bluuebunny/crossref_metadata_2025_split huggingface dataset:
Penetration-depth Dependence of Photochemical Conversions in the Dye-sensitized Heterogeneous Photopolymerization of Acrylamide
Authors: Yamase Toshihiro , Ikawa Tsuneo 
Published: July 2006

Abstract
The Amethyst violet-sensitized photolysis of p-tolyl p-anilinobenzenediazo sulfone initiated the polymerization of acrylamide in ethanol-water (9.3 : 0.7, v/v) to yield insoluble polymers. The polymer particles formed scattered the incident 546 nm light, leading to a change in the rate of photopolymerization. Using a 632.8 nm laser beam for viewing the sample at various penetration depths normal to the 546 nm light beam, a new method of determining the penetration-depth dependence of the yield of polymers was presented on the basis of the approximately linear relationship between the optical density at 632.8 nm and the polymer concentration. The method had the advantage that the progress of the photopolymerization, which takes place rapidly, can be easily followed with a high sensitivity below a 2.2% monomer conversion. From an evaluation of the magnitude of both the shadowing and forward scattering arising from the increasing number of polymer particles at various depths, it was confirmed that 546 nm light scattered by polymer particles brought about an effective photopolymerization over a wide range of the depths as a forward-scattering effect. Furthermore, the exposure to the 546 nm beam intensity range from 142 μW/ cm2 to 15.6 μW/ cm2 at sample depths up to 10 mm exhibited equal contributions of shadowing and forward scattering at the depth of ∼1.5 mm.
Hyperconjugative Deuterium Isotope Effects on the Redox Decomposition of Hydroxymercurated 2-Butenes in an Aqueous Solution
Authors: Kosaki Miharu , Shinoda Sumio , Saito Yasukazu 
Published: July 2006

Abstract
The relative magnitude of the isotope effects of the deuterium atoms at the positions hyperconjugative to α- and β-carbons has been determined for the title reaction by monitoring the reaction of 2-butene-1,1,1,3-d4 by PMR. On the basis of our results, the cation character in the transition state is concluded for both of the carbons, in support of the structure proposed previously.
Enthalpies of Combustion of Organic Compounds. III. d-, l- and Dl-Alanines
Authors: Kamaguchi Akeji , Sato Tomoko , Sakiyama Minoru , Seki Syûzô 
Published: July 2006

Abstract
Enthalpies of combustion of d-, l- and Dl-alanines were measured by oxygen static bomb calorimetry. Derived thermodynamic quantities at 298.15 K for d-, l- and Dl-isomers are as follows: ΔEc°=−1619.24±0.58, −1620.26±0.63 and −1617.97±0.50 kJ mol−1; ΔHc°=−1619.86±0.58, −1620.88±0.63 and −1618.59±0.50 kJ·mol−1; ΔHf°=−561.08±0.71, −560.06±0.76 and −562.35±0.65 kJ mol−1, respectively.
The Circular Dichroism Spectra of the β-Cyclodextrin Complex with Naphthalene Derivatives
Authors: Harata Kazuaki , Uedaira Hisashi 
Published: July 2006

Abstract
The circular dichroism spectra of β-cyclodextrin complexes with naphthalene derivatives were investigated. A remarkable difference in the spectra was observed between the 1-substituted naphthalene complex and the 2-substituted naphthalene complex, indicating that the steric effect of substituents on the formation of the complex is so strong that the structures may be different for these complexes. The calculation of the rotational strength by the method of Kirkwood-Tinoco revealed that the structure of the 2-substituted naphthalene complex is an axial inclusion.
Phenylations of β-Nitrostyrene Derivatives with Benzene by the Use of Palladium(II) Acetate
Authors: Yamamura Kimiaki , Watarai Setsuo 
Published: July 2006

Abstract
The phenylations of several β-nitrostyrene derivatives with benzene in the presence of palladium(II) acetate have been studied. The nitro group of the β-nitrostyrenes investigated affects the phenylations very strongly, because of its powerful electron-withdrawing nature, and a high reactivity and regiospecificity were observed.
Synthesis of Sugar Derivatives of N-Alkyl-N-nitrosourea
Authors: Machinami Tomoya , Kobayashi Kazuki , Hayakawa Yoshiki , Suami Tetsuo 
Published: July 2006

Abstract
Thirteen sugar derivatives of N-alkyl-N-nitrosourea have been prepared as follows. The reaction of a sugar amine with alkyl isocyanate gives a sugar derivative of N-alkylurea. When the product is treated with sodium nitrite in aqueous acetic acid, it gives the N-alkyl-N-nitrosourea derivative.
Physico-chemical Studies of the Reversible and Irreversible Phase Transitions in Potassium Ferrocyanide Trihydrate and Its Deuterate Analogue
Authors: Oguni Masaharu , Matsuo Takasuke , Suga Hiroshi , Seki Syûzô 
Published: July 2006

Abstract
Phase transitions of K4Fe(CN)6·3H2O and its deuterate were studied through the measurements of differential thermal analysis curves, heat capacity, volume expansion and Raman spectra. Samples prepared by recrystallization from the aqueous solution were found to be in the metastable phase. The ferroelectric transition temperature between two stable monoclinic phases was determined to be 247.8 K and 252.7 K for the hydrate and deuterate, respectively. The enthalpy and entropy changes of the transition were estimated to be 2592 J mol−1 and 12.41 JK−1 mol−1, respectively, for the hydrate, and 3017 J mol−1 and 14.36 JK−1 mol−1, respectively, for the deuterate. The molecular mechanism of the transition was discussed in terms of entropy change. The transition was also concluded to be of the second order according to Ehrenfest’s criterion. Irreversible transformation of tetragonal to monoclinic phase was observed for the first time for the deuterate as a new type of phase change having a Martensitic nature. These irreversible transformations took place in the temperature region covering 20 K below ca. 232 K and ca. 237 K for the hydrate and deuterate, respectively. The anhydrous salt showed no transformation in the temperature region between 13 K and room temperature.
Nuclear Quadrupole Resonances of Tellurium Tetrachloride and Tellurium Tetrabromide
Authors: Okuda Tsutomu , Yamada Koji , Furukawa Yoshihiro , Negita Hisao 
Published: July 2006

Abstract
The nuclear quadrupole resonances (NQR) due to 35Cl and 81Br in TeCl4 and TeBr4 have been observed and their Zeeman effects have been examined. Each spectrum consists of six resonance lines with equal intensities, which are assigned to the two species of TeCl3+ ions or TeBr3+ ions. The asymmetry parameter of the electric-field gradient is, at most, 5% in each case. The relative orientation among the zero-splitting patterns of six resonance lines is consistent with the crystal structure of TeCl4, which consists of the tetramers of (TeCl3+Cl-)4, as was recently determined by X-ray diffraction analysis. The zero-splitting patterns of the TeBr4 crystal are so similar to those of TeCl4 that the former crystal seems likely to consist of tetramers of (TeBr3+Br-)4 as well. The average ∠X–Te–X bond angles in TeX3+ ions were found to be 95.9° for the chloride and 96.7° for the bromide. The values for the chloride are in good agreement with those obtained by the X-ray analysis. On the other hand, the bond character of the TeX3+ ions in TeX4AlX3 (X=C1, Br) was compared with that of TeX4 from NQR.
A Torsional Braid Analysis of Polymethacrylates, Polyacrylate, Poly(vinyl alcohol), and Their Related Polymers during the Thermal Degradation
Authors: Furusho Noboru , Komatsu Tsuyoshi , Nakagawa Tsurutaro 
Published: July 2006

Abstract
The torsional braid analysis (TBA), thermogravimetry, and IR spectroscopy of polymethacrylates, polyacrylate, poly(vinyl alcohol), and their related polymers were carried out in air. The chemorheological properties of these polymers are markedly dependent on their chemical structures. First, the α-hydrogen atom plays an important role. In poly(methyl acrylate), the chemorheological behavior is similar to that of the polymers which have tendency to crosslink, whereas poly(methyl methacrylate) does not show any such behavior. A similar situation was found when comparing poly(acrylic acid) with poly(methacrylic acid). At the same time, the influence of the functional groups was examined. Second, the change in the mechanical properties due to crosslinking becomes more noticeable with an increase in the side-chain length of the methacrylate polymers. Furthermore, in addition to procedures used in the previous work, a new method of kinetic analysis of the heating-rate dependence was carried out in the case of poly(acrylic acid). The apparent activation energies estimated by this treatment are in good agreement with those estimated by other procedures.
Anomalous Phosphorescence of p-Methylacetophenone in Nonpolar Solvent at 77 K
Authors: Tanimoto Yoshifumi , Hirota Noboru , Nagakura Saburo 
Published: July 2006

Abstract
Absorption and phosphorescence spectra were studied for p-methylacetophenone in 3-methylpentane—isopentane mixed solvent at low temperature. From the concentration and temperature dependencies of the absorption spectrum, it is concluded that the monomer-dimer equilibrium exists in the solution of the p-methylacetophenone at low temperature. The phosphorescence of p-methylacetophenone in the mixed solvent at low temperature was found to be composed of two components, with lifetimes of 23 and 42 ms at 77 K. They are ascribed to the π,π* triplet states of the monomer and dimer, respectively.
Several Novel Ru(II) and Ru(III) Complexes Formed by Reduction of [RuO4bipy] and [RuO3phen]2O with Hydroquinone and Methanol
Authors: Ishiyama Toshio 
Published: July 2006

Abstract
The geometrical isomers, cis-dichlovo-trans-(methanol) (hydroquinone) (2,2′-bipyridine)ruthenium(II) and cis-dichlovo-cis-(methanol)(hydroquinone)(2,2′-bipyridine)ruthenium(II), [RuCl2(MeOH)(QH2)bipy] (complex I and II), were synthesized by reduction and substitution reactions of [RuO4bipy] and [RuO2(OH)2bipy] with hydroquinone in hydrochloric acid solution, and methanol. cis-Chloro(hydroquinonato)bis(2,2′-bipyridine)-ruthenium(II), cis-[RuCl(QH)(bipy)2], was obtained from the substitution reaction of complex I or II with 2,2′-bipyridine in methanol, and cis-chloro(hydroquinone)bis(2,2′-bipyridine)ruthenium(II) chloride, cis-[RuCl(QH2)-(bipy)2]Cl, was also obtained from the substitution of cis-trans-[RuCl2(MeOH)(QH2)bipy] in methanol containing hydrochloric acid. cis-Dihydroxobis(2,2′-bipyridine)ruthenium(II),cis-[Ru(OH)2(bipy)2], was obtained by heating an aqueous solution of cis-[RuCl (QH) (bipy) 2]. Trihydroxoaquo (1,10-phenanthroline) ruthenium (III), [Ru(OH)3(H2O)phen] was also synthesized from [RuO3phen]2O and [Ru(OH)3phen]2O by reduction reactions similar to those used for [RuCl2(MeOH)(QH2)bipy]. These complexes were characterized by the infrared, visible and ultraviolet absorption spectra, and also by polarographic and magnetic measurements. The structures are discussed.
Metal Complexes of Amino Acids. VII. The trans(N) and cis(O)cis(N) Isomers of the Type [Co(aa)2phen]X and [Co(aa)2dipy]X
Authors: Yasui Takaji 
Published: July 2006

Abstract
Fourteen complexes of the type [Co(aa)2phen]X and [Co(aa)2dipy]X (where aa is the anion of glycine, β-alanine, l-serine, or l-proline) were newly prepared. Two geometrical isomers (trans(N) and cis(O)cis(N)) for the glycinato and β-alaninato complexes, four geometrical and/or diastereomeric isomers ((+)d- and (−)d-trans(N) and -cis(O)cis(N)) for the l-serinato complexes, and two diastereomers ((+)d- and (−)d-trans(N)) for the l-prolinato complex were separated. These complexes were characterized by absorption, circular dichroism spectra, and 1H and 13C NMR spectra. The absolute configurations of the l-serinato and l-prolinato complexes were assigned as Λ and Δ for the (+)d- and (−)d- isomers, respectively.
Studies of the Mixed Amino Acid Complexes of Cobalt(III). III. Absorption and Circular Dichroism Spectra of Bis(amino acidato)ethylenediamine cobalt(III) and Bis(amino acidato)oxalatocobaltate(III) Complexes
Authors: Matsuoka Nobuko , Hidaka Jinsai , Shimura Yoichi 
Published: July 2006

Abstract
Three isomers of cis(O)-bis(l-alaninato)ethylenediaminecobalt(III) perchlorate, four isomers of potassium cis(N)-bis(l-alaninato)oxalatocobaltate(III) and two isomers of potassium trans(N)-bis(l-prolinato)oxalatocobaltate(III) have been prepared, and their configurations have been assigned by absorption and circular dichroism spectra. From analysis of the circular dichroism spectra of about 25 complexes of these types (the aminoacidato ligands are glycinato, l-alaninato, l-serinato and l-prolinato), the configurational and the vicinal circular dichroism curves have been separated and discussed. The vicinal circular dichroism curve shows a pattern characteristic of the absolute configuration of α-aminoacidato ligand and of the geometrical structure of the complex.
A Synthesis of 3-Hydroxy-5-methoxyphenanthro[4,5-bcd]furan
Authors: Horaguchi Takaaki , Shimizu Takahachi 
Published: July 2006

Abstract
3-Hydroxy-5-methoxyphenanthro[4,5-bcd]furan (Ia) was synthesized by the dehydrogenation of 5-methoxy-3-oxo-1,2,3,8,9,9a-hexahydrophenanthro(4,5-bcd)furan (IVa), starting from 8-hydroxy-7-methoxy-1-tetralone (IIb).
Resonance Energies of Annulenes and Radialenes
Authors: Aihara Jun-ichi 
Published: July 2006

Abstract
Resonance energies of annulenes and radialenes were estimated on the basis of the π-bond energies of infinitely large annulene and radialene, respectively. The widely accepted Hückel’s (4n+2)π rule was verified for annulenes, whereas radialenes were substantially nonaromatic regardless of the number of π-electrons.
The Stereochemistry of the Reaction of Hydrogen Bromide with Cyclohexene and 1-Methylcyclohexene in the Presence of Oxygen
Authors: Miyajima Shingo , Ichihara Sadao , Simamura Osamu 
Published: July 2006

Abstract
The reaction of hydrogen bromide with cyclohexene or 1-methylcyclohexene in the presence of oxygen, followed by reduction with lithium aluminium hydride afforded trans-2-bromocyclohexanol or t-2-bromo-1-methyl-r-1-cyclohexanol. These findings show that oxygen attacks intermediate bromocyclohexyl radicals formed by addition of a bromine atom to a double bond exclusively on the side opposite to the bromine substituent. Mechanistic implications are discussed.
Structural Studies of Tryptophan Metabolites by X-ray Diffraction Method. III. The Crystal and Molecular Structure of 5-Methoxyindole-3-acetic Acid
Authors: Sakaki Toshimasa , Wakahara Akio , Fujiwara Takaji , Tomita Ken-ichi 
Published: July 2006

Abstract
The crystal structure of 5-methoxyindole-3-acetic acid (5-MIAA) has been solved by application of the direct method with symbolic addition procedure. 5-MIAA, colorless transparent prism, is monoclinic, space group C2/c, with lattice parameters: a=34.461(9) Å, b=6.150(5) Å, c=9.480(5) Å, β=96.14(2)°, Z=8. The molecules are hydrogen-bonded into dimers related by the center of symmetry, which are held together in an infinite double-layered sheet structure perpendicular to the a-axis with N–H···O hydrogen bond between indole nitrogen and carboxyl oxygen atoms. The methyl groups of adjacent molecules contact to each other by van der Waals forces. The conformation of the side-chain is quite distinguishable from that of indole-3-acetic acid. The dihedral angle between carboxyl and indole planes is 59.5° in this molecule, whereas that is 90.0° in indole-3-acetic acid, and the carboxyl group sticks out to be perpendicular to the indole plane.
ESR Studies of Reduced Molybdovanadophosphoric Heteropoly Acids. II. Homogeneous Reduction
Authors: Otake Masayuki , Otaki Tadaaki 
Published: July 2006

Abstract
ESR spectra of the chemically reduced molybdovanadophosphoric heteropoly acids (H3+xMo12−xVxPO40·nH2O, where x=1 and 2) were observed in the solution and glassy state in various organic solvents. On addition of equimolar amounts of reductants such as SnCl2·2H2O, HSCH2CH2SH, and CH3SCH3, a transient ESR signal(B) appeared with eight hfs lines referred to as V(IV), I=7⁄2, and with &lt;g&gt;=1.96 and &lt;T&gt;=−0.83×10−2cm−1. However, it disappeared within ca. 5 hr at 20°C and another signal(C) with &lt;g&gt;=1.962 and &lt;T&gt;=−1.00×10−2 cm−1 gradually increased in intensity. The hyperfine coupling constant of the transient species was thus unusually small as compared with that of the ordinary V(IV) species and the C species. The mechanistic pathways of the reduction were discussed. The splitting observed in the low-field parallel components of the B signal was satisfactorily explained by a “geometrical charge isomerism” characteristic of the structure of the heteropoly anion. The origin of the unusually small hfs constant was discussed in the light of its molecular structure.
Aromatic Thiocyanation by a Mixture of Antimony(V) Chloride and Lead(II) Thiocyanate
Authors: Uemura Sakae , Onoe Akira , Okazaki Hajime , Okano Masaya 
Published: July 2006

Abstract
Alkyl- and halobenzenes give thiocyano-derivatives when treated with a mixture of SbCl5 and Pb(SCN)2 in CCl4. The reaction proceeds via in situ formation of ClSCN from SbCl5 and Pb(SCN)2 followed by its attack on aromatic compounds catalyzed by SbCl5, the reaction species being SCN+SbCl6−.
Reactions of 2,4,6-Tri-t-butylnitrosobenzene with Grignard Reagents
Authors: Inagaki Yoshio , Okazaki Renji , Inamoto Naoki 
Published: July 2006

Abstract
Reactions of 2,4,6-tri-t-butylnitrosobenzene (1) with alkylmagnesium halides afforded 6-alkyl-1-hydroxy-imino-2,4,6-tri-t-butyl-2,4-cyclohexadienes (2), 4-alkyl-1-hydroxyimino-2,4,6-tri-t-butyl-2,5-cyclohexadienes (3), and N-alkyl-2,4,6-tri-t-butylanilines (4) depending on the Grignard reagents used. The distribution of the reaction products indicated that the oximes were formed via an attack of the anionic species on the ortho- and the para-carbons, respectively, to the nitroso group, but that the N-alkylanilines via a free radical mechanism involving an electron transfer from the Grignard reagent to 1. The free radical mechanism was confirmed in the case of t-butylmagnesium chloride by trapping the t-butyl radicals as 1-t-butoxyimino-2,4,4,6-tetra-t-butyl-2,5-cyclohexadiene (8). Such a mechanistic difference has been explained in terms of the difference in electron affinities of the free radicals derived from Grignard reagents.
Surface Tension of Aqueous Solutions of Disodium Monoalkyl Phosphates and Their Mixtures
Authors: Nakagaki Masayuki , Handa Tetsurou 
Published: July 2006

Abstract
Disodium mono-dodecyl, mono-tetradecyl, and mono-hexadecyl phosphates were synthesized and the surface tension of aqueous solutions of each disodium monoalkyl phosphate (SAP) and of their mixtures were measured. On the basis of the surface tension values thus obtained, the influence of the hydrocarbon chain length of SAP and the effect of the mixing of SAP on the adsorption and the micelle formation were discussed. A modified Szyszkowski equation was derived from the Gibbs adsorption equation and the modified Langmuir adsorption equation by using the activity instead of the concentration. The modified Szyszkowski equation gave calculated values which were in good agreement with the experimental values of the surface tension. It was also found that the energy of adsorption per methylene group, ω, is 682 cal/mol. In mixed solutions, the modified Szyszkowski equation was used to obtain results in good agreement with the measured values of the surface tension, assuming an ideal mixing of SAP in the adsorption layer. Further, the change in the standard free energy was calculated for the micelle formation for each SAP from the hypothetical standard state of the hydrated monomer in solution; it gave the energy of micelle formation per methylene group, ωm, is 613 cal/mol. The theoretical equation to give the cmc of SAP, was obtained also, assuming the ideal mixing of SAP in the mixed micelle phase; it was proved to be in good agreement with the experimental values of the cmc.
Electron Spin Resonance of Oriented Solid of Isocyanic Acid Irradiated with γ-Rays
Authors: Hirai Hidefumi , Fujiwara Masato 
Published: July 2006

Abstract
Free radicals in the γ-irradiated solid of isocyanic acid at −196 °C have been studied by electron spin resonance (ESR) spectroscopy at −196–−100 °C. An oriented solid of isocyanic acid was prepared by solidification of isocyanic acid around an aluminum rod with cooling for the measurement. The ESR spectra consisted of a pair of triplets and a pair of sextets, when the longitudinal axes of the oriented solid were parallel and perpendicular, respectively, to the dc magnetic field. The absorptions were assigned to an anion radical (HNCO−) by analysis of anisotropy of the spectrum and by deuteration of isocyanic acid. The observed constants were: g⊥=2.0025, g⁄⁄=1.9985; Ax(N)=21.2 G, Ay(N)=24.8 G, Az(N)=21.8 G. The anion radical was assumed to be preferentially oriented in the oriented solid, taking two orientations whose g⁄⁄ axes were perpendicular both to each other and to the longitudinal axis of the oriented solid.
Reaction of Iron(III)-Form Ion Exchanger with Acetylacetone
Authors: Ohzeki Kunio , Ikeuchi Mayumi , Kambara Tomihito 
Published: July 2006

Abstract
It was found that ferric ions are removed from resin by acetylacetone(Hacac) to form trisacetylacetonatoiron-(III), Fe(acac)3. By the addition of a small amount of pyridine-water mixture to the iron(III)-form resin in acetylacetone milieu, the ferric ions are quantitatively removed from the resin, and in their place the pyridinium ions are adsorbed onto it. The reaction was successfully applied to the synthesis of Fe(acac)3 in over 95% yield.
Polarogpraphy of Europium(III) in Acetonitrile in the Presence of Thiocyanate and Halide Ions
Authors: Aihara Makoto , Misumi Seizo 
Published: July 2006

Abstract
Studies were carried out on the polarographic behavior of europium in acetonitrile in the presence of SCN−, Br−, I− and Cl−. Two reduction waves were found in the Eu(III)–SCN− system, one corresponding to the reduction of [Eu(NCS)6]3− and the other to the reduction of [Eu(NCS)2]. In the Eu(III)–Br− system, the reduction potential of Eu(III)–bromide complex species was more positive than that of the [HgBr4]2−/Hg couple. In the Eu(III)–I− system, iodide ions were oxidized in acetonitrile by europium(III). The formation constants of Eu(III)–SCN− system were found to be: logβ6=24.4 for [Eu(NCS)6]3− and logβ2=6.0 for [Eu(NCS)2. The degree of complexation of europium(III) and mercury(II) with bromide ion was also determined.
A-Subustituted 5β-Steroids. VI. trans-Sn2′ Reaction in Acylolysis of 4β-Bromo-3-keto-5β-steroids
Authors: Takahashi T Tomoyoshi , Satoh J Yasuo 
Published: July 2006

Abstract
A new type of SN2′ reaction in which the nucleophile enters to the leaving group occurs in the acylolysis of 4β-bromo-3-keto-5β-steroids (1) to give 2α-acyloxy-3-keto-5β-steroids (2) as a product. This reaction pathway was observed by NMR and by tlc.
Ionic Equilibria in Mixed Solvents. XI. A Critical Survey of Hydroxo Complexes of Beryllium in Aqueous and Aqueous Mixed Solvents
Authors: Tsukuda Hitoshi , Kawai Takayoshi , Maeda Masunobu , Ohtaki Hitoshi 
Published: July 2006

Abstract
Hydrolytic reactions of beryllium ion were studied in water-methanol, water-ethanol, and water-acetone mixtures, 0.2 mole fraction of an organic component being contained. In all the solutions containing 3M LiClO4 as an ionic medium at 25 °C, we found the Be2OH3+, Be2(OH)22+, Be3(OH)33+, and Be(OH)2 complexes. However, in a supplementary work in a 3M LiClO4 aqueous medium in which the solution had been equilibrated with precipitates of beryllium hydroxide and the supernatant was subjected to titration, we found Be6(OH)84+ instead of Be(OH)2. From a very slow equilibrium observed in the high pH region, we concluded that the Be(OH)2 complex formed by the addition of an alkaline solution gradually polymerizes to Be6(OH)84+ by releasing some OH− ions. Through these observations a critical survey is described for the species reported by various authors. The solvent effect on the formation constants of hydroxo complexes is also discussed.