bluuebunny/crossref_metadata_2025_split huggingface dataset:
ESR Study of γ-Irradiated Ammonia-Silica Gel System
Authors: Nagai Siro 
Published: July 2006

Abstract
Ammonia-silica gel system was γ-irradiated at −196 °C. ESR spectrum observed from samples with low ammonia content showed a marked linewidth anomaly in the hf lines at −196 °C and changed with temperature reversibly. The free radical responsible for the spectrum was assigned to NH2 radical which undergoes a preferential rotation about an axis perpendicular to the radical plane at low temperatures and a substantially free rotation above −90 °C.
Properties of Water in Macromolecular Gels. V. Anomalous Temperature Dependence of the Nuclear Magnetic Resonance Line-width of Water in Macromolecular Gels
Authors: Aizawa Masuo , Suzuki Shuichi , Suzuki Teruo , Toyama Hiroshi 
Published: July 2006

Abstract
The line-width of the nuclear magnetic resonance (NMR) signal gets narrow, in general, with an increase in the temperature. In contrast, the NMR line-width of the water proton in agarose gels was found to increase with an increase in the temperature up to about 30°C. As for the other polysaccharide gels, such as curdlan-type polysaccharide, and κ-and λ-carrageenan gels, the NMR line-width of water increases with an increase in the temperature. The anomalous temperature dependence of the line-width was most marked in agarose gels than in other polysaccharide gels. The close relationship between the gel network, which consists of small cavities (microspace) of the micelle, and the magnitude of the anomality was revealed, this anomalous effect was named the “Micro-Space Effect.”
The Oxidation of Iron(II) by Molecular Oxygen Catalyzed by Chloride Ion, Thiocyanate Ion, and Ethylenediamine in Dimethyl Sulfoxide
Authors: Unno Yuriko , Wada Goro 
Published: July 2006

Abstract
The rates of the oxidation reactions of iron(II) to iron(III) by molecular oxygen in DMSO were measured under the catalyses of Cl−, SCN−, and en. The rate was proportional to the partial pressure of oxygen and was of the second order to [Fe(II)] in catalyses of Cl− and SCN− while it was of the first order to [Fe(II)] in catalysis of en. The reaction rate was also linear to [X]2 and [H+], where X represents Cl− or SCN−, indicating that the reaction proceeds via both the electron-transfer and hydrogen-atom-transfer mechanisms, side by side. The reaction order of [Fe(II)] depends upon which step is rate-determining among those of the oxygenation of Fe(II), its spontaneous decomposition, and its bimolecular reaction with another Fe(II) and, therefore, may be variable according to the concentrations of the reacting species. The autoxidation rate can be affected by the kinds of the catalyzing ligands. The autoxidation may be slow when an Fe(II) complex with low spin is oxidized to an Fe(III) complex with high spin and may be fast when from high spin type to low spin one. In the present cases of Cl−, SCN−, and en in DMSO, it seems to go from high spin type to high spin one with moderately large rates.
The Calculation of Dipole Polarizability and Anisotropy by the CNDO Method
Authors: Miyazaki Tomoo , Shinoda Hiroyuki 
Published: July 2006

Abstract
The dipole polarizabilities and the anisotropies of small linear molecules have been calculated according to a formula in which the frequency of the incident light is taken into account, as derived by the time-dependent perturbation theory. The wave functions and the energies were calculated by the CNDO method, involving the configuration interaction treatment. The effect of the parametrization in the CNDO method on the calculated polarizability and anisotropy has also been discussed. The method has been used to calculate the variations in the anisotropy, the polarizability, α, and its derivatives, (∂α⁄∂Si)0 and (∂2α⁄∂Si2)0, with the frequency of the incident light, where Si is the appropriate symmetry coordinate of the molecular vibration.
Studies on Reactions of the JV-Phosphonium Salts of Pyridines. II. A New Method for the Activation of Carboxylic Acids via the N-Phosphonium Salts by Means of the Oxidation of Phosphorous Acid and Its Monoesters in the Presence of Tertiary Amines
Authors: Yamazaki Noboru , Higashi Fukuji 
Published: July 2006

Abstract
The oxidation of phosphorous acid and its monoesters with mercuric chloride was carried out in pyridine; they were then treated with carboxylic acids and with aniline. The oxidation reaction was conducted also in the presence of carboxylic acids, after which the mixture was treated with aniline. By both procedures, the corresponding anilides were obtained in good yields. The influence of the steric factors of carboxylic acids, their acidity, and the tertiary amines were observed in the reaction. Phosphorous acid provided a better result than the monoesters. In addition, the chain length of carboxylic acids in the case of the esters influenced the yields of the anilides, which decreased with an increase in the chain length. The structural effect of tertiary amines was studied on pyridine derivatives. The ester residues also affected the yield, and of the esters examined the monophenyl ester was more favorable than the alkyl esters. Other mercuric halides and mercuric acetate were also found effective as oxidizing agents. The reaction was proposed to proceed via the N-phosphonium salts of pyridines.
Stereospecific Addition Reaction between Butadiene and Amines
Authors: Narita Tadashi , Imai Nobuyoshi , Tsuruta Teiji 
Published: July 2006

Abstract
The reaction of butadiene with secondary amines initiated by n-butyllithium was found to proceed selectively to produce 1-dialkylamino-cis-butene-2 under appropriate reaction conditions. For instance, diethylamine produced 1-diethylamino-cis-butene-2 in a 98–99% purity. By kinetic and spectroscopic studies, it was concluded that the lithium dialkylamide-dialkylamine (1:2) complex plays an important role in this addition reaction. The second-order rate constants of the reaction are 0.85×10−3 l/mol sec for diethylamine and 2.4×10−3 l/mol sec for diisobutylamine.
Studies on Aminosugars. XXXIV. Synthesis of 4-O- and 6-O-(4-amino-4-deoxy-α-d-glucopyranosyl)-2-deoxystreptamine
Authors: Nishimura Yoshio , Tsuchiya Tsutomu , Umezawa Sumio 
Published: July 2006

Abstract
Racemic O-isopropylidene derivative of N,N′-diethoxycarbonyl-2-deoxystreptamine was glycosidated with 4-azido-2,3,6-tri-O-benzyl-4-deoxy-α-d-glucopyranosyl chloride to afford two kinds of position isomers of α-glucoside, which was led to 4-O-(4-amino-4-deoxy-α-d-glucopyranosyl)- and 6-O-(4-amino-4-deoxy-α-d-glucopyranosyl)-2-deoxystreptamine.
The SCF Screened Potential in π-Electron Systems
Authors: Terasaka Toshitaka , Ijima Taizo , Fujimura Yuichi , Nakajima Takeshi 
Published: July 2006

Abstract
The screened potentials π-electron systems have been calculated using the SGF orbitals and energies, and compared with Little’s screened potentials calculated using the Hückel orbitals and energies. The characteristics of the screened potentials in benzenoid and nonbenzenoid aromatic hydrocarbons and in linear polyenes have been studied. It has been found that the use of the screened potential brings about considerable improvements in the triplet excitation energies in particular.
Studies on Fragment Ion Distribution and Reaction by the Use of a Charge Spectrometer. I. Mass Spectra of Methylamine after Charge Exchange with Fast Positive Ions and Their Recombination Energies
Authors: Nagatani Toshio , Yosihara Kenji , Shiokawa Takanobu 
Published: July 2006

Abstract
Charge exchange reactions with fast positive ions were used to obtain the break down curve and internal energy distribution function of methylamine which differ in several points from those obtained by Sjögren with very slow ions. In the higher region, our results on the population in internal energy distribution function is greater than the previous ones. A valley of the internal energy distribution curve was found in the region 12.0–13.8 eV which is higher than that obtained by Sjögren. The values of RE were reestimated according to recent results.
Determination of the Intersystem Crossing Probabilities of Acridine in Various Alcohols
Authors: Tokumura Kunihiro , Kikuchi Koichi , Koizumi Masao 
Published: July 2006

Abstract
Intersystem crossing probabilities φST of acridine in methanol, ethanol, and 2-propanol were determined by two newly developed methods, relative (r) and absolute (a). The results are as follows. Methanol; 0.27 (r), 0.31 (a). Ethanol; 0.29 (r), 0.33 (a). 2-Propanol; 0.43 (r), 0.45 (a). The above φST values added to the quantum yield values already obtained of photoreduction occurring at T(n-π*), viz., 2φRT (radical mechanism via T(n-π*), disproportionation of semiquinone being taken into account by a factor of 2) + φMT (molecular mechanism via T(n-π*)), become about the same for the three alcohols. Thus the present data are consistent with our previous data on photoreduction if the intersystem crossing is assumed to occur mainly via S*(π-π*)→T(n-π*)→T(π-π*) with the same total φST for the three alcohols but with T(n-π*) participating in the reaction in different extent according to the alcohol.
The Determination of the CMC of Surfactants in Some Organic Solvents
Authors: Muto Shinya , Meguro Kenjiro 
Published: July 2006

Abstract
Extra absorption spectra appeared when 7,7,8,8-tetracyanoquinodimethane (TCNQ) was solubilized into surfactant organic solvent solutions above the critical micelle concentration (CMC). It was found also that extra absorption spectra appeared when iodine was solubilized into surfactant organic solvent solutions above the CMC. In the former case, the extra absorption spectra are attributed to TCNQ anion radical salts formed between TCNQ and the surfactants. In the latter, the extra absorption spectra are due to charge-transfer interactions of iodine with the surfactants. The intensity of the absorption bands increased with the concentrations of the surfactant. The values of the CMC of the surfactants were determined from this spectral change. The CMC values obtained by the TCNQ solubilization method were larger than those obtained by the iodine solubilization technique. The difference in the CMC between the two methods was interpreted in terms of the difference in solubility and chargetransfer power to the organic solvent between iodine and TCNQ, and the difference in type of electron transition, that is, n(D)→σ(A) or n(D)→π(A).
Effective Ionic Charges of Several Uniaxial Crystals
Authors: Hiraishi Jiro 
Published: July 2006

Abstract
A simple equation was derived for obtaining the effective ionic charges of uniaxial crystals on the basis of a rigid ion model by using the optically active lattice vibration frequencies of the TO and LO modes. It was applied to several uniaxial crystals such as wurtzite type (ZnO, ZnS, CdS, and BeO) and rutile type (ZnF2, TiO2, SnO2, and GeO2) crystals. Lattice vibration frequencies of orthorhombic hydrogen chloride crystal were calculated by means of a point charge model to estimate the effect of the long range Coulomb interaction on the vibrational frequencies of molecular crystals.
ESR of Hot Ions: Ni(I) Complex Ions Produced in Rigid Solutions by γ-Irradiation
Authors: Amano Chikara , Fujiwara Shizuo 
Published: July 2006

Abstract
Electron spin resonance has been used to study Ni(I) complex ions produced at 77 K through reduction by γ-irradiation of Ni(II) complexes in glassy solvents. The Ni(I) complex ions give axially symmetrical spectra, suggesting that the Ni(I) ions favor tetragonally elongated octahedral form. From the g-values it can be shown that the Ni(I)-to-ligand bonding for different ligands increases in covalency in the order: H2O&lt;edta&lt;&lt;py∼en∼xanthate&lt;phen&lt;dipy&lt;&lt;CN−. It can also be shown that the metal-to-ligand bonding of the Ni(I) complex ions is less covalent than that of the corresponding Cu(II) complexes. Measurement of the integrated intensity of the ESR spectrum of [Ni(I)(H2O)6]+ with reference to a standard sample of [Cu(II)(H2O)6]2+ shows that at a total dose of 1×106 R the yield of the Ni(I) species is 0.21±0.04% of the host complex [Ni(II)(H2O)6]2+. In addition to the anisotropic spectra of the Ni(I) complex ions, isotropic spectra have been observed in several cases, which are probably due to Ni(III) complex ions. Isotropic feature of these spectra may be explained in terms of dynamic Jahn-Teller effect involving the Ni(III) complex ions.
Kinetics and Mechanism of the Transformation of Vaterite to Calcite
Authors: Rao M Subba 
Published: July 2006

Abstract
The transformation of vaterite to calcite was investigated systematically. The transition temperature and the energetics of the transformation were determined from differential thermal curves. The variations of lattice constants and crystallite size, accompanying the transformation were studied by X-ray diffractometry. The kinetics of transformation were investigated in the temperature range 460–490°C. The kinetic data were analysed with the help of three separate solid-state models.
A Method of Correction of the Angular Resolution for Determination of Absolute Total Cross Sections Using Molecular Beams
Authors: Kusunoki Isao 
Published: July 2006

Abstract
A general method is given for the correction of angular resolution for the case in which primary beams have a monochromatic velocity and the target gases in the scattering chamber have Maxwellian distribution. In the center-of-mass system the differential cross section for small angles are expressed by three analytical formulas. An apparent differential cross section in the laboratory system is given by averaging contributing differential cross sections in the center-of-mass system. For correction of the angular resolution, the detection probability R is defined for rectangular beams and detector. Using the apparent differential cross section with R-function and beam profile, we can determine the correction factor ΔQeff(vi)⁄Qeff(vi). The expression of angular resolution has been applied to previous experimental data.
Derivatographic Studies on Transition Metal Complexes. X. Thermal Octahedral-to-Square Planar Transformation of Ni(NN-deen)2X2·nH2O in Solid Phase
Authors: Tsuchiya Ryokichi , Joba Seiji , Uehara Akira , Kyuno Eishin 
Published: July 2006

Abstract
Thermal reactions of the complexes [Ni(H2O)2(NN-deen)2]X2·nH2O (NN-deen is N,N-diethylethylene-diamine and X is Cl or Br) were investigated. It was found by derivatography and spectral and magnetic measurements that the bromide undergoes transformation from octahedral to square planar structure by “deaquation” upon heating, whereas the chloride turned to the dichloro complex by thermal “deaquation-anation” losing the coordinated water and drawing chloride ion into the coordination sphere with retention of octahedral structure around the central metal. No such transformation could be found in the corresponding iodide and nitrate, since only diamagnetic complexes, [Ni(NN-deen)2]X2 (X is I or NO3), and no paramagentic complexes were obtained.
Electronic Spectra of High-Spin Iron(III) Tetraphenylporphins
Authors: Kobayashi Hiroshi , Yanagawa Yasuo , Osada Hisajiro , Minami Shuji , Shimizu Masayuki 
Published: July 2006

Abstract
Characterization of the electronic absorption spectra of high-spin iron(III) porphyrins was carried out on the basis of observation and theoretical calculation for tetraphenylporphinatoiron(III) and -manganese(III) complexes.
Formation of Sulfur Ylids by Catalytic Action of Dialkoxy Disulfides
Authors: Matsuyama Haruo , Minato Hiroshi , Kobayashi Michio 
Published: July 2006

Abstract
In the presence of a catalytic amount of a dialkoxy disulfide, dimethyl diazomalonate spontaneously reacted with a dialkyl sulfide in the absence of light at room temperature, and the corresponding sulfonium ylid was formed. The kinetics and products of this reaction were investigated, and its mechanism was discussed.
The Synthesis of Crystalline Rare Earth Carbonates
Authors: Nagashima Kozo , Wakita Hisanobu , Mochizuki Akihiko 
Published: July 2006

Abstract
The factors which influence the crystallization of rare earth carbonates were studied. Crystalline rare earth carbonates were precipitated at various temperatures from aqueous solutions by using sodium carbonate, sodium bicarbonate, trichloroacetic acid, and urea as precipitants. The crystal parameters, compositions, and factors concerning the formations of various carbonates, such as lanthanite-type Ln2(CO3)3·8H2O(Ln=La, Ce), tengeritetype Ln2(CO3)3·nH2O(Ln=Nd, Sm, Gd, Dy, Ho, Er, and Y, n=2–3), monoxocarbonate-type Ln2O(CO3)2·nH2O(Ln=La, Ce, Nd, and Sm, n=1–2) and a hydrated double carbonate of rare earth and sodium (rare earth= La, Ce, Nd, Sm, Gd, Dy, and Y) were determined by chemical analysis and X-ray powder diffractometry.
The Adiabatic Compressibility of Nonelectrolyte Aqueous Solutions in Relation to the Structures of Water and Solutions. II.
Authors: Endo Harumi 
Published: July 2006

Abstract
From the temperature dependency of the adiabatic compressibility in aqueous systems of nonelectrolytes, established by ultrasonic measurements, it is concluded that structural units to be termed “liquid clathrate hydrates” do exist for various systems, the concentration of the zero temperature coefficient of adiabatic compressibility representing the composition-mole-ratio, rcβ(water/solute), for these hydrates. Hydrates with rcβ=7.2⁄3 (for methanol, formamide, and urea) and 17 (for acetone and ethanol) correspond to the solid clathrate hydrates of Structures I and II respectively, while those with rcβ=24, 28, 32, etc, can be explained on the basis of appropriate assumptions.
The Absolute Configuration of the (−)589-Oxalatobis(ethylenediamine)-cobalt(III) Ion as Determined by X-Ray Structure Analysis
Authors: Aoki Tadashi , Matsumoto Keiji , Ooi Shun’ichiro , Kuroya Hisao 
Published: July 2006

Abstract
The absolute configuration of (−)589-[Co ox en2]+ has been determined by the X-ray diffraction method. The crystals of (−)589-[Co ox en2]Br·H2O are orthorhombic, with the space group P212121, and the unit cell dimensions are: a=16.67(1)Å, b=12.40(1)Å, c=6.183(7)Å, and Z=4. The crystal structure was solved by the conventional Patterson and Fourier methods, and refined by the least-squares procedure to an R factor of 9.97%. The cobalt atom has an octahedral coordination, being chelated by an oxalate anion and two ethylenediamine molecules which are of the ob-lel conformation. The absolute configuration of the complex cation can be denoted as Δ(δλ).
Methylene Analogs of Cyclobutenedione. VI. Interconversion between 3,4-Dimethylcyclobut-3-ene-1,2-dione and 3,4-Dimethylenecyclobutane-1,2-dione
Authors: Toda Fumio , Ooi Nobuhiro 
Published: July 2006

Abstract
Treatment of 3,4-bis(diphenylmethyl)cyclobut-3-ene-1,2-dione (I) with bromine in ROH (R=H, Me, Et, and i-Pr) afforded 3,4-bis(diphenylmethylene)cyclobutane-1,2-dione (IV) and 3-diphenylmethyl-4-alkoxydi-phenylmethylcyclobut-3-ene-1,2-dione (III) in various ratios depending on the steric bulkiness of R of ROH. Acidification of a solution of III in KOH–MeOH, in which III exists in the form of enolate anion (VIII), afforded III and IV in various ratios depending on the steric nature of the substituent R. Bromination of IV in 99% acetic acid afforded 3,4-bis(hydroxydiphenylmethyl)cyclobut-3-ene-1,2-dione (XI). Although the bromination of XI with phosphorus tribromide afforded IV, that with bromine afforded the 2,5-dihydrofuran derivative (XVII). The reaction of I with o-phenylenediamine to afford azamethylenecyclobutane derivatives XXV and XXVI is described.
N-Halogen Compounds of Cyanamide Derivatives. I. Rearrangement of N-Alkylhaloamidines
Authors: Fuchigami Toshio , Ichikawa Eiichi , Odo Keijiro 
Published: July 2006

Abstract
The reactions of N-chloroamidines with various dehydrochlorinating reagents were studied. N-Alkyl-N-chloroamidines were treated with sodium alkoxide, sodium hydroxide, and silver oxide to form O-alkylisoureas, ureas, and carbodiimides, respectively. However, N′-chloro-N′,N′-dialkylamidines did not afford corresponding products. The mechanisms for the rearrangements are discussed.
A New Route for the Preparation of Pyrazolo[4,3-c]pyridines
Authors: El-sayed Abdou Ahmed , Ohta Masaki 
Published: July 2006

Abstract
The anhydride (II) of 4-carboxy-1,5-diphenylpyrazole-3-acetic acid (I) has been prepared. The reactions of II with primary amines resulted in the formation of the monoamides IIIa–c. 2,3-Diphenylpyrazolo[4,3-c]pyridine-(5H,7H)-4,6-dione (VIIa), has been obtained by heating the ammonium salt of I in a vacuum at 220 °C. The ring closure of IIIc with acetyl chloride in benzene afforded VIIb. Compound VIIb was coupled with benzenediazonium chloride to give the 7-phenylazo derivative (XII) and also condensed with aromatic aldehydes giving 7-arylidene derivatives (XV).
The Stability of Fused Rings in Metal Chelates. IX. Copper(II) and Nickel(II) Complexes of Schiff Bases Derived from Salicylaldehyde and Dipeptides Containing Glycine and/or β-Alanine
Authors: Nakao Yasuo , Nakahara Akitsugu 
Published: July 2006

Abstract
Copper(II) and nickel(II) complexes of Schiff bases derived from salicylaldehyde(Sal) and dipeptides containing glycine and/or β-alanine have been prepared. It has been found that Schiff base ligands containing glycylglycine (Gly·Gly), glycyl-β-alanine (Gly·β-Ala) or β-alanylglycine (β-Ala·Gly) as the peptide moieties give rise to square-planar, quadridentate copper(II)- and nickel(II)-chelates, while the N-salicylidene-β-alanyl-β-alanine (Sal=β-Ala·β-Ala) does not form the same type of copper(II)- or nickel(II)-chelate. It is concluded on the basis of spectrophotometric, polarographic and other measurements that the stability decreases in the order 6-5-5-([Cu(Sal=Gly·Gly)])≥6-5-6-([Cu(Sal=Gly·β-Ala)])≥6-6-5-([Cu(Sal=β-Ala·Gly)])&gt;&gt;6-6-6-([Cu(Sal=β-Ala·β-Ala)])fused-ring system.
Syntheses of Isoprenoids by Telomerizations. IX. Stereoselectivity of Telomers and the Effect of Telogens in Anionic Telomerizations Using Secondary Amines
Authors: Takabe Kunihiko , Katagiri Takao , Tanaka Juntaro 
Published: July 2006

Abstract
The stereoselectivity of the telomers and the effect of the telogens in the anionic telomerizations of isoprene with secondary amines were investigated. Dimethyl-, diethyl-, di-n-propy-1, diisopropyl-, and methylphenyl-amines, pyrrolidine, morpholine, and piperidine were used as the telogens. The ratio of N,N-dialkyl(3,7-dimethyl-2,6-octadienyl)amine(2A) to N,N-dialkyl(2-isopropenyl-5-methyl-4-hexenyl)amine(2B), which were obtained in these reactions, was varied with the sort of secondary amines, the yield of the telomers was found to be dependent on the acidity of the secondary amines. Moreover, 2A, which was the main component of the n=2 telomers, was confirmed to have a cis-configuration—that is, N,N-dialkylnerylamine. However, the n=1 telomer of myrcene with secondary amine was N,N-dialkylgeranylamine. These results were interpreted in terms of the stability of the cyclic intermediate of the carbanions.
Modified CNDO 2 Calculations of Ionization Potentials for Some Unsaturated Hydrocarbons
Authors: Ohno Koichi , Hirooka Tomohiko , Harada Yoshiya , Inokuchi Hiroo 
Published: July 2006

Abstract
The orbital energies of several unsaturated hydrocarbon molecules have been calculated using a modified CNDO/2 method, with the electron repulsion integrals evaluated from Klopman’s formula and the σ–π separation factor proposed by Tinland and Jaffé. The empirical parameters are determined to reproduce the observed ionization potentials for ethylene and benzene via Koopmans’ theorem. The results are shown to agree well with the available experimental ionization potentials and with the assignments of the photoelection spectra.