bluuebunny/crossref_metadata_2025_split huggingface dataset:
ESR Study of 63Cu(II) Doped in Single Crystals of Bis(methyl 3-alkylidenedithiocarbazato)nickel(II)
Authors: Oniki Takayuki 
Published: July 2006

Abstract
ESR spectra of 63Cu(II) diluted by various single crystals of the title Ni(II) complexes are reported. The alkylidene groups denote 1-(2-naphthyl)ethylidene, 1-(p-tolyl)ethylidene, 1-phenylethylidene, benzylidene, 1-(m-nitrophenyl)ethylidene, and 1-(p-nitrophenyl)ethylidene, and the corresponding Ni(II) complexes are abbreviated as Ni(nedc)2, Ni(tedc)2, Ni(pedc)2, Ni(bdc)2, Ni(mndc)2, and Ni(pndc)2 respectively. Before the analyses of the ESR data, the crystal structures of Ni(nedc)2 and Ni(tedc)2 were determined. In both Ni(II) complexes, the molecules have been found to be of a C2 symmetry, with a tetrahedrally distorted cis-NiN2S2 arrangement. The unpaired electrons of the Cu(II) complexes were thus described in terms of C2 symmetry except for the case of Cu(bdc)2. The d-orbital coefficients of the ground-state Kramers doublet were determined from the observed g values in such a way that the hyperfine parameters calculated from the coefficients closely reproduce the observed values. In 63Cu(II)/Ni(bdc)2, the g values are rhombic, and an additional hyperfine structure due to atoms which do not directly coordinate to Cu(II) ion was observed. The coordination of the Cu(II) ion in Ni(bdc)2 was concluded from the ESR data to be a trans arrangement.
Analytical Application of Oleophilic Quaternary Ammonium Salts. XV. Extraction of the Uranium(VI)–4-(2-Pyridylazo)resorcinol Complex with Tridodecylethylammonium Bromide
Authors: Shijo Yoshio , Sakai Kaoru 
Published: July 2006

Abstract
The uranium(VI)–4-(2-pyridylazo)resorcinol(PAR) chelate anion was extracted with tridodecylethylammonium bromide (TDEABr) into chloroform to form an ion associate. The ternary complex has an absorption maximum at 550 nm in the organic layer. The optimum pH range for the extraction is 6.8–10.7. The distribution ratio and the molar absorptivity are 1.34×102 and 4.25×104 cm−1 mol−1 1, respectively. The composition of the ternary complex is estimated to be UO2(X)(PAR)(R3R′N). The equation representing the extraction equilibrium would be
UO2(X)(PAR)−+R3R′NBr(o)=UO2(X)(PAR)(R3R′N)(o)+B r−.
The extraction constant Kex is given by logKex=3.07.
Syntheses of Cyano Derivatives of Triphenylphosphoniocyclopentadienide
Authors: Yoneda Shigeo , Watanabe Masatake , Yoshida Zen-ichi 
Published: July 2006

Abstract
Bromo derivatives of triphenylphosphoniocyclopentadienide were found to react with copper cyanide in N,N-dimethylformamide to give the corresponding nitriles without decomposition. The mono- and dicyano derivatives were prepared under relatively mild reaction conditions, but no tricyano derivatives were obtained from the cyclopentadienide having more than three bromine atoms in the cyclopentadienyl ring.
α,β-Unsaturated Carboxylic Acid Derivatives. XV. The Reaction of Ethyl 3-Nitro-2-alkenoate with Bromine Azide or Bromine, and Transformations of the Products
Authors: Shin Chung-gi , Yonezawa Yasuchika , Suzuki Kaoru , Yoshimura Juji 
Published: July 2006

Abstract
The reaction of ethyl (Z)-3-nitro-2-alkenoate (1) with one or two equivalents of bromine azide gave a one-to-one mixture of ethyl (E)-2-azido-3-nitro-2-alkenoate (3) and 4-ethoxycarbonyl-1,2,5-oxadiazole 2-oxide (5), or ethyl 3-bromo-2,2-diazido-3-nitroalkanoate (6), respectively, and the subsequent thermal and photochemical reactions of (E)-3 gave 2-ethoxycarbonyl-3-nitro-l-azirine, together with a small amount of 5. The addition of bromine to 1, and the subsequent elimination of hydrogen bromide from the product, gave exclusively, the (Z)-2-bromo derivative (9). The reduction of 6 and 9 with diethyl phosphonate was examined, and the reaction mechanisms were discussed.
α,β-Unsaturated Carboxylic Acid Derivatives. XVI. Synthesis and Configuration of Diels-Alder Adducts from Ethyl 3-Nitro-2-alkenoate and 1,3-Butadiene
Authors: Shin Chung-gi , Yamaura Masanori , Inui Eiji , Ishida Yuzuru , Yoshimura Juji 
Published: July 2006

Abstract
The Diels-Alder reaction of individual (E)- and (Z)-isomers of ethyl 3-nitroacrylate and 3-nitrocrotonate with 1,3-butadiene, 1-acetoxy- or 1,4-diacetoxy-1,3-butadiene was conducted to give ethyl 6-nitro-3-cyclohexene-, 5-acetoxy-, and 2,5-diacetoxy-6-nitro-3-cyclohexene-carboxylates, respectively. The stereochemistry of the cycloaddition products has been elucidated by analysis of the NMR spectrum.
Solvolysis in Carboxamides. IV. Solvolytic Elimination of exo-2-Norbornyl Arenesulfonates in Carboxamides. Kinetic, Product, and Deuterium Tracer Studies
Authors: Saito Seiki , Moriwake Toshio , Takeuchi Ken’ichi , Okamoto Kunio 
Published: July 2006

Abstract
Solvolysis of exo-2-norbornyl arenesulfonates (RX: X=OTs (1a), –OSO2C6H4–p–OCH3, –OSO2C6H5, and OBs) and the deuterium labeled tosylates (1a-3-endo-d, 1a-3-exo-d, and 1a-3,3-d2) has been carried out in four carboxamides (N-methylformamide, N-methylacetamide, N,N-dimethylformamide, and N,N-dimethylacetamide (DMA) at 25–100 °C. The solvolysis has also been conducted in the solvents containing 0.01–0.2 mol/dm3 water. On the basis of kinetic measurements, product analyses, and the examination of isotopic distribution in the reclaimed substrate and the products (nortricyclene, norbornene, and exo-norbornyl carboxylates) it has been suggested that the reaction proceeds by syn-E1 and SN1 mechanisms, and that the carboxylates which are produced in the presence of water are derived from an imidatonium ion [R-Amide]+, which is formed by the attack of carboxamide on the intimate ion-pair [R+X−]. It has been observed that the isotopic scrambling occurs only between C(3) and C(7) positions of both norbornene and the reclaimed 1a-3-endo-d in DMA solvolysis at 75 °C, and that the isotopic distribution to these positions in norbornene is 57:43 at 10% completion and reaches 50:50 at half-life, indicating that only Wagner-Meerwein rearrangement is predominant in the course of norbornene formation, and also that the intimate ion-pair, from which norbornene is formed, is unsymmetrical and most probably with “classical” norbornyl-cation structure.
Synthesis and Absolute Stereochemistry of (+)-7,14-Dihydro-7,14-ethanodibenz[a,h]anthracene and Its Derivatives
Authors: Harada Nobuyuki , Takuma Yuki , Uda Hisashi 
Published: July 2006

Abstract
(7R,14R)-(+)-7,14-Dihydro-7,14-ethanodibenz[a,h]anthracene (1), and the 2,9-dimethyl- (2) and 2,4,9,11-tetramethyl- (3) derivatives were synthesized from (9R,10R)-(+)-9,10-dihydro-9,10-ethanoanthracene-1,5-dicarbaldehyde (4) of known absolute configuration. The CD spectra of 1, 2, and 3 clearly exhibit positive first and negative second Cotton effects due to the coupling of the 1Bb transitions of two naphthalene chromophores: Δε237.0=+326.5, Δε224.0=−180.5, A=+507.0, for 1; Δε240.6=+371.5, Δε227.0=−149.4, A=+520.9, for 2; Δε242.0=+340.3, Δε225.0=−88.0, A=+428.3, for 3. Since the sign of the A values is positive, positive exciton chirality between the two long axes of the naphthalene moieties is assigned. The (7R,14R) absolute configuration of 1, 2, and 3 is established by both CD exciton chirality and X-ray Bijvoet methods.
Chlorination of Phenylsulfinylcyclopropanes and Phenylthiocyclopropanes
Authors: Masuda Toshiaki , Furukawa Naomichi , Oae Shigeru 
Published: July 2006

Abstract
Chlorination of phenylsulfinylcyclopropanes or phenylthiocyclopropanes with various chlorinating agents provides the corresponding 1-chloro-1-(phenylthio)cyclopropanes but not any ring opening product. Kinetic isotope effects, (kH⁄kD), for the chlorination were measured with 1-deuterated cyclopropane derivatives and found to be small, i.e., 1.6–2.8. The chlorination is considered to be a kind of the Pummerer reaction of the chlorosulfonium salt formed as the initial intermediate in the reaction of sulfides or sulfoxides with such chlorinating agents as N-chlorosuccinimide (NCS) or thionyl chloride and proceeds via the ylide-ylene intermediate.
The Removal of Heavy Metal, Phosphate, and COD Substances from Wastewater by the Lime Sulfurated Solution (Calcium Polysulfide) Process
Authors: Aratani Toshiro , Nakata Yasuyuki , Matoba Hitoshi , Yasuhara Shigeki , Yano Takeo 
Published: July 2006

Abstract
A new chemical precipitation process that had been developed for the removal of heavy metals was extended to the removal of phosphate and COD substances. For simulated wastewater contaminated with heavy metal, phosphate, and COD substances, removal experiments were undertaken in a batch, stirred vessel by using the lime sulfurated solution as a single coagulant. The coagulant, the main component of which is CaSx, decomposes in water on contact with air or CO2 gas, and liberates H2S, CaS2O3, CaCO3, CaSO4, and solid sulfur particles. While heavy metals are precipitated as metal sulfides or hydroxides, phosphate is precipitated as calcium phosphate and COD substances are sorbed on the surfaces of the precipitates and they removed. The experimental findings are as follows: (1) The simulated wastewater contaminated simultaneously with phosphate and cadmium ions can be treated better than that contaminated only with the phosphate ion. Also, the CaSx process is found to be more effective than the Ca(OH)2 process for the removal of phosphate. (2) The removal percentages of COD substances ranged from 40% to 90% according to the sort of substance. The COD removal can be attained by the sorption of the substances mainly on the liberated solid sulfur particles, and partly on the calcium salts.
Complexing Behaviour of 2H-1,2,4-Triazole-3-thiol Complexes of Co(II), Ni(II), Cu(II), Ru(II), Rh(III), Pd(II), Pt(II), and Au(I)
Authors: Gupta Birendra Kumar , Gupta D S , Agarwala U G 
Published: July 2006

Abstract
Complexes of Co(II), Ni(II), Cu(II), Ru(II), Rh(III), Pd(II), Pt(II), and Au(I) with 2H-1,2,4-triazole3-thiol have been prepared. Probable structures have been proposed for the complexes on the basis of visible and infrared spectra, magnetic susceptibility, and chemical analysis. Crystal field parameters have been calculated wherever possible.
The Polarographic Behavior of 6-Mercaptopurine in Aqueous Solutions
Authors: Yao Toshio , Uda Junji , Wasa Tamotsu , Musha Soichiro 
Published: July 2006

Abstract
The polarographic reduction of 6-mercaptopurine at the dropping mercury electrode took place in two steps; they were a two-electron process producing the 1,6-dihydro derivative, followed by a further two-electron process producing the 1,2,3,6-tetrahydro derivative. An anodic wave corresponding to the reaction with the mercury of the electrode material was observed at a relatively low potential, and its analytical utility for the determination of 6-mercaptopurine is suggested.
Hetero-atom Effect on the Benzene-Prismane and Related Reactions Perturbation Density Matrix of Intramolecular Cycloadditions
Authors: El-Basil Sherif , Hilal Rifaat 
Published: July 2006

Abstract
A formalism is presented for studying intramolecular cycloadditions in terms of their corresponding perturbation density matrices. The effect of hetero-atom on a particular intramolecular cycloaddition is discussed.
Effect of Water Structure on Mixed Synthetic Polypeptide–Lipid Monolayers
Authors: Shibata Akira , Yamashita Shinsuke , Yamashita Takuya 
Published: July 2006

Abstract
The effect of water structure on the interaction of synthetic polypeptides with fatty acids in monolayers at the air-water interface was investigated. It was found that SCN−, F−, and urea exert a remarkable effect upon the hydrophobic interaction in monolayers. SCN− and urea disrupt the hydrated structure biult up around the hydrocarbon moieties of polypeptides and lipids at the interface. On the other hand, the presence of F− as a structure maker tends to stabilize the hydrophobic bonding. The infrared spectra of polymer components were practically identical for the collapsed films in the absence and presence of SCN−, F−, and urea.
Study of Metal Oxide Catalysts by Temperature Programmed Desorption. 3. Formation and Reactivity of Adsorbed Oxygen over α-Ferric Oxide
Authors: Iwamoto Masakazu , Yoda Yukihiro , Yamazoe Noboru , Seiyama Tetsuro 
Published: July 2006

Abstract
Formation and reactivity of oxygen adsorbates on the surface of α-Fe2O3 were investigated in the temperature range 0–600 °C by means of a temperature programmed desorption (TPD) technique. At least four different states of adsorbed oxygen were indicated by four TPD peaks, the maxima of which appeared at 50–300 (α), 350–360 (β), 480–490 (γ), and &gt;600 °C (δ), respectively. Mode of preparation hardly affected the essential nature of oxygen adsorption (or desorption) except the relative amounts of respective desorptions. Of these adsorbates, α, whose desorption peak shifts over a wide temperature range depending upon adsorption conditions, was interpreted to be molecular oxygen (O2 or O2−) bonded to the oxide surface with an extraordinarily broad heterogeneity, while β and γ species were tentatively assigned to O2− and O−, respectively, adsorbed on different sites. The activation energies of desorption were 23.8 and 54.6 kcal/mol for β and γ, respectively. On exposure to gaseous hydrogen, β species as well as α turned more reactive than γ, though γ was also reactive at higher temperatures. The reaction of β and α species with hydrogen at lower temperatures gave rise to an increase in γ adsorption. This is accounted for by assuming a reaction in which the molecular adsorbates (α and β) react with hydrogen to leave the atomic adsorbates (γ) behind.
Relaxation Phenomena after an Area Strain on the Adsorbed Surfaces of Aqueous Solutions of Poly(oxyethylene) Dodecyl Ethers
Authors: Nakamura Masao , Takeuchi Shinichi 
Published: July 2006

Abstract
The relaxations were observed after suddenly dilating or compressing the equilibrium surfaces of aqueous solutions of poly(oxyethylene) dodecyl ethers, C12H25(OC2H4)nOH (n= 5 and 7), at 303 K. The relaxation is expressed as the Maxwell model, with a Hookean surface-area modulus and a Newtonian surface-area viscosity, if the absolute value of an area strain is less than 0.3. The surface-area modulus is dependent upon the amount of surfactant molecules adsorbed in the surface, Γ, regardless of the sign of the area strain. The relaxation time, τc, in the case of compression is dependent on Γ, and τd in the case of dilation depends on the monodispersed concentration of the surfactant in the bulk solution, C. The surface dilational viscosity, ηbA, has a maximum around the concentration at which the surface reaches the saturated adsorption. The rate constants for the adsorption and desorption were estimated by determining empirically the functions of 1/τd and 1/τc with respect to C and Γ respectively.
Theoretical Studies on the Electronic Structure of the H2S Anion Radical
Authors: Nagata Shinichi , Yamabe Tokio , Fukui Kenichi 
Published: July 2006

Abstract
The electronic structure of the H2S anion radical has been investigated by means of the non-empirical unrestricted Hartree-Fock method. The most stable conformation of this radical has been obtained at bond length R(S–H)=1.550 Å and bond angle θ (&lt;HSH)=160°. These values are relatively larger in comparison with observed values of the neutral molecule (R=1.335 Å and θ=92.2°). ESR hyperfine coupling constants and excitation energies have also been examined through analyses of the electronic structure of the most stable conformation of this radical. Furthermore, the dissociation process, H2S→H2+S− or HS−+H, has been discussed.
A Finite Element Approach to the Two-dimensional Vibrational Schrödinger Equation and Its Application to the Hydrogen Bond
Authors: Kanesaka Isao , Arai Hideyuki , Kawai Kiyoyasu 
Published: July 2006

Abstract
The finite element method was examined in relation to the two-dimensional vibrational Schrödinger equation. Some boundary conditions were used because of the symmetry of the potential, resulting in a higher precision in the case of the symmetrical potential, where the harmonic oscillators and the symmetrical hydrogen bond without anharmonicity were examined satisfactorily. An application was made to the symmetrical hydrogen bond with an-harmonicity, where the precision was less for the higher levels. By a comparison of the calculated with the observed infrared spectra, the anharmonic potential constants for the assumed potential function were estimated.
Nuclear Quadrupole Resonance Study of β-Chloroisocrotonic Acid
Authors: Ichimura Kiyoshi , Nakamura Nobuo , Chihara Hideaki 
Published: July 2006

Abstract
35Cl nuclear quadrupole resonance frequencies have been measured in powders of β-chlorocrotonic acid, and β-chloroisocrotonic acid to be 34.966 and 34.261 MHz, respectively, at 78 K. Zeeman effect experiments were conducted on a single crystal of β-chloroisocrotonic acid and the asymmetry parameter of the electric field gradient has been determined to be 0.174±0.016 at 78 K. The π-electron density on the chlorine site has been estimated from the asymmetry parameter according to Bersohn and discussed on the basis of the semi-empirical Pariser-Parr-Pople molecular orbital treatment.
The Enantioselective Dehydrogenation of Racemic Secondary Alcohols Catalyzed by Dimeric Ruthenium(II) Chiral Diphosphine Complexes
Authors: Ohkubo Katsutoshi , Terada Ikuhiro , Yoshinaga Kohji 
Published: July 2006

Abstract
The asymmetric dehydrogenation of racemic alcohols by an effective Ru2Cl4((−)-diop)3 (diop=2,3-O-isopropylidene-1,4-bis(diphenylphosphino)butane) was investigated with and without unsaturated hydrogen acceptors at 120–195 °C, with particular reference to the enantioselective factors and the reaction mechanism. The magnitude of enantioselectivity was substantially affected by the structures of the alcohols and of the hydrogen acceptors and by the reaction temperature; the hydrogen acceptors (R1CH=CHR2: R1\eweqH and R2\eweqH) contributed to the enhancement of the selectivity through the newly formed asymmetric centers which result from their coordination to the chiral Ru(II) complex. The activation parameters (ΔH\eweq and ΔS\eweq) obtained from the linear Arrhenius dependence of the rate constants of each enantiomer (R- or S-alcohol) established an isokinetic relationship, and the defference in the parameters of the each enantiomer (ΔΔH\eweq and ΔΔS\eweq) also showed a satisfactorily linear correlationship between them. It is deduced from the present study that the enantioselection of R- and S-alcohols occurs at different coordination distances toward the chiral Ru(II) complex between the enantiomers under asymmetric circumstances.
Intramolecular Charge Transfer in the Polar Fluorescent State of 1- and 2-Acylanthracenes
Authors: Tamaki Takashi 
Published: July 2006

Abstract
The absorption and emission spectra of 1- and 2-aroyl- and acetylanthracenes were measured in various solvents. The emission spectra moved to longer wavelengths and their forms changed from the structured ones to the structureless ones with increasing solvent polarity, while the absorption spectra showed no appreciable changes under the same conditions. These emissive features became more distinguished with increasing electronwithdrawing ability of the aroyl group. The dipole moments of the fluorescent state as estimated from the Lippert-Mataga formula were 7–16 D for these compounds. The assignments of the low-lying excited states are described in terms of the electronic transitions of the parent anthracene, 1La and 1Lb, which undergo perturbation by the substitution.
A Study on the Anode Effect in KF-2HF System. III. Influence of Bath Temperature and Surface Tension and Addition of Fluoride Particles on the Occurrence of the Anode Effect
Authors: Imoto Hiroki , Ueno Kazuo , Watanabe Nobuatsu 
Published: July 2006

Abstract
The decomposition reaction of the graphite fluoride film formed on the edge plane of pyrolytic graphite, carbon, and graphite electrodes was faster in a KF·HF bath (250 °C) than in a KF·2HF bath (100 °C) due to the higher temperature of KF·HF bath. The critical current densities (CCD’s) were about 0.1 A/cm2 for the layer and edge planes of pyrolytic graphite, carbon, and graphite electrodes in the KF·HF bath, and the CCD for each electrode was larger in the KF·HF bath than in the KF·2HF bath. The anode effect took place easily on the glassy carbon electrode in the KF·2HF bath. However, the anode effect did not take place in liquid hydrogen fluoride due to its very low surface tension, although the graphite fluoride film was formed on the electrode surface. The zeta-potential of aluminum fluoride particles in liquid hydrogen fluoride containing 0–20 mol of potassium fluoride/1 and that of magnesium fluoride particles in liquid hydrogen fluoride were almost zero at 0 °C. From the results it is not proper that the effect of the addition of dispersed particles upon the anode effect is explained by the view of electrostatic force of the particles proposed so far.
Multiple Transmission Method of Time Domain Spectroscopy
Authors: Sato Hiroshi , Itoh Koichi , Takahashi Hiroaki 
Published: July 2006

Abstract
A new multiple transmission method of time domain spectroscopy was developed. A small amount of the sample (0.6 cm3) is needed in this measurement. The dielectric dispersion and absorption curves of 1-propanol, 1-butanol, and 1-pentanol have been obtained as recorder traces of the spectra stored in the minicomputer. Three dielectric parameters, ε∞, ε0, and τ, are estimated for these alcohols.
Proton Diffusion in the Premelted State of 1-Hexadecanol
Authors: Murase Norio , Fujita Teruyuki , Morikawa Naotake , Koga Shozo 
Published: July 2006

Abstract
Proton diffusion in the α-phase of polycrystalline 1-hexadecanol was studied using C16H33O3H and C15H31–14CH2OH. It was found that hydroxyl proton diffuses translationally more easily than the whole molecule. A value of (7±5)×10−7 cm2/s was obtained for the diffusion coefficient of the hydroxyl proton in the α-phase. This fast diffusion is ascribed to the presence of molecular rotation involving hydrogen-bond networks in the α-phase of the crystal. Since the mechanism for the proton diffusion seems to be the same as that for the protonic conduction in this α-phase, proton mobility can be calculated from the diffusion coefficient, assuming that molecular rotation makes the rate determining step in both processes.
Phosphorescence Emissions and Nonradiative Properties of Vapors of Aromatic Carbonyl Compounds at Low Pressure
Authors: Itoh Takao , Baba Hiroaki , Takemura Takeshi 
Published: July 2006

Abstract
The phosphorescence quantum yields of benzaldehyde, acetophenone, p-fluorobenzaldehyde, p-chlorobenzal-dehyde, and benzophenone vapors, measured at low pressure down to the order of 10−3 Torr as a function of excitation wavelength, are essentially constant in the region of excitation energy corresponding to the S1(n, π*) state, whereas the yields decrease very sharply as the excitation energy is raised to the value corresponding to the S2(π, π*) state. This indicates that the nonradiative pathway in the carbonyl compound varies according to the type of the singlet state to which the molecule is initially excited. When excited to the S1 and S2 states, the molecule passes to the phosphorescent triplet state and a decomposing state, respectively. Two mechanisms are suggested and examined for understanding the nonradiative properties of the carbonyl compound vapors: (I) The internal conversion S2→S1 is slow compared with the conversion from S2 to the decomposing state; (II) the vibrational energy redistribution in S1 between the vibrational mode populated through S2→S1 and the mode to be populated optically is slow compared with the conversion from the former mode to the decomposing state.