bluuebunny/crossref_metadata_2025 huggingface dataset:
Enzyme Sensors Based on Coated-Wire Electrode. Use of Carboxyl-Substituted Poly(vinyl chloride) as a Support for Immobilizing Penicillinase
Authors: Anzai Jun-ichi , Shimada Masahiko , Osa Tetsuo , Chen Chien-wu
Published: July 2006

A poly(vinyl chloride) derivative which contained 1.8% carboxyl residue was used to prepare a potentiometric sensor sensitive to penicillin G. A pH-sensitive base electrode was fabricated by covering an Ag wire electrode with the membrane composed of the carboxyl-substituted poly(vinyl chloride), o-nitrophenyl octyl ether, and tridodecylamine. The sensitive layer of the pH-sensitive electrode was modified with penicillinase to make a penicillin-sensitive electrode. Penicillinase was adsorbed to the surface of the polymer membrane by immersing the sensitive layer of the electrode in the penicillinase solution. Treatment of the pH-sensitive electrode with ca. 0.3% penicillinase solution at pH 6.7 (1 mM phosphate buffer) resulted in favorable performance of the penicillin sensor. The long-term stability of the penicillin sensor thus prepared was satisfactorily good.
A New Method for the Determination of Optical Purity of Norleucine Based on Enthalpy of Transition in Solid–Solid Phase Transition
Authors: Matsumoto Masayuki , Yajima Hirofumi , Endo Ryuichi
Published: July 2006

A new method for determining the optical purity based on enthalpy of transition in solid–solid phase transition was introduced. The enthalpy of transition of norleucine recovered by an optical resolution procedure was measured by means of DSC. The magnitude of optical purity based on enthalpy of transition was in agreement with that based on specific rotation.
The Influence of Ureas on the Phase-Transition Behavior of the Dipalmitoylphosphatidylcholine Vesicle Membrane
Authors: Inoue Tohru , Miyakawa Kenji , Shimozawa Ryosuke
Published: July 2006

The gel-to-liquid-crystalline phase transition of the dipalmitoylphosphatidylcholine vesicle membrane was observed in the presence of urea, ethylurea, and butylurea by monitoring the scattered light intensity of the vesicle suspension. Urea showed no significant effect on either the transition temperature, Tm, or the transition width, W, whereas ethylurea and butylurea depressed Tm without affecting W.
Prediction of Mutual Solubility Curve for t-Butyl Alcohol–Water System Utilizing Salting Out Phenomenon
Authors: Qing-zhi Zhang , Jian-ji Wang , Yan Lu , Jin-suo Lu , Kato Tadashi
Published: July 2006

The consolute temperatures (Ts) for ternary solutions of water-tetrahydrofuran-salt and water–t-butyl alcohol (TBA)–salt (salt: ammonium chloride or potassium chloride) were measured. From a plot of Ts against the salt concentration, the mutual solubility curve for the water–TBA system was predicted. The critical solution temperature and the critical composition were estimated to be about 200 °C and 0.15–0.2 (mole fraction of TBA), respectively.
Re-extraction Behavior of Nitrosyl Ruthenium Complex in Tributyl Phosphate–Dodecane Solvent System
Authors: Sasahira Akira , Izumida Tatsuo , Kawamura Fumio
Published: July 2006

A re-extraction of the nitrosyl ruthenium complex from a tributyl phosphate-dodecane solvent system to a nitric acid solution was carried out. A longer aging of the organic phase before re-extraction lowered the re-extraction yield, while nitric acid extracted into the organic phase increased it. These results could be explained using a model with two organic species.
Effects of NH3 on 13C-Selective Infrared Multiple Photon Decomposition of CF2HCl by a CO2 Laser
Authors: Sugita Kyoko , Arai Shigeyoshi
Published: July 2006

The effects of NH3 on product yields and 13C enrichment factors have been examined for the IRMPD of CF2HCl using a CO2 TEA laser. The IRMPD of neat CF2HCl yields only C2F4 and HCl as final products. The addition of NH3 resulted in the formation of CF3H and NH4Cl in addition to C2F4, and enhanced significantly the decomposition of CF2HCl. The enrichment factors of 13C in C2F4 and CF3H decreased with increasing NH3, but the decreases were relatively small. The mechanism of the IRMPD in the presence of NH3 is discussed on the basis of the observed results.
Spectroscopic Investigations on 9-(4-Dimethylaminophenyl)-10-cyanoanthracene
Authors: Baumann Wolfram , Schwager Beate , Detzer Norbert , Okada Tadashi , Mataga Noboru
Published: July 2006

Excited state dipole moments of 9-(4-dimethylaminophenyl)-10-cyanoanthracene determined from the electric field effect on solutions in several solvents as well as fluorescence spectra, ground state absorption and Sn–S1 transient absorption spectra show that this molecule most probably fluoresces from two excited states in nonpolar and medium polar solvents, whereas only one highly polar excited state emits in polar solvents.
A High-Resolution Solid-State 13C NMR Study of the Secondary Structure of Linear (1→3)-β-d-Glucans: A Conformational Elucidation of Noncrystalline and Crystalline Forms by Means of Conformation-Dependent 13C Chemical Shifts
Authors: Saitô Hazime , Tabeta Ryoko , Yokoi Motoko , Erata Tomoki
Published: July 2006

The high-resolution solid-state 13C NMR spectra of annealed curdlan, a (1→3)-β-d-glucan, were recorded in order to obtain reference data on the 13C chemical shifts of the triple helix form, which would be useful for the conformational elucidation of two distinct noncrystalline forms, curdlan- and laminaran-types. It was found that the C-3 peak of crystalline annealed glucan is substantially displaced from that of noncrystalline starting powder, reflecting the conformational change. The laminaran-type conformation, which is found in either laminaran or a number of fungal branched glucans, was identical with the triple helix, judging from the similarity in the 13C NMR spectra, although the linewidths of the former are much larger than those of the latter. The curdlan-type form, on the other hand, was ascribed to the single helix form on the basis of the previous data on high-resolution 13C NMR. In addition, the 13C NMR spectra of crystalline paramylon showed a number of additional signals other than the peaks of triple-helical annealed curdlan, in spite of the similarity in the X-ray diffraction patterns.
Syntheses of Steroidal trans-Iodo Acetates
Authors: Horiuchi C Akira , Satoh J Yasuo
Published: July 2006

The reaction of the following steroidal olefins with iodine–copper(II) acetate in acetic acid afforded the corresponding steroidal trans-iodo acetates: 5α-cholest-1-, -2-, and -3-ene; and 5β-cholest-1-, -2-, and -3-ene.
Structural Retention of Decatungstates upon Photoreduction
Authors: Sasaki Yoh , Yamase Toshihiro , Ohashi Yuji , Sasada Yoshio
Published: July 2006

The crystal structures of oxidized and photoreduced decatungstates are compared. Three specimens of decatungstate complexes were prepared in mixed solvents of H2O–CH3CN and were characterized by X-ray diffraction. Unit cell parameters are as follows: (C6H16N)4[W10O32]·2CH3CN; DECA Mr=2841.4, monoclinic, P21⁄n, a=14.617(2), b=17.783(3), c=11.755(2) Å, β=100.27(2)°, V=3006.5(9) Å3, Z=2; (C6H16N)4[H1.5W10O32]·8H2O; RED1 Mr=2905.4, monoclinic, P21⁄n, a=15.902(3), b=12.233(2), c=15.673(4) Å, β=93.76(2)°, V=3042(1), Å3  Z=2; Na4[H1.8W10O32]·14H2O; RED2 Mr=2696.7, monoclinic, C2⁄m, a=16.123(5), b=12.636(3), c=12.168(4) Å, β=117.40(2)°, V=2202(1) Å3, Z=2; There is no obvious change in the anion frame among the three decatungstate complexes. Photoreduced decatungstates may coordinate protons which neutralize excess charge injected into anions. It is concluded that the structure of W10O32 is not largely altered up to two-electron reduction.
Photoreactions of N-Methyl-1,2-naphthalenedicarboximide with Dienes. Formation of Naphthazepinediones and Their Secondary Reactions
Authors: Kubo Yasuo , Toda Rie , Araki Takeo
Published: July 2006

In the photolysis of a benzene solution of N-methyl-1,2-naphthalenedicarboximide (5) in the presence of dienes, i.e., 2,3-dimethyl-1,3-butadiene and 1,3-butadiene, insertion of one of the double bond in the dienes into a C(=O)–N bond of 5 was observed to give naphthazepinediones. These products were found to convert further into cyclobutanes and α,β-unsaturated ketones via photochemical intramolecular cycloaddition and via hydrogen migration, respectively.
Stereospecific and Nucleophilic Additions of 2- and 3-Thienylmethylene. Reactions of 2- and 3-Thienylmethylene with cis- and trans-Stilbene, Dimethyl Maleate, Dimethyl Fumarate, and Styrene Derivatives
Authors: Saito Katsuhiro , Ishihara Hiraku , Murase Toyonobu , Horie Yoichi , Maekawa Etsuro
Published: July 2006

The addition reactions of 2-thienylmethylene with cis- and trans-stilbene afforded stereospecific adducts, respectively, indicating that the multiplicity of the carbene is singlet. The nucleophilicity of the carbenes was elucidated by an investigation of the relative rate ratio of the reactions of the carbene with various styrenes. An analogous result was afforded by reactions of 3-thienylmethylene with the same olefins mentioned above.
Quantitative Analysis of Partition Behavior of Substituted Phenols from Aqueous Phase into Liposomes Made of Lecithin and Various Lipids
Authors: Miyoshi Hideto , Maeda Hiroaki , Tokutake Nobuya , Fujita Toshio
Published: July 2006

The partition coefficient of a series of substituted phenols in lecithin-liposome–water systems, P(L/W), was quantitatively analyzed by use of physicochemical molecular and substituent parameters. The effects on the P(L/W) value of the incorporation of cholesterol and charged lipids such as cardiolipin or stearylamine into the liposomal membranes were examined with the perturbation of the bilayered membrane structure induced by these lipids being taken into account. The partition behavior of phenols was primarily decided by the hydrophobicity, represented in terms of the 1-octanol–water partition coefficient, P(O/W). The partitioned phenols seemed to be in membrane close to the interface. The steric and electronic effects of substituents on the partitioning into liposomes varied significantly depending upon the type of lipids incorporated. The variations in these effects reflect differences in the structure of the interfacial region of the lecithin bilayer modified by the incorporation of various lipids.
Kinetics of Oxidation of Pyridoxine by Chloramine-T in Acid Medium
Authors: Jayaram Beby , Made Gowda Netkal M
Published: July 2006

The kinetics of oxidation of pyridoxine (PRX) by chloramine-T (CAT) in the presence of hydrochloric acid (0.04–0.14 M) have been studied over the temperature range of 303–323 K. The rate of the reaction shows first-order dependence on each of CAT, PRX, and chloride ion concentrations. The reaction rate is independent of hydrogen ion concentration. Variations of ionic strength and dielectric constant of the medium have negligible effect on the rate. Addition of the reaction product, p-toluenesulfonamide, decreases the rate showing a negative first order dependence. The solvent isotope effect has been studied by using heavy water. The activation parameters, Ea, ΔH\ewq, and ΔS\ewq are computed from the reaction rates at various temperatures. The mechanism of PRX oxidation proposed and the rate law derived are consistent with the observed kinetics.
Excited-State and Ground-State Proton-Transfer Reactions in 5-Aminoindole
Authors: Sinha Hemant Kumar , Dogra Sneh Kumar , Krishnamurthy Mannam
Published: July 2006

Dual fluorescence emissions are observed when the electron-donating group (–NH2) is present at the position 5 of indole moiety. From the study of solvent effect and the large blue shift observed in the fluorescence spectra at 77 K, it is concluded that the long wavelength fluorescence band (480 nm) is assigned to the more polar state and the short wavelength band (350 nm) to the less polar state of 5-aminoindole (AI). Monocation is formed by protonating the amino group and no proton-induced fluorescence quenching of the neutral species is observed prior to its being protonated. This is mainly due to the shorter life of the conjugated acid–base pair. CNDO/S calculations indicate that dication is formed by protonating the C-3 position of the monocation of AI in the S0 state but position 4 of monocation of AI in the S1 state. Monoanion is formed by the deprotonation of >NH group in the S0 state, but from the deprotonation of –NH2 group in the S1 state.
Reaction between Copper(II) Chloride and Active Carbon for the Formation of Solid Carbon Monoxide Adsorbent
Authors: Komiyama Makoto , Ando Hiroaki , Hirai Hidefumi
Published: July 2006

Evolution of hydrochloric acid on the preparation of carbon monoxide adsorbents from copper(II) chloride and active carbon has been experimentally confirmed. Relationship between the amount of hydrochloric acid evolved and the adsorbing capacity shows that the efficient adsorption by the adsorbents is attributable to the function of the copper(I) chloride, which is formed during the preparation by the reaction between copper(II) chloride and active carbon.
Ortho Substituent Effect of the Side-Chain Phenyl Group on the Dehydrogenation of Flavanones with 2,3-Dichloro-5,6-dicyano-p-benzoquinone
Authors: Hoshino Yukio , Takeno Noboru
Published: July 2006

Rates of the dehydrogenation of 2′-substituted flavanones with 2,3-dichloro-5,6-dicyano-p-benzoquinone were measured by means of HPLC analyses. All substituents at the ortho position of the side-chain phenyl group of flavanones showed a retarding effect on the reaction. A correlation analysis for the ortho effect using the linear combination model has led to a conclusion that the inductive effect is much more important than the steric and the resonance effect, and that the steric effect is slightly greater than the resonance effect.
The Effect of the Carbonyl Group, Phenyl Ring, and Ring Size of α-Iodo Cycloketones on the Nature of the Photochemical Carbon–Iodine Bond Cleavage
Authors: Šket Boris , Zupan Marko
Published: July 2006

UV irradiation of 2-iodo-3,4-dihydro-1(2H)-naphthalenone and 2-iodo-1-indanone has been found to involve competing radical and ionic photoprocesses. The carbonyl group, phenyl ring and ring size of cycloketones have an influence on the nature of the photochemical carbon–iodine bond cleavage.
Conductance of Potassium Iodide in Supercooled Water
Authors: Nakahara Masaru , Zenke Masanobu
Published: July 2006

The conductance of potassium iodide was measured in water as a function of concentration (between 2×10−3 and 10−2 mol dm−3) and temperature (between −6 and 0 °C). The effect of temperature on the mobility of such halide ions as I− and Cl− ions was discussed by taking the ionic residual friction coefficient Δζ, which was defined as the overall friction coefficient subtracted by the Stokes one for slip, instead of the conventional Walden product. We compared the experimental results with the predictions due to the Hubbard–Onsager dielectric friction theory. Of the monovalent ions so far studied, the iodide ion shows the largest negative value of Δζ with the largest positive temperature coefficient; their signs are opposite to those theoretically predicted. These findings were explained in terms of the special ionic transport mechanism called the passing-through-cavities.
Calorimetric and Spectrophotometric Studies of Chloro Complexes of Nickel(II) and Zinc(II) Ions in N,N-Dimethylformamide
Authors: Ishiguro Shin-ichi , Ozutsumi Kazuhiko , Ohtaki Hitoshi
Published: July 2006

Complexation of Ni(II) and Zn(II) with Cl− ions has been studied by calorimetry and spectrophotometry in N,N-dimethylformamide (DMF) containing 0.4 mol dm−3 (C2H5)4NClO4 as a constant ionic medium at 25 °C. Calorimetric titration curves obtained in each system were well-explained in terms of formation of [MCln](2−n)+ (n=1–4 and M2+=Ni2+ or Zn2+), and their formation constants, enthalpies and entropies were determined. Formation of the nickel(II) chloro complexes in DMF was also supported by spectrophotometry. In the nickel(II) chloride system, the stepwise enthalpy ΔH3° and entropy ΔS3° values are remarkably large and positive as compared with the ΔHn° and ΔSn° (n=1, 2, and 4) values. Individual electronic spectra of nickel(II) ion, [NiCl]+ and [NiCl2] are significantly different in both intensities and peak positions from those of [NiCl3]− and [NiCl4]2− over the range 300–850 nm. These thermodynamic and spectrophotometric results were explained in terms of formation of the octahedral [NiCl]+ complex as well as [Ni(dmf)6]2+ and of formation of the tetrahedral [NiCl3]− and [NiCl4]2− complexes in DMF. On the other hand, in the zinc(II) chloride system, the ΔSn° (n=1 and 2) values are large and positive, but the ΔSn° (n=3 and 4) values are significantly small. The corresponding ΔHn° (n=1 and 2) values are positive but the ΔHn° (n=3 and 4) values are significantly negative. It is thus postulated that the [ZnCln](2−n)+ (n=2 and 3) complexes have the tetrahedral coordination structure as well as the [ZnCl4]2− complex in DMF.
The Optical Resolution and Asymmetric Transformation of Dl-p-Hydroxyphenylglycine with (+)-1-Phenylethanesulfonic Acid
Authors: Yoshioka Ryuzo , Tohyama Masanori , Ohtsuki Osamu , Yamada Shigeki , Chibata Ichiro
Published: July 2006

Optically active 1-phenylethanesulfonic acid was found to be an efficient resolving agent for the optical resolution and asymmetric transformation of Dl-p-hydroxyphenylglycine. When Dl-p-hydroxyphenylglycine was resolved by the fractional crystallization of its diastereomeric salt with (+)-1-phenylethanesulfonic acid, less soluble d-p-hydroxyphenylglycine (+)-1-phenylethanesulfonate [d-HPG·(+)-PES] was obtained in a good yield. Soluble l-HPG·(+)-PES was easily epimerized into Dl-HPG·(+)-PES by heating it at 100 °C in glacial acetic acid in the presence of a small amount of salicylaldehyde. Under such epimerizing conditions, the asymmetric transformation of Dl-HPG·(+)-PES was attempted by simultaneously combining the fractional crystallization of the less soluble d-HPG·(+)-PES and the epimerization of the soluble l-HPG·(+)-PES. This asymmetric transformation was achieved successfully; that is, 80% of the Dl-HPG used as the starting material was converted into d-HPG.
Improvement of Porphyrin Photovoltaic Cells in Panchromaticities and Quantum Yields by Use of Tetrabenzoporphyrin Skeleton
Authors: Yamashita Kazuo , Harima Yutaka , Kubota Hideyuki , Suzuki Hitomi
Published: July 2006

Expansion of the porphyrin π electron system by using a tetrabenzoporphyrin (TBP) skeleton leads to better spectral match to the solar spectrum and high quantum yields when the porphyrins are used as sensitizers. Metallotetrabenzoporphyrins such as MgTBP and ZnTBP rank among the most efficient organic photoconducting materials studied so far.
Effect of Aryl Substituents on 2-Aryl-1,4,5,6,7,7-hexachloronorbornadiene–Quadricyclane Reversible Isomerization
Authors: Tomioka Hideo , Hamano Yukinobu , Izawa Yasuji
Published: July 2006

2-Arylhexachloronorbornadiene undergoes photoisomerization to the corresponding quadricyclane, which returns back to the norbornadiene upon heating without catalyst. Effect of aryl substituents on the thermal reversion suggests that both spin delocalization and polar effect equally contribute to the stabilization of the transition state.
Synthesis of Three Acyclic All-trans-Tetraterpene Diols, Putative Precursors of Bacterial Lipids
Authors: Chappe Bertrand , Musikas Hélène , Marie Dominique , Ourisson Guy
Published: July 2006

Three acyclic all-trans-tetraterpene diols, A, B, and C have been synthesized from geraniol (1), by a convergent scheme involving six different C10 synthons derived from geraniol, and coupling by known reactions of three different types: substitution of allylic chlorides by carbanions α to sulfones, duplication of allylic alcohols, and Pd(0)-catalyzed coupling of allylic carbonates with doubly stabilized carbanions. A, B, and C represent postulated phylogenetic precursors of known membrane reinforcers, and are the three possible distally dihydroxylated dimers of geranylgeraniol: tail-to-tail, head-to-head, and head-to-tail.
An ESR Study of 5-Formazanyl Copper(II) Complexes as an Analogy to Three Types of Copper-Containing Proteins
Authors: Kawamura Yoshiko , Deguchi Yasuo , Yamauchi Jun , Ohya-Nishiguchi Hiroaki
Published: July 2006

The Electron Spin Resonance(ESR) spectra of ten 5-formazanyl copper(II) complexes in toluene solutions have been observed at room temperature and at that of liquidnitrogen. The ESR(g⁄⁄ and A⁄⁄) and bonding(α2) parameters of the copper ion were greatly affected by substituting several groups at the ortho position of 1-phenyl ring of formazan. Based on these results, the complexes are classified into three groups: Group I, in which A⁄⁄\simeq0.012–0.013 cm−1 and α2\simeq0.5; Group II, in which A⁄⁄\simeq0.017 cm−1 and α2\simeq0.7, and Group III, in which two copper ions are interacting. It is clarified that they correspond nicely to three types of copper-containing proteins previously investigated.
The Effect of “Chemiluminescence Quenching” on the Chemiluminescence Quantum Yields from 9-Benzylacridine and 9-Benzyl-10-methylacridinium Iodide
Authors: Kamiya Isao , Sugimoto Takashi , Yamabe Kuniaki
Published: July 2006

A visible chemiluminescence (CL) has been found from the air oxidation of 9-benzyl-10-methylacridinium iodide, in contrast to the case of 9-benzylacridine, from which only a feeble CL could be detected. The difference in the CL quantum yields from the acridinium salt and acridine is interpreted in terms of a “CL quenching” of the chemiexcited species by benzaldehyde generated simultaneously in a solvent cage.
The 1H and 13C NMR of the Tetraphenylcyclopentadienone Dianion
Authors: Hirayama Masatoshi , Koiwai Kazuhiko , Takemura Kazumi , Kobayashi Masaaki , Seki Akihiko , Takahashi Kensuke
Published: July 2006

The stable monomer dianion of the title compound was formed by the contact of its tetrahydrofuran-d8 or 1,2-dimethoxyethane-d10 solution with sodium metal at 5 °C and was characterized by means of its 1H and 13C NMR spectra.
Studies of the Stabilities of Scandium, Yttrium, and Lanthanoid-Ion Complexes of 2-Nitroso-5-(N-propyl-3-sulfopropylamino)phenol
Authors: Yoshida Isao , Sagara Fumio , Ueno Keihei
Published: July 2006

The stability constants of the 1:1 complexes formed by 2-nitroso-5-(N-propyl-3-sulfopropylamino)phenol (NPSAP:H2L) with tervalent scandium, yttrium, and lanthanoids, but not promethium, have been determined potentiometrically in aqueous solutions at an ionic strength of 0.1 with potassium nitrate and at 25 °C. The stability constants of the 1:1 complexs increased with the increase in the atomic number of the lanthanoid, with the slight decrease at gadolinium. The stability constant of the 1:1 complex of scandium was the highest among the metal complexes investigated, while that of the yttrium complex was found to be between those of the cerium and praseodymium complexes.
The Thermal Decomposition of 1-Methyl-1-phenylethyl 2,2-Dimethylperoxypropionate in Cumene
Authors: Komai Takeshi , Kato Kenji , Matsuyama Kazuo
Published: July 2006

The thermal decomposition of 1-methyl-1-phenylethyl 2,2-dimethylperoxypropionate was studied in cumene. Based on the kinetic parameters and the decomposition products, it was concluded that the peroxyester was decomposed mainly by means of the radical process in cumene.
The Lowest Triplet States of 2-Amino- and 2-Amino-d2-pyrimidines
Authors: Nibu Yoshinori , Maehara Masayoshi , Shimada Hiroko , Shimada Ryoichi
Published: July 2006

The vibrational analyses of the sublevel phosphorescence spectra of 2-amino- and 2-amino-d2-pyrimidines were made. The result shows that the lowest triplet 3A1(π, π*) state is strongly perturbed by closely lying 3B1(n, π*) and 3A2(n, π*) states and the polarization of the very weak 0–0 bands in the dark sublevel spectra suggests that the symmetry of the molecular structure in the lowest triplet state is slightly lowered from the point group C2ν to the C2.
Radical Cyclization to Seleno-Substituted Thiahomoprotoadamantanone and Its Unexpected Conversion to the Vinyl Selenide
Authors: Toru Takeshi , Kanefusa Toshiya , Maekawa Eturô , Ueno Yoshio , Kondo Kazumoto , Eguchi Shoji
Published: July 2006

Heating Se-phenyl bicyclo[3.3.1]non-6-ene-3-(selenothioperoxy)carboxylate with AIBN gives 5-phenyl-seleno-3-thia-2-homoprotoadamantan-2-one which is unexpectedly converted to the vinyl selenide via the selenoxide by oxidation with hydrogen peroxide or mCPBA.
Efficient Reduction of Acyl Chlorides with Zn(BH4)2/N,N,N′,N′-Tetramethylethylenediamine
Authors: Kotsuki Hiyoshizo , Ushio Yasuyuki , Yoshimura Naka , Ochi Masamitsu
Published: July 2006

Aliphatic and aromatic acyl chlorides were efficiently reduced to give the corresponding alcohols when treated with Zn(BH4)2 in the presence of N,N,N′,N′-tetramethylethylenediamine. The reactions with other bases were also examined.
Structure of Physalin M Isolated from Physalis alkekengi var. francheti
Authors: Kawai Masao , Ogura Toichi , Nakanishi Masaki , Matsuura Taketoshi , Butsugan Yasuo , Mori Yuji , Harada Ken’ichi , Suzuki Makoto
Published: July 2006

The structure of physalin M, isolated from Physalis alkekengi var. francheti was determined as 7-deoxyphysalin L by spectroscopic studies and chemica correlation with a known compound. Physalin M exhibitec weak cytotoxicity against tumor cells.
The Determination of a Small Amount of Biological Constituent by the Use of Chemiluminescence. XIII. High Sensitive Metal Chelate Affinity Chromatography
Authors: Hara Tadashi , Tsukagoshi Kazuhiko , Yoshida Tatsunari
Published: July 2006

A chemiluminescence detector using a 1,10-phenanthroline–hydrogen peroxide–copper(II) system was successfully combined with a metal chelate affinity column. A mixture comprising bovine serum albumin, lysozyme, and bovine serum γ-globulin as model proteins was completely separated by the pH-gradient elution method on a TSK gel Chelate-5PW adsorbed with zinc ions, also, each protein could be quantitatively determined. According to the present method, using a 0.4 cm3 column of bed volume, 1) the determinable concentration range for bovine serum γ-globulin was formed to be 1.0×10−4–1.0×10−1 g dm−3 with a detection limit of 5 ng for a 50 mm3 of injection volume, 2) the recovery of 1.0×10−3 g dm−3 bovine serum γ-globulin was 85% with 7.9% of the coefficient of variation (n=5), and 3) the time necessary for an analysis was about 50 min. The present method was about 200 times more sensitive than that using an ultraviolet detector and was also applicable to a human serumn sample.
Mechanistic Study on the Photochemical Conversion of Disilanyliron(II) Complexes to Monosilyliron(II) Complexes
Authors: Tobita Hiromi , Ueno Keiji , Ogino Hiroshi
Published: July 2006

Photolysis of a C6D6 solution of CpFe(CO)2SiMe2SiMe3 (Cp=η5-C5H5) or (MeCp)Fe(CO)2SiMe2SiMe3 (MeCp=η5-C5H4Me) resulted in the formation of monosilyl derivative, CpFe(CO)2SiMe3 or (MeCp)Fe(CO)2SiMe3 in 64 or 59% yield, respectively, together with small quantities of ferrocene and Cp2Fe2(CO)4 or their methylated derivatives. The yield of CpFe(CO)2SiMe3 increased to 88% when the photolysis was carried out under a carbon monoxide atmosphere, while decreased to 22% when argon was vigorously bubbled through the reaction mixture. These results are consistent with a mechanism involving dissociation and recombination of a carbonyl ligand which are common processes in photoreactions of transition-metal carbonyl derivatives. Dimethylsilylene moiety released during the photolysis was tried to be trapped with a hydrosilane, diene, and cyclotrisiloxane, but none of the expected products from the trapping reactions was detected, even in a trace amount. Photolysis of CpFe(CO)2SiMe2SiMeEt2 afforded, accompanying alkyl migration between silicon atoms, CpFe(CO)2SiMeEt2, CpFe(CO)2SiMe2Et, and CpFe(CO)2SiMe3 in 26, 33, and 4% yields, respectively. Photolysis of a 1 : 1 mixture of CpFe(CO)2SiMe2SiMeEt2 and (MeCp)Fe(CO)2SiMe2SiMe3 provided only products expected from intramolecular alkyl migration mechanism. A possible mechanism involving silyl(silylene)iron intermediates is proposed to explain these results.
The Synthesis, and the Crystal and Molecular Structures of Tetraethylammonium [Aquaheptakis(thiocyanato)lanthanoidate(III)], [(C2H5)4N]4[M(SCN)7(H2O)], (M=La, Ce, Pr; Nd, Dy, Er): The Complexes in a Cubic Octa-Coordination Geometry
Authors: Tateyama Yoshikuni , Kuniyasu Yasumitsu , Suzuki Yasuo , Ouchi Akira
Published: July 2006

The title complexes have been synthesized, and their crystal and molecular structures were determined by the X-ray diffraction method using their single crystals. Among them, the crystals of the La, Ce, and Pr complexes are isomorphous; cubic, space group Pm\bar3, Z=1, and the cell constants of the Pr complex, for example, are a=11.513(2) Å, U=1526.1(5) Å3, and the final R value was 0.093. The Nd, Dy, and Er complexes, another group of the isomorphous complexes obtained almost by the same synthetic method, are tetragonal, space group I4/m, Z=2, and the cell constants of the Er complex, for example, are a=1.564(2), c=22.627(4) Å, U=3026(3) Å3, and the final R value was 0.071. The coordination geometry around the metal atoms of both types of complexes are almost the same: seven thiocyanato nitrogen and one water oxygen atoms are coordinated in a cubic geometry, being disordered as if each ligating atomic position is equally occupied by 1/8 atom of the water oxygen and 7/8 atoms of the thiocyanato nitrogen. In the lattice of the former three complexes, the tetraethylammonium nitrogen atoms occupy all Cl− ionic positions of the NaCl-type lattice, while the metal atoms only the apex Na+ ionic positions; not the face-center ones. The unit cells of the latter three complexes are apparently consist of the two former cubic type cells being piled on the c-axis direction, where the arrangement of the atoms is different from the former only on the plane where two original cells are contact: metal and ammonium nitrogen positions slide 0.5 both to a- and b-axis directions. Thus each metal atom of the both type complexes is surrounded by six tetraethylammonium nitrogen atoms on both sides of the a, b, and c-axis directions.
Chemical Reaction Dynamics–The Study of Molecular Reactivity and Disequilibrium
Authors: Levine Rephael David
Published: July 2006

Recent progress in molecular reaction dynamics is discussed with special reference to the selectivity in the reactivity and the specificity in product formation. Topics considered in some detail include dynamical aspects of stereochemistry, rotational state distributions in reactive collisions and intramolecular dynamics of larger molecules. The conceptual foundations of the thermodynamic-like approach to molecular disequilibrium are considered.
Synthesis of Homoiceane (Tetracyclo[6.3.1.12,7.04,10]tridecane) and 3,13-Dehydrohomoiceane (Pentacyclo[7.3.1.02,4.03,8.05,11]tridecane) through Homo-Diels–Alder Reaction
Authors: Yamaguchi Ryohei , Ban Masakazu , Kawanisi Mituyosi
Published: July 2006

Homo-Diels–Alder reaction of tricyclo[5.3.1.04,9]undeca-2,5-diene with maleic anhydride proceeds very nicely in refluxed o-dichlorobenzene to give a single cycloadduct in 81% yield. The stereochemistry of the adduct is determined to be exo by leading to the exo-dimethyl ester and comparing it with the endo-dimethyl ester which is prepared by homo-Diels–Alder reaction of the above diene with dimethyl acetylenedicarboxylate followed by catalytic hydrogenation. Basic hydrolysis of the cycloadduct followed by oxidative decarboxylation with Pb(OAc)4 in pyridine affords 3,13-dehydrohomoice-5-ene, catalytic hydrogenation of which gives 3,13-dehydrohomoiceane. Photoinduced intramolecular [π2+σ2] cycloaddition of 3,13-dehydrohomoice-5-ene produces the compound which contains two cyclopropane rings in its rigid structure. When this strained cage compound is treated with Pd-black under H2, hydrogenolysis of the two cyclopropane rings takes place simultaneously to afford homoiceane.
The Effect of the Wettability of the Injection Nozzle on the Size of Oil Droplets in Water
Authors: Ogino Keizo , Ohki Hiroshi , Abe Masahiko , Hirano Jiro , Funada Tadashi
Published: July 2006

The effect of the wettability of an injection nozzle on the size of oil droplets in water has been studied. Dodecane as an oil was dispersed into a continuous water phase through various polymers attached to the top of each single nozzle. The polymer filters used were polyethylene (PE), poly(vinyl chloride) (PVC), poly(vinyl alcohol) (PVA), cellophane (CP), and cotton (CT). The hydrophilic cotton filter is found to be more effective as the injection nozzle than any other hydrophobic polymer filter tested to disperse smaller oil droplets of dodecane into the continuous water phase. The droplet size is reduced with an increase in the hydrogen-bonding force of the polymer-filter surfaces. This may be attributed to the strong adhesion tension between the water molecules and hydrophilic groups of the polymer surface.
Proton NMR Spectra of Methyl Alkanoates in Aromatic Solvents
Authors: Hoshino Takashi , Imamura Yoshio
Published: July 2006

The splitting of methylene peaks in 1H NMR spectra was studied for long-chain methyl alkanoates in 1-chloronaphthalene as a function of the carbon number, nc, of alkyls. With increase in nc, the singlet peak of methylene is first split into a doublet and then into a triplet.
Potentiometric Study of Cadmium(II) Halide and Thiocyanate Complexes in Methanol. Determination of Thermodynamic Stability Constants of Third and Fourth Complexation Step
Authors: Soe Khin Nwe , Doe Hidekazu , Kitagawa Toyokichi
Published: July 2006

The stability constants, K3 and K4 of [CdIIXn]2−n (X−=Cl−, Br−, I−, NCS−) complexs in methanol have been determined by X− ion measurements with Ag–AgX and NCS− ion selective electrodes at 25 °C.
Selective Reduction of Carbon–Carbon Double Bonds with an NAD(P)H Model–Acetic Acid System
Authors: Inoue Yoshio , Imaizumi Shin , Itoh Hiromitsu , Shinya Takao , Hashimoto Harukichi , Miyano Sotaro
Published: July 2006

The carbon–carbon double bond in conjugated nitro and certain carbonyl compounds was reduced smoothly and selectively by Hantzsch ester (HEH), an NAD(P)H model, in the presence of a small amount of acetic acid.
The 19F Solid-State High-Resolution Nuclear Magnetic Resonance Study of K2SiF6, K2GeF6, and K2SnF6
Authors: Yoshioka Yoshichika , Nakamura Nobuo , Chihara Hideaki
Published: July 2006

High-resolution 19F NMR experiments were carried out on K2SiF6, K2GeF6 and K2SnF6, and the chemical shift shielding tensors were determined. In all three substances, the shielding tensors are axially symmetric, and the most shielded direction is parallel to the MF (M=Si, Ge, and Sn) bond. The values of the shielding tensor elements (σ⁄⁄ and σ⊥) change systematically from K2SiF6 to K2SnF6, except for the σ⊥ component of K2SiF6, which is very large compared with those in the Ge and Sn-complexes. The analysis of σ’s by a simple MO treatment indicates that π-backbonding is the strongest in the Si-F bond, probably because of the extraordinarily low electronegativity of Si. At room temperature, the reorientation of MF62− anions is rapid enough to average out the shielding tensor components in the Si and Sn-complexes.
Hopping Phenomena of [1-14C]Octadecanoic Acid Molecules at the Surface of the Langmuir–Blodgett Film Regarded as an Extremely Thin Crystal
Authors: Iwahashi Makio , Itoh Kiyoharu , Ohshima Katsumi , Seimiya Tsutomu , Yoshida Akira , Kobayashi Koichi , Takaoka Kei
Published: July 2006

The desorption of [1-14C]octadecanoic acid molecules in vacuo from a Langmuir-Blodgett film, which is regarded as an extremely thin crystal, was studied by using three kinds of radioactive samples containing ten molecular layers: The first sample was labeled at the tenth (the outermost) layer; the second one, at the ninth layer and the third one, at both the ninth and tenth layers. From the initial slopes in the desorption curves for these samples it is suggested that most of the acid molecules desorb from the tenth layer and some acid molecules desorb as a dimer consisting of a pair of molecules from the ninth and tenth layers. The scanning electron micrographic observations were carried out for nonradioactive samples stored for a week at 298.2 or 278.2 K under atmospheric pressure; it was concluded that the fatty acid molecules jump back and forth between a boundary (stagnant) layer and the surface of the LB multilayer and coagulate into micron-size crystals.
The Brillouin Scattering of Highly Viscous Liquids-Triacetin and Propylene Glycol Diacetate
Authors: Hashitani Ryuki , Matsui Hirohito , Koda Shinobu , Nomura Hiroyasu
Published: July 2006

The sound velocities of triacetin and propylene glycol diacetate were measured by means of Brillouin scattering in the temperature range from 200 to 350 K. The velocity dispersions due to the structural relaxation were observed in the gigahertz region. The relaxation behaviors could not be interpreted by the empirical equation proposed by Barlow et al., which holds in megahertz region and also the relaxation curves were located in higher frequency region than those predicted by the Maxwell model. The relaxation curves were well reproduced by single relaxation equation. In the temperature ranges of relaxation region, the temperature dependences of viscosity were expressed by Arrhenius’ viscosity equation. The relaxation behaviors can be interpreted in terms of the weak cooperative motions of molecules.
Spectroscopic Studies on the Intramolecular Hydrogen Abstraction Reactions of n-Alkyl Anthraquinone-2-carboxylates
Authors: Tanimoto Yoshifumi , Uehara Megumu , Takashima Masanobu , Itoh Michiya
Published: July 2006

Chain length dependence of the intramolecular hydrogen abstraction reaction of n-alkyl anthraquinone-2-carboxylates (AQ-n, n=2–20) has been studied by steady-state photolysis, phosphorescence, laser flash photolysis, and two-step laser induced fluorescence spectroscopies. All the results indicate that the excited triplet of the anthraquinone chromophore abstracts a hydrogen atom from its methylene side chain, whose rate increases with increasing chain length. The rate constant of AQ-8 is 1×104 s−1 and the increase in the rate is about 1.5×104 s−1 per one additional methylene unit for n≥10.
Seasonal Movements of Phosphorus and Iron Compounds, Dissolved Hydrogen Sulfide, and Others in Anoxic Seawater at Lake Hamana
Authors: Ichinose Norio , Adachi Kyoko , Mitsui Mina , Shimizu Chiaki , Okamoto Ken , Kurokura Hisashi , Inui Takuo , Tamura Hisae
Published: July 2006

The sea bottom in the vicinity of the center of Lake Hamana in Japan forms a sea basin, and anoxic seawater appears in this bottom layer in summer. We examined the seasonal movements of phosphorus and iron compounds, dissolved hydrogen sulfide, and others in this anoxic seawater with a view to investigating their elution processes from the sediments of the sea basin into the anoxic seawater. Some parts of the elution phenomena of these components from the sediments of the sea basin in Lake Hamana into the anoxic seawater in summer will be described in the present work.
Molecular Structures of cis-[Co(CN)2(acac)(dppe)] and trans(C,N)-[Co(CN)2(acac)(edpp)]·H2O and Trans Influence of Phosphine and Cyanide Ligands
Authors: Kita Masakazu , Kashiwabara Kazuo , Fujita Junnosuke
Published: July 2006

Molecular structures of cis-[Co(CN)2(acac)(dppe)] (a) and trans(C,N)-[Co(CN)2(acac)(edpp)]·H2O (b) have been determined by X-ray analysis, where acac, dppe, and edpp denote an acetylacetonate ion, 1,2-bis(diphenylphosphino)ethane and (2-aminoethyl)diphenylphosphine, respectively. Crystal data for a: monoclinic, P21⁄a, a=13.975(2), b=19.709(2), c=11.575(2) Å, β=109.71(1)°, V=3001.5(6) Å3, Z=4, and R=0.049. Crystal data for b: monoclinic, P21⁄c, a=17.870(3), b=7.354(2), c=16.709(3) Å, β=105.45(2)°, V=2116.5(5) Å3, Z=4, and R=0.056. The Co–O bonds trans to the phosphine and the cyanide ligands are longer, respectively, by ca. 0.06–0.08 Å and ca. 0.03–0.05 Å than those usually found in Co(III)–acac complexes such as [Co(acac)3], indicating stronger trans influence of the former than the latter.
Skimmiarepin A and B, Two New Insect Growth Inhibitory Triterpenoids from Skimmia japonica Thunb. var. intermedia Komatsu f. repens (Nakai) Hara
Authors: Ochi Masamitsu , Tatsukawa Akira , Seki Naoki , Kotsuki Hiyoshizo , Shibata Kozo
Published: July 2006

Two new triterpenoids, skimmiarepin A and B, which both exhibit an insect growth inhibitory activity against the silkworm, Bombyx mori L., have been isolated from the leaves and the fruit of Skimmia japonica Thunb. var. intermedia Komatsu f. repens (Nakai) Hara. Their structures have been determined by extensive 2D NMR studies and chemical methods.
Retentive Solvolysis. 16. Reinvestigation of the Retentive Phenolysis of 1-Phenylethyl Chloride. The Mechanism and the Structure of Ion Pair Intermediate
Authors: Kinoshita Tomomi , Ueno Takuya , Ikai Keizo , Fujiwara Masataka , Okamoto Kunio
Published: July 2006

The effect of added aniline on the polarimetric (kp) and titrimetric rate constants (kt) has been reexamined for the phenolysis of 1-phenylethyl chloride (RCl) in phenol–benzene (1:1 w/w). The kp–kt plot against the aniline concentrations exhibited the pattern C, instead of A which was the previous results in our laboratory. It has been revealed that the previous rate constants at the lower aniline concentrations, including the case of absence of aniline, were underestimated due to overlooking the reverse reaction caused by the liberated hydrogen chloride. The pattern C indicates that the first ion pair intermediate, not the second one, is nucleophilically attacked by solvent phenol molecule. The major products were the partially retained o-RC6H4OH, the partially inverted p-RC6H4OH, together with the partially retained ROPh. The same kp–kt pattern C has been observed for the competitive solvolysis of RCl in phenol–methanol (85:15 w/w), which produced the partially retained ROMe and ROPh, the partially inverted o- and p-RC6H4OH, and styrene. Such stereochemical outcomes for both solvolyses demonstrate that the major first ion pair intermediate should be a rear-side-shielded ion pair intermediate.
Reaction of 2-Hydroxyacetophenones with Thionyl Chloride in the Presence of a Catalytic Amount of Pyridine
Authors: Ali Syed Mashhood , Ilyas Mohd , Tanimoto Shigeo
Published: July 2006

Reaction of 2-hydroxyacetophenone (5) with excess thionyl chloride in the presence of a catalytic amount of pyridine at room temperature afforded a thiirane 6, while 2-hydroxy-4-methoxyacetophenone (7) furnished 8 when subjected to almost identical conditions. The products were characterized by microanalyses data and spectroscopic techniques including the mass spectroscopy. Plausible mechanisms for the conversions have been proposed in the light of available literature.
The Retardation of Methanol Oxidation at a Platinum Electrode in an Acid Solution
Authors: Matsui Hiroshi
Published: July 2006

The rate retardation of the oxidation of methanol at the potential range of about 0.65–0.8 V vs. a reversible hydrogen electrode on a platinum electrode in 0.5 mol dm−3 H2SO4 was studied. The rate retardation of the overall oxidation was caused by that of the oxidation, Reaction D, not via COad. From the relationship among the rate of Reaction D, the COad coverage, and the potentials, three types of rate retardation were found out: Type 1– Reaction D is not accelerated by the potential, and the rate of the reaction is determined by the COad coverage and the methanol concentration. Type 2– the rate of Reaction D decreases at stationary COad coverages as the oxidation is prolonged. Type 3– the rate decreases at COad coverages close to the limiting value. It is proposed that Types 1 and 2 of the rate retardations take place when the adsorption of methanol molecules is rate-determining, and when the formaldehyde and formic acid formed from methanol are accumulated in the vicinity of the electrode, respectively. Type 3 of the rate retardation has been explained in a preceding paper in terms of the aggregate damaging effect of COad.
The Addition Effect of CH3Br and CH3Cl on Ignition of CH4 by Shock Wave
Authors: Takahashi Kazuo , Inomata Tadaaki , Moriwaki Takao , Okazaki Satiko
Published: July 2006

Ignition delay times were measured in the CH4–CH3X (X: Cl or Br)–O2 system diluted in Ar using a shock tube. The times were shorter than those without CH3X, indicating that CH3X accelerates the ignition of CH4. A theoretical model including 8 elementary reactions concerning CH3X, with a CH4 oxidation mechanism consisting of 93 reactions, was used to examine the role of halogen for the ignition. The compounds containing Br formed a chain reaction with CH4 and accelerated the decomposition of CH4, while CH3Cl acted only as a fuel which was easily decomposed.
The Magnetic Properties of the Copper(II) Alkanoate Adducts with Benzimidazole and Related Nitrogen Donors
Authors: Emori Shuji , Kurihara Hikari , Muto Yoneichiro
Published: July 2006

Various copper(II) alkanoate adducts with benzimidazole, N-acetylbenzimidazole, and benzoxazole have been prepared. The influence of the hydrogen bonded structure in the benzimidazole adducts on their magnetic properties are discussed.
The Cathodic Desulfonylation of 1-Ethoxycarbonyl- and 1-Cyano-1-(p-tolylsulfonyl)-2-phenylethenes at the Mercury Electrode in Nonaqueous Solvents
Authors: Kunugi Akira , Abe Kyo
Published: July 2006

The cathodic reduction of 1-ethoxycarbonyl-1-(p-tolylsulfonyl)-2-phenylethene in MeCN and DMF is characterized by the selective elimination of the p-tolylsulfonyl group, resulting in the formation of ethyl (E)-cinnamate in good yields, in the presence of such efficient proton donors as benzoic acid and acetic acid. On the other hand, the cathodic desulfonylation of 1-cyano-1-(p-tolylsulfonyl)-2-phenylethene proceeds with low efficiencies, even in the presence of acetic acid and benzoic acid.
Photochemical Generation of μ-Amido-μ-peroxo-bis[bis(ethylenediamine)cobalt(III)] Complex from the Corresponding μ-Hyperoxo Complex in Neutral Aqueous Solution
Authors: Shinohara Nobuyoshi , Kose Emiko , Ohkubo Wataru
Published: July 2006

A μ-amido-μ-hyperoxo complex, [(en)2Co(NH2,O2−)Co(en)2]4+, was found to generate the corresponding μ-peroxo complex, together with mononuclear cobalt(III) complexes upon irradiation with near-ultraviolet light in a neutral aqueous solution. The result is different from that obtained in an acidic aqueous solution, in which the products are [Co(NH3)(en)2(H2O)]3+ and Coaq2+. The photochemical reaction mechanisms are discussed.
The Structure and Absolute Stereochemistry of a Halogenated Chamigrene Derivative from the Red Alga Laurencia Species
Authors: Suzuki Minoru , Kurosawa Etsuro , Furusaki Akio
Published: July 2006

The structure of a halochamigrene derivative, 2,10-dibromo-3-chlorochamigran-7-en-9-ol, isolated from the red alga Laurencia species has been determined by spectral and chemical methods as well as X-ray crystallographic analysis of the ketone derivative. Furthermore, the conformations of this compound and its derivatives are briefly discussed.
XRD Characteristics of Na–ZSM-5 Synthesized from an Organic-Free System
Authors: Dai Feng-Yuen , Suzuki Minoru , Takahashi Hiroshi , Saito Yasukazu
Published: July 2006

XRD profiles of as-synthesized Na– and TPA–ZSM-5 were not identical. They became similar to each other, however, when both zeolites were converted into organic-free or organic-contained forms. In terms of the framework topology, Na–ZSM-5 resembled TPA–ZSM-5 but differed from so-called ZSM-8. SEM images revealed the Na–ZSM-5 crystal to exhibit a hexagonal-lath-shaped morphology. Due to the preferred orientations, the intensities of (0k0) and (h0l) reflections were intensified and diminished, respectively. The hexagonal flat plane of the Na–ZSM-5 crystal was (010). Therefore, the 10-membered-ring straight channels were strongly indicated to penetrate perpendicularly to the hexagonal flat plane of the as-synthesized Na–ZSM-5 crystal.