bluuebunny/crossref_metadata_2025 huggingface dataset:
Microwave Spectrum of Ethyl Isothiocyanate
Authors: Sakaizumi Takeshi , Ohashi Osamu , Yamaguchi Ichiro
Published: July 2006

The microwave spectrum of ethyl isothiocyanate, CH3CH2NCS, has been obtained in the frequency region from 8.5 to 35 GHz. The spectrum identified is attributed to the cis configuration, namely, the methyl group eclipses the isothiocyanato group. The rotational constants for the ground vibrational state obtained are A=1419±10, B=1799.27±0.02 and C=1612.14±0.02 MHz. The dipole moment of this rotamer is μtotal=3.33±0.03 D (μa=3.33±0.03 D, μb=0.07±0.02 D). Two sets of vibrational satellites were observed and assigned to the modes of C–N torsion (58±30 cm−1) and CNC bending (107±30 cm−1).
Studies on the Electrode Processes of Oxovanadium(IV). II. Electrolytic Reduction of Vanadyl Acetylacetonate in Acetonitrile Solution at Mercury Electrode
Authors: Kitamura Mitsutaka , Yamashita Kazuo , Imai Hideo
Published: July 2006

The electrolytic reduction of vanadyl acetylacetonate in acetonitrile solution was investigated by means of conventional and AC polarography, cyclic voltammetry and controlled-potential electrolysis. A well-defined polarographic cathodic wave was obtained in a solution containing excess acetylacetone. The wave-form was outwardly a single step with two-electron transfer. However, logarithmic analysis revealed that it consists of two steps. The first step is slightly irreversible, being accompanied by V–O bond breaking, and the second one is controlled by the rate of coupled chemical reactions. The reaction mechanism is discussed in detail. The reversible half-wave potentials of the species [VO(acac)2] and [V(acac)3] were determined to be −1.93 and −1.78 V vs. Ag/0.1 M AgClO4, respectively, from the logarithmic analysis.
Photoionization of Chlorpromazine Hydrochloride in Binary Mixed Solvent Systems
Authors: Iwaoka Teiki , Kondo Michio
Published: July 2006

Flash photolytic photoionization of chlorpromazine hydrochloride has been investigated in several binary solvent systems, one component being always water. With changing solvent composition, the ionization yield in aerated state shows a convex curve. Opposite roles of oxygen toward photoionization have been found in aqueous and organic solutions: i.e. the deaeration causes an efficient ionization in organic solvents, but practically no ionization in water. A change in the reaction mechanism has been suggested in the mixed solvent with water content of about 85 %. It has been found that the photoionization proceeds monomolecularly via an excited state, the lifetime of which is far shorter than that of the lowest excited (π-π*) triplet state.
Isomerization of Butenes over Thorium Dioxide
Authors: Imizu Yuzo , Yamaguchi Tsutomu , Hattori Hideshi , Tanabe Kozo
Published: July 2006

The isomerization of butenes has been studied over four kinds of ThO2 catalysts which differ in starting materials or preparative procedures. The selective ThO2 catalysts for the formation of 1-olefin in the dehydration of 2-alkanol, which were prepared from nitrate and oxalate, were active and gave high cis/trans ratios in the isomerization of 1-butene, whereas the non-selective ThO2 catalyst, which was prepared from chloride, was completely inactive. The isomerization reaction was poisoned by both CO2 and NH3. The activity was enhanced by the treatment with hydrogen, but was reduced by the treatment with oxygen, the selectivity being unchanged with both treatments. The coisomerization of cis-2-butene and cis-2-butene-d8 showed that the isomerization involved an intramolecular hydrogen transfer, and a large isotope effect, 6.0, for the formation of 1-butene and a small isotope effect, 1.5, for the formation of trans-2-butene were observed. With these results, the nature of active sites on thorium oxide, and the reaction mechanism were discussed.
Reactivities of Stable Rotamers. II. Lithiation of 9-(2-Methyl-1-naphthyl)fluorene and Related Compounds
Authors: Nakamura Mikio , Nakamura Nobuo , Oki Michinori
Published: July 2006

Studies were carried out on the rates of lithiation of 9-arylfluorenes, in which the aryls are hydrocarbons. The reactivities of these compounds are explained in terms of the effective blocking of the reaction site by the substituent. The steric effect of the substituent which is attached to the aryl group but is over the fluorene ring is found to play a role in the reactivities.
Preparation and Properties of Stable Alkylcopper(I) Complexes Containing Tertiary Phosphine Ligands
Authors: Miyashita Akira , Yamamoto Akio
Published: July 2006

A variety of stable alkylcopper(I) complexes of composition RCuLn (n=1–3) containing various monodentate tertiary phosphine ligands (L), such as triphenylphosphine, diphenylmethylphosphine, dimethylphenylphosphine, tributylphosphine, triethylphosphine, and tricyclohexylphosphine have been prepared by the reactions of copper-(II) acetylacetonate, dialkylaluminium monoethoxide, and the tertiary phosphines. Similar reactions employing 1,2-bis(diphenylphosphino)ethane(dpe) give (RCu)2(dpe)3. The complexes have been isolated and characterized by elemental analysis, determination of molecular weight, chemical reactions, IR and NMR spectroscopy. All the isolated complexes show considerable thermal stability compared with alkylcopper compounds without phosphine ligand indicating the marked contribution of these phosphine ligands to the stabilization of the copper-carbon bond. The dpe-coordinated alkylcopper complexes are thermally stable in the solid state but readily decompose in solution with hydrogen abstraction accompanied by scission of the C–P bond of dpe to give Ph2PCu-(dpe), Ph2PCH=CH2, and alkane. These alkylcopper complexes initiate the polymerization of vinyl monomers such as acrylonitrile, methacrylonitrile, methyl acrylate, and methyl methacrylate. Alkyl halides and acyl halides react with the alkylcopper complexes to give cross-coupling products of alkyl groups and alkyl-acyl groups.
Vibration Spectra and Rotational Isomerism of Chain Molecules. III. Ethyl Methyl Sulfide and Deuterium Compounds
Authors: Sakakibara Masaaki , Matsuura Hiroatsu , Harada Issei , Shimanouchi Takehiko
Published: July 2006

The Raman spectra of ethyl methyl sulfide and its three deuterated compounds CD3SC2H5, CH3SCH2CD3, and CH3SC2D5 were measured for the liquid and crystalline states. The Raman spectra of the undeuterated species in the gaseous state were measured at different temperatures. The normal vibration frequencies were calculated by using a consistent set of force constants for aliphatic sulfides. The combination of the spectral observations of the deuterated compounds and the normal vibration calculations showed that only the gauche form exists in the crystalline state and the trans and gauche forms coexist in the liquid and gaseous states. The enthalpy difference between the gauche and trans forms in the gaseous state, ΔHG–T, was obtained as −30±50 cal/mol.
The Nucleophilic Displacement Reactions of 8-Chloro- and 2,8-Dichloro-3-phenyl-1-azaazulenes
Authors: Yamane Kameji , Fujimori Kunihide , Sin Je-Kyun , Nozoe Tetsuo
Published: July 2006

The reaction of 3-phenylpyrrolo[2,3-b]tropone (7) with phosphoryl chloride gave 8-chloro-3-phenyl-1-azaazulene (5). When 5 and 7 were treated with N-chlorosuccinimide, 2,8-dichloro-3-phenyl-1-azaazulene (6) and 2-chloro-3-phenylpyrrolo[2,3-b]tropone (8) were obtained respectively. 6 was also obtained from 8 by treatment with phosphoryl chloride. The reactions of 5 and 6 with nucleophilic reagents gave the corresponding substituted products (14a–m and 15a–m). 8-Hydrazino-3-phenyl-1-azaazulene (14m) and 2-chloro-8-hydrazino-3-phenyl-1-azaazulene (10), which had been obtained by the reaction of 5 and 6 with hydrazine hydrate, were decomposed by treatment with copper(II) sulfate in acetic acid to give 3-phenyl-1 -azaazulene (2) and 2-chloro-3-phenyl-1-azaazulene (11) respectively.
Rishitin. II. Synthesis
Authors: Murai Akio , Nishizakura Kouichi , Katsui Nobukatsu , Masamune Tadashi
Published: July 2006

The regio- and stereo-selective synthesis of rishitin (1) from (−)-α-santonin (2) is described. The transformation involves twelve steps including two known processes, the overall yield amounting to 2.9% from the santonin (2).
Lubimin and Oxylubimin. The Structure Elucidation
Authors: Katsui Nobukatsu , Matsunaga Akira , Kitahara Haruo , Yagihashi Fujio , Murai Akio , Masamune Tadashi , Sato Norio
Published: July 2006

The isolation and structure elucidation of lubimin (3) and oxylubimin (4), stress metabolites from diseased white potato tubers, are described.
ESR Studies of the g- and D-Tensor Values of Stable p- and m-Phenylenebis(gralvinoxyl) Biradicals
Authors: Mukai Kazuo , Tamaki Toshiko
Published: July 2006

The g- and D-tensor values of p- and m-phenylenebis(galvinoxyl) biradicals in several solvents have been determined from their asymmetric frozen ESR spectra. The spectra suggested that only one conformer out of two possible ones, “propeller” and “anti-propeller” structures, exists in each biradical. The D-tensor values were calculated for the two possible conformers, based on assumed molecular structures and spin distribution. The results indicate that the “propeller” structure with a 30° twist angle is preferable for the m-phenylenebis(galvinoxyl). In the case of the p-phenylenebis(galvinoxyl), a considerable accordance between the measured and calculated values for the two conformers with a 30° twist angle was obtained. Notable solvent effects in the g- and D-tensor values were observed for the m-phenylenebis(galvinoxyl), but not for the p-phenylenebis(galvinoxyl).
The Structure of the Cyclodextrin Complex. IV. The Crystal Structure of α-Cyclodextrin–Sodium 1-Propanesulfonate Nonahydrate
Authors: Harata Kazuaki
Published: July 2006

α-Cyclodextrin, which is a cyclic oligosaccharide consisting of six d-glucose residues, forms a 1 : 1 complex with sodium 1-propanesulfonate. The crystal structure was determined by the X-ray method. The crystal is orthorhombic, and the space group is P21212 with cell dimensions of a=21.608(2), b=16.700(2), and c=8.302(1) Å, and Z=2. The structure was solved on the basis of 2219 diffractometer data and refined by the block-diagonal leastsquares method to the final R-value of 0.077. The α-cyclodextrin molecule is nearly hexagonal with diagonal distances of 8.40–8.59 Å between the glycosidic oxygen atoms. The framework of the crystal is built up of a stack of α-cyclodextrin rings along the c axis in head-to-tail arrangement, with channel-type structure. The adjacent α-cyclodextrin molecules along the channel are linked by six O(3)···O(6) hydrogen bonds. The guest 1-propanesulfonate anions are located in channels, having statistical disorder. The primary hydroxyl groups of α-cyclodextrin exhibit gauche-trans conformation, and they form hydrogen bonds with the sulfonato group resulting in oxygen-oxygen distances of 2.72–2.80 Å. The propyl group is in contact with the O(2), O(3) side of the α-cyclodextrin ring. The sodium ion is located outside the channel, and is surrounded by five oxygen atoms which form a distorted trigonal bipyramid.
Electronic Absorption and Fluorescence Spectra of 5-Hydroxytryptamine (Serotonin). Protonation in the Excited State
Authors: Kishi Tohru , Tanaka Masashi , Tanaka Jiro
Published: July 2006

The fluorescence spectra of 5-hydroxytryptamine (serotonin) in acidic media have been studied by means of fluorescence polarization, temperature dependence of fluorescence, and kinetics of the protonation in H2O and D2O. The red-shifted emission appearing by protonation in the excited state is ascribed to the protonated form of serotonin at C4. In order to confirm the assignment of electronic spectra, the absorption spectra of the single crystal of 5-methoxyindole-3-acetic acid have been measured by means of reflection technique, the directions of transition moments being determined by polarization analysis. Calculation was carried out on the energy levels of the excited state for serotonin and its protonated forms, and the directions of transition moments were compared with the experimental results.
13C Spin-Lattice Relaxation Times in Liquid Crystalline p,p′-Azoxyanisole
Authors: Hayamizu Kikuko , Yamamoto Osamu
Published: July 2006

The 13C spin-lattice relaxation time T1 in the liquid crystalline compound p,p′-azoxyanisole; (PAA; 4,4′-dimethoxyazoxybenzene) was observed in the nematic and isotropic liquid phases. From the obtained T1’s of the ring and the methyl carbons, the anisotropic rotational diffusion constants were determined. It is concluded that the rotational reorientation around the molecular axis is faster by an order of 103 than the rotational motion around the axis perpendicular to the molecular axis in the nematic and isotropic liquid states.
Microwave Spectrum, Dipole Moment, Structure, and Internal Motion of 1-Silabicyclo[2.2.1]heptane
Authors: Ikeura Taso , Tanaka Keiichi , Hirota Eizi , Inaba Shin-ichi , Nagai Yoichiro
Published: July 2006

The rotational constants of 1-silabicyclo[2.2.1]heptane in the ground vibrational state were determined to be A0=2744.775 (2) MHz, B0=2662.017 (2) MHz, and C0=2145.994 (2) MHz, with the standard deviations in parentheses. Because the spectrum was very rich, the Stark effects of two transitions were analyzed by a simulation technique. The dipole moments thus obtained are μb=0.5±0.1 D, μc=0.05±0.01 D, and μt=0.5±0.1 D. The observed spectra did not exhibit any anomalies which were due to deviations of the molecular symmetry from Cs. Three structural parameters, Si–C(7), ∠C(2)–Si–C(6), and ∠Si–C(2)–C(3), were adjusted so as to reproduce the rotational constants observed for the ground state. The Si–C(7) bond was found to be longer than Si–C(2) by 0.07 Å. Two vibrational satellites were detected and were assigned to the v=1 and the v=2 states of a torsional mode of the skeleton. A relative-intensity measurement resulted in the excitation energies of 70±25 cm−1 and 160±60 cm−1 for v=1 and v=2, respectively. The molecular structure and the internal motions were discussed in terms of intramolecular forces.
Extraction of Nickel(II) in Aqueous Thiocyanate—Perchlorate Solutions with Trioctylphosphine Oxide in Hexane and with 4-Methyl-2-pentanone
Authors: Murai Ryokichi , Iwahori Shigehisa , Sekine Tatsuya
Published: July 2006

The liquid-liquid partition of nickel(II) between hexane containing trioctylphosphine oxide or 4-methyl-2-pentanone and 1 mol dm−3 Na(SCN, ClO4) solutions at 25 °C was measured. The absorption spectra of the organic and aqueous phases at equilibrium were also measured. From an analysis of these data, the extraction constant and absorption spectrum of each organic species were determined. By comparing the extraction and optical absorption of cobalt(II) complexes in the same systems with the above results for nickel(II), it was concluded that cobalt(II) thiocyanate complexes changed from octahedral to tetrahedral form upon extraction, but that nickel(II) thiocyanate complexes remained in octahedral form throughout.
Infrared Spectrum and Electronic State of p-Iodanil
Authors: Iida Yôichi
Published: July 2006

The infrared spectrum of p-iodanil was measured and the fundamental frequencies were assigned by using simple Urey-Bradley force field. The electronic state of p-iodanil was also discussed on the basis of those experimental results.
Synthesis of Some Imidazo[1,2-c][1,2,3]triazolo[4,5-e]pyrimidines
Authors: Sugimoto Takashi , Matsuura Sadao
Published: July 2006

The reaction of 7-amino[1,2,3] triazolo[4,5-d]pyrimidine (1a) with chloroacetaldehyde gave imidazo[1,2-c][1,2,3]triazolo[4,5-e]pyrimidine (2a) which underwent facile ring opening in dilute hydrochloric acid. The methyl derivatives (2b,c,d) were similarly made from the appropriate triazolopyrimidine (1b,c,d) and chloroacetaldehyde.
A Theoretical Study on Biradicals. I. Theoretical Characteristics of Biradicals
Authors: Fukui Kenichi , Tanaka Kazuyoshi
Published: July 2006

An interpretation is given on the characteristics of biradicaloids, such as the bonding, polar, and biradical characters of singlet biradicals. Systematization of the reactivity of singlet and triplet biradicals is based on the principle that 1) deformation takes place in the direction of bonding in singlet biradicals, and 2) deformation or bond formation occurs to separate unpaired-electrons from each other in triplet biradicals. Combination of the two principles is applied to the theory of orientation and stereoselection in excited-state reactions.
On the Gibbs Adsorption Equation for Electrolyte Solutions
Authors: Ikeda Shoichi
Published: July 2006

A general method is developed to derive the Gibbs adsorption equation in the form applicable to aqueous solutions of electrolytes, either strong or weak, composed of multi-components. Assuming that the solution is ideal, the chemical potentials of solute electrolytes are represented by their concentrations, and the lowering of surface tension is calculated as a function of variations of these concentrations. Explicit expressions for surface excesses of various species are obtained on aqueous solutions of two strong electrolytes having a common cation, such as sodium dodecyl sulfate and NaCl, and on solutions containing a weak acid adjusted its ionization by addition of alkali, such as fatty acid or soap, in the presence of an added salt. The convention for drawing the Gibbs dividing plane is discussed when the Gibbs adsorption equation is represented in terms of all the species in solution.
Enhancement of the Pfeiffer Effect Arising from the Cation-Cation Interaction
Authors: Miyoshi Katsuhiko , Kuroda Yasushige , Okazaki Hiroshi , Yoneda Hayami
Published: July 2006

The influence of added sodium and potassium chloride, bromide, and sulfate was examined on the Pfeiffer effect of the [Co(phen)3]2+- and [Ni(phen)3]2+-d-cinchoH+ systems in water (phen=1,10-phenanthroline, and d-cinchoH+=dextro-cinchoninium ion). It was found that the added anions enhance the circular dichroism (CD) induced in the d-d transition region of [Co(phen)3]2+ and [Ni(phen)3]2+ ions, and that the CD-enhancing order is Br−>Cl−>SO42−/2. These findings were well interpreted in terms of reduced electrostatic repulsion between [Co(phen)3]2+ or [Ni(phen)3]2+ and d-cinchoH+ by the added anions, and of the resulting enhanced enantiomerization of these cationic complexes in favor of Δ-isomers in the presence of d-cinchoH+. Logarithm of the magnitude of the induced CD was found to be a linear function of logarithm of the total anion concentration in all the systems examined. This fact gives a strong support to the above interpretation, and suggests a close resemblance of these Pfeiffer-active systems to aqueous cationic surfactant solutions.
The Correlation between Photo-electrochemical Cell Reactions and Photocatalytic Reactions on Illuminated Rutile
Authors: Miyake Mikio , Yoneyama Hiroshi , Tamura Hideo
Published: July 2006

Photocatalytic reductions of MnO4−, Cr2O72−, and Fe3+ on illuminated rutile were demonstrated. The suitability of a method to analyze the reduction process of the photocatalytic reaction was discussed. It was concluded that a high utilization of light energy could not be expected for photocatalytic reactions because both bands of the semiconductor participated in the reaction. In such a case, the development of the photocatalvtic process into a photoelectrochemical cell has a great advantage from the point of view of energy utilization.
Nanosecond Fluorescence Anisotropy of the DNA–Acridine Complexes
Authors: Kubota Yukio , Steiner Robert F
Published: July 2006

The rotational motions of various acridine dyes bound to DNA were investigated by the measurements of nanosecond fluorescence anisotropy. It was found that the total decay of fluorescence is a single exponential, whereas the decay of fluorescence anisotropy is a sum of an exponential function and a constant. The apparent values of the rotational relaxation time of the complexes calculated from anisotropy data range from 21 to 31 ns. The results are discussed by comparing with those obtained from the measurements of steady-state fluorescence depolarization.
The Benzannelated Annulenones. Syntheses and Properties of 12-Methylbenzo[f]- and Dibenzo[f,l]-8,10-bisdehydro[17]annulenone
Authors: Ojima J\={u}ro , Ishiyama Miyako , Kimura Akihiko
Published: July 2006

The benzannelated annulenones VII and XI have been synthesized to establish the effect of annelation of benzene ring on the seventeen-membered ring system. An examination of the NMR spectra suggested that both of VII and XI are paratropic and the paratropicities decrease in the order of VII>XI with the number of benzene ring fused to seventeen-membered ring system.
A Facile Ring Enlargement Reaction via β-Oxido Carbenoid
Authors: Taguchi Hiroaki , Yamamoto Hisashi , Nozaki Hitosi
Published: July 2006

A general method of transforming a cyclic ketone to the next higher ring homolog chlorinated at the α-carbon or alternatively to its parent ketone is described. Treatment of a dichloromethyllithium-carbonyl adduct 2 with butyllithium affords a β-oxido carbenoid 3 at low temperature. Upon warming, 3 decomposes to a lithium enolate 4, which is quenched with diluted hydrochloric acid to give the α-chloro ketone 5. Cycloalkanone is converted to a one-carbon ring enlarged halogenated ketone. Meanwhile, dibromomethylcarbinol 7 is transformed to the halogen-free ketone 8  via monobromo β-oxido carbenoid upon treatment with butyllithium. α-Methyl substituted ketone is exclusively converted to the β-methyl substituted homolog and therefore dl-muscone is synthesized from cyclotetradecanone according to this new method.
Stereoselective One-pot Dialkylation of gem-Dihalocyclopropanes by Means of Dialkylcopperlithiums
Authors: Kitatani Katuzi , Hiyama Tamejiro , Nozaki Hitosi
Published: July 2006

The transformation of gem-dihalocyclopropanes (1) into 1-alkyl-1-butylcyclopropanes (2 and 3) is established by successive treatment with dibutylcopperlithium and several electrophiles. This sequence is found to be stereochemically controllable and is successfully applied to dl-sirenin synthesis. In contrast to the reaction of dibutylcopperlithium, dimethyl- and divinylcopperlithiums convert 1,1-dibromo-2-phenylcyclopropane (1a) into 1-bromo-1-methyl- and 1-bromo-1-vinyl-2-phenylcyclopropanes (15a, 16a and 15b, 16b) respectively.
The Behavior of Aerosol OT in Organic Solvents
Authors: Ueno Masaharu , Kishimoto Hiroshi
Published: July 2006

The parameters concerning the micelle formation of Aerosol OT in organic solvents were determined. In order to determine CMC, an apparatus was constructed for the measurement of the interfacial tension between mercury and organic media. The association numbers were estimated by vapor pressure depression measurements.
Radiative Lifetimes of NH2(2A1) Produced by Photodissociation of NH3 on Irradiation with Vacuum Ultraviolet Light
Authors: Koda Seiichiro
Published: July 2006

NH2(\ ildeA2A1) was produced by photolysis of NH3 on irradiation with vacuum ultraviolet light. The zero pressure lifetimes were evaluated to be ca. 15 μs from the phase lag of the emission excited by modulated Xe and Kr resonance lamps. The quenching rate coefficient of NH2(2A1) for NH3 was determined to be ca. (1.6±0.3)×10−10 cm3/molecule·s.
Time-Resolved Fluorescence Study of Exciplex and Triple Exciplex in 1,4-Dicyanobenzene and Alkylnaphthalenes
Authors: Mimura Tsutomu , Itoh Michiya
Published: July 2006

Exciplex (DA)* and triple exciplex (DDA)* formation between 1,4-dicyanobenzene (DCB) and alkylnaphthalenes was investigated by steady-state and nanosecond time-resolved fluorescence spectroscopies at room temperature. Typical two-component decay of the exciplex and the fluorescence rise of the triple exciplex were observed in dioxane solutions of DCB and several alkylnaphthalenes. The results imply a significant dissociation process of (DDA)* to (DA)*. Triple exciplex formation via excimer (DD)* was proposed to be significant in a concentrated solution of alkylnaphthalene (>10−1 M), while the triple exciplex was formed via the exciplex in a dilute solution of the electron donor.
Direct Measurement of the Rates of Ionic Dissociation by Dynamic NMR Technique. Dissociation of α-Chlorodibenzyl Sulfides
Authors: Arai Kazutaka , Oki Michinori
Published: July 2006

Exchange processes of diastereotopic protons of α-chlorodibenzyl sulfides were observed by means of dynamic nuclear magnetic resonance. Polar effects of solvents and substituent effects on the ease of the exchange process of protons in p,p′-disubstituted α-chlorodibenzyl sulfides indicate that the process occurs with the dissociation of the compounds into benzylic cations and chloride ion. It is possible to measure the rates of ionic dissocation by observing the change in the line shape of signals in 1H NMR spectra. The scope of the method is discussed.
The Daphniphyllum Alkaloids with A New Nitrogen Heterocyclic Skeleton
Authors: Yamamura Shosuke , Lamberton J A , Irikawa Hazime , Okumura Yasuaki , Toda Masaaki , Hirata Yoshimasa
Published: July 2006

The isolation and structures of six new alkaloids [yuzurine, daphnigracine, daphnigraciline, oxodaphnigracine, oxodaphnigraciline, and epioxodaphnigraciline] are described. The structure of yuzurine, which has been elucidated by means of an X-ray crystallographic analysis of the corresponding methiodide, is in full agreement with its spectral data. The structures of the other five alkaloids, all of which were isolated from the plant Daphniphyllum gracile Gage collected in New Guinea, were deduced on the basis of an exhaustive comparison of their spectral data coupled with chemical evidences. Finally, a plausible biogenesis of these alkaloids with a new type of nitrogen heterocyclic skeleton is discussed.
Layered Compounds. XLIII. Syntheses and Properties of [2.2]Naphthaleno-and [2.2]Anthraceno-heterophanes
Authors: Otsubo Tetsuo , Mizogami Shigeyoshi , Osaka Norihisa , Sakata Yoshiteru , Misumi Soichi
Published: July 2006

Several [2.2]naphthaleno- and [2.2]anthraceno-heterophanes were synthesized by cross-breeding Hofmann degradation of the corresponding two quaternary ammonium hydroxides. Two isomers, anti- and syn-forms, were obtained for [2.2](1,4)naphthaleno(2,5)thiophenophane, and one isomer, anti-from, for the [2.2](1,4)anthraceno homologue. The structures of the heterophanes were determined by variable temperature NMR analysis. Transannular π-electronic interactions between the condensed aromatic ring and the heteroaromatic ring were examined on the basis of electronic and emission spectra. The thiophene ring interacts more strongly with the condensed aromatic ring than the furan ring. For anthracenophanes, 9,10-bridged system shows more effective interaction than 1,4-bridged one.
A Reductive Elimination of Steroidal Diol Monoesters with Zinc Giving the Corresponding Olefins
Authors: Goto Giichi
Published: July 2006

Steroidal cis-diol monoacetates (1,9,11, and 13) were refluxed with zinc powder in acetic acid to give the corresponding olefins (2,10,12, and 14) in good yield. Under the reaction conditions, no reaction occurred with diol diacetates (1b: R1=R2=H, R3=R4=Ac and 1m: R1=C6H5, R2=H, R3=R4=Ac) and trans-diol monoacetates (15 and 16). Acyclic erythro and threo diol monoacetates (17 and 19) underwent highly stereoselective reduction affording 18 and 20, respectively. The olefin-forming elimination proceeded with syn-elimination of a cyclic orthoacetate intermediate (21). The effect of some metals on the reduction and the behavior of a number of esters (26) and orthoesters (27) were also investigated.
Purification of Xylenol Orange by the High-Speed Liquid Chromatography
Authors: Nakada Shoji , Yamada Mutsuo , Ito Tasuku , Fujimoto Masatoshi
Published: July 2006

A relatively large amount of 3,3′-bis[N,N-bis(carboxymethyl)aminomethyl]-o-cresolsulfonphthalein (Xylenol Orange, XO) is purified easily by the high-speed liquid chromatography (HSLC).
The Nuclear Quadrupole Spin-Lattice Relaxation of 35Cl in Methylammonium Hexachlorostannate(IV) and Hexachloroplatinate(IV)
Authors: Furukawa Yoshihiro , Kiriyama Hideko , Ikeda Ryuichi
Published: July 2006

The 35Cl nuclear quadrupole spin-lattice relaxation time, T1 in (CH3NH3)2MCl6 (M=Sn and Pt) was measured from 4.2 to 434 K in order to clarify the dynamic aspect of the phase transitions at 156 and 125 K respectively. The relaxation process in both low-temperature phases is dominated by the rotational vibration of the octahedral [MCl6]2− ions. Far above the transition point, Ttr, the T1 decreases very rapidly with an increase in the temperature. This indicates that each octahedron reorients about its threefold axis, with the activation energies of 77±3 for [SnCl6]2− ions and 95±10 kJ mol−1 for [PtCl6]2− ions. At Ttr the log(T1⁄s) vs. kK/T curve shows a distinct minimum, as in some K2PtCl6-type compounds. This anomalous behavior can be explained in terms of a soft rotary mode of the [MCl6]2− ions. The softening is estimated to be about 60%, according to Armstrong’s approach.
Polarographic Behavior of Chloramine-T in an Acidic Solution at a Rotating Platinum Electrode
Authors: Matsuda Toshio
Published: July 2006

The polarographic behavior of chloramine-T at a rotating platinum electrode has been investigated in an acidic solution. Chloramine-T gives a well-defined reduction wave at a relatively positive potential. This is found to be due to the reduction of the non-ionized species of N-chloro-p-toluenesulfonamide and of dichloramine-T produced by disproportionation reaction of chloramine-T. The chemical process attributed to the disproportionation reaction is involved in the electrode process. The shape of the wave which varies with the recording procedure is correlated with the change of surface conditions. At pH lower than 4, a small prewave of hypochlorous acid produced by hydrolysis is observed at a more positive side. The diffusion current of the total wave, very stable and proportional to the concentration, is due to a two-electron reduction.
Reaction between 2,2-Diphenyl-1-picrylhydrazyl and Phenols. Substituent and Solvent Effects
Authors: Nishimura Norio , Moriya Toshimichi , Okino Yoshiko , Tanabe Kazue , Kawabata Kimio , Watanabe Toshihiko
Published: July 2006

A kinetic study has been made of the reaction between 2,2-diphenyl-1-picrylhydrazyl and phenols in various solvents. Polar effects in the rate-determining transition state are discussed in terms of the Hammett type relationship. Remarkable solvation effects were observed. For p-methoxyphenol the reaction rate is the greatest in the solvents which do not form strong H-bond with phenols, and the smallest in aprotic H-accepting solvents. For o-methoxyphenol the rate is the greatest in protic solvents. The results are interpreted in terms of the difference in the mode of hydrogen bondings. The rate for the reaction of the radical with α-naphthol was followed in dioxane–2,2,4-trimethylpentane mixtures. The results are explained by the theory of Kondo and Tokura, indicating that the free energy depression in the ground state takes place mainly through hydrogen bonding.
Synthesis of 3(2H)-Furanones by the Iron Carbonyl-promoted Cyclocoupling Reaction of α,α′-Dibromo Ketones and Carboxamides. A Convenient Route to Muscarines
Authors: Hayakawa Yoshihiro , Takaya Hidemasa , Makino Shinji , Hayakawa Norihiro , Noyori Ryoji
Published: July 2006

Reaction of α,α′-dibromo ketones and N,N-dimethylcarboxamides with the aid of Fe2(CO)9 affords the corresponding reductive cyclocoupling products, 5-(dimethylamino)tetrahydro-3-furanones. In usual, the adducts derived from di-s-alkyl ketone dibromides easily eliminated dimethylamine to afford 3(2H)-furanones. N,N-Dimethylformamide (DMF), N,N-dimethylacetamide, N,N-dimethylbenzamide, and N-methylpyrrolidone have been used as dibromo ketone receptors. Thus, this general method provides a new, singleflask procedure for the preparation of the oxygen-containing five-membered ketones. The iron carbonyl-promoted 3+2 cyclocoupling reaction is interpreted as proceeding via a stepwise cycloaddition of a reactive 2-oxyallyl–Fe(II) intermediate and carboxamide. A facile conversion of such furanones to muscarine alkaloids is described.
Aromatic Sextets and Aromaticity in Benzenoid Hydrocarbons
Authors: Aihara Jun-ichi
Published: July 2006

The aromatic sextet theory of Clar was used to estimate the degree of aromaticity in benzenoid hydrocarbons. The resonance energies obtained correlate well with the Dewar-type resonance energies calculated in a previous paper.
Ion-Molecule Reactions in the Binary Mixture of Ethylene Oxide and Trioxane. I. Hydrogen Atom and Proton Transfer Reactions
Authors: Kumakura Minoru , Sugiura Toshio
Published: July 2006

The formation mechanism of protonated molecular ions by cross–reactions in ethylene oxide–trioxane mixtures has been studied with use of a modified time-of-flight mass spectrometer. The precursors of the product ions were determined by analysis of the fine structure of their ionization efficiency curves using deuterated ethylene oxide. Protonated ethylene oxide is formed by the hydrogen atom transfer reaction of ethylene oxide molecular ion with trioxane, and protonated trioxane by the proton transfer reaction of CHO+ (from ethylene oxide) with trioxane. In the ion-molecule reactions of ethylene-d4 oxide–trioxane mixtures, appreciable isotope effect was observed. The CHO+ from ethylene oxide is an important reactant ion as compared with that from trioxane in the proton transfer reaction, and CHO+ from ethylene oxide was suggested as a thermal reactive ion. The order of proton affinity could be estimated from the proton transfer reactions involving CHO+. It was found that the proton affinity of trioxane is smaller than that of ethylene oxide.
The Effect of 1,10-Phenanthroline on the Rate of Xylenol Orange Indicator Color Change
Authors: Wada Hiroko , Ishizuki Tomosuke , Nakagawa Genkichi
Published: July 2006

1,10-Phenanthroline(phen) accelerates the rate of the color change of Xylenol Orange(XO) in the copper(II)–EDTA titrations due to the formation of a mixed-ligand complex, (Cuphen)2xo. The rate of the substitution reaction of Cu2xo with 1,10-phenanthroline or with EDTA in the presence of 1,10-phenanthroline has been determined by the stopped-flow method over the pH range of 6.9–7.6 at μ=0.1 (KNO3) and 25±1°C. At 6.2×10−5–1.2×10−3M 1,10-phenanthroline, the rate-law is expressed as –d[(Cu2xo)′]/dt=k1[H][(Cu2xo)′]. The reaction mechanism proposed is (Remark: Graphics omitted.), and k1=5.5×107 M−1 s−1. By the addition of 2.5×10−6–10−5 M 1,10-phenanthroline, copper(II) can be titrated with EDTA at room temperature with XO as an indicator.
Formose Reactions. IV. The Formose Reaction in Homogeneous Systems and the Catalytic Functions of Calcium Ion Species
Authors: Shigemasa Yoshihiro , Shimao Masayuki , Sakazawa Chikahiro , Matsuura Teruo
Published: July 2006

By using the previously developed analytical method of oxidation-reduction potential measurement, the formose reaction homogeneously-catalyzed by calcium formate-potassium hydroxide at pH 10.5–12.0 was found to proceed as effectively as that heterogeneously-catalyzed by calcium hydroxide. Other calcium salts, including chloride, bromide, acetate, and propionate, could be used in place of calcium formate. Kinetic studies with the calcium formate–KOH system showed a linear dependence of the concentration of the dissolved calcium ion species on the induction period (Tmin) and the formose-forming period (Tmax–Tmin) at a given pH. From the results, the relationships, Tmin=a[CaOH+]+c and Tmax–Tmin=a[CaOH+]+b[Ca(OH)2]+c, were obtained, suggesting that CaOH+ is the principal catalytic species in the induction step, while both CaOH+ and Ca(OH)2 (or OH−) are present in the formose-forming step. The effects of various factors on both steps and the sugar yield were also examined.
Syntheses of Gramicidin S Analogs Containing δ-Aminovaleric Acid. [5–1′-δ-Aminovaleric Acid]-Gramicidin S and [5–1′, 5′-1-Bis(δ-Aminovaleric Acid)]-Gramicidin S
Authors: S\={o}fuku Sh\={o}suke , Yoshida Akio , Baba Hiroki , Muramatsu Ichiro
Published: July 2006

Gramicidin S (GS) analogs, [5–1′-(δ-aminovaleric acid]-GS dihydrochloride (XIII) and [5–1′, 5′–1-bis(δ-aminovaleric acid)]-GS dihydrochloride (XIX), were synthesized. Both peptides are the analogs in which one or two l-prolyl-l-valyl residues of GS are replaced with one or two δ-aminovaleric acid residues. The spectra of optical rotatory dispersion (ORD) and circular dichroism (CD) of XIII and XIX were measured. The molar optical rotation of XIII is smaller than that of GS, but its ORD spectrum resembles that of GS. Analog XIII shows some antimicrobial activity, but not the analog XIX.
Substitution on Carbenoid Carbon of α-Halocyclopropyllithium. A Novel Stereoselective Synthesis of Geminally Substituted Cyclopropanes
Authors: Kitatani Katuzi , Yamamoto Hajime , Hiyama Tamejiro , Nozaki Hitosi
Published: July 2006

The halogen atom of the title carbenoids is susceptible to displacement by butyllithium. 1-Butyl-1-lithiocyclopropanes are formed, in which the butyl group occupies the less hindered site trans or exo position). The new reaction provides a means for the preparation of geminally disubstituted cyclopropanes with high degree of stereoselectivity.
Preparation of Perfluoroalkylated Benzoheterocyclic Compounds Using Hexafluoro-1,2-epoxypropane
Authors: Ishikawa Nobuo , Sasaki Shigekuni
Published: July 2006

Utilizing the high reactivity of hexafluoro-1,2-epoxypropane (HFPO, hexafluoropropylene oxide), several new benzoheterocyclic compounds containing CF3 and C2F5 were prepared as follows: (1) 2-(pentafluoroethyl)benzoxazoles by treating 2-aminophenols with HFPO/Et3N, followed by dehydrating cyclization, (2) 3-(trifluoromethyl)2H-1,4-benzoxazin-2-ones, 3-(trifluoromethyl)-2(1H)-quinoxalinone and 2-fluoro-2-(trifluoromethyl)-2,3-dihydro-1,4-benzothiazin-3-one by reactions of ortho-bifunctional benzenes with HFPO, and (3) 2-(pentafluoroethyl)-4H-3,1-benzoxazin-4-one by treating anthranilic acid with HFPO/Et3N.
An ESR Study of Photo-Induced Electron Transfer Reaction between Zinc(II)–Tetraphenylporphyrin and p-Benzoquinone in Solutions
Authors: Shiozawa Masayuki , Yamamoto Haruhiko , Fujita Yuzaburo
Published: July 2006

The titled reaction was studied, by means of the ESR technique at room temperature, as a model reaction of the primary process in the photosynthesis. Two kinds of radicals were observed in dichloromethane upon illumination with light of the porphyrin excitation; the zinc–tetraphenylporphyrin cation radical and the semiquinone neutral radical.
1,3-Dithian-2-one Tosylhydrazone. Synthesis and Carbenoid Decomposition
Authors: Obata Naruyoshi
Published: July 2006

1,3-Dithian-2-one tosylhydrazone was prepared by the reaction of potassium 3-tosyldithiocarbazate and 1,3-dibromopropane. Carbenoid reactions of the tosylhydrazone were investigated.
Statistical Thermodynamics of Liquid Mixtures
Authors: Tokiwano Kazuo , Arakawa Kiyoshi
Published: July 2006

A statistical thermodynamic theory of binary liquid mixtures has been worked out on the basis of the equivalent free volume defined without use of lattice model. A liquid mixture is regarded as a mixture of hard spheres immersed in a uniform background potential. The total free energy is expressed as the sum of terms given by the analytical solution of the generalized Percus-Yevick equation for the hard sphere mixture and the term resulting from the uniform background potential. Thermodynamic functions are in a simple form convenient for practical applications. The nature of the equivalent free volume for the mixture which consists of molecules differing in size is elucidated. The energy interaction parameters and excess thermodynamic functions for eight binary mixtures composed of nonpolar molecules are calculated, and the results are discussed.
ENDOR Studies on Low-Symmetry Triphenylmethyl with ortho- or para-Methoxy Substituents
Authors: Ishizu Kazuhiko , Mukai Kazuo , Shibayama Atsuko , Kondo Kyoko
Published: July 2006

ENDOR observations were carried out for several triphenylmethyl derivatives with ortho- or para-methoxy substituents. The alteration of the spin-density distribution caused by steric hindrance, in particular, due to the low symmetrical substitution, was investigated. Using a revised MO parameter proposed by Kulkarni, McLachlan MO calculations were carried out and the twisting angles of the hindered phenyl groups are estimated.
Simultaneous Determination of the Atomic Ratio between C, H, O, and N by the Pyrolytic Sulfurization Method
Authors: Tsuji Katsuya , Fujinaga Kaoru , Hara Tadashi
Published: July 2006

From a sample subjected to pyrolytic sulfurization in a sealed quartz tube, the evolved gases, carbon disulfide, carbon monoxide, carbon dioxide, carbonyl sulfide, hydrogen sulfide, and a nitrogen molecule were simultaneously estimated. Determination of the atomic ratio between C, H, O, and N was carried out by means of three calibration curves obtained by use of glycine, l-glutamic acid, l-citrulline, and fumaric acid. They are applicable to carboxylic acids and the other compounds, but not to compounds including nitro and/or sulfo groups.
The Absolute Configuration and Circular Dichroism of the (−)260-Diammine((S)-1-N-methyl-1,2-propanediamine)platinum(II) Ion, (−)260-[Pt(NH3)2(N1-Me-(S)-pn)]2+
Authors: Nakayama Yasuji , Matsumoto Keiji , Ooi Shun’ichiro , Kuroya Hisao
Published: July 2006

The optical resolution of [Pt(NH3)2(N1-Me-(S)-pn)]Cl2 is effected by using silver di-μ-(+)-tartrato(4−)-bis(antimonate(III)) (Ag2[Sb2(+)-tart2]) as the resolving agent. X-Ray structure analysis of the less soluble diastereoisomeric salt, (+)350-[Pt(NH3)2(N1-Me-(S)-pn)][Sb2(+)-tart2]·H2O, revealed that the asymmetric secondary nitrogen is of the R configuration. The crystal is orthorhombic, with a P212121 space group, a=19.302(7) Å, b=14.791(4) Å, c=7.925(2) Å, and Z=4. The structure was determined from counter intensity data and refined to R 0.049 using the least-squares method for 1955 independent non-zero reflections. The Pt atom has a square-planar coordination with 4 N atoms and both the N–CH3 and C–CH3 groups are equatorial with respect to the chelate ring. The circular dichroism spectrum of R-[Pt(NH3)2(N1-Me-(S)-pn)](ClO4)2, which was obtained from the less soluble di-μ-(+)-tartrato(4−)-bis(antimonate(III)) salt, is presented and discussed on the basis of the distribution of the possible conformers, the relative abundances of which were infered from 13C NMR data.
13C-NMR-Spektren von thermischen Oligomeren des Cyclopentadiens
Authors: Nakagawa Kiyoshi , Iwase Shoji , Ishii Yasutaka , Hamanaka Sawako , Ogawa Masaya
Published: July 2006

Die zwei Isomere des Dicyclopentadiens und vier Isomere des Tricyclopentadiens werden isoliert und ihre 13C-NMR-Spektren werden vorgelegt, wobei die Trimerisationsstufe des Cyclopentadiens systematisch in allen Einzelheiten behandelt wird. Die 13C-NMR-Spektren von Oligomeren des Cyclopentadiens werden durch Vergleich mit Spektren von Vergleichssubstanzen zugeordnet. Es ist beachtenswert, dass zwei neue Stereoisomere des Tricyclopentadiens isoliert und nachgewiesen werden.
Coenzyme Models. IX. Micellar Catalysis of Isoalloxazine (Flavin) Oxidation of Dithiol
Authors: Shinkai Seiji , Kunitake Toyoki
Published: July 2006

The influence of micelles on the reaction of isoalloxazines and 1,4-butanedithiol(BDT) was studied. The pKa of BDT was lowered by 0.3 pK unit in the presence of the hexadecyltrimethylammonium bromide(CTAB) micelle, indicating the formation of “hydrophobic ion pairs.” The apparent second-order rate constant for the reaction of 3-methyl-10-ethylisoalloxazine and BDT increased by 18-fold on addition of CTAB(3 mM). The UV-visible spectrum of 3-hexadecyl-10-butylisoalloxazine in the presence of the CTAB micelle was similar to that in organic solvents, the rate being enhanced by more than 400-fold as compared with that in a nonmicellar system. Anionic(SDS) and nonionic(Brij-35) micelles suppressed the reaction. The results show that the flavin oxidation of dithiol is facilitated by the environments of the CTAB micelle.
Yields of Excited Triplet Products Generated from the Air Oxidation of 3-Methyl-2-butanone and Isopropyl Phenyl Ketone in a Dimethyl Sulfoxide Solution Containing Potassium t-Butoxide
Authors: Kamiya Isao
Published: July 2006

An attempt has been made to evolve the kinetic scheme in order to evaluate the yields (φreact*) of excited triplet products generated from the air oxidation of 3-methyl-2-butanone (1) and isopropyl phenyl ketone (2). Expressions for the total light emission and quantum yield of the indirect chemiluminescence (CL) can be derived, from which the rates of energy transfer from excited triplet products to singlet 9,10-dibromoanthracene (DBA), kTS, and φreact* were determined on the basis of the CL intensity measured for various DBA concentrations. The values of kTS from 1 and 2 (4×108 and 1×109 1 mol−1 s−1) are in fair agreement with the values proposed by several investigators who measured the indirect CL from the thermal cleavage of 1,2-dioxetanes. The markedly small φreact* values (1×10−5 and 1×10−3) result from the fact that the CL arises from a minor reaction.
Cobalt(III) Complexes Containing Large Chelate Rings. II. Syntheses and Properties of Cobalt(III)–Ammine Complexes Containing α,ω-Alkanediamines
Authors: Ogino Hiroshi
Published: July 2006

Reactions of [Co(H2O)(NH3)5](ClO4)3 with H2N(CH2)nNH2 (N–N) in dimethyl sulfoxide were examined by changing the number of methylene groups in N–N (n=2–5, 7, 8, 10, 12, and 14). Complexes of the Co(NH3)4(N–N)3+ type were found to be formed for n=2–4, 12, and 14, but, not for n=5, 7, 8, and 10. In addition to these products, a number of new cobalt(III) complexes were isolated.
The Crystal Structure and Magnetic Property of Di-μ-propionato-O,O′-bis[N-p-tolylsalicylideneaminatocopper(II)]
Authors: Mikuriya Masahiro , Kida Sigeo , Ueda Ikuhiko , Tokii Tadashi , Muto Yoneichiro
Published: July 2006

The crystal structure of di-μ-propionato-O,O′-bis[N-p-tolylsalicylideneaminatocopper(II)] was determined by X-ray diffraction method using the data collected by counter diffractometer techniques. The space group is P\bar1 and the cell constants are a=12.565(2), b=13.040(2), c=12.230(2) Å, α=107.73(1), β=115.72(1), γ=100.18(1)°, and Z=2. The structure was solved by the heavy atom method and refined by the block-diagonal leastsquares method to an R factor of 0.029. The crystal is composed of one-dimensional chains extended along the c axis, where the two copper atoms coordinated by the Schiff bases are bridged by two propionate groups. The magnetic property was discussed on the basis of the crystal structure.
ESR and ENDOR Study of the Carbonization of Rubrene
Authors: Yamada Yoshio , Sanada Yuzo
Published: July 2006

An ESR spectrum of the radical produced during the carbonization of rubrene was measured and analyzed from an ENDOR spectrum and using computer simulations.
Adsorption of Phosphate on Synthetic Silica–Alumina Possessing Lewis-acid Sites
Authors: Takimoto Kazuto , Fujita Akira , Tsuda Satoru
Published: July 2006

It was confirmed from measurements of the adsorption isotherms of phosphates in aqueous solutions that there were adsorption sites with very high reactivity on the surface of silica–alumina. The concentration of adsorption sites which is estimated from the adsorption amount extrapolated to zero equilibrium concentration is nearly twice the concentration of Lewis-acid sites for silica–alumina of higher alumina content. Furthermore, the concentration of phosphate adsorbed on the surface of various silica–alumina is relatively well correlated with the concentration of Lewis-acid sites.
Dye-sensitization on the Photocurrent at Zinc Oxide Electrode in Aqueous Electrolyte Solution
Authors: Matsumura Michio , Nomura Yoichi , Tsubomura Hiroshi
Published: July 2006

The dye-sensitized photocurrents generated from the electrochemical systems  have been studied. The action spectra for the photocurrent, its dependence on the concentration of the dye solution and other experimental results have revealed that the photocurrent is caused by the dye adsorbed on the electrode, not from that dissolved in the liquid phase. From the analysis of the decay of the photocurrent with the time of illumination, the quantum yield for the electron injection from the excited dye has been determined. Rose Bengal showed the quantum yield of 22%. The influence of halide ions on the photocurrent has also been studied.