bluuebunny/crossref_metadata_2025 huggingface dataset:
The Micelle Formation of Alkylammonium Chloride in 1-Propanol–Water and Acetone–Water Mixtures
Authors: Miyagishi Shigeyoshi
Published: July 2006

The change in the critical micelle concentrations (CMC) of alkylammonium chlorides (C12–C18) and in the degree of the dissociation of the micelle (α) of dodecylammonium chloride was determined by adding 1-propanol and acetone to water. Both the CMC and the α increased with an additive concentration, each reaching a maximum at a certain concentration (critical composition of solvent for micelle formation, CCSM) and decreasing beyond the CCSM. The increment in the CMC was more influenced by the alkyl-chain length in the surfactant molecule in the presence of 1-propanol than in that of acetone. The effective coefficient of electrical energy (Kg) and the cohesive energy difference per methylene group between the micelle and the monomer states (ω) were calculated from the CMC and the α. The Kg values in both mixed solvents were constant beyond the respective CCSM. The value of ω was less in the presence of 1-propanol than in that of acetone.
Ultrasonic Absorption Mechanisms in Aqueous Solutions of Alcohols
Authors: Nishikawa Sadakatsu , Mashima Mitsuo , Maekawa Michio , Yasunaga Tatsuya
Published: July 2006

Ultrasonic absorption measurements in aqueous solutions of tert-butyl and allyl alcohols were carried out in the frequency range of 4.5–220 MHz at 25 °C. Two relaxation processes were observed in aqueous solution of tert-butyl alcohol and a single one in that of allyl alcohol. The former relaxation mechanisms were revealed to be due to the perturbation of the equilibria expressed by (Remark: Graphics omitted.) where A and B were alcohol and water molecule respectively. The latter mechanism was due to that expressed by (Remark: Graphics omitted.). The rate constants for all these processes were determined from the concentration dependence of the relaxation frequencies. The water structure in aqueous solutions was discussed in terms of a hydrophobic interaction, and it was concluded that the hydrophobic interaction decreased in this sequence, tert-butyl, n-propyl and allyl alcohols.
Non-isothermal Studies of Adduct Molecules of Metallic Halides with Oxo-Compomids in Solid State. I.
Authors: Chaudhuri N Ray , Mitra S , Pathak G K
Published: July 2006

Non-isothermal studies of some adduct molecules of metallic halides with dioxane as the type MX2·y(dioxane) in;solid state, where M=Mn(II), Co(II), Ni(II), Cu(II), Zn(II) or Cd(II), X=Cl− or Br− and y=0.5–2, were carried out with a Derivatograph. These inorganic adduct molecules lose dioxane molecule in single or multiple steps on heating. Thermally stable intermediate products were isolated and characterised by elemental analysis and IR spectra. The activation energy for each step of decomposition of the adduct was evaluated from the analysis of TG, DTG and DTA curves. Enthalpy change was evaluated from the DTA peak area and the order of reaction was found to be unity for each step of decomposition. Thermal stability of the adducts was discussed.
Energy Difference between Rotational Isomers of 1,2-Dibromoethane
Authors: Hiraishi Jiro , Shinoda Takako
Published: July 2006

The energy difference between the rotational isomers of 1,2-dibromoethane in the liquid state was determined to be 910±80 cal/mol on the basis of the relative intensity of the Raman band at 660 cm−1 (trans form) to that at 551 cm−1 (gauche form) in the temperature range from 24.5 to 105.1 °C.
Photoelectron Spectroscopic Study of Skew Compounds. III. N,N′-Dimethylhydrazine, Dimethyl Peroxide, and Dimethyl Disulfide
Authors: Kimura Katsumi , Osafune Kazuteru
Published: July 2006

He I photoelectron spectra of CH3HNNHCH3, (CH3)2O2, and (CH3)2S2 have been measured and the spectra below 18 eV have been resolved into nine ionization bands corresponding to p-type localized molecular orbitals. Orbital assignments of the resulting vertical ionization energies have been carried out with CNDO/2 calculations in which orbital energies were calculated as a function of the dihedral angle in the region 0–180°. The separation of the nonbonding photoelectron bands suggests that CH3HNNHCH3 exists in outer-inner skew form, whereas (CH3)2O2 is in trans form. The sum rule consideration previously proposed by the present authors has been applied to the compounds studied here. The total sum of the vertical ionization energies in the p-type region for each compound has been well reproduced in terms of appropriate empirical parameters based on the photoelectron spectra of simple molecules. The effects of methyl substitution on the ionization-energy total sums for N2H4, H2O2, and H2S2 have been found to be very similar to those for ethane and ethylene.
The Enthalpy of Vitreous Beryllium Fluoride
Authors: Tamura Seiichi , Yokokawa Toshio
Published: July 2006

The enthalpy increments of beryllium fluoride were measured by the drop method in the glassy and liquid states from 450 to 914 K. The other thermodynamic functions were also calculated. The estimated configurational entropy of the supercooled liquid showed its temperature dependence to be small compared with those of nearly all other glass-forming liquids. The theory of Adam and Gibbs was applied to explain both the present enthalpy data and the Arrhenius viscosity behaviour over an unusually wide temperature range. The similarity between beryllium fluoride and silicon dioxide was also shown with respect to the heat capacities of the glassy and supercooled liquid states.
The Acid-catalyzed Reaction of Cycloalkanones with Formaldehyde
Authors: Hirano Fukumi , Wakabayashi Shoji
Published: July 2006

The acid-catalyzed reactions of several cycloalkanones, such as cyclopentanone (1a), 2-methylcyclopentanone (1b), cyclohexanone (1c), 2-methylcyclohexanone (1d), and 2-isopropyl-5-methylcyclohexanone (1e), with formaldehyde were investigated. These reactions involved an aldol condensation analogous to the Prins reaction, and they afforded methylol derivatives and cyclic ethers. It was found that the formation of the products is strongly influenced by the skeletal structure and by the substituent on the cycloalkanones. That is, 1a, 1c, and 1d gave mainly 1,3-dioxanes, while 1b and 1e formed only methylol derivatives. The reaction of cycloalkanone enol esters with formaldehyde was also studied.
Studies on the Ruthenium Complexes. IX. Kinetic Studies on the Deaquation-anation Reaction of Aquapentaammineruthenium(III) Complexes
Authors: Ohyoshi Akira , Hiraki Shun-ichi , Odate Tomio , Kohata Susumu , Oda Junko
Published: July 2006

The deaquation-anation reaction of [Ru(OH2)(NH3)5]X3-type complexes in the solid state, as shown by the [Ru(OH2)(NH3)5]X3(s)→[RuX(NH3)5]X2(s)+H2O(g) equation, where X is Cl, Br, I, and NO3 respectively, was kinetically studied by means of thermogravimetry (TG) along with differential thermal analysis (DTA). The activation energy and entropy in the reaction process (Ea kcal/mol, ΔS\eweq e.u.) are, respectively, found by isothermal kinetic study to be (22.7, −7.1) for the chloride, (23.4, −5.2) for the bromide, (26.7, 5.8) for the iodide, and (19.3, −15.9) for the nitrate. The reaction seems to proceed through the following two steps, except in the case of the iodide: [Ru(OH2)(NH3)5]X3→[RuX(OH2)(NH3)5]X2→[RuX(NH3)5]X2+H2O. The first step is regarded as the rate-determining one.
Ion Association of Some 2 : 2 Electrolytes in Water at 25 °C. II. Spectrophotometric Studies of the Ion Association of Magnesium, Calcium, Manganese, Copper, and Zinc Sulfates
Authors: Yokoyama Haruhiko , Yamatera Hideo
Published: July 2006

Simple and mixed aqueous solutions of copper, magnesium, calcium, manganese, and zinc sulfates were spectrophotometrically studied in order to obtain the ion-association constants of the divalent metal ions with the sulfate ion. The ion-association constant of copper sulfate was obtained from the measured absorbances of copper sulfate solutions at 250 nm as a function of the closest distance of approach of ions. For the other metal sulfates which show a negligible absorption at 250 nm, absorbances were measured on the mixed solutions with copper sulfate, and the results were analyzed by the use of the results on copper sulfate in order to obtain the ion-association constants. The best values of the ion-association constant and the closest distance of approach were determined for each metal sulfate with the help of the theory of ion association. The results were compared with those obtained from the measurements of osmotic coefficients and electric conductivities. The numerical results are summarized in Table 6 of the text.
Metachromasy. III. Metachromatic Behavior of Trypaflavine in the Presence of Polyphosphates with Various Chain Lengths
Authors: Yamaoka Kiwamu , Takatsuki Mineo , Miura Masaji
Published: July 2006

The interaction of trypaflavine with sodium polyphosphate in aqueous solutions in the pH range 6–7 has been investigated by means of light absorption spectroscopy, conductometric titration and ultrafiltration. The metachromatic behavior of the bound dye was characterized in terms of hypso- and hypochromic effects in both visible and UV regions where no pronounced metachromasy band was observed. The effects were studied by varying the mixing ratio of polymer residue to dye, P/D, from 0.1 to 10000. They were found to be maximum in the P/D range 2–10. The effect of the chain length of polyphosphate on metachromasy was determined by use of fourteen refractionated samples with the degree of polymerization, \barn, ranging from 8 to 158. No metachromasy appeared in samples with \barn<7. It fully developed for those with \barn>20, sharply depending on the chain length between 7 and 20. By conductometric titration and ultrafiltration, it was verified that the dye binds to the ionized phosphate almost at 1 : 1, and that the disappearance of metachromasy with the increase in P/D values or with the addition of salts results from two entirely different processes. The results were compared with the data for other dyes.
Soret Coefficients and Heat of Transport of Polyvalent Electrolytes in an Aqueous Solution
Authors: Sugisaki Masayasu
Published: July 2006

The Soret coefficients of aqueous electrolytes were measured by the conductometric method for salts of K2SO4, Na2SO4, ZnSO4, and CdSO4 in the concentration range from 0.001 to 0.01 M at 25 °C and 35 °C. The heats of transport were calculated from the Soret coefficients. The concentration dependence of the heat of transport was ascertained to be proportional to the square root of the ionic strength, and the slopes for Na2SO4 and K2SO4 salts at 25 °C were found to be larger than those reported by Snowdon and Turner. The temperature dependence of the heat of transport was examined based on the data at 25 °C and 35 °C. The heat capacities concerning the transported entropy were found to be negative for the four salts examined.
Molecular Reorientational Motion of the Benzene Molecule in a Mixture of Benzene with Carbon Tetrachloride by Raman Band Spape Analysis
Authors: Nomura Hiroyasu , Miyahara Yutaka
Published: July 2006

The reorientational correlation times of the benzene molecule in mixtures of benzene with carbon tetrachloride were measured by the method of the Raman line shape analysis. The reorientational relaxation times τor of C6H6 in solutions increased with increasing mole fraction of CCl4. Information was also obtained on an intermolecular vibration-vibration energy transfer process which primarily affects the mean life time of the first excited vibrational state ν2 (a1g) in benzene in solutions.
Total Synthesis of (±)-Tetrahydroligularenolide
Authors: Tatee Tochiro , Takahashi Takeyoshi
Published: July 2006

A total synthesis of (±)-tetrahydroligularenolide [(±)-2] is described. 10β-Methyl-5β-tetrahydropyranyloxy-trans-2-decalone (6) was converted in seven steps into 3-methoxycarbonyl-5,10-dimethyl-trans-2-decalone (15), which on alkylation with ethyl α-iodopropionate gave 3-(1-ethoxycarbonylethyl)-3-methoxycarbonyl-5,10-dimethyl-trans-2-decalone (19) and 6-(1-ethoxycarbonylethoxy)-7-methoxycarbonyl-1β,8aβ-dimethyl-1,2,3,4,4a,5,8,8a-trans-octahydronaphthalene (20). Hydrolysis of 19 proceeded with a loss of carbon dioxide to afford (±)-tetrahydroligularenolide [(±)-2].
Metal Chelates of 9-Hydroxy-1-phenalenone
Authors: Demura Yoichi , Kawato Toshio , Kanatomi Hajime , Murase Ichiro
Published: July 2006

Metal chelates of 9-hydroxy-1-phenalenone(9-hydroxyperinaphthenone) have been prepared. Metalligand compositions were 1:2 for Cu(II), Ni(II), Co(II), Mn(II), Zn(II), Mg(II), UO2(II), and Be(II) chelates and 1 : 3 for Fe(III) and Al(III) chelates. The structure of the Cu(II) chelate was determined to be squareplanar by the spectral analogy to copper(II) acetylacetonate. The Ni(II), Co(II), Mn(II), Zn(II), and Mg(II) chelates were octahedral with further coordination of two moles of water. The structure determination dealt at first with the Ni(II) chelate by means of its electronic spectrum and magnetic property; the others were studied using the similarity of their X-ray diffraction diagrams to that of the Ni(II) chelate. The Fe(III) and Al(III) chelates were also octahedral and probably have D3 symmetry. Infrared spectra were studied for the free ligand and the metal chelates and the assignment of the carbonyl and metal-oxygen stretching vibrations was discussed by comparison with those of metal acetylacetonates.
Synthesis of 2,3,6,7-Tetramethylnaphthalene from 2,3-Dimethylsuccinic Anhydride and o-Xylene
Authors: Dozen Yasuhiko , Hatta Masato
Published: July 2006

2,3,6,7-Tetramethylnaphthalene (7b) was prepared from 2,3-dimethylsuccinic anhydride (1) and o-xylene in five steps, and the configurations of their intermediates were studied. The higher-melting isomer (threo form) of 1 gave higher-melting products in each step, while the lower-melting isomer (erythro form) of 1 gave lowermelting ones. The configurations of the intermediates were confirmed by the MNR spectral data of tetramethyltetralines (6b). Similar reactions were carried out with 3-benzoyl-2,3-dimethylpropionic acid (2a) in order to learn the configurations of the intermediates. 3-Aroyl-2,3-dimethylpropionic acids (2) gave 2,3-dimethyl-4-aryl-3-buten-4-oildes (3) upon heating with hydrochloric acid.
Electroorganic Chemistry XVIII Anodic Oxidation of Substituted Cyclopropanes
Authors: Shono Tatsuya , Matsumura Yoshihiro
Published: July 2006

The anodic oxidations of polyalkyl-substituted cyclopropanes (1–3) and spiro[2.n]alkanes (4–6) were carried out in methanol. Monomethoxyolefin and dimethoxy compound resulted from the selective cleavage at the most substituted carbon–carbon bond. The decrease in the oxidation potential brought about by the substitution of the one methyl group was observed to be about 0.3 V vs. SCE. The analysis of the products and oxidation potentials of the cyclopropanes suggested that the σ-electron transfer from cyclopropane to the anode may be the initiation process and that the stereochemistry at the surface of the solid electrode plays an important role in this anodic oxidation.
Circular Dichroism in Lyotropic Liquid Crystals of Polyglutamate Solutions
Authors: Tsuchihashi Nobuaki , Nomori Hiroyuki , Hatano Masahiro , Mori Shigeo
Published: July 2006

A poly-γ-ethyl-l-glutamate solution with a cholesteric color exhibits a circular dichroism due to the selective reflection of circularly polarized light of one sense by the cholesteric helical structure existing in the solution. On the other hand, an induced circular dichroism is observed in the wavelength region corresponding to the absorption bands of an achiral dye molecule when the molecule is dissolved in the poly-γ-benzyl-d-glutamate liquid crystalline phase. The two modes of circular dichroism are correlated to the structure and the chirality of the cholesteric phase of concentrated polyglutamate solutions.
Sesquiterpenes from Acorus calamus L.
Authors: Niwa Masatake , Nishiyama Atsuko , Iguchi Masanobu , Yamamura Shosuke
Published: July 2006

Three new sesquiterpenes, acoragermacrone (1), acolamone (2), and isoacolamone (3) were isolated from Acorus calamus L., and their structures were elucidated. In particular, acoragermacrone, a ten-membered ring sesquiterpene, is the most important precursor of the other sesquiterpenes included in the same plant. Acoragermacrone was converted into shyobunone, epi-shyobunone, preisocalamendiol, acolamone, and isoacolamone.
A Study of Optically Active (Benzoin-α-oxime)dichlorocopper(II)
Authors: Kudo Tomikatsu , Kaizaki Sumio , Hidaka Jinsai , Shimura Yoichi
Published: July 2006

An optically active complex, [(S)-benzoin-α-oxime]dichlorocopper(II), was prepared and its absorption and circular dichroism spectra were investigated in organic solvents.
A Structural Investigation of the 2-Methylthiophene Trimer and Its Related Compounds
Authors: Ishigaki Akira , Shono Toshiyuki
Published: July 2006

A structural investigation of the 2-methylthiophene trimer and its crystalline oxidation product has been performed. These compounds have been found to be identical with 2,4-bis(5′-methyl-2′-thienyl)-2-methylthiolane and its sulfone derivative.
Uranyl Ion-Sensitized Isomerization of the Stilbenes in Solution
Authors: Matsushima Ryoka , Kishimoto Tsuneo , Suzuki Morio
Published: July 2006

By selective excitation of the uranyl ion with light of λ≥365 nm, a deoxygenated acetone solution containing cis- or trans-stilbene and the uranyl ion finally reaches a photostationary state, whose isomer ratio, (t⁄c)pss, varies from 1 to 3 depending on the concentrations of the uranyl ion and the stilbenes. A close correlation is found between the features in the sensitized isomerization and the phosphorescence quenching of the sensitizer. Comparison with the results of halogen radical induced isomerization suggests that catalytic isomerization by free radicals is not an important process. A triplet-triplet energy transfer mechanism is proposed, which is supported by the oxygen effect and considerations on the lowest excited state of the uranyl ion, i.e., its long lifetime and triplet energy level higher than that of the stilbenes.
An Adiabatic Calorimeter for High-resolution Heat Capacity Measurements in the Temperature Range from 12 to 300 K
Authors: Tatsumi Masami , Matsuo Takasuke , Suga Hiroshi , Seki Syûzô
Published: July 2006

Construction of a high resolution calorimeter of an adiabatic type for single crystals is described. It uses a bank of thermistors for high resolution measurements in addition to a miniature platinum resistance thermometer. The results of heat-capacity measurements on benzoic acid as a standard material showed the inaccuracy of ±0.1% and the imprecision was confirmed to be less than ±0.05% between 50 and 275 K.
Photochemistry in the Adsorbed Layer. VI. The Type I Selectivity in the Photolysis of Adsorbed 2-Pentanone
Authors: Anpo Masakazu , Kubokawa Yutaka
Published: July 2006

A marked high selectivity of the type I reaction in the photolysis of adsorbed 2-pentanone decreases with increasing amount of 2-pentanone adsorbed, approaching the selectivity in the water solution photolysis. In the solution photolysis the type I selectivity decreases in the order water>methanol>n-heptane. From these results together with comparison of the blue shifts of the (n,π*) bands in solution and in the adsorbed layer it has been concluded that such an enhancement of the type I reaction in the adsorbed layer is attributed to a heterogeneity of the surface, i.e., the presence of special active sites, as well as to the surface polarity.
Effects of Foreign Gases on Dual Fluorescences of Pyrene Vapor
Authors: Chihara Kohji , Baba Hiroaki
Published: July 2006

The characteristics of the dual fluorescences of pyrene vapor at 170 °C and 0.2–0.3 Torr have been investigated in the presence of cyclohexane or oxygen. With increasing cyclohexane pressure, the S1-fluorescence shows a blue shift and an increase in quantum yield and in lifetime, while the S2-fluorescence shows only a slight blue shift and a marked decrease in yield and in lifetime. Oxygen efficiently quenches the S1- and S2-fluorescence according to the Stern-Volmer relation. The experimental results are well explained by kinetic analyses based on the following assumptions: (1) The internal conversion is reversible and is much faster than other radiative and radiationless processes; (2) cyclohexane causes only vibrational relaxation which can be described in terms of a simple stepladder model; (3) oxygen acts as a quencher on both S1- and S2-fluorescence emissions. It is found that one collision with cyclohexane removes on the average a vibrational energy of the order of 1000 cm−1 or less from S1 or S2 of pyrene, and that one collision with oxygen quenches S1 or S2 with a probability close to unity. It is concluded that the S2-fluorescence consists mainly of a slow component originating from S2 which is in equilibrium with S1.
Vapor-Phase Photolysis of cis- and trans-4,5-Dimethylcyclohexenes
Authors: Inoue Yoshihisa , Takamuku Setsuo , Sakurai Hiroshi
Published: July 2006

Direct and sensitized photolyses of 4,5-dimethylcyclohexene vapor were investigated using a stereochemical approach at room temperature over the pressure range from 1 to 9 Torr. In the direct photolysis, decomposition of the retro-Diels-Alder type was the main course of the reaction, leading to the formation of 2-butene and 1,3-butadiene with the retention of the original configuration; 3,4-dimethyl-1-methylenecyclopentane was also formed as a minor product from a pressure-independent process. Mercury sensitization, on the other hand, produced cis- and trans-2-butenes, butadiene, 2,3-dimethyl-1-vinylcyclobutane, and cis-trans isomers of the substrate together with radical-induced products, i.e., hydrogen, 1,2-dimethylcyclohexane, and dimeric products. The intermediacy of a “hot,” “triplet” biradical was suggested from the pressure-dependence of the trans- to cis-2-butene ratio in the mercury sensitization. The differences in the results between the direct and sensitized photolyses are interpreted in terms of spin correlation effects.
Electronic Spectra of Tetraphenylporphinatoiron(III) Methoxide
Authors: Kobayashi Hiroshi , Higuchi Tadatoshi , Kaizu Youkoh , Osada Hisajiro , Aoki Masaru
Published: July 2006

Tetraphenylporphinatoiron(III) methoxide in the high-spin state S=5⁄2 gives rise to an absorption spectrum which has been assigned to that of low-spin iron(III) porphyrins. The excited states characteristic of the spectrum of high-spin iron(III) porphyrins are the configuration-interaction admixtures of the lowest triplet and singlet porphyrin (π,π*) excited states and the low-lying “porphyrin to iron (III)” charge-transfer excited states. The charge-transfer excited states in tetraphenylporphinatoiron(III) methoxide, however, are so high that the chargetransfer excited states are not sufficiently mixed with the lowest triplet (π,π*) excited states. Thus the high-spin methoxo complex does not exhibit a spectrum characteristic of high-spin iron(III) porphyrins.
Metallic Impurity-Activated Crystal Growth of Boron Phosphide by Chemical Vapor Deposition and Its Physical Properties
Authors: Motojima Seiji , Miura Yasuo , Sugiyama Kohzo , Takahashi Yasutaka
Published: July 2006

Needle single crystals of boron monophosphide as large as 5–100 μm in diameter and 4 mm in length were obtained by chemical vapor deposition on an impurity painted zone of quartz substrate at 1060–1120 °C. The impurities such as Mn, Ni, Pt, Ag or Au were painted on the substrate in a form of aqueous solution of their salts and decomposed or reduced to the respective metal in hydrogen atmosphere at 1000 °C. Needle crystals with the homo p-n junction were also prepared using Ni impurity. The colors of grown crystals varied with the change of gas composition. Differences of electrical resistivity and thermoelectric power were found between the crystals of different colors.
An NMR and Mössbauer Spectroscopic Study of Mixed-valence Iron Fluoride Heptahydrate and Related Compounds
Authors: Sakai Takuhiko , Tominaga Takeshi
Published: July 2006

The powder X-ray patterns of FeIIIFeIIF5·7H2O, AlFeIIF5·7H2O, FeIIIZnF5·7H2O and AlZnF5·7H2O indicate that they are all isomorphous. When the Mössbauer spectra of the fluorides containing iron were measured, FeII and/or FeIII oxidation states were recognized distinctly. The 19F NMR spectra reveal that all the fluorine atoms are bonded to the trivalent metal ion (Al or FeIII) in these compounds. On the basis of these results, a possible structure is proposed for FeIIIFeIIF5·7H2O.
Influence of Anhydrous Hydrogen Fluoride on Hen Egg-White Lysozyme. I. Effects on Native Hen Egg-White Lysozyme
Authors: Aimoto Saburo , Shimonishi Yasutsugu
Published: July 2006

The influences of anhydrous hydrogen fluoride on the native form of hen egg-white lysozyme under standard conditions of peptide synthesis were investigated by measuring the enzymatic activities of materials recovered from mixtures of anhydrous hydrogen fluoride and hen egg-white lysozyme. The enzymatic activity of hen egg-white lysozyme gradually decreased on incubation with anhydrous hydrogen fluoride at a given temperature. After incubation of the mixture at 0 °C for 60 min, at least three fractions could be separated by gel-filtration on Sephadex G-50. One of these was eluted in the same position as native lysozyme and was fully active enzymatically. Its ultra-violet, and circular dichroism absorptions were identical with those of native lysozyme, and the tetragonal crystals obtained from this fraction could not be distinguished from those of native lysozyme.
Nucleophilic Displacement Catalyzed by Transition Metal. I. General Consideration of the Cyanation of Aryl Halides Catalyzed by Palladium(II)
Authors: Takagi Kentaro , Okamoto Tadashi , Sakakibara Yasumasa , Ohno Atsuyoshi , Oka Shinzaburo , Hayama Naomi
Published: July 2006

The displacement reaction of various non-activated aryl halides with cyanide ions was investigated in the presence of palladium salts. Various aryl iodides and bromides were converted into the corresponding aryl cyanides in good yields under mild conditions. The addition of certain substances, such as potassium hydroxide and potassium carbonate, enhanced the catalytic activity. Hexamethylphosphoric triamide, in which potassium cyanide was scarcely soluble, was an outstanding solvent for the reaction. The reduced palladium species was supposed to be the active catalyst.
The Substituent Effect. VII. Substituent Chemical Shifts of NH Proton of Acetanilides
Authors: Fujio Mizue , Tsuno Yuho , Yukawa Yasuhide , Takai Yoshio
Published: July 2006

NMR chemical shifts of the NH proton of fifty-three m- and p-substituted acetanilides were determined in dilute DMSO solutions. The substituent chemical shifts were correlated with σ0 constants with considerable scatter. Deviations Were particularly significant for −R groups having α-hydrogen. Improved correlation was found for −R substituents with (σ0)DMSO values which had been derived from the phenol hydroxyl chemical shifts in DMSO. Application of the LArSR equation using the DMSO-modified substituent parameters gave a good linear correlation for all substituents; ΔδNHAc=0.686 [(σ0)DMSO+0.277 (Δ\barσR−)DMSO]. These results indicate that the deviations are caused primarily by solvent-modification of substituents, the modification being essentially the same for both the acetanilide and the phenol systems in DMSO. The lower r− value 0.277 in the chemical shifts for the acetanilides than for the phenols suggests that the π-electronic contribution of +R  para substituents is less important in the acetanilide system than in the phenol one. The resonance substituent parameter for these solvent-modified substituents was found to be proportional to both (\barσpOH−\barσpNH), the difference between the apparent \barσp constants of the two systems, and to \barσp−0.85\barσm of each series. Estimation of a practical set of inductive and resonance substituent parameters for DMSO-modified substituents is attempted.
The Substituent Effect. VIII. Solvolysis of m- and p-Substituted α-Methylbenzyl Chlorides
Authors: Tsuno Yuho , Kusuyama Yoshiaki , Sawada Masami , Fujii Takahiro , Yukawa Yasuhide
Published: July 2006

The rates of solvolysis of twenty-two m- and p-substituted α-methylbenzyl chlorides were determined in 80% aqueous acetone. The relative rates at 45 °C are not correlated linearly with σ0 or σ. The use of Brown’s σ+ improves the fit but the resulting correlation is still concave. An excellent correlation, logk⁄k0=−4.950(σ0+1.147Δ\barσR+), was obtained by applying the LArSR equation. The r value 1.15 suggests that the π-electronic contribution relative to the inductive contribution of −R  para substituents at the transition states differs with reaction, and is more important in the present α-methylbenzyl than Brown’s t-cumyl solvolysis (r=1.00 by definition). A set of Δ\barσ+ and σ+ corresponding to the substituent constants for unit r were calculated. The calculated σ+ values are in precise agreement with Brown’s primary σ+ values. The generality of the LArSR equation and some new substituent constants are illustrated.
A Stoichiometric Investigation of the Reaction of Nitrosylpentaamminechromium(2+) with Ethylenediaminetetraacetatoaquachromate(II)
Authors: Ogino Hiroshi , Tsukahara Keiichi , Tanaka Nobuyuki
Published: July 2006

The reaction of Cr(NH3)5NO2+ with CrII(edta)(H2O)2− gives four chromium products: CrIII-(edta)(H2O)−, Cr(NH3)63+, a reddish-violet species which is considered to be a chromium dimer with a +2 charge, and a trace amount of Cr(H2O)(NH3)53+.
Oxidation of Isocyanides by Hg(II), Tl(III), and Pb(IV) Acetates
Authors: Tanaka Sakuya , Kido Hiroshi , Uemura Sakae , Okano Masaya
Published: July 2006

Isocyanides were oxidized to isocyanates in acetic acid in the presence of Hg(II), Tl(III), or Pb(IV) acetate through acetoxymetallation. The reaction of an isocyanide with Tl(III) acetate in various alcohols gave the corresponding carbamates in good yields.
Antineoplastic Agents. The Preparation of 5-Fluorouracil-1-acetic Acid Derivatives
Authors: Tada Masao
Published: July 2006

The condensations of 5-fluorouracil with α-halogenoacetic acid derivatives in the presence of alkali gave the 5-fluorouracil-1-acetic acid derivatives.
The Calculations of Dipole Polarizabilities and Anisotropies by the CNDO Method: The Effect of an Extended-basis Set
Authors: Shinoda Hiroyuki , Akutagawa Tatsuo
Published: July 2006

The dipole polarizabilities and the anisotropies of several small molecules have been calculated according to a formula derived from the time-dependent perturbation theory. The wave functions and the energies were calculated by means of the CNDO-CI version, with an extended-basis set. The effects on the calculated results of the introduction of the atomic vacant orbitals into the basis set have been discussed.
Photochemical Reduction of Vanadium(V) in Aqueous Perchloric Acid Solutions
Authors: Jeliazkowa Bojana G , Nakamura Shigeru , Fukutomi Hiroshi
Published: July 2006

It was found that irradiation of V(V) solution gives V(IV) and an equivalent amount of oxygen. The dependence of the quantum yield on light intensity, acid concentration, wave number and the concentration of V(IV) was investigated.
Photosolvation Reactions and Their Quantum Yields of Hexacyanocobaltate(III) in Non-aqueous Solvents
Authors: Nakamaru Katsumi , Jin Kazuo , Tazawa Atsuko , Kanno Masaru
Published: July 2006

The photoreactions of hexacyanocobaltate(III) in non-aqueous solvents (methanol, ethanol, acetonitrile, DMF, pyridine) caused by irradiation at 365 nm or 313 nm are found to be the photosolvation

[Co(CN)_6]^3- + Solv. \oversethν→ [Co(CN)_5(Solv.)]^2- + CN^-

In pyridine, in addition to the photosolvation product, a fluorescent substance which is perhaps an aromatic compound is also formed by the irradiation at 365 nm. The quantum yields are almost the same as that in aqueous solution. In ethanol, the quantum yields irradiated at both 313 nm and 365 nm are the same, indicating that the quantum yield is independent of the exciting wavelength. The sensitized photosolvation using several donors failed to occur because of the solubility limitation. Interesting spectral results are also reported.
Non-empirical Calculation of the G-Values for the Ionization and Excitations in Diatomic Molecules Irradiated by 100 keV Electrons
Authors: Okazaki Kiyoshi , Sato Shin
Published: July 2006

The binary-encounter collision theory has been applied to the calculation of the G-values for the ionization and excitations of diatomic molecules irradiated by 100 keV electrons. The obtained G-values of electrons are as follows, in the order of H2, N2, CO, NO, and O2: 2.83, 2.55, 2.68, 3.61, and 2.98. These values are in fair agreement with the experimental ones. The present non-empirical method is compared with the semi-empirical ones proposed by other investigators. The G-values of some other products were also calculated: the excited hydrogen atoms in the radiolysis of H2 (0.9) and the ozone formation in the radiolysis of O2 (12.6). These G-values are also in fair agreement with the experimental ones.
Anharmonic Potential Functions of Simple Molecules. II. Direct Numerical Diagonalization of Vibratinal Hamiltonian Matrix and Its Application to CO2 and CS2
Authors: Suzuki Isao
Published: July 2006

A general formalism is presented for the calculation of the vibration-rotation energy levels of linear symmetrical XY2 type molecules through direct numerical diagonalization of the vibrational hamiltonian matrix. This method is applied to the CO2 and CS2 molecules, of which the general quartic force fields have been known accurately. The results are compared with those obtained by an ordinary perturbation treatment, and the truncation effects of the matrix sizes as well as of the expansions of the potential functions are discussed. Special attention is paid to the peculiarities in the potential function of CO2 for which very strong mixings of the basis harmonic oscillator wave functions are observed. The general formula for evaluating the matrix elements of the transition moment are also discussed and its applicability to the problems of vibrational intensities and the dipole moment functions is discussed.
Vibrational Spectra and Molecular Structure of Ethyl Methyl Sulfide
Authors: Nogami Norimasa , Sugeta Hiromu , Miyazawa Tatsuo
Published: July 2006

The Raman spectra of the liquid, unannealed solid and annealed solid, and the infrared spectra of the gas, liquid, and annealed solid of ethyl methyl sulfide were measured. Normal vibrations were treated of the trans and gauche isomers. C–S stretching, CH2 rocking and skeletal deformation vibrations were discussed in relation with molecular structures. Only the gauche isomer was found to exist in the annealed solid. In the liquid state, the gauche isomer was found to be more stable, by 0.14±0.05 kcal/mol, than the trans isomer. The vibrational assignment made of ethyl methyl sulfide is consistent with those of related sulfides and disulfides.
The Preparation of 3- and 4-Fluorophthalic Anhydrides by Fluorodenitration
Authors: Ishikawa Nobuo , Tanabe Toshio , Hayashi Dan
Published: July 2006

3- And 4-fluorophthalic anhydrides were prepared by heating the respective nitrophthalic anhydrides with potassium fluoride with or without an aprotic polar solvent.
The Mechanism of the Hydrolysis of Condensed Phosphates. III. The Mechanism of the Hydrolysis of Trimeta- and Tetrametaphosphates
Authors: Watanabe Makoto , Sato Shoji , Saito Hajime
Published: July 2006

The hydrolysis of sodium trimeta- and tetrametaphosphates was run in water, dioxane–water, and formic acid–water solvents with an initial concentration of 0.025 mol/l at various pH values and temperatures. The hydrolysis of both the metaphosphates followed first-order kinetics with respect to the concentration of the phosphate under all the conditions studied and was an acid- and base-catalyzed reaction. In acidic solutions, the rate of hydrolysis of both the metaphosphates in water is faster than that in formic acid–water and slower than that in dioxane-water. Therefore, it is concluded that, in the formic acid–water solvent, the nucleophilicity of the water molecule may decrease on account of the solvation of the water molecule with the acid, while, in the dioxane–water solvent, since the scission of the hydrogen bond between water molecules may occur by the interaction of dioxane and water molecules, the nucleophilicity of the water molecule may increase. The hydrolysis of both metaphosphates in acidic solutions is considered to be an SN2 reaction, because the overall-reaction rate is highly dependent upon the nucleophilicity of the water molecule. In basic solutions, the rate of hydrolysis of sodium trimeta- and tetrametaphosphates in water is faster than or almost the same as that in dioxane-water. Consequently, the mechanism of the hydrolysis of both the metaphosphates in basic solutions seems to differ from that in acidic solutions. The increase in the rate of hydrolysis of small-ring phosphates in acidic solutions depends upon the activation energy and frequency factor, while that in basic solutions depends significantly upon the frequency factor. This may cause the difference in the solvent effect on the rate of hydrolysis of small-ring phosphates between acidic and basic solutions. The activation energy of the hydrolysis of both ring phosphates was 20–40 kcal/mol in the pH range of 1.0–12.5. The rate of hydrolysis of the metaphosphates in an aqueous sodium hydroxide solution is faster than that in an aqueous tetramethyl ammonium hydroxide solution and this can be attributed to catalysis by a sodium ion. The hydrolysis of sodium tripolyphosphate was also carried out in basic water and dioxane–water solvents. The solvent effect on the rate of hydrolysis of tripolyphosphate in basic solutions was the same as that in acidic solutions.
The Addition Reaction of Benzenesulfinic Acid to N-Substituted Maleimides
Authors: Matsuda Itsuo , Akiyama Keiichi , Toyoshima Takaaki , Kato Shinji , Mizuta Masateru
Published: July 2006

It was found that benzenesulfinic acid reacted with N-substituted maleimides in aqueous ethanol to give sulfoneimides in good yields. The rate for the reaction was determined by the use of the neutralization titration, the effect of a substituent in N-substituted maleimides on the rate was studied, and the reaction route of benzenesulfinic acid with N-substituted maleimide was deduced.
Reaction of Organoboranes with Lithium Aldimines. A New Procedure for the Synthesis of Unsymmetrical Ketones
Authors: Yamamoto Yoshinori , Kondo Kaoru , Moritani Ichiro
Published: July 2006

Unsymmetrical ketones are obtained in good yields via the reaction of dialkylchloroboranes with lithium aldimines followed by treatment with (i) thioglycolic acid and (ii) H2O2–NaOH. The reaction permits the introduction of both primary and secondary alkyl groups into R and R′ substituents of ketones (RR′C=O), and can even be extended to the accommodation of a functional group. The reaction of B-n-hexyl-9-borabicyclo[3.3.1]-nonane with lithium aldimine derived from n-butyllithium also gives unsymmetrical ketone, 5-undecanone, upon treatment with H2O2–NaOH.
Complex Cation-radical Salts Derived from Phenothiazine and Related Compounds
Authors: Doi Susumu , Matsunaga Yoshio
Published: July 2006

A new class of complex cation-radical salts is formed by the reaction of phenothiazine bromide with phenoxazine, phenothiazine, its benzo derivatives, and phenoselenazine.
Determination of Silver in Sea Water after Flotation with 2-Mercaptobenzothiazole
Authors: Hiraide Masataka , Mizuike Atsushi
Published: July 2006

Nanogram quantities of silver in 3000 ml of acidified sea water were quantitatively coprecipitated with 2-mercaptobenzothiazole. The precipitate was then floated with the aid of small nitrogen bubbles, and the silver determined by atomic-absorption spectrophotometry after wet oxidation. The silver concentration was 0.09 μg per liter.
Michael Reactions of α-Phenylthio and α-Phenyisulfinyl Crotonic Esters with Cyclic Enones
Authors: Hagiwara Hisahiro , Nakayama Kiyoshi , Uda Hisashi
Published: July 2006

The Michael reactivities of ethyl α-phenylthio- and α-phenylsulfinylcrotonates with 2-cyclohexenone, 3-methyl-2-cyclohexenone, and 3-methyl-2-cyclopentenone have been investigated.
Pressure Effect on the Optical Spectra of Some One-Dimensional Pt-Complexes
Authors: Hara Yoji , Shirotani Ichimin , Ohashi Yukako , Asaumi Katsuyuki , Minomura Shigeru
Published: July 2006

The absorption and luminescence spectra of the polycrystalline magnesium, barium, and potassium salts of tetracyano platinate (II) were measured at hydrostatic pressures up to 5.4 kbar. These three salts showed an anomalously large red shift with pressure in both the absorption and luminescence spectra. The X-ray powder diffraction measurement was carried out for the magnesium salt up to 70 kbar. At 70 kbar the Pt–Pt distance decreased from 3.16 Å to 2.93 Å, 7.3% in linear compressibility. In the low pressure region up to ∼20 kbar, the Pt–Pt distance was observed to decrease greatly. The intramolecular transition 5dz2→6pz energy was calculated as a function of the Pt–Pt distance. By comparing the calculated and observed values, such a large red shift in the absorption spectra was tentatively explained in terms of electrostatic stabilization of the intramolecular transition 5dz2→6pz due to the decrease of the intermolecular distance and due to the consequent increase of the 5dz2→6pz intermolecular CT character.
ESR Studies on the Anion Radicals of Some Triptycene and [2.2]Paracyclophane Derivatives
Authors: Hayashi Toyoharu , Mataga Noboru , Sakata Yoshiteru , Misumi Soichi
Published: July 2006

ESR spectra of anion radicals of some triptycene and [2.2]paracyclophane derivatives were observed and analyzed in order to study the delocalization interactions between composite aromatic rings.
An Investigation of the Hebb-Wagner’s d-c Polarization Technique I. Steady-state Chemical Potential Profiles in Solid Electrolytes
Authors: Mizusaki Jun-ichiro , Fueki Kazuo , Mukaibo Takashi
Published: July 2006

Using an electrochemical cell, Ag/AgX (X=Br or I)/C, the steady-state chemical potential profiles of silver in AgX were determined under d-c polarization conditions. Several Pt probes were attached to the AgX specimens, and the potential differences between the Ag electrode and the Pt probes were measured. It was found that, in order to obtain the correct chemical potential profiles, the Pt probes must be embedded in the specimen to avoid influences of the degradation of AgX at the surface of the specimen. The results obtained by the cell with carefully assembled probes revealed that Wagner’s theory holds for AgX.
A Convenient Synthesis of 5-Substituted-2,5-dihydro-2-furoic Acids
Authors: Masamune Tadashi , Ono Mitsunori , Matsue Hajime
Published: July 2006

Nine 5-alkyl- and 5-aryl-2-furoic acids were reduced under controlled Birch conditions and then esterified with acidic methanol. 2-Furoic acids with 5-alkyl groups gave good yields of methyl 5-alkyl-2,5-dihydro-2-furoates, which were obtained as mixtures of cis- and trans-diastereoisomers. These 2,5-dihydrofuroates revealed interesting spectroscopic properties; (1) large long-range coupling constants, 5–7 and 3–4 Hz, between protons at C2 and C5 were observed in the NMR spectra of cis- and trans-diastereoisomers, respectively, and (2) two high absorption maxima due to the ester carbonyl group of each furoate appeared near 1750 and 1730 cm−1 in the IR spectrum. On the other hand, the furoic acids with 5-aryl substituents afforded 5-arylpentanoate or 5-arylpent-3-enoate as main products. These esters would be produced as a result of reductive cleavage at C5 of 5-aryl-2,5-dihydrofuroates formed as intermediates.
Metalation of 2-Methyl-4H-pyran-4-one and its Reactions
Authors: Yamamoto Makoto , Sugiyama Noboru
Published: July 2006

2-Methyl-4H-pyran-4-ones formed metalated products in the presence of sodium amide in liquid ammonia, and the metalated product reacted with alkyl and aralkyl halides or carbonyl compounds to give alkylated or condensed products. Self condensation reactions of 2-methyl-4H-pyran-4-ones also occurred in liquid ammonia to give flavone and the γ-pyrone dimer.
Synthesis of Dihydrostreptobiosamine
Authors: Umezawa Sumio , Sano Hiroshi , Tsughiya Tsutomu
Published: July 2006

The isopropylidene derivative (4) of benzyl dihydrostreptoside and 3,4,6-tri-O-acetyl-2-amino-N-anisylidene-2-deoxy-α-l-glucopyranosyl bromide (7) were prepared, and they were coupled by a modified Koenigs-Knorr condensation. After hydrolysis of the N-ankylidene group of the product, N-methoxycarbonylation followed by N-methylation was accomplished to afford the fully protected derivative (9) of dihydrostreptobiosamine, which was, after deblocking, led to benzyl dihydrostreptobiosaminide and dihydrostreptobiosamine.
Total Synthesis of Dihydrostreptomycin
Authors: Umezawa Sumio , Yamasaki Tetsuro , Kubota Yutaka , Tsuchiya Tsutomu
Published: July 2006

Dihydrostreptomycin has been synthesized from dihydrostreptobiosamine and streptidine. A glycosyl chloride derivative (10) of the former was coupled with a protected derivative (26) of the latter to give a mixture of four isomeric glycosides, which were separated by chromatography. Deblocking of the desired glycoside led to dihydrostreptomycin. Several other protected derivatives of dihydrostreptobiosamine have also been described.
Synthesis of (3S, 4S)- and (3S, 4R)-4-Amino-3-hydroxy-6-methylheptanoic Acid, and Their N-(Acetyl-l-valyl-l-valyl) Derivatives
Authors: Kinoshita Mitsuhiro , Hagiwara Akito , Aburaki Shinpei
Published: July 2006

Natural (−)(3S,4S)-4-amino-3-hydroxy-6-inethylheptanoic acid (10a) present in pepstatins, specific inhibitors of acid proteases, and its (+) (3S,4R) diastereomer (10b) were synthesized starting from 3-deoxy-1,2-O-isopropylidene-α-d-erythro-pentodialdo-1,4-furanose (1) through highly stereoselective and stereospecific routes. The partial pep tide of pepstatin Ac, N-(acetyl-l-valyl-l-valyl)-(3S,4S)-4-amino-3-hydroxy-6-methylheptanoic acid (15a) and its (3S,4R) diastereomer (15b) were synthesized via azide-coupling of the t-butyl esters of 10a and 10b with acetyl-l-valyl-l-valine azide, respectively. Compound 15a inhibited proteolysis by pepsin, however, the diastereomer 15b showed no inhibition against pepsin.
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

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.