g., chelex 100. Cadmium was eluted with hydrochloric acid (1 : 99), copper and lead with acetone–hydrochloric acid mixture (9 : 1), and zinc with an acetate–hydrochloric acid buffer solution (pH 4.0). Then, the quantities of the four metals in their effluents were determined by atomic absorption spectrometry.
The Transannular Cyclization and Hydrogen Shift in the Chlorination of 1,5-Cyclooctadiene and cis-Cyclooctene with Antimony(V) Chloride
Authors: Uemura Sakae , Onoe Akira , Okano Masaya
Published: July 2006

The slow addition of SbCl5 to a CCl4 solution of 1,5-cyclooctadiene or cis-cyclooctene gives an isomeric mixture of endo- and exo-2, anti-8-dichlorobicyclo[3.2.1]octanes (1 and 2) or an isomeric mixture of trans- and cis-1,4-dichlorocyclooctanes (12 and 13) respectively in a good yield. The former reaction involves the transannular cyclization, while the latter is accompanied by the transannular hydrogen shift. The addition of 1,5-cyclooctadiene to a CCl4 solution of SbCl5 (reverse addition) affords endo-2,6- and endo, exo-2,6-dichlorobicyclo[3.3.0]octanes (6 and 7) as additional products, besides 1 and 2. In the case of cis-cyclooctene, however, a reverse addition produces only chlorocyclooctane. It has been revealed that a mixture of 6 and 7 is readily isomerized to a mixture of 1 and 2 by the interaction with SbCl5. The 1,4-chlorination of cis-cyclooctene which gives 12 and 13 also occurs with VCl4, SeCl4, PhICl2, and PCl5, although the selectivity and the yield are low compared to the case of SbCl5.
Thermal Stability of Alkylcopper(I) Complexes Coordinated with Tertiary Phosphines
Authors: Miyashita Akira , Yamamoto Takakazu , Yamamoto Akio
Published: July 2006

Thermolysis of isolated alkylcopper(I) complexes having tertiary phosphine ligand(s) RCuLn (R=CH3, C2H5, n-C3H7, i-C4H9) in the solid state and in toluene has been studied in order to clarify the role of the tertiary phosphine ligand in stabilizing the alkylcopper(I) complexes. The distribution of the thermolysis products shows that the thermolysis of the alkylcopper complexes having ethyl or longer alkyl chain proceeds through a β-elimination mechanism. The rate of the thermolysis obeys the first order rate law, −d[RCuLn]/dt=k[RCuLn]. The activation parameters of the thermolysis were obtained from the temperature dependence of k and a compensation effect between ΔH\eweq and ΔS\eweq was demonstrated. The activation energy Ea of the thermolysis of RCu(PPh3)2 increases in the order of R=C2H5<n-C3H7<i-C4H9. Coordination of electron-donating tertiary phosphine decreases Ea and a linear relationship between ν(Cu–CH3) frequencies and Ea for thermolysis of the methylcopper complexes was observed. Addition of PPh3 into the toluene solutions of CH3Cu(PPh3)2(diethyl ether)0.5 and C2H5Cu(PPh3)2 causes some retardation of the thermolysis. The major role of the tertiary phosphine ligand in stabilizing the alkylcopper complexes is proposed to strengthen the Cu–C bond by changing the electronic state of copper atom. An energetic consideration based on Chatt and Shaw’s theory is given in order to account for the results concerning the stabilities of the alkylcopper complexes. Photolysis of the alkylcopper complexes takes a quite different decomposition pathway producing mainly RH from RCuLn.
Enzyme-like Reaction Catalyzed by NAD+–Reduced Keratin Systems
Authors: Hirano Morio , Takahashi Fujio
Published: July 2006

Reduced keratin, which was obtained by reductive cleavage of human hair, was found to form a 1 : 1 complex with nicotinamide adenine dinucleotide (NAD+). The complex exhibited catalytic activity for the oxidation of glyceraldehyde to form glyceric acid. It was found from the results of pH titration, polarograms and NMR measurements that the NAD+-reduced keratin complex binds to glyceraldehyde to form an intermediate, which is susceptible to oxidation by oxygen. It was concluded from kinetic studies that this catalytic reaction showed a homotropic effect.
Photochemical Reactions of 4-Flavanols in the Presence of Ketone Sensitizers
Authors: Suzuki Morio , Amano Jiro , Morioka Motonobu , Mizuno Hideo , Matsushima Ryoka
Published: July 2006

Irradiation of an oxygen-free benzene solution of cis-4-flavanol 1a by a mercury lamp in the presence of benzophenone gave 4-flavanone (32%), benzopinacol (85%), cis- and trans-2-(diphenylhydroxymethyl)-4-flavanols (7.6%), and 2-(diphenylhydroxymethyl)-4-flavanone (7.7%), whereas photolysis of cis-4-acetoxyflavane under similar conditions gave cis-2-(diphenylhydroxymethyl)-4-acetoxyflavane(24%), 2,2′-bi-4-acetoxyflavane (6%), and benzopinacol. Photolysis of 1a in acetone gave 4-flavanone (3.6%), trans-4-(1-hydroxy-1-methylethyl)-4-flavanols (9.9%). The cis isomers of the parent and substituted 4-flavanols showed higher reactivities than the corresponding trans isomers.
Sequential Polypeptides. The Steric Hindrance of l-Valine Residues in the Polycondensation of Peptide Active Esters
Authors: Katakai Ryoichi
Published: July 2006

Five tripeptide N-hydroxysuccinimide esters with N-terminal l-valine, l-phenylalanine, and l-alanine were polymerized in N,N-dimethylformamide with a variety of concentration of the monomers. The yields and molecular weights of the resulting sequential polypeptides were then compared in order to demonstrate the presence of the steric hindrance of the l-valine residue in polycondensation. The results of the polycondensation and the conformational study of the resulting polypeptides suggest that the side chain of the l-valine residue at the N-terminal position of the monomers hinders the polycondensation of the monomers.
The Reactions of Aryldiazomethanes with Sulfur Dioxide in the Presence of Enamines
Authors: Tanabe Toyoshige , Nagai Toshikazu
Published: July 2006

The reactions of several arydiazomethanes with sulfur dioxide in the presence of 2-methyl-1-morpholinopropene gave cyclic sulfones, thietane 1,1-dioxides, indicating the existence of sulfene as a reaction intermediate. The stereoselectivity of the sulfene-enamine cycloaddition showed that the less thermodynamically stable cis orientation was generally preferred. On the other hand, the reactions in the presence of 1-morpholinocyclohexene, which has a labile proton β to the morpholino moiety, afforded acyclic or cyclic sulfones, depending on the substituents of diazomethanes. The mechanism of these reactions is discussed.
Gas Chromatographic Studies of the Thermal Decompositions of Hexaammine-, Chloropentaammine-, and trans-Dichlorotetraammine-cobalt(III) Chloride in the Solid State
Authors: Onodera Sukeo
Published: July 2006

This paper will describe gas chromatographic studies of the thermal decomposition of cobalt(III) ammine complexes in the solid state. The sample is pyrolyzed in a chamber in a helium atmosphere at a heating rate of 1 °C/min. The evolved products are directly led into a chromatographic separation column at periodic intervals of 10 °C. The preliminary gaseous product for these compound is ammonia. The gas evolution(GE) curves for each compound could be made as function of the temperature on the basis of the various gas chromatograms. These GE curves show two maximum peaks; the first is a sharp peak at about 250 °C, while the second is a broad peak in the 280–340 °C temperature range. The combination of these GE curves with the results of TG and DTA studies allows more complete interpretations of the thermal-decomposition reactions of the cobalt(III) ammine complexes.
Studies of the Isomerization of Unsaturated Carboxylic Acids. III. Thermal Rearrangement of Dimethyl Methylenesuccinate to Dimethyl Mesaconate
Authors: Sakai Mutsuji
Published: July 2006

Dimethyl methylenesuccinate (1) was found to equilibrate with dimethyl mesaconate (3) at elevated temperatures. Thermal rearrangements of 1 and 3 were studied kinetically and a plausible mechanism is proposed.
ESR Study on the Photoreduction of N-Acetyldiphenylmethyleneamine in 2-Propanol
Authors: Toshima Naoki , Aoki Kyoji , Hirai Hidefumi
Published: July 2006

Photoreduction of N-Acetyldiphenylmethyleneamine (1) in 2-propanol was studied both by the ESR spectroscopy of irradiated imine 1 in a matrix solvent at −196 °C and by the deuteration analysis of acetone formed from 2-propanol-d in the photoreduction process. The ESR spectrum consists of a broad singlet and a quartet. The latter is assigned to the CH3CH(OH)\dotCH2 radical, which can be produced by β-hydrogen abstraction by the excited imine 1 from 2-propanol, but not by the excited benzophenone. Formation of acetone-d on irradiation of 1 in 2-propanol-d suggests that the imine 1 in the excited state has a hydrogen abstracting character.
Dichroism and Configuration Analysis of 2-Ethylthio-1,3-Diazaazulene
Authors: Hiratsuka Hiroshi , Tanizaki Yoshie , Hoshi Toshihiko
Published: July 2006

Electronic absorption spectrum of 2-ethylthio-1,3-diazaazulene (ESDA) is investigated by means of dichroism analysis using the stretched PVA film. Seven π-π* bands and an allowed n-π* band are assigned. The experimental assignment of π-π* bands is in good agreement with the theoretical result using the PPP calculation. The effect of substituent groups on 1,3-diazaazulene (DA) is discussed by making use of a correlation diagram of SCF MO’s of ESDA, 2-ethoxy-1,3-diazaazulene (EODA), DA, and the substituent groups. Configuration analysis of wave functions for ESDA and EODA is carried out, and the substituent effects of the ethylthio and ethoxyl groups are compared. The result shows that the ethylthio group perturbs the electronic structure of DA more strongly than the ethoxyl group.
Vibrational Spectra and Normal Coordinate Calculations for Trimethyiarsine–Borane
Authors: Watari Fumio
Published: July 2006

Studies were carried out on the infrared spectra (33–4000 cm−1) of eight isotopic trimethylarsine–boranes, (CH3)3AsBH3, (CH3)3As10BH3, (CH3)3AsBD3, (CH3)3As10BD3, (CD3)3AsBH3, (CD3)3As10BH3, (CD3)3AsBD3, and (CD3)3As10BD3, in the solid state at low temperature, and on the Raman spectra (0–4000 cm−1) in the solid state and in solution of dichloromethane at room temperature. The spectra were interpreted on the basis of C3V molecular symmetry, complete assignments for all fundamentals except the internal torsion being made. Normal coordinate calculations were carried out utilizing a symmetry force field in order to confirm the assignments. One of the methyl rocks was found to be mixed with the borane rock, making the assignments of these frequencies complicated. The As–B and As–C force constants were found to have the values 1.849 and 3.087 mdyn/Å, respectively.
A New Spectrophotometric Method for the Determination of Some Reducible Compounds by the Reduction with Chromium(II) Ion
Authors: Terada Kikuo , Honnami Hiromi , Kiba Toshiyasu
Published: July 2006

A number of reducible compounds, such as nitrates, nitrites, nitro, nitroso, azoxy compounds, aldehydes, carbon tetrachloride, oximes, and chloramine T, can be determined by reducing them with chromium(II) ion prepared in an aqueous solution in a special vessel and measuring the absorbance of the resulting chromium(III) in the solution. In this reducing process, nitrate and nitrite are reduced to hydroxylamine quantitatively in hydrochloric acid at room temperature; carbon tetrachloride, nitrobenzene, and chloramine T each consume definite amounts of chromium(II) in an acidic medium at room temperature; propionaldehyde and azoxybenzene react with the reagent only in a basic solution; dimethylglyoxime and 1-nitroso-2-naphthol react only under heating at 80 °C in an basic medium. The absorbance of the resulting chromium(III) ion in the presence of the excess chromium(II) is found to obey Beer’s law at the wavelengths of 410–425 nm over the range of 4×10−3–8×10−2 mol/l of chromium(III). This concentration range corresponds to about 10−5–10−4 mol of the reducible compounds mentioned above. A rapid and precise method has been established with few disadvantages.
Kinetics of the Proton-Transfer Reaction of 4-(2,4-Dihydroxyphenylazo)nitrobenzene in Dioxane–Water Media
Authors: Yoshida Noboru , Fujimoto Masatoshi
Published: July 2006

Kinetics of proton-transfer reactions in 4 to 50%(v/v) dioxane–water media between hydroxide ion and 4-(2,4-dihydroxyphenylazo)nitrobenzene (Magneson; MAG) having a strong OH···N intramolecular hydrogen-bond are studied by means of the temperature-jump method. The forward and the backward rate constants kf and kr[H2O] for the reaction OH−+HA−\oversetkf\undersetkr\ightleftharpoonsH2O+A2− are evaluated to be in the range of 9.2×105–1.3×105 mol−1 dm3 s−1 and 5.5×103–1.8×103 s−1, respectively. The dependence of the kf and the acid dissociation constant Kac on the dioxane contents of the medium is interpreted on the basis of solute-solvent interactions.
An MO-Theoretical Study of the Electronic Structures of Formyloxyl and Acetoxyl Radicals
Authors: Kikuchi Osamu , Utsumi Kayoko , Suzuki Keizo
Published: July 2006

A semi-empirical NDDO MO method was applied to formyloxyl(HCOO) and acetoxyl(CH3COO) radicals in order to determine whether the ground-state electronic structure of the acyloxyl radical is of σ- or π-type. A σ-type state was found to be more stable than a π-type state over the entire range of values of the OCO angles of these radicals. This appears to be in agreement with the experimental facts which have been derived from the ESR spectra of several acyloxyl radicals.
ESR of F Center in HgI2·2HgS Darkened with Sunlight
Authors: Takei Kunio , Hagiwara Hitoshi , Tanaka Hiroshi
Published: July 2006

When yellow powders of HgI2·2HgS turn black in sunlight in a few seconds, the black powders show an ESR signal, whose intensity increases with the time of irradiation; its g-value is 2.0046±0.00028. The result of analysis shows that this signal is due to F centers, consisting of electrons captured by positive holes prepared at sites of S2− ions in the crystal.
Synthesis and X-Ray Structure of Triethylenetetramine-palladium(II) Complex
Authors: Hori Fumio , Matsumoto Keiji , Ooi Shun’ichiro , Kuroya Hisao
Published: July 2006

The triethylenetetraminepalladium(II) perchlorate and the potassium triethylenetetraminepalladium(II)tris-(hexafluorophosphate) were prepared; the X-ray structure analysis has been carried out for the latter compound. The crystal of [Pd(trien)](PF6)2·KPF6 is orthorhombic, with space group Pbca: a=21.645 (5), b=20.873 (5), c=9.541 (2) Å, and Z=8. The structure has been determined from X-ray diffractometer data and refined to R=0.091 (1166 reflections). The Pd atom has a planar coordination of 4N atoms disposed in a somewhat trapezoidal form. The complex cation has a pseudo symmetry plane which is perpendicular to the 4 N plane and bisects the H2N–Pd–NH2 angle. In the quadridentate triethylenetetramine ligand, each of the terminal H2N–CH2–CH2–NH– fragments forms a 5-membered chelate ring with the asymmetric envelope conformation, whereas the chelate ring formed by the middle –NH–CH2–CH2–NH– fragment has the symmetric envelope conformation. The electronic spectrum of [Pd(trien)]2+ is presented.
Metal-ion Complexation of Noncyclic Poly(oxyethylene) Derivatives. I. Solvent Extraction of Alkali and Alkaline Earth Metal Thiocyanates and Iodides
Authors: Yanagida Shozo , Takahashi Kazutomo , Okahara Mitsuo
Published: July 2006

The reaction of noncyclic poly(oxyethylene) derivatives with alkali and alkaline earth metal ions was investigated by means of the solvent extraction of their thiocyanates or iodides. Polyethylene glycols with more than 23 oxyethylene units showed a strong extracting power comparable to those of the crown ethers, and the power increased with the increasing number of oxyethylene units in them. Extraction studies using homogeneous poly(oxyethylene) monododecyl ethers revealed that more than 7 oxyethylene units were necessary to bind the potassium ion in the water phase and to transfer the complexed salt to the organic phase, and that the extracting ability of octa(oxyethylene) monododecyl ether was about one sixth of that of 18-crown-6. The monododecyl ether is fairly effective as a complexing agent for potassium picrate even below its critical micelle concentration; the stoichiometry of the extractable complex was found to be 0.8:1 with respect to the ether and the picrate. There was no remarkable difference in the selectivity for alkali metal ions between noncyclic poly (oxyethylene) derivatives and 18-crown-6.
Mechanism of the Reduction of Nitric Oxide with Ammonia over Cu(II) Ion-Exchanged Zeolites
Authors: Arakawa Tsuyoshi , Mizumoto Mamoru , Takita Yusaku , Yamazoe Noboru , Seiyama Tetsuro
Published: July 2006

The catalytic NO reduction with NH3 over Cu(II) ion-exchanged zeolite was studied with special attention to the temperature dependence of catalytic activity which reaches maximum at ca. 120 °C. ESR study showed that in the catalytic system all the exchanged copper ions exist as Cu(II) up to ca. 120 °C, above which Cu(II) ions decrease with a rise in temperature. The reaction rates measured at 110 and 140 °C were found to show similar dependence on both NO and NH3 partial pressures, indicating that the reaction mechanism does not differ much. By lowering temperature the Cu(I) ions formed at higher temperatures were reoxidized to Cu(II), accompanied by N2O formation due to the disproportionation of NO. From the results and the IR spectroscopic data a reaction mechanism was proposed. It includes a step in which NO reacts with NH3 adsorbed to Cu(II) ions to give rise to the evolution of N2 and the reduction of Cu(II) ions, and steps in which Cu(II) ions are regenerated accompanying the evolution of N2+N2O.
Optical Resolution and Ternary System Solubility Isotherms of Cobalt(III) Complex Salts
Authors: Shimura Yoichi , Tsutsui Katsuyuki
Published: July 2006

The characteristics of three-component phase diagrams consisting of water and a pair of enantiomeric or diastereomeric cobalt(III) complex salts have been clarified experimentally by constructing the solubility isotherms of the following 6 ternary systems at 25 °C: H2O–Δ-[Co(ox)(en)2]X–Λ-[Co(ox)(en)2]X, where X stands for Cl−, I−, (R,R)-C4H5O6–, Δ-[Co(edta)]−, 1/2[Sb2{(R,R)-C4H2O6}2]2− or d-C10H14OBrSO3−. It has been found that the latter two anions form an active racemate, rac-[Co(ox)(en)2]2[Sb2{(R,R)-C4H2O6}2]·5H2O and rao[Co(ox)(en)2](d-C10H14OBrSO3)·H2O, respectively. Solubility of the [Co(ox)(en)2]+ salts containing optically active counterions was determined at 5–60 °C in water.
Kinetic Study of Oxidative Addition and Replacement Reactions of Chlorotris(triphenylphosphine)rhodium(I) in Benzene
Authors: Ohtani Yoshimi , Fujimoto Masatoshi , Yamagishi Akihiko
Published: July 2006

Chlorotris(triphenylphosphine)rhodium (I) exists in benzene as RhCl(PPh3)3, a dimeric species [RhCl(PPh3)2]2 and a reaction intermediate RhCl(PPh3)2. The rates of oxidative addition and replacement reactions were examined in benzene. For the oxidative addition reaction, RhCl(PPh3)3, RhCl(PPh3)2, or [RhCl(PPh3)2]2+X1\oversetkadd\ightleftarrowsProducts (X1=H2, O2, C2H4, CHCl=CCl2 CH3I), it was found that the reaction intermediate RhCl(PPh3)2 is most reactive, the degree of its reactivity depending largely on the reactants (X1). A significant enhancement of the rate (ksub>kadd) was observed for the ligand substitution reaction, RhClX1(PPh3)m+X2\oversetksub\ightleftarrowsRhClX2(PPh3)n+X1 (m, n=3 or 2), where X1=H2 and X2=olefin and vice versa. The results are discussed in relation to the mechanism of hydrogenation.
The Fluorometric Determination of Indium with 8-Quinolinethiol
Authors: Watanabe Kunihiro , Fujiwara Akio , Kawagaki Ky\={o}z\={o}
Published: July 2006

8-Quinolinethiol reacts with indium in the presence of acetic acid to give a yellow ternary complex. The complex, which has a greenish-yellow fluorescence with an emission maximum at 515 nm, can be extracted into chloroform at pH 2–4. In the ternary complex, the fluorescence intensity was about two times as large as that of the indium 8-quinolinethiolato complex containing no acetate ion. The fluorescence was stable for at least 1 h. By the use of a 0.2 μg/ml uranine solution as the setting reagent, 0–25 μg of indium in 10 ml of chloroform was determined. The coefficient of the variation was 3% for 12 μg of indium. The extractability of the ternary complex from 50 ml of an aqueous solution into 10 ml of chloroform was 99%. Iron, mercury, and silver, which interfere with the determination of indium, were masked with ascorbic acid, potassium iodide, and thiourea. Other interfering elements, including zinc, cadmium, gallium, nickel, palladium, cobalt, antimony, gold, copper, bismuth, and vanadium, must be removed before any analysis.
The Effect of Steric Condition on the Structure of Cobalt(II), Nickel(II), and Copper(II) Complexes with Schiff Bases Obtained from Salicylaldehyde Derivatives and 9-Aminofluorene
Authors: Yamada Shoichiro , Tanaka Hideaki , Yamanouchi Kuniko
Published: July 2006

Cobalt(II), nickel(II), and copper(II) complexes with N-(9-fluorenyl)salicylideneaminates (abbreviated as X-sal-fl) have been examined in relation to the effect of steric condition on the structure of the metal complexes. Compounds of the type M(X-sal-fl)2 and their pyridine adducts were isolated as crystals. Complexes of the type Cu(X-sal-fl)Cl were also obtained. Both in the solid state and in non-donor solvents, the complexes Co(X-sal-fl)2 have a tetrahedral configuration, and Ni(X-sal-fl)2 and Cu(X-sal-fl)2 have a square-planar configuration. Possible structures of the pyridine adducts are discussed. The results indicate that the steric hindrance caused by fluorenyl is greater than that by diphenylmethyl.
Secondary Ion Mass Spectrometry for Diffusion Studies in Glass
Authors: Mizuike Atsushi , Iino Akira
Published: July 2006

A procedure has been established for obtaining quantitative diffusion profiles by means of an ion microanalyzer in the narrow region within 1 μm of the glass surface. The interdiffusion of silver and sodium ions in Pyrex glass immersed in molten silver nitrate was studied as an example.
Metal Complexes of Sulfur–Nitrogen Chelating Agents. IV. Complexes of Ni(II), Pd(II), Pt(II), and Rh(III) with Methyl Ester of 2-Amino-1-cyclopentene-1-carbodithioic Acid
Authors: Joardar D S , Mondal S K , Nag K
Published: July 2006

The methyl ester of 2-amino-1-cyclopentene-1-carbodithioic acid (HE) acts both as an unidentate and a bidentate ligand. With Ni(II) and Pd(II) the deprotonated chelates of the ME2 type are obtained readily, the corresponding Pt(II) complex being obtained on the addition of an equivalent amount of alkali. In these compounds, bond formation takes place from the nitrogen and the sulfur atoms and there is strong delocalization in the chelate ring. Unidentate bonding behavior of the ligand is observed in the complexes Pt(HE)2Cl2 and Rh(HE)3Cl3, where the bonding takes place through the nitrogen atom only.
Kinetic Studies of the Inversion of η2-trans-2-Butene in Platinum(II) Complexes Containing Various Amino Carboxylates
Authors: Terai Yoshiro , Kido Hiroaki , Kashiwabara Kazuo , Fujita Junnosuke , Saito Kazuo
Published: July 2006

Platinum(II) complexes containing S,S- or R,R-trans-2-butene and various l-amino carboxylate, i.e.  cis(N,olefin)[PtCl(l-prolinate)(S,S-trans-2-butene)] and trans(N,olefin)[PtCl(l-am)(S,S- or R,R-trans-2-butene)], were synthesized (l-am=l-prolinate, N-methyl-l-prolinate, N-benzyl-l-prolinate, l-alaninate and l-valinate). The kinetics of the inversion reaction of the coordinated S,S- or R,R-trans-2-butene was investigated in acetone in the presence of an excess of trans-2-butene at 8.0 °C. Second order rate law was obeyed with respect to the concentrations of the complex and free olefin, and no solvent path was observed. In the trans (N,olefin) complexes, interactions steric around the coordinated nitrogen atoms seems to be responsible in determining the ease of inversion via an associative mechanism. On the other hand, smaller rate for the cis(N,olefin) complex than the corresponding trans isomer seems to be due to the trans effect.
A One-step Synthesis of 2,7-Dimethyl-5-silaspiro[4.4]nona-2,7-diene and the Synthesis of Its Derivatives
Authors: Terunuma Daiyo , Hatta Satoshi , Araki Tsunao , Ueki Tadashi , Okazaki Tsutomu , Suzuki Yasutaka
Published: July 2006

The in situ reaction of dialkoxydichlorosilanes, such as dimethoxy-, diethoxy-, dipropoxy-, dibutoxy-, and diisobutoxydichlorosilane, with isoprene and magnesium in tetrahydrofuran (THF) was investigated. It was found that the double annelation product, i.e., 2,7-dimethyl-5-silaspiro[4.4]nona-2,7-diene (1), was obtained from diethoxy-, dipropoxy-, and dibutoxydichlorosilane in 87.0, 65.2, and 66.5% yields respectively. On the other hand, the reaction of dimethoxy- and diethoxydichlorosilane with butadiene and magnesium in THF gave 5-silaspiro[4.4]nona-2,7-diene (7) in 20.7 and 35.4% yields respectively. Several silaspirononane derivatives were synthesized from 1.
A Synthesis of 3′,4′-Dideoxykanamycin B
Authors: Nishimura Tomo , Tsuchiya Tsutomu , Umezawa Sumio , Umezawa Hamao
Published: July 2006

3′,4′-Dideoxykanamycin B was prepared from kanamycin B via 4″,6″-O-cyclohexylidenation, N-benzyloxycarbonylation, 3′,4′,2″-tri-O-benzylsulfonylation, double bond formation at C-3′,4′, removal of the cyclohexylidene group, simultaneous removal of the N,O-protecting groups with sodium metal in liquid ammonia and hydrogenation of the resulting 3′,4′-dideoxy-3′-eno-kanamycin B.
Synthesis of Mesoionic Triazolopyridine. I. N-Alkylation of 1,2,4-Triazolo[4,3-a]pyridin-3(2H)-one
Authors: Saito Akio , Shimizu Bunji
Published: July 2006

Mesoionic anhydro-1-alkyl-3-hydroxy-1,2,4-triazolo[4,3-a]pyridinium hydroxide (6) was synthesized by selective alkylation at the N1-position of 1,2,4-triazolo[4,3-a]pyridin-3(2H)-one (8). The selectively depends on the use of a mercuric salt catalyst in combination with the trimethylsilyl derivative of 8, and its mechanistic features were also studied with reference to the benzylation of 8.
Synthesis of Mono-O-tritylraffinoses and Deca-O-acetylraffinoses
Authors: Suami Tetsuo , Otake Toshiki , Ikeda Toshihide , Adachi Ryoichi
Published: July 2006

Starting from raffinose (1), its 6″-O-trityl (2) and 6′-O-trityl derivative (6) have been prepared. Acetylation of 2 and 6 gave deca-O-acetyl-6″-O-tritylraffinose (3) and deca-O-acetyl-6′-O-tritylraffinose (7) respectively. Detritylation of 3 gave two products: 1′,2,2″,3,3′,3″,4,4′,4″,6′-deca-O-acetylraffinose (4) as a main product and 1′,2,2″,3,3′,3″,4,4′,6′,6″-deca-O-acetylraffinose (5) as a minor product, which were successfully separated by a column chromatography. On the other hand, detritylation of 7 gave 1′,2,2″,3,3′,3″,4,4′,4″,6″-deca-O-acetylraffinose (8) as a sole product. Their structures were established by NMR spectra, together with a chemical evidence.
Kinetics and Mechanism of the Oxidation of Substituted Benzyl Alcohols by Chloramine-T in Acid Solution
Authors: Banerji Kalyan K
Published: July 2006

The oxidation of benzyl alcohol and eight monosubstituted benzyl alcohols by chloramine-T in acid solution has been studied. The reaction is of first order with respect to the concentration of alcohol and oxidant. The rate constant is proportional to the square of hydrogen ion concentration. The kinetic isotope effect (kH⁄kD) is 4.13 at 303 K. The solvent isotope effect (k(D2O)/k(H2O)) is 5.93 at 303 K. The activation enthalpies and entropies are linearly related. The reaction exhibited a reaction constant ρ+=−2.08±0.08 at 303 K. The active oxidizing species is considered to be (H2OCl)+. A mechanism involving transfer of a hydride ion to the oxidant is suggested.
Branched-Chain Deoxy Nitro and Amino Sugar Derivatives from Ketose
Authors: Abdel-Rahman M M A
Published: July 2006

The nitromethane addition to 1,2-O-isopropylidene-5-O-trityl-α-d-erythro-pentofuranos-3-ulose (1) proceeded smoothly to give the corresponding branched-chain sugar (2), which on acetylation afforded (3) followed by elimination of acetic acid in presence of a base catalyst, resulted in the formation of the corresponding nitro olefin (4). The nitro olefin when subjected to borohydride reduction gave 5-O-acetyl-3-deoxy-1,2-O-isopropylidene-3-(nitromethyl)-α-d-ribofuranose (5), which on catalytic hydrogenation followed by acetylation yielded the 3-(acetamidomethyl)-5-O-acetyl-3-deoxy-1,2-O-isopropylidene-α-d-ribofuranose (6). By the study of the NMR spectra of 3-deoxy derivatives (5) and (6), their d-ribo configurations were established.
The Microwave Spectra, Molecular Structures, and Quadrupole Coupling Constants of Methyltrichlorosilane and Trichlorosilane
Authors: Takeo Harutoshi , Matsumura Chi
Published: July 2006

The microwave spectrum of methyltrichlorosilane has been re-examined in order to determine the precise molecular structure by observing the spectra due to the isotopic species. The previously reported value of the nuclear quadrupole coupling constant of trichlorosilane has been corrected by the reinvestigation of the hyperfine structure.
Additions of Dibenzyl Selenoxides and Selenonium Ylides to an Electron-Deficient Ethylene and Acetylene
Authors: Tamagaki Seizo , Akatsuka Ryuji , Kozuka Seizi
Published: July 2006

Dibenzyl selenoxides reacted with dimethyl acetylenedicarboxylate and tetracyanoethylene to give new ylides, while the reaction of selenonium ylides produced new ylides or cyclopropane derivatives.
Cation Distribution in Mixed Formates. I. Change in Lattice Constants and in Infrared Spectra with the Chemical Constitution of (Cu,MII)(HCOO)2·2H2O
Authors: Ogata Toshiko , Taga Tooru , Osaki Kenji
Published: July 2006

Mixed crystals of formates, with the general formula of (Cu,MII)(HCOO)2·2H2O, were found to show non-uniform changes in lattice constants with the change in the chemical constitution. The reason for this unusual change was sought in relation to a possible non-uniform distribution of the cations over the two non-equivalent sites for metal ions. A simple model based merely on the difference in the radii of metallic ions did not agree with the results of IR measurements nor with those of an ESR study by Wagner et al. Another model, incorporating the change in the direction of the longest axis of the octahedron coordinating to the Cu2+ ion at the Ml-site, as suggested from the results of a related work (Part II), was found not only to explain the changes in lattice constants, but also to conform with other evidences; it seems to be an essentially correct interpretation.
Cation Distribution in Mixed Formates. II. The Structure of the Mixed Crystal Cu0.5Zn0.5(HCOO)2·2H2O
Authors: Ogata Toshiko , Taga Tooru , Osaki Kenji
Published: July 2006

The structure of the 1 : 1 mixed crystal between Cu(HCOO)2·2H2O and Zn(HCOO)2·2H2O has been determined on the basis of 878 visual intensity data. The space group is P21/c, with a=8.77, b=7.25, c=9.17 Å, β=98.0°, and Z=4. The structure is similar to that of Cu(HCOO)2·2H2O, except that the two metal ions are distributed over two metal ion sites, the Cu2+ ions being mostly localized in the [Cu(HCOO)2] sheet, and except that the longest axis of the coordination octahedron around the Cu2+ ion in this sheet is nearly perpendicular to it. It is suggested that the type of sheet found in the mixed crystal as well as in Cu(HCOO)2·4H2O is more favorable than that in Cu(HCOO)2·2H2O for an independent [Cu(HCOO)2] sheet.
Ultrasonic Study of Aqueous Solutions of Amines
Authors: Nishikawa Sadakatsu , Otani Unpei , Mashima Mitsuo
Published: July 2006

Ultrasonic absorptions in aqueous solutions of allylamine have been measured in the frequency range from 8.5 to 220 MHz at 20 °C. Only a single relaxational absorption has been observed in the concentration range from 0.0562 to 4.00 M; this absorption has been attributed to the proton-transfer reaction. The rate constants and the standard volume change due to the reaction have been determined, and the results are compared with those for aqueous solutions of other amines previously published. It has been elucidated from the ultrasonic absorption data that the presence of the intermediate in the proton-transfer reaction is required in order to analyze the ultrasonic absorption mechanisms quantitatively. The hydrophobic effect in the aqueous solutions of amines has also been discussed.
Electrical Conductivity of Single Crystals of N-Methylphenazinium–TCNQ and Rb–TCNQ
Authors: Fujii Genshiro , Shirotani Ichimin , Nagano Hiroshi
Published: July 2006

Temperature and pressure dependence of the electrical conductivity of NMP(I)–, NMP(II)–, Rb(I)– and Rb(II)–TCNQ single crystals was studied. NMP(I)–TCNQ showing diffuse streaks was found to have a semiconductive behavior at atmospheric pressure and no conductive maximum appeared at low temperatures. Moreover the metallic behavior was not shown even at 100 kbar. The crystal structure of NMP(II)–TCNQ is not similar to that of NMP(I)–TCNQ. The difference of physical properties of two phases is discussed. The anomalous electrical behavior in the pressure range from 1 bar to 40 kbar was observed for Rb(I)–TCNQ. The resistivity of Rb(II)–TCNQ decreased monotonously with increasing pressure. The magnitude of their activation energies was 0.15 eV for Rb(I) salt and 0.11 eV for Rb(II) salt at 100 kbar. The insulator to metal transition could not be observed at least up to 100 kbar.
Bimolecular Quenching of Triplet Exciton in Crystalline p-Dibromobenzene
Authors: Kobayashi Takayoshi , Hirota Noboru
Published: July 2006

The rate constants of the bimolecular quenching (γ), the hopping rate (λ), and the diffusion coefficient (D) of triplet exciton in crystalline p-dibromobenzene at temperatures between 160 and 77 K were obtained by analyzing the phosphorescence decay curves at high and low density excitations with the use of an N2 laser as an exciting pulsed light source. Estimated values of γ, λ, and D at room temperature (300 K) are (2±1)×10−12 cm3· s−1, 9±4×109s−1, and 2±1×10−4 cm2 s−1, respectively. The activation energy of the exciton hopping was obtained to be 290±50 cm−1. This implies that the triplet exciton in p-dibromobenzene crystal is described in terms of a localized exciton model.
Color and Precipitation Reactions of Lanthanoids with Chlorophosphonazo III
Authors: Taketatsu Tomitsugu
Published: July 2006

Aqueous solutions of pH 1–3 containing Chlorophosphonazo III chelates of lanthanoids give an absorption spectrum of the α-type, the spectrum showing two maximum peaks at approximately 620 and 670 nm, in the presence of an excessive amount of the reagent. However, the chelates of heavier lanthanoids give an absorption band of the β-type, which extends from 700 to 800 nm with a maximum at 745 nm, with an increase in the mole ratio of the metal against the reagent. A dark-violet precipitate forms from the solution, giving the β-type spectrum under certain experimental conditions. The combining ratio of the metal against the reagent in the precipitate is estimated to be 1:1. Since a reaction rate from the α-type to the β-type corresponds to the second order, the combining form between the metal and the reagent in the β-type chelate is assumed to be 2:2, i.e., a dimer. The chelates of lanthanum to samarium do not give the β-type spectrum under the same conditions.
Kinetics of the Oxidation of Formate by Iodine in the Water–Methanol and the Water–Ethanol Mixed Solvents
Authors: Hayakawa Katumitu , Sato Makoto
Published: July 2006

The kinetics of the iodine–formate reaction gives an identical rate equation in several water–alcohol mixed solvents: rate=k[HCOO−] [I3−]/(a[I−]+1). The values of k/M−1 s−1 and 10−3  a/M−1 are 5.5 and 16 in ethanol at 35 °C, 3.6 and 12 in methanol at 30 °C, and 0.06 and 0.7 in water at 30 °C, respectively. The values of a are comparable to the formation constants of I3− in the water–alcohol mixtures. The rate-determining step is the reaction between an iodine molecule and a formate ion. The activation parameters, ΔH\eweq/kJ mol−1 and ΔS\eweq/J K−1 mol−1, are 71 and −1 in the 0.95 mole fraction of methanol, 60 and −32 in the 0.92 mole fraction of ethanol, and 75 and −20 in water, respectively. The entropy term contributes to the acceleration by alcohol in the water–methanol mixtures, whereas both the entropy term and the enthalpy term contribute to the acceleration in the water–ethanol mixtures. These effects of the mixed solvents suggest that the specific interactions of the solvent molecule with the reactants and the activated complex, such as a specific solvation or a hydrogen bond, play an important role in the rate-determining step.
Crystal and Molecular Structure of a Chelating Ylide Complex of Palladium: [(Benzoylmethylene)diphenyl-2-(diphenylphosphino)ethylphosphorane]dichloropalladium(II) Toluene Solvate
Authors: Takahashi Hirofumi , Oosawa Yoshinao , Kobayashi Akiko , Saito Taro , Sasaki Yukiyoshi
Published: July 2006

The crystal structure of the title compound was solved by single-crystal X-ray diffraction techniques. Crystals are monoclinic, space group P21/c, with cell dimensions a=13.39(5), b=16.88(1), c=19.85(6) Å, β=123.54(1)°, Z=4. The final R was 0.065. The ylide ligand coordinates to palladium through the ylide carbon Pd–C, 2.115(15) Å and phosphine phosphorus Pd–P, 2.230(8) Å forming a six-membered chelate ring. The chelating ligand together with two chlorine atoms forms a square-planar geometry around the palladium. The Pd–Cl distances are discussed in terms of trans-influence of the ylide carbon.