bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dipolar Interaction in TEMPAD Biradical. II
Authors: Nakajima Akira , Yamauchi Jun , Ohya-Nishiguchi Hiroaki , Deguchi Yasuo 
Published: July 2006

Abstract
The EPR of TEMPAD single crystals diluted in diamagnetic matrices was studied. The results of the 10% TEMPAD were almost the same as those of the very dilute one studied previously. In the case of the 25% TEMPAD, the spectra are composed of three parts. The central broad line, whose linewidth was analyzed in comparison with the pure TEMPAD case using the three-dimensional Anderson-Weiss formula, is the spectrum of clusters constructed by the free radicals. The side lines with the hyperfine splitting are the spectrum of the isolated TEMPAD molecule, and the outer broad lines are from the molecules coupled in pairs along the a-axis. The EPR spectra of the pure TEMPAD at very low temperature were also measured in order to have information concerning the dipolar interaction in the pure crystal. These spectra are the superposition of the spectra caused by the intra-molecular dipolar interaction and of the spectra due to impurities. All the results were explained with the suitable molecular stack model and the triplet exciton theory.
Microwave Spectrum of syn-Acetaldehyde Oxime-d
Authors: Ohashi Osamu , Ishihara Ryoji , Murakami Kakuji , Sakaizumi Takeshi , Onda Masao , Yamaguchi Ichiro 
Published: July 2006

Abstract
The microwave spectrum of syn-acetaldehyde oxime-d was investigated in the frequency region 7.5∼35 GHz. Several a-type R-branch transitions were identified and the following rotational constants in MHz were obtained: A=45682, B=4057.21, C=3806.13. The transitions of syn-acetaldehyde oxime-d are split into the A and E species by tunneling of the methyl group through the potential barrier hindering the internal rotation. From these separations the height of the barrier was determined to be 1948 cal mol−1. The dipole moment of the molecule was determined to be 0.938 D from the Stark effect.
Effect of Water on Crystallization Process of Coesite
Authors: Kameyama Tetsuya , Naka Shigeharu 
Published: July 2006

Abstract
The effect of water on crystallization process of coesite was studied at 450 to 700 °C under 30 kbars by using different starting materials. The presence of water under compression and heating was found to have remarkable effects not only on the kinetics of crystallization of coesite also on the morphology of metastable quartz, consequently of coesite crystals. Under anhydrous condition, from amorphous silica and silica glass, the spherulitic aggregates of metastable quartz appeared. The coesite crystals were developed in the spherulites of quartz as elongated crystals with different sizes and appeared to be defective. When synthetic quartz was used as a starting material, however, no formation of spherulitic aggregates of quartz was observed and granular coesite crystals were obtained. Under hydrous condition, granular coesite crystals with homogeneous size were developed rapidly at 450 °C from both amorphous silica and silica glass through the discrete particles of metastable quartz.
Microwave Spectrum of Ethyl Isothiocyanate
Authors: Sakaizumi Takeshi , Ohashi Osamu , Yamaguchi Ichiro 
Published: July 2006

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.
Synthesis of Some Imidazo[1,2-c][1,2,3]triazolo[4,5-e]pyrimidines
Authors: Sugimoto Takashi , Matsuura Sadao 
Published: July 2006

Abstract
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

Abstract
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

Abstract
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

Abstract
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−&gt;Cl−&gt;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

Abstract
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

Abstract
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

Abstract
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&gt;XI with the number of benzene ring fused to seventeen-membered ring system.