bluuebunny/crossref_metadata_2025 huggingface dataset:
Biionic Potential across Liquid Membranes with Some Anionic Surfactants
Authors: Nomura Kazuo , Matsubara Akira , Kimizuka Hideo
Published: July 2006

The biionic membrane potential was measured with the system in which a solution of calcium chloride was separated by a liquid membrane from a solution of another metal chloride. Four kinds of liquid membranes were prepared by dissolving calcium hexadecyl sulfate, stearate, cholate or deoxycholate in aqueous 1-octanol. All of the membranes studied were nearly permselective to cation. The membrane potential was analysed according to the Goldman-type equation based on the irreversible thermodynamics. The slope of a linear portion of the biionic potential vs. logarithmic activity curve showed fairly good agreement with the theoretical slope, i.e., 2.303×2RT⁄(ZCa+ZM)F per a ten-fold increase in activity, where ZCa and ZM were the valencies of calcium ion and another metal ion M existing across a membrane, respectively. The selective permeation coefficients of various metal ions were estimated for each membrane. The surprisingly small differences in the selective permeation coefficient between uni- and bi-valent cations were observed for the liquid membranes with calcium stearate, cholate or deoxycholate, while the about ten-fold increase in the coefficient per valency was observed for the liquid membrane with calcium hexadecyl sulfate. These results were discussed according to the theory previously presented.
Stopped-flow Studies on Binding of Cu2+ Ion to Human Serum Albumin
Authors: Kure Naohisa , Nakatsuka Thoru , Sano Takayuki , Yasunaga Tatsuya
Published: July 2006

Both static and kinetic investigations have been carried out regarding the interaction between Cu2+ and human serum albumin (HSA). The static experiment, using a UV spectrophotometric technique, shows the presence of one primary binding site and other weaker binding sites at pH 5.2. The kinetic experiment, using stopped-flow apparatus, revealed a reaction process on the order of several seconds and a rapid absorbance change within the dead-time of the apparatus. These results are discussed from the viewpoint of the substitution effect of the second residue of the N-terminal position in the protein with reference to the previously reported results for a Cu2+–bovine serum albumin (BSA) system.
Volume Changes and Equilibrium Constants for Protonation of [M(edta)]2−
Authors: Yoshitani Kouzou
Published: July 2006

The volume changes and the equilibrium constants for the first protonation of [Co(edta)]2−, [Ni(edta)]2−, and [Cu(edta)]2− (H4edta=ethylenediaminetetraacetic acid) have been determined from density and pH measurements at 25 °C. In the case of [Cu(edta)]2−, a second protonation is assumed to successively occur. The volume change and the equilibrium constant for the second protonation have been estimated. The volume changes for the first protonation of Co(II)-, Ni(II)-, and Cu(II)-edta chelates were small and positive (3.5, 3.3, and 4.8 cm3 mol−1, respectively) and that for the second protonation of a Cu(II)-edta chelate was larger than the first one (8 cm3 mol−1).
Surface Behaviors of Nucleic Acid Base-Containing Lipids in Monolayer and Bilayer Systems
Authors: Kitano Hiromi , Ringsdorf Helmut
Published: July 2006

Three kinds of nucleic acid base-containing lipids were synthesized and the surface behaviors of these compounds in monolayer and bilayer systems were examined. In the monolayer systems, the addition of a complementary nucleoside to a subphase solution extended the monolayer much more efficiently than that of other nucleosides because of hydrogen bonding between a pair of complementary bases. In the monolayer and bilayer systems, the photodimerization reaction of a thymine ring was confirmed by the change in the surface pressure of the monolayer and the decrease in absorbance and the broadening of the phase-transition peak in the DSC curve of the liposome solution.
α,β-Epoxy Sulfoxides as Useful Intermediates in Organic Synthesis. II. A Novel Synthesis of α-Sulfenylated Ketones and α-Sulfenylated Aldehydes from α,β-Epoxy Sulfoxides
Authors: Satoh Tsuyoshi , Kumagawa Takumi , Yamakawa Koji
Published: July 2006

Treatment of α,β-epoxy sulfoxides, prepared from 1-chloroalkyl phenyl sulfoxides and carbonyl compounds, with various kinds of alkane- or arenethiolates afforded α-sulfenylated ketones in good yields. This method also offered a novel procedure for a synthesis of α-sulfenylated aldehydes.
Preparation and Thermolysis of N-Ammonioamidates Containing Hydroxyl Group in Acyl Moiety
Authors: Masuyama Araki , Tsuchiya Kikuo , Okahara Mitsuo
Published: July 2006

The title N-ammonioamidates (aminimides) were prepared in satisfactory yields from lactones or α-hydroxy carboxylates. By the thermolysis of these aminimides in mesitylene, some types of urethane compounds were formed, depending on the structure of the aminimide and on the concentration of the solutions.
Photochemical Electron-transfer Reactions of Biphenyl-2,2′-dicarboximide and Naphthalene-1,8-dicarboximide with Olefin. Dependence of the Reaction Course on the Structure of the Aromatic Imide
Authors: Kubo Yasuo , Araki Takeo , Maruyama Kazuhiro
Published: July 2006

Photoreactions of N-methylbiphenyl-2,2′-dicarboximide and N-ethylnaphthalene-1,8-dicarboximide (2) with 1,1-diphenylethylene (3) in methanol gave methanol-incorporated 1 : 1 : 1-adduct (7) and 2,2-diphenylethyl methyl ether (6), an anti-Markovnikov adduct of methanol to 3. The ratio of the two types of products largely depends on the structure of the aromatic imides. Probably the spin densities of the radical anions of the aromatic imides seem to play an important role to determine the reaction courses after the photochemical electron-transfer process. Similar results were obtained in the photoreaction of N-(2-phenylallyl) aromatic imides; elimination induced by methanol-incorporation vs. anti-Markovnikov addition of methanol. Photoreactions of N-(trans-3-phenylallyl) aromatic imides in methanol gave methanol-incorporated O-cyclized products (20 and 27) and C-cyclized products (21 and 28). A tentative mechanism for the O-cyclization is proposed; i.e., intramolecular electron transfer followed by anti-Markovnikov addition of methanol to the radical cation of the double bond moiety, nucleophilic attack of the aromatic imide radical anion moiety, secondary electron-transfer, and then polar addition of methanol.
Mechanism of the Direct and Triplet-sensitized Photolysis of N-(1-Naphthoyl)-O-(p-toluoyl)-N-phenylhydroxylamine
Authors: Sakurai Tadamitsu , Sukegawa Hidenori , Inoue Hiroyasu
Published: July 2006

Quantum yields (Φ) were determined for benzophenone-sensitized and direct photolysis of the title hydroxylamine (NT). Analysis of linear Stern-Volmer plots of the reciprocal of Φ against the reciprocal of NT concentration reveals that the sensitized decomposition of NT takes place via its first triplet excited state (T1) produced by triplet-triplet energy transfer from benzophenone to NT. The fact that the quantum yields for the direct photolysis are independent of NT concentration indicates no occurrence of both self-quenching and induced decomposition of NT by the photochemically generated radicals. Closer examination of the micellar and solvent viscosity effects on the quantum yields for the direct photolysis with 313-nm light shows the existence of at least two spin-correlated (singlet) radical pairs: One is a contact radical pair whose recombination eventually yields 1,3-toluoyloxyl-migrated product and the other a solvent-separated radical pair from which 1,5-toluoyloxyl-migrated product is derived in competition with diffusive escape from the solvent or micelle cage. Exclusive occurrence of the direct photolysis from the first singlet excited state (S1) was explained on the basis of the large energy gap between S1 and T1 (31 kcal mol−1) which is likely to make intersystem crossing from S1 to T1 very inefficient.
The Wittig-type Reaction of O=C–, C=C–, and N=C–Substituted Methylenetriphenylphosphoranes with N-Sulfinyl-p-toluenesulfonamide. An Intramolecular 1,3-Dipolar Cyclization of Imidoylconjugated Thione S-Imides
Authors: Saito Takao , Nakane Michio , Watanabe Toshihiko , Motoki Shinichi , Kobayashi Kimiko , Sakurai Tosio
Published: July 2006

The Wittig-type reactions of N-sulfinyl-p-toluenesulfonamide with (1) O=C–, (2) C=C–, and (3) N=C-conjugated phosphorus ylides were investigated. In the reaction with (1), N-sulfinyl-p-toluenesulfonamide reacted at both the ylide and the carbonyl moiety to form TsN=C-conjugated thione S-imide, which underwent intramolecular 1,3-dipolar cycloaddition of the CSN group with the aromatic C=C bond of the tosyl group giving a structurally unique spiro-fused tricyclic adduct. The structure of the adduct was determined by means of X-ray diffraction. In the reactions with (2) and (3), 1-azadiene and sulfobetaines were obtained instead of the expected conjugated thione S-imides.
The Pressure Effect on Conductances of KCl in Ethanol–Water Mixtures at 25 °C
Authors: Ueno Masakatsu , Tsuchihashi Noriaki , Shimizu Kiyoshi
Published: July 2006

The molar conductances of KCl in 5, 10, 15, 20, and 30 mol% ethanol–water mixtures were measured in the dilute concentration range of (2–8)×10−4 M (1 M=1 mol dm−3) at 25 °C up to 1500 kgf cm−2 (1 kgf cm−2=0.9807×105 Pa). The Fuoss-Onsager conductance equation for unassociated electrolytes was used to determine the limiting molar conductance, Λ°, of KCl in 5 and 10 mol% of ethanol. In 15, 20, and 30 mol% of ethanol, where the ionic association takes place, the Shedlovsky equation was employed to obtain Λ° and the association constant KA of KCl. The limiting ionic molar conductances of the K+ and Cl− ions were determined by combining Λ° with the limiting transference number for KCl. The Walden products of both K+ and Cl− ions decrease with an increase in the pressure in 5 mol% of ethanol, but in 15 mol% of ethanol and above they increase with an increase in the pressure. These facts indicate that the breaking effect of these ions appears prominently in about 5 mol% of ethanol.
Use of Propagators in the Hückel Model. VI. Magnetic Perturbation and Ring Current
Authors: Ohmae Takayuki , Nishikawa Kiyoshi , Aono Shigeyuki
Published: July 2006

The electron propagator in the magnetic field is investigated under the Hückel approximation, and the electronic energy and the aromatic ring current are evaluated. The perturbation treatment for the ring current developed by McWeeny is easily reformulated in terms of propagator and then the physical features involved in this problem have been made considerably clearer.
The Crystal and Molecular Structure of 2,3,6,8,9-Pentaphenyl-1-thia-6-azaspiro[4.4]nona-2,8-diene-4,7-dione
Authors: Yasuoka Noritake , Kai Yasushi , Kasai Nobutami
Published: July 2006

The title compound crystallizes in monoclinic form, space group P21/c with a=20.810(1), b=16.000(1), c=18.131(1) Å, β=107.77(1)°, Z=8. The structure was established by the direct method and refined including all hydrogen atoms by the blockdiagonal least-squares procedure, R=0.062 for 4609 observed reflections. The heterocyclic spiran skeletons in two independent molecules have the same structure; however, four phenyl rings out of five take different conformations to the hetero rings to which they attached.
Preparation and Characterization of Cobalt(III) Complexes Containing (CH3)2As(CH2)nAs(CH3)2 (n=2, 3)
Authors: Iwata Katsumi , Kojima Masaaki , Fujita Junnosuke
Published: July 2006

Twelve new complexes, trans-[CoX2(dmae or dmap)2]+ (X=Cl, Br, I; dmae=1,2-bis(dimethylarsino)ethane, dmap=1,3-bis(dimethylarsino)propane), cis-[CoX2(dmap)2] (X=Cl, Br), [Co(CO3)(dmae or dmap)2]+, and [Co(acac)3−n(dmap)n]n+(n=0, 1, 2; acac=2,4-pentanedionate ion) were prepared and characterized. From a comparison of the 1A1g→1Eg (D4h) d-d absorption bands of analogous trans-dichloro complexes of phosphines and amines, the order of spectrochemical series for the group 5B elements was suggested to be P>As>N. Largely reduced interelectronic repulsions between the crystal field levels were observed for the carbonato complexes. Isomerization of cis-[CoCl2(dmap)2]+ to the trans isomer was studied in methanol in the temperature range of 20.1–49.9 °C. The rate has a first-order dependence on the complex concentration. The rate constant at 54.9 °C, calculated from the ΔH\eweq (115.2 kJ mol−1) and ΔS\eweq (53.8 J mol−1 K−1) values, is 103 times as large as that reported for cis-[CoCl2(diars)2]+ (diars=o-phenylenebis(dimethylarsine)) at the same temperature.
Oxidation of Coals in Liquid Phases. VII. Oxidation of Oxygen-containing Model Compounds of Coal by Oxygen in Concentrated Sodium Hydroxide Solutions
Authors: Furuya Hirohide , Uwabe Ryoichi , Sutoh Nobuyuki , Okuwaki Akitsugu , Amano Akira , Okabe Taijiro
Published: July 2006

Oxidation of 26 model compounds of low-ranked coal was performed to study the formation mechanisms of oxalic acid from coal. A mixture of 0.02 mol of the model compound, 4–60 g of NaOH, and 50 g of water was placed in a 300 cm3 autoclave and oxidized at 523 K and PO2=5 MPa for 120 min. Acetic acid was produced from phenols within 15 min and oxidized selectively to oxalic acid. The yield ratio(yield of oxalic acid(%)/yield of CO2 (%)) from most of the model compounds was higher than 1. These phenomena agreed well with those of low-ranked coal under the same oxidation conditions. The overall reaction rates, yields of oxalic acid, and yield ratios increased rapidly with an increasing concentration of NaOH as in the oxidation of coal. This behavior can be explained resonably well by an alkali-catalyzed oxidation mechanism regarding organic substances.
A Set of Rate Constants for the Reactions of OH Radicals with Aromatic Hydrocarbons
Authors: Ohta Tomohiro , Ohyama Toshiro
Published: July 2006

The rate constants for the reactions of OH radicals with seventeen aromatic hydrocarbons were determined at atmospheric pressure and room temperature from competitive reactions with hexane, using H2O2 as the OH-radical source. A useful trend was found in the structure-reactivity relationship.
A Method for Determining Absolute Configuration of Cycloalkanamines and Related Compounds by CD Spectra of Their 2,4-Dinitrophenyl Derivatives
Authors: Kawai Masao , Iwase Teruhiko , Butsugan Yasuo , Nagai Ukon
Published: July 2006

N-(2,4-Dinitrophenyl) derivatives of cycloalkanamines and related compounds having an amino and an aromatic groups in vicinal positions were prepared. Their CD spectra exhibited marked Cotton effect around 400 nm, the sign of which was shown to coincide with the chirality between the two chromophore-bearing bonds. This relation, as a special example of exciton chirality method, is useful for determining absolute configuration of cyclic compounds having a primary amino group.
Thermal Decomposition of 2,2-Bis(t-butyldioxy)-3-methylbutane
Authors: Komai Takeshi , Suyama Shuji
Published: July 2006

The activation parameters for decomposition of 2,2-bis(t-butyldioxy)-3-methylbutane (2) in diphenylmethane are ΔH\eweq=144.8 kJ mol−1 and ΔS\eweq=49.4 JK−1 mol−1. The decomposition products of 2 are t-butyl alcohol, acetone, isopropyl methyl ketone and t-butyl peracetate. t-Butyl peracetate (4) is an intermediate which decomposes during reaction. This peroxide 2 decomposes with homolytic one-bond cleavage at one of the peroxide groups and the resulting 1-(t-butyldioxy)-1,2-dimethylpropoxyl radical (3) decomposes subsequently to t-butyldioxy or isopropyl groups with β-elimination.
Photochemical Reaction of 1,4-Naphthoquinone Derivatives with Pyrrole Derivatives. Synthesis of 2-(2-Pyrrolyl)-1,4-naphthoquinone Derivatives
Authors: Maruyama Kazuhiro , Otsuki Tetsuo , Tamiaki Hitoshi
Published: July 2006

Photochemical reaction of 2-bromo-1,4-naphthoquinone derivatives with pyrrole derivatives in benzene gave regioselectively 2-(2-pyrrolyl)-1,4-naphthoquinone derivatives. Photoinduced electron transfer process may be involved in the reaction.
Replacement of a Carbonyl Group of Camphor by an Oxygen Atom. Synthesis of 1,7,7-Trimethyl-2-oxabicyclo[2.2.1]heptane
Authors: Suginome Hiroshi , Yamada Shinji
Published: July 2006

A four-step transformation of (+)-camphor into a hitherto undescribed 1,7,7-trimethyl-2-oxabicyclo[2.2.1]heptane is described.
Enzymic Synthesis and Biochemical Activity of Various Indazole Adenine Dinucleotides
Authors: Tono-oka Shuichi , Tone Yukiko , E. Marquez Victor , A. Cooney David , Sekikawa Isao , Azuma Ichiro
Published: July 2006

Each of 5- or 6-amino-, acetamido-, hydroxy-, methoxy-, and chloroindazoles (including an unsubstituted one) and β NAD were subjected to an NADase-catalyzed base-exchange reaction to produce a corresponding title compound with a 41–76% yield. A difficulty, due to the poor solubility in water of indazole bases, was overcome by the addition of DMSO (∼20%) without a remarkable decrease in NADase activity. In most cases, the obtained dinucleotides were ascertained to be N2-ribosylated compounds. From 5- and 6-aminoindazoles, however, N1-ribosylated dinucleotide was also obtained as a minor product. In some of the N2-ribosylated dinucleotides, an unusual tautomerism was suggested to occur on the benzene ring of an indazole moiety. Finally, the synthesized title compounds were examined for inhibition activity against NAD-linked inosine monophosphate dehydrogenase. Four compounds among them were markedly effective at a 10−3 M concentration.
The Crystal and Molecular Structure of Two Triple-layered Metaparacyclophanes
Authors: Koizumi Yosuke , Toyoda Toshihiro , Kasai Nobutami , Misumi Soichi
Published: July 2006

Molecular structures of triple-layered metaparacyclophanes containing two and one para-bridged, outside benzene rings([2.2]paracyclo(4,6)[2.2]metaparacyclophane (PMP) and [2.2]metacyclo(4,6)[2.2]metaparacyclophane (MMP), respectively) have been determined by means of X-ray diffraction. PMP: monoclinic, space group P21/a, a=15.989(1), b=9.932(1), c=5.991(1) Å, β=100.61(1)°, Z=2. MMP: monoclinic, space group P21/c, a=8.969(2), b=22.774(4), c=10.339(2) Å, β=119.32(1)°, Z=4. The structure of PMP was solved by the vector search method and that of MMP by the direct method. They are refined anisotropically by the least-squares procedure, final R values are 0.066 for PMP and 0.096 for MMP. Of the two possible conformers PMP has a centrosymmetric staircase structure(anti-form) whereas MMP takes a platform shape(syn-form).
The Thermodynamic Behaviour of Nickel in a Molten LiF–KF–O2− System
Authors: Ito Yasuhiko , Hayashi Hidetaka , Itoh Yasuhiko , Yoshizawa Shiro
Published: July 2006

The thermodynamic behaviour of nickel in a molten LiF–KF–O2− system was investigated by using Pt(O2)/stabilized zirconia electrode as an oxide-ion-concentration indicator. The potentials of the Pt(O2)/stabilized zirconia/LiF–KF–O2− electrode and the Ni/NiO/LiF–KF–O2− electrode at 550 °C were measured as :

E=2.25−\fracRT2FlnX02−(V.vs.Li-K⁄Li+,K+)

and:

E=1.42−\fracRT2FlnX02−(V.vs.Li-K⁄Li+,K+)

respectively. The solubility product of NiO in the melt was thus determined to be Ksp=1.3×10−6 at 550 °C. With these results, a potential-pO2− diagram of the nickel in the system was presented.
Catalytic Epoxidation of Olefins with t-Butyl Hydroperoxide in the Presence of Polymer-supported Vanadium(V) and Molybdenum(VI) Complexes
Authors: Yokoyama Toshiro , Nishizawa Masato , Kimura Tetsuo , Suzuki Toshishige M
Published: July 2006

Oxovanadium(V) and oxomolybdenum(VI) ions have been incorporated into cross-linked polystyrene resins functionalized with iminodiacetic acid or diethylenetriamine derivatives. The polymer complexes have been used as catalysts in the epoxidation of olefins with t-butyl hydroperoxide. Vanadium(V) complexes promote epoxidation of allylic alcohols in a highly regioselective manner, e.g., 2,3-epoxide has been preferentially obtained in 98% selectivity from (E)-geraniol at 80 °C. The catalytic activity of the vanadium(V) complexes is generally higher than that of the molybdenum(VI) complexes in the epoxidation of allylic alcohols whereas an opposed trend holds for the epoxidation of cyclohexene. Life time of catalysts have been examined by repeated use of the complexes in the epoxidation of (E)-geraniol at 80 °C in benzene. Approximately 15–25% of vanadium has been leaked out of the polymer beads on five time recycles leading to the decrease in the yield of 2,3-epoxide from initial value of 98% to 95–93%. Neither appreciable loss of metal nor reduction of catalytic activity has been observed in the molybdenum complex systems over five runs.
Natural Homologs of Gramicidin S. II. Synthesis of Gramicidin S-2 and S-3
Authors: Nozaki Sukekatsu , Muramatsu Ichiro
Published: July 2006

Two cyclic dodecapeptides corresponding to newly found members of gramicidin S family, gramicidin S-2: cyclo(–Val–Orn–Leu–d-Phe–Pro–Abu–Orn–Leu–d-Phe–Pro–), and gramicidin S-3: cyclo(–Abu–Orn–Leu-d-Phe–Pro–Abu–Orn–Leu–d-Phe–Pro–), were synthesized. In the synthesis, the linear decapeptide precursors of the antibiotics prepared by a combination of the “hold-in-solution” method and the usual liquid phase method were converted to cyclic ones in excellent yields by one-pot reaction using 1-ethyl-3-(3-dimethylaminopropyl)carbo-diimide hydrochloride and 1-hydroxybenzotriazole. The synthesized antibiotics were identical with the natural products in HPLC analysis and assays of the antibiotic activities. The proposed structures for gramicidin S-2 and S-3 were confirmed. The CD spectra showed that the ring conformations of gramicidin S-2 and S-3 closely resemble each other and also that of gramicidin S-1, which has the already known structure.
Improved Synthesis and Crystal Structure of 7H-Dibenz[a,kl]anthracen-7-one
Authors: Fujisawa Shoji , Oonishi Isao , Aoki Junji , Ohashi Yuji , Sasada Yoshio
Published: July 2006

An improved synthetic method gives pure 7H-dibenz[a,kl]anthracen-7-one, C21H12O, in a higher yield than those reported so far. The crystal structure has been determined by X-ray analysis. The space group is Pn21a, with unit cell dimensions of a=23.325(5), b=14.149(3), c=3.986(1) Å, and Z=4. The structure was solved by the direct method and refined by the block-diagonal least-squares method to an R value of 0.044. The molecule is greatly distorted from the planar conformation because of an intramolecular steric repulsion between the hydrogen atoms.
Preparation of (l-Cysteinato)(l- or d-histidinato)chromium(III) Complex
Authors: Odaka Yoshio , Hasegawa Yuichi , Watabe Masatoshi
Published: July 2006

Mixed-ligand chromium(III) complexes of the form [Cr(l-cys)(l-or d-his)] (l-cys=l-cysteinate and l-his=l-histidinate anions) were prepared. Isolated isomers of each complex were assigned structures on the basis of their high-speed liquid chromatograms and the distribution of the isomers.
The Electrochemical Cleavage of Carbon–Halogen Bonds of Haloferrocenes
Authors: Saji Tetsuo , Ito Naoyuki
Published: July 2006

The cyclic voltarmmetric studies for haloferrocenes, FcX (X=Cl, Br, and I), in etylene glycol dimethyl ether at −45 °C have been reported. The cyclic voltammogram and the absorption spectrum of the solution after the exhaustive controlled-potential reduction for the reduction step of haloferrocene show a quantitative formation of ferrocene and a cleavage of the carbon–halogen bond of haloferrocene.
UV Photoelectron Spectra of Peralkylated Catenates of Group 4B Elements (Silicon, Germanium, and Tin)
Authors: Mochida Kunio , Worley S D , Kochi J K
Published: July 2006

The low-energy photoelectron spectra (PES) of twelve peralkylated catenates of group 4B elements (silicon, germanium, and tin) were recorded. The trends in the energies and the nature of the metal–metal and metal–carbon bonds are discussed.
Convenient Synthesis of β-Truxinic Acid via Photodimerization of p-Nitrophenyl Cinnamate in the Crystalline State
Authors: Nishikubo Tadatomi , Takahashi Eiji , Miyaji Takatoshi , Iizawa Takashi
Published: July 2006

β-Truxinic acid was synthesized in extremely high yield via a topochemical photodimerization of p-nitrophenyl cinnamate crystals, followed by the hydrolysis of the obtained dimer.
The Total Synthesis of (15R)- and (15S)-16-Hydroxyferruginol
Authors: Matsumoto Takashi , Imai Sachihiko , Miuchi Shigekazu , Sugibayashi Hidenori
Published: July 2006

In order to assign the absolute configuration of C-15 in natural 16-hydroxyferruginol, (5S,10S,15R)- (1a) and (5S,10S,15S)-8,11,13-abietatriene-12,16-diol (1b) have been synthesized. Optical resolution of 2-(2-methoxyphenyl)propanoic acid, prepared from methyl (2-methoxyphenyl)acetate, with cinchonidine afforded (R)- and (S)-enantiomers, which were converted into [(R)-4-methoxy-3-(2-methoxy-1-methylethyl)benzyl]triphenylphosphonium chloride (3a) and its (S)-isomer (3b) respectively. The Wittig reaction of (R)-(−)-α-cyclocitral with 3a, followed by partial catalytic hydrogenation and intramolecular cyclization gave (5S,10S, 15S)-12,16-dimethoxy-8,11,13-abietatriene (16a) together with its (5S,10R,15R)-isomer. Similarly, 3b was also converted into (5S,10S,15S)-12,16-dimethoxy-8,11,13-abietatriene (16b) and its (5S,10R,15S)-isomer. Demethylation of 16a gave 1a which was identical with natural 16-hydroxyferruginol. The dimethoxy compound 16b was also demethylated to give 1b.
Temperature Dependence of Walden Product of 18-Crown-6–K+ Complex in Water
Authors: Takeda Yasuyuki , Arima Osamu
Published: July 2006

Limiting ionic molar conductivities of the 18-crown-6–K+ complex in water were determined at 15 and 35 °C. Walden product values of the complex at 15, 25, and 35 °C are nearly identical within experimental errors of conductance measurements. Solvation properties of the complex in water were discussed in detail.
Comparison of the Excited-state Dipole Moments and Polarizabilities Estimated from Solvent Spectral Shifts with Those from Electrooptical Measurements
Authors: Abe Takehiro , Iweibo Idowu
Published: July 2006

On the assumption that the average energy for all transitions from a low-lying excited state to all other states was approximately the same as that for all transitions from the ground state to all excited states, Abe’s improved expression for the solvent spectral frequency shift (Bull. Chem. Soc. Jpn., 54, 327 (1981)) was applied to spectral data for some neutral organic molecules in solution in order to estimate their excited-state dipole moments and polarizabilities. The changes in the dipole moments and/or polarizabilities of these molecules upon excitation were compared with those obtained from electrooptical measurements. Both methods give results that are consistent.
Photoionization Study of the Sulfur Monoxide Radical Produced by Pyrolysis of Ethylene Sulfoxide
Authors: Nishitani Eisuke , Fukuda Kenichi , Tanaka Ikuzo
Published: July 2006

Sulfur monoxide (SO) radical has been produced in the gas phase by pyrolysis of ethylene sulfoxide (C2H4=SO) at 510 °C. The vacuum ultraviolet photoionization efficiency curve between 915 and 1220 Å has been obtained for the first time. Several thermodynamic data about C2H4=SO have also been obtained from direct photoionization. The values of the bond energies of D0(C2H4=SO) and D0(C2H4=SO+) are 4640±30 and 5160±30 cm−1 respectively. Ionization potentials (IP) of the SO(X3Σ−) radical and C2H4=SO, and the appearance potential (AP) of SO+ fragment ion from C2H4=SO are 10.28±0.01, 9.49±0.02, and 10.13±0.01 eV. In the system of C2H4=SO, the AP is lower than the IP and this phenomenon has only been found in this system.
Photolytic Generation and the Subsequent Dimerization of 4-Alkyl-1-methylpyridinyl Radicals in Solution as Studied by Steady-state and Kinetic ESR Spectroscopy
Authors: Akiyama Kimio , Ishii Toru , Tero-Kubota Shozo , Ikegami Yusaku
Published: July 2006

1-Methylpyridinyl and 4-alkyl-1-methylpyridinyl (alkyl=methyl, ethyl, isopropyl, and t-butyl) radicals were generated photolytically from their dimers in solution. Hyperfine splitting constants for these radicals were assigned and the temperature dependence was discussed. Absolute dimerization rates of these radicals in the range of −50–−100 °C were determined by analyzing the ESR signal decay during the dark period. A nearly constant activation energy of dimerization was observed for five radicals, while the frequency factor decreased with the bulkiness of 4-substituent, which are discussed in terms of the steric hindrance for the dimerization.
exo-Selective Peripheral Cycloaddition Reactions of Pyrido[2,1-a]isoindole
Authors: Kajigaeshi Shoji , Mori Seiji , Fujisaki Shizuo , Kanemasa Shuji
Published: July 2006

Pyrido[2,1-a]isoindole cycloadds to olefinic dipolarophiles in a highly exo-selective fashion giving the kinetically controlled cycloadducts which gradually isomerize into the Michael adducts. With acetylenic dipolarophiles, the hydrogen-migrated cycloadducts are the only products. The mechanism of cycloadditions is discussed.
Excess Volume of Mixing of Quaternary Phosphonium Chlorides with Potassium Chloride in Water
Authors: Takaizumi Katsuko , Wakabayashi Toshiki
Published: July 2006

Volume changes upon mixing aqueous solutions of potassium chloride and the quaternary phosphonium chloride, n·Bu4−nPhnPCl, (n=0–4), have been measured at various constant total ionic strengths (I=0.25, 0.5, 1.0) at 25 °C. Based on Friedman’s theory for a mixed electrolyte solution, volume-interaction parameters, υo, were determined at each ionic strength. The dependence of υo on I shows that contributions to the excess volume due to structural effects of a pairwise interaction between the cations and triplet interactions including a single anion are most significant for the Bu4P+ ion and decrease with increasing n. A comparison of the υo’s with the excess-volume properties of the salts in each pure solution shows that the interaction between the phosphonium cations and the potassium ion results in negative contributions to the excess volume of mixing, which also decreases as n increases.
A Straightforward Access to 5-Deoxy-d-arabinono-1,4-lactone, a Versatile Intermediate in the Lauraceae Lactones Syntheses
Authors: Torii Sigeru , Inokuchi Tsutomu , Masatsugu Yoshinori
Published: July 2006

5-Deoxy-d-arabinono-1,4-lactone (2) was synthesized by a RuO4-catalyzed oxidative cleavage of 6-deoxyglucal diacetate (5d), derived from d-glucal triacetate (3), followed by alkaline hydrolysis and acidic work-up.
A Common Factor Determining the Features of the Photocatalytic Hydrogenation and Isomerization of Alkenes over Ti–Si Oxides
Authors: Kodama Sukeya , Nakaya Hiroaki , Anpo Masakazu , Kubokawa Yutaka
Published: July 2006

On addition of SiO2 to TiO2 photocatalysts, it has been found that the yields of C2H6 and CH4 in the photocatalytic hydrogenation of propylene as well as that of 1-butene in the photocatalytic isomerization of cis-2-butene decrease simultaneously. This gives some support for the mechanisms for both reactions where [Ti3+–O−] pairs are important.
The Microwave Spectrum of (Z)-(Acrylaldehyde Oxime)
Authors: Terashima Mariko , Ohashi Osamu
Published: July 2006

The microwave spectrum of (Z)-(acrylaldehyde oxime) was observed in the frequency region from 10 to 40 GHz.

Several a-type R-branch transitions in the ground vibrational state were identified and the rotational constants in MHz were determined to be A=17430.7(35), B=3022.514(15), and C=2576.504(16). The conformation of (Z)-(acrylaldehyde oxime) has been plausibly deduced to be the s-trans Z-form from the rotational constants experimentally determined. The angle of C–C=N is discussed.
Atomic Absorption Spectrophotometric Determination of Cadmium
Authors: Kabil Mohamed A , Mostafa Mohamed A
Published: July 2006

In the determination of cadmium by atomic absorption spectrophotometry(AAS), the interfering effects of different species can be completely eliminated by adding excess cyanide. The mechanism by which the cyanide eliminates interference by influencing the atomization process is discussed. Also the AAS for the analysis of cadmium in complex form is elaborated. The aim of this investigation is to achieve a determinate characterization of compound formation. The way to reach this purpose is the utilization of the continuous titration technique.
1,8-Diazabicyclo[5.4.0]undec-7-ene. An Effective and Selective Catalyst for the t-Butyldimethylsilylation of Alcohols
Authors: Kim Sunggak , Chang Heung
Published: July 2006

The use of 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) as a catalyst has been found to be very effective and selective in the t-butyldimethylsilylation of primary and secondary alcohols.
Mechanochemical Changes of Neodymium Phosphates by Grinding
Authors: Nariai Hiroyuki , Motooka Itaru , Doi Mayumi , Tsuhako Mitsutomo
Published: July 2006

The effect of mechanochemical treatment on some neodymium phosphates was investigated. It is worth noting that on mechanochemical treatment NdPO4·0.5H2O (hexagonal) is gradually transformed into NdPC4 (monoclinic) at room temperature, while thermal change of NdPO4·0.5H2O to NdPO4 (monoclinic) happens at above 600 °C. Condensed phosphates, meta- and ultraphosphates, easily turned to X-ray amorphous structure by grinding.
New Synthesis of trans-γ-Irone
Authors: Takazawa Osamu , Kogami Kunio , Hayashi Kazuo
Published: July 2006

trans-γ-Irone was successfully synthesized starting from 3,4-dimethyl-2-cyclohexenone by sevenstep reactions including TiCl4-promoted reaction of enol silyl ether and cross-aldol reaction of vinyloxyborane.
A New Synthetic Model for Myoglobin: “Tulip Garden” Porphyrin
Authors: Takagi Shigeru , Miyamoto T Ken , Sasaki Yukiyoshi
Published: July 2006

A new model compound “tulip garden” porphyrin, has a long half-lifetime, thus satisfying the demand for the synthetic analogue of myoglobin. At the same time, “tulip garden” porphyrin has high O2 affinities as compared to other protected porphyrins; especially, its Co(II) complex shows almost the same affinity (P1/2O2) as coboglobins. The difference in oxygen affinities between “tulip garden” and “picket fence-type” porphyrins can be ascribed to the bulkiness of pendant groups. The strong “side” influence of the adamantyl group can be expected to bring about a high O2 affinity.
Hydrolysis of Active Esters of Aliphatic Carboxylic Acids with Cyclic Dipeptide Catalysts Consisting of l-Histidine and Different Aliphatic α-Amino Acids
Authors: Masuda Yoshihiko , Tanihara Masao , Imanishi Yukio , Higashimura Toshinobu
Published: July 2006

The hydrolyses of a series of p-nitrophenyl carboxylates with different acyl chains were investigated at 25 °C, pH 7.8 using cyclic dipeptides[cyclo(–l- or d-Xyz–His–) consisting of l-histidine (l-His) and an α-amino acid (Xyz) with different aliphatic side chains] as catalysts. Consequently, cyclo(–d-Leu–l-His–) and cyclo(–d-Val–l-His–) were found to be specifically effective catalysts for the hydrolysis of p-nitrophenyl laurate. These trans (d-l-type) cyclic dipeptides were much more efficient catalysts than their diastereomers, and were more reactive than imidazole, despite the fact that the former are less basic than the latter. The conformation of the cyclic peptides in solution was investigated using proton magnetic resonance spectroscopy and the relationship between conformation and catalytic activity was investigated. Consequently, it was found that the hydrophobic interaction between a catalyst and a substrate and the stereochemical fit for the cooperation of functional groups in the intramolecular nucleophilic catalysis are very important in order to attain a highly efficient catalysis. It was also found that the functional groups should have a certain size and flexibility in order to realize an effective stereochemical fit between functional groups of catalysts and substrates.
Sodium Sulfate Mixed with Rare Earth Sulfates(Ln=Y and Gd) and Silicon Dioxide as a Solid Electrolyte for a Sulfur Dioxide Detector
Authors: Imanaka Nobuhito , Yamaguchi Yasuo , Adachi Gin-ya , Shiokawa Jiro
Published: July 2006

Sodium sulfate mixed with rare earth sulfates(Ln=Y and Gd) and silicon dioxide exhibits a Na2SO4-I-like phase as well as a small amount of silicon dioxide phase. The former phase is excellent in Na+ ion conduction. The electrical conductivity of the Na2SO4–Ln2(SO4)3–SiO2(Ln=Y and Gd) systems is considerably higher than that of pure sodium sulfate. When the Na2SO4–Ln2(SO4)3–SiO2(Ln=Y and Gd) sample is applied as a solid electrolyte for a SO2 gas concentration cell, the measured EMF is in good agreement with the calculated EMF for a SO2 gas concentration range from 0.1% (1000 ppm) to 23%, and 0.32% (3200 ppm) to 10%, respectively.
Oxidative Cyclization of 3-(3-Heterocycle-substituted 2-Propenoyl)tropolones
Authors: Honda Masaaki , Imafuku Kimiaki
Published: July 2006

3-[3-(2-Furyl)-2-propenoyl]- (2a), 3-[3-(2-thienyl)-2-propenoyl]- (2b), 3-[3-(3-thienyl)-2-propenoyl]- (2c), and 3-[3-(3-pyridyl)-2-propenoyl]tropolone (2d) were prepared by the condensation of 3-acetyltropolone with the corresponding heterocyclic aldehydes. The compounds 2a–d were oxidized with selenium dioxide to afford 2-heterocycle-substituted cyclohepta[b]pyran-4,9-diones, while oxidation with both alkaline hydrogen peroxide and 2,3-dichloro-5,6-dicyano-p-benzoquinone gave 2-(heterocycle-substituted methylene)-2H-cyclohepta[b]furan-3,8-diones.
Reaction of Substituted Benzaldehydes with Sodium Hydrogensulfide or Sodium Sulfide in Liquid Ammonia
Authors: Takikawa Yuji , Shimada Kazuaki , Minami Tetsuo , Sato Ryu , Takizawa Saburo
Published: July 2006

Reactions of substituted benzaldehydes with sodium hydrogensulfide in the presence of nitrobenzene, nitrosobenzene, or azobenzene in liquid ammonia produce the corresponding benzyl alcohols and benzamides. On the other hand, reaction of benzaldehyde with sodium sulfide produces benzyl alcohol and benzamide. A reaction mechanism has been proposed which involves benzaldehyde anion radical.
Solvent Effects on the Monomer-Dimer Equilibrium and Dimerization of the 1-Methyl-2-methoxycarbonylpyridinyl Radical
Authors: Shimoishi Hirami , Tero-Kubota Shozo , Ikegami Yusaku
Published: July 2006

Solvent effects on the hyperfine splitting constants, monomer-dimer equilibrium, and kinetic parameters of the dimerization of the 1-methyl-2-methoxycarbonylpyridinyl radical have been examined in detail, using methylcyclohexane, toluene, 2-methyltetrahydrofuran, acetone, and acetonitrile as the solvents. A comparatively large activation energy for the fast step in the two-step dimerization mechanism suggests strongly that the dimeric intermediate is the 2,2′-dimer of the radical, which subsequently rearranges to the stable 4,4′-dimer.
Mössbauer Study of 60Co γ-Ray Irradiated FexMg1−x(NH4)2(SO4)2·6H2O
Authors: Sakai Nobuhiko , Sakai Fumiko , Sekizawa Hisashi
Published: July 2006

The γ-ray radiolytic oxidation of Fe2+ ions in FexMg1−x(NH4)2(SO4)2·6H2O (x=1.0, 0.75, 0.56, 0.35, and 0.075) is studied by Mössbauer spectroscopy. For x≤0.75, a part of Fe2+ ions remain unoxidized even after heavy irradiation of 60Co γ-rays in contrast to the complete disappearance of Fe2+ ions for x=1.0. At least three kinds of Fe3+ ions are produced, and two of them order magnetically at liquid He temperature. Their saturated relative amount after heavy irradiation depends on the concentration of Fe, and is well explained by the random distribution probability of Fe and Mg ions among the six neighboring metallic sites around the Fe2+ ion.
The Distribution of Mercury, Arsenic, and Antimony in Sediments of Kagoshima Bay
Authors: Sakamoto Hayao
Published: July 2006

Mercury, arsenic, and antimony were determined in marine sediments collected from Kagoshima Bay, and their distribution was investigated. The contents of mercury, arsenic, and antimony in surface sediments were higher than those in the marine sediments of the open ocean. The average contents of mercury, arsenic, and antimony in surface sediments in the northern part of the bay were higher than in the southern part. The high-temperature sediments (about 200 °C) in the vicinity of a sea bottom fumarole, located at a depth of about 200 m in the northern part of the bay, showed abnormal concentrations of mercury, arsenic, and antimony derived from the fumarole gas; the contents of these components decreased sharply with an increase in the distance from the fumarole. A high degree of positive correlation was found among the contents of the three components (mercury, arsenic, and antimony) over the northern part of the bay. In contrast, no such correlation was observed in the southern part of the bay. This is in accord with the fact that volcanic activity is more vigorous in the northern than in the southern part of the bay.
DNA Sequence and Intramolecular Evolutionary Tree of Calmodulin Gene. Application of Maximum Likelihood Method
Authors: Iida Yôichi
Published: July 2006

DNA sequences of calmodulin genes taken from chicken and electric eel were examined to investigate the molecular evolution of its protein. One notable feature of the amino acid coding region of the gene is that it can be subdivided into four domains having a similar amino acid sequence. In the present paper, an intramolecular evolutionary tree was constructed with the DNA sequences of the four domains.
Infrared Intensities in Methyl Chloride. III. Improvement of the Anharmonic Force Field and the Analysis of the Overtone and Combination Band Intensities
Authors: Kondo Shigeo , Koga Yoshinori , Nakanaga Taisuke
Published: July 2006

A recently obtained anharmonic ab initio force field of methyl chloride has been improved by the method of “predicate observations” using the observed values of the spectroscopic constants. The newly obtained force field was used to make re-analysis of the absorption intensities of the binary overtone and combination bands for CH3Cl and CD3Cl. Contribution from the electrical anharmonicity to the band intensities was estimated and compared with the ab initio result.
The Role of Aroyloxyl Radicals in the Formation of Solvent-derived Products in Photodecomposition of Diaroyl Peroxides. The Reactivity of Substituted Cyclohexadienyl Radicals and Intermediacy of ipso Intermediates
Authors: Takahara Shigeru , Urano Toshiyuki , Kitamura Akihide , Sakuragi Hirochika , Kikuchi Osamu , Yoshida Masayuki , Tokumaru Katsumi
Published: July 2006

Photolyses of bis(2-thiophenecarbonyl) peroxide (TPO) in benzene and toluene afforded, among free-radical products, biphenyl and dimethylbiphenyls, respectively, which were solely derived from the aromatic solvents. The yields of biphenyls depended upon the rate with which the radical intermediates were generated from the peroxides in sufficiently high concentrations for their dimerization. Photolyses of TPO and dibenzoyl peroxide in 1,3,5-trimethylbenzene afforded also a solvent-derived product, 2,3′,4,5′,6-pentamethyldiphenylmethane. Its formation provides clear evidence for participation of cyclohexadienyl radicals bearing the aroyloxyl group on the methyl-substituted ipso carbon atom.
Spectroscopic Studies on the Interaction of Polymeric In-chain Biguanide Biocide with Phospholipid Membranes as Probed by 8-Anilinonaphthalene-l-sulfonate
Authors: Ikeda Tomiki , Tazuke Shigeo , Bamford Clement H , Ledwith Anthony
Published: July 2006

Interaction of a highly effective polymeric biocide poly(hexamethylene biguanide hydrochloride)(PHMB) with phospholipid model membranes was investigated spectroscopically by using 8-anilinonaphthalene-l-sulfonate (ANS) as a fluorescent probe. PHMB enhanced the fluorescence intensity and shifted the maximum wavelength of fluorescence of ANS embedded in the negatively-charged liposome composed of egg PC and dicetyl phosphate, while it had only small effect on the neutral liposome composed of egg PC alone. These results were interpreted in terms of preferred binding of PHMB to negatively-charged species. The Benesi-Hildebrand type plots revealed that PHMB was adsorbed to a greater extent onto the negatively-charged membrane than onto the neutral membrane: the dissociation constants for the liposome–ANS complexes derived from the plots gave quantitative evidence for the enhanced binding of PHMB to the negatively-charged membrane. Diaminohexyl biguanide (DAHB), a corresponding monomer to PHMB, was found to have no significant effect on either the neutral nor the negatively-charged liposome, a finding probably related to the fact that DAHB is practically inactive.
Thermal Investigations of 1,4-Butanediamine Complexes of Nickel(II) in the Solid Phase
Authors: De Goutam , Chaudhuri Nirmalendu Ray
Published: July 2006

[NiL3]Cl2·H2O, [NiL2(H2O)2]Br2, and [NiL2(NCS)2] (L=1,4-butanediamine) have been synthesized and their thermal investigations have been carried out. [Ni2L3Cl4], [NiLCl2], [Ni4L3Br8], and [NiL(NCS)2] have been synthesized pyrolytically in solid phase by temperature arrest technique from their corresponding parent diamine complexes. All the parent tris and bis(diamine) complexes possess Oh geometry. [NiLCl2 possesses Td geometry, whereas, [NiL(NCS)2] possesses Oh though 1,4-butanediamine is chelated in both of these mono(diamine) complexes. Thiocyanate is found to be bridged in [NiL(NCS)2]. The probable mechanistic paths of decomposition of these diamine complexes have been propsoed.
Effect of Choline Derivatives on the Critical Micelle Concentrations of Anionic and Cationic Surfactants
Authors: Nakagaki Masayuki , Yokoyama Shoko
Published: July 2006

The decrease of the critical micelle concentration (cmc) of sodium dodecyl sulfate (SDS) was larger, while the decrease of that of dodecyltrimethylammonium chloride (DTAC) was smaller in the presence of choline derivatives than in the presence of NaCl at the same molar concentration.
The Magnetic Properties of the Ammonium Chloride Adducts of Copper(II) Chloroacetates
Authors: Emori Shuji , Haramaki Nobuyuki , Muto Yoneichiro
Published: July 2006

Various ammonium chloride adducts of copper(II) chloroacetate and copper(II) dichloroacetate were prepared. The variable-temperature magnetic susceptibilities of the dimethylammonium chloride adducts obey the Bleaney-Bowers equation, indicating the existence of the copper(II) acetate type of dinuclear moiety in their crystals. The effect of the counter cations on their magnetic moments was discussed.
Stereoisomers of trans- Dichlorocobalt(III) Complex with 1,7-Bis[(S)-2-pyrrolidinyl]-2,6-diazaheptane
Authors: Saburi Masahiko , Obata Shusei , Yamaguchi Motowo , Yoshikawa Sadao
Published: July 2006

The complex trans-[CoCl2(SS-pyht)]+ (SS-pyht=1,7-bis[(S)-2-pyrrolidinyl]-2,6-diazaheptane), prepared via the HCl treatment of Λ-β-[CoCO3(SS-pyht)]+, was found to take the (R,R) configuration with regard to the secondary nitrogen centers involving the central chelate. The isomer ratio of two diastereomers (trans(R,S) and trans(R,R)) was estimated at the equilibrium in methanol; (R,S)/(R,R)=10.4±2.6.
Synthesis of Chiral Crown Ethers Derived from trans, trans- and cis, trans-2,2′-Spirobiindan-1,1′-diols. Their Chiral Recognition and Complexation Properties
Authors: Naemura Koichiro , Ebashi Iwao , Nakazaki Masao
Published: July 2006

trans,trans-2,2′-Spirobiindan-1,1′-diol (1) was resolved as its (−)-ω-camphanic ester and the absolute rotation of the glycol 1 was determined. Two crown ethers and the acyclic analog were derived from (+)-1. Two crown ethers incorporating (+)-cis,trans-2,2′-spirobiindan-1,1′-diol were also prepared. Their chiral recognition properties in transport of methyl (±)-phenylglycinate hydrochloride and abilities to extract alkali metal picrates were investigated.
Solubilization of Alkyl p-Hydroxybenzoates in Hexa(oxyethylene) Dodecyl Ether Micelle
Authors: Goto Ayako , Endo Fumio , Higashino Takeo
Published: July 2006

An experimental study was made on the effect of the alkyl-chain length of alkyl p-hydroxybenzoates on their solubilization in nonionic micelle. The location of alkyl p-hydroxybenzoate in micelle and the change in micelle structure are discussed on the basis of the experimental result.