bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Interstitial-Electron Model for the Structure of Metals and Alloys I. Description of Model for Metallic Binding
Authors: Johnson Oliver 
Published: July 2006

Abstract
Application of the Hellmann-Feynman Theorem to Metals has led to an interstitial-electron model in which there is some localization of itinerant electron density in octahedral or tetrahedral interstices of close-packed metal ion cores. A flat maximum of electron density at centers of interstices is proposed as well as preferential occupancy of either octahedral or tetrahedral interstices. Such occupancy is rather precisely determined by the requirements of minimum electron-electron repulsion and of opposite spins for electrons in adjacent interstices. Writing the interstitial-electron structure of a metal in terms of interstice occupancy thus includes electron correlation effects. The interstitial-electron structures are instantaneous pictures of electron density which are representative of the highly dynamic situation of electrons in metals. The model leads to localization of d-electrons on the metal-ion core when interstices are fully occupied by itinerant electrons, i.e. at M6+. The presence of vacant interstices is required for metallic properties. On the basis of the model, chemical binding in metals differs from that in polyhedral molecules or metal cluster compounds only in the greater delocalization of electron density in metals. The concepts of the interstitial-electron model are closer to those of the method of pseudopotentials than to the Bloch Band Theory although all of these descriptions of metals can be considered equivalent.
The Solvent Extraction of Iron(III) in Perchlorate Solutions Containing Chloride or Bromide Ions with 2-Thenoyltrifluoroacetone and Trioctylphosphine Oxide
Authors: Sekine Tatsuya , Tetsuka Toshihiro 
Published: July 2006

Abstract
Iron(III) in aqueous solutions, in which [H+]=1.0m, [Na+]=3.0m, and [L−]+[ClO4−]=4.0m, where L− is a chloride or bromide ion, was extracted with thenoyltrifluoroacetone (TTA) in carbon tetrachloride or with trioctylphosphine oxide (TOPO) in hexane. From the TTA extraction, it was concluded that iron(III) formed the first and the second complexes with both chloride (β1=100.88 and β2=100.80) andbromide (β1=10−0.10 and β2=100.00) ions in the aqueous phase. The distribution data of iron(III) with TOPO were then explained in terms of the extraction of the ion-pairs, Fe(ClO4)3, FeL(ClO4)2, and FeL2(ClO4), by using these stability constants. When the aqueous phase contained only chloride or bromide ions, and no perchlorate ion, the increase in the extraction with the increase in the halide ion concentration was much larger than that observed when the aqueous phase contained both halide and perchlorate ions. From the determination of the extraction of hydrogen ions and halide ions with TOPO, the extracted species in the absence of a perchlorate ion were identified as FeL3 and/or HFeL4. It was concluded that the difference in the extraction of iron(III) when a perchlorate ion was present and when it was absent is mainly caused by (i) the extraction of perchloric acid, which combines with TOPO in the organic phase and interferes with the extraction of the iron(III) halide complexes, and (ii) the extraction of iron(III) species containing one or more perchlorate ions which are large enough to be extractable with TOPO in the organic phase.
Liquid Crystalline Properties of Terminally Substituted Benzylideneanilines
Authors: Murase Kei 
Published: July 2006

Abstract
The preparation and mesomorphic characteristics of certain anils (p-alkoxybenzylidene-p′-alkylanilines and p-alkoxybenzylidene-p′-alkoxyanilines) are described. Fifteen new compounds were found to exhibit nematic behavior below 100°C. The structural effects of the terminal substituents on nematic temperature range are discussed. It has been found that the anils containing n-alkyl substituents in the p-position of the aniline moiety exhibit mesophases in a much lower temperature range than those containing n-alkoxy substituents. Among p-isoalkoxybenzylideneanilines, all compounds except one are non-mesomorphic.
On the Configuration of Branched-Chain Derivatives of 1,2 : 5,6-Di-O-isopropylidene-α-d-ribo-hexofuranos-3-ulose
Authors: Yoshimura Juji , Kobayashi Kazuhiko , Sato Ken-ichi , Funabashi Masuo 
Published: July 2006

Abstract
In order to obtain a 3-C-hydroxymethyl-d-glucose derivative some nucleophilic reactions of 1,2 : 5,6-di-O-isopropylidene-α-d-ribo-hexofuranos-3-ulose (1) and the configurations of products have been examined. Gluco-and allo-configurations of known 3-C-nitromethyl derivatives of 1 were confirmed by the fact that 3-C-acetaminomethyl-1,2-O-isopropylidene-α-d-xylo- and ribo-pentodialdofuranoses, derived by four successive transformations, showed the absence and presence of the aminal-ring formation between the aldehyde and acetamino groups, respectively. A 3-C-carbethoxymethyl derivative obtained by the Reformatsky reaction of 1 with ethyl bromoacetate was proved to be of allo-configuration by the lactone-formation between C5-hydroxyl and carboxyl groups. The configuration of 3-C-hydroxymethyl derivative (15) obtained by treatment of known 3-C-methylene derivative of 1 with permanganate was proved to be of gluco-typc by comparison of the corresponding 3-C-aminomethyl derivative (5), derived by three-step conversions, with that obtained from 3-C-nitromethyl derivatives. 15 was also obtained by epoxidation of 1 with diazomethane followed by ring-opening with alkali. Treatment of 5 and its allo-epimer with nitrous acid gave, respectively, a ring-expanded product and the 3′,5-anhydride, the former being also recognized in the epoxidation products. Structures of new compounds were examined by NMR spectra and stereoselectivity of reactions discussed.
Layered Compounds. V. Synthesis and Properties of [m.n]Paracyclophadiynes
Authors: Matsuoka Takahiro , Negi Taichi , Otsubo Tetsuo , Sakata Yoshiteru , Misumi Soichi 
Published: July 2006

Abstract
A series of bisethynyl compounds, IX and XII, were prepared by a modified ethynylation using N-methyl-2-pyrrolidone in good yields. Intramolecular oxidative coupling of the bisethynyl compounds has been achieved with high-dilution technique to give relatively good yields of highly strained or strainless [m.n]paracyclophadiynes I and cyclic diacetylenes XIII. From the comparison of the electronic spectra of these diacetylenic compounds, it is concluded that abnormal spectra of Ic and Id are attributed to the transannular π-electronic interaction between benzene nucleus and diacetylenic unit rather than the ring strain in the molecules. In addition, a marked down-field shift of aromatic protons in Ic compared with the other paracyclophadiynes is explained in terms of the transannular shielding effect of diacetylenic linkage.
The Preparation and General Properties of Ion-exchange Carbon Fiber
Authors: Otani Sugio , Tamura Masao , Yoshida Yatsuo , Tsuji Yoshio 
Published: July 2006

Abstract
Cation-exchange carbon fibers were prepared from pitch-based carbon fiber by oxidizing treatment with a mixture of K2Cr2O7, HNO3, and water. Their most characteristic properties were a large electric conductivity, a large thermal stability, and their shape. Their exchanging properties varied with the composition of the mixture and the treating conditions. The following composition and the conditions were adopted as standard.
Composition of the mixture: K2Cr2O7, 10 g; HNO3, 20 ml; H2O, 80 ml
Condition of the treatment: temperature, 104°C; period, 2.5 hr
Amount of carbon fiber: carbon fiber prepared at 1000°C 1 g
The cation-exchange capacity obtained by the standard procedure was 2.0±0.1 mequiv/g. Carbon fiber prepared at 1000°C was a better material than that prepared at 2000°C. Even after the exchangers were heated at 220°C in air, no change was observed in the capacity measured at room temperature. The electric resistivity increased from 7×10−3 ohm-cm to 8×102 ohm-cm with an increase in the capacity, and no difference was obserbed between exchangers of the acidic form and the sodium form. The tensile strength of the filament(1.9 mequiv/g in the capacity) was 6.7×106 g/cm2, and the breaking load of the spinning yarn of 1300 den. (2.0 mequiv./ g) was 3.0 kg.
Substituent Effect of Dipole and Dipolarophile in the Reaction of Nitrones with N-(Substituted phenyl)maleimides
Authors: Iwakura Yosio , Uno Keikichi , Hong Suck-Ju , Hongu Tatsuhiko 
Published: July 2006

Abstract
The reactions of C-(p-substituted phenyl)-N-(p-substituted phenyl) nitrones with N-(p-substituted phenyl)maleimides were carried out in THF to give both trans- and cis-isoxazolidines. The formation ratios of trans- to cis-isoxazolidines (IT⁄Ic) were determined by the NMR spectra of the cycloadduct mixtures. Though the values of IT⁄Ic varied with the electronic characters of the substituents, R1, R2, and R3, they were always found to be larger than unity.
Photo-decoloration Process of the Reverse Photochromic Spirans
Authors: Inoue Eiichi , Kokado Hiroshi , Shimizu Isamu , Kobayashi Hajime , Takahashi Yohnosuke 
Published: July 2006

Abstract
The unstable colorless form (A′) of the reverse photochromic spiran (SP-3) (1,3,3-trimethyl-5-methoxyspiro[indoline-2,2′-benzopyran]-8′-carboxylic acid) was obtained in a stable state by vacuum evaporation (10−5 Torr) on a KBr substrate. It was confirmed by IR spectral analysis that reverse photochromism occurred between the colored (B′; merocyanine-like structure) and the colorless forms (A′; spiropyran). A colorless transient intermediate (X) was observed in the photo-decoloration process of the (SP-3). X was transformed into both A′ and B′. Thus the photo-decoloration efficiency (φB′→A′) depends on the ratio of the conversion from X to A′. State (B′) is stabilized in a polar or proton donative solvent. The life time of X is greatly influenced by the solvent as well as the stability of B′. The photo-decoloration efficiency (φB′→A′) of the spirans is effectively improved by substituting SP-2 with (methoxyl group) at 5-position. Whether X is observable or not depends on the substituent and its position. The reversibility of photochromic cycle of the spirans was restricted by the photobleaching of B′ by UV irradiation. It was observed that the photo-bleaching of B′ is accelerated in a degassed solution.
Calorimetric Study of the Glassy State. VII. Phase Changes between the Crystalline Phases of Cycloheptanol with Various Degrees of Stability
Authors: Adachi Keiichiro , Suga Hiroshi , Seki Syûzô 
Published: July 2006

Abstract
The heat capacities of 8 kinds of stable and meta-stable crystalline phases including the glassy crystal of cycloheptanol were measured at temperatures from 13 to 300 K. The crystalline phases have been named crystals I, II, II′, III, III′, III″, Iβ, and glassy crystal. Transition temperatures between crystals II and I, III and II, II′ and II, III′ and III, III″ and III were determined to be 258.45, 227.26, 172.23, 152.30, and 128.2 K, respectively. The melting point and glass transition point of the glassy crystal were determined to be 280.30 and 140 K, respectively. The heats of transition between crystals II and I, III and II, III′ and III and the heat of melting were determined to be 876, 554, 58.1, and 1604Jmol−1, respectively. The residual entropy of the glassy crystal was found to be 0.7 JK−1mol−1 assuming that of crystal III′ to be zero. The stabilization phenomenon in the glassy crystalline state was also studied from the measurements of enthalpy relaxation. The stability of the various phases was determined by calculating their free energies. The degree of freedom which is frozen in the glassy crystalline state was discussed from molecular viewpoints. Classification of various phase transitions found in this material was also made from the viewpoint of thermodynamical stability.
An Electron Spin Resonance Study of the Tropone Anion Radical
Authors: Ikegami Yusaku , Watanabe Hidetoshi , Seto Shuichi 
Published: July 2006

Abstract
The ESR spectrum of the tropone anion radical has been examined. The radical was generated from the neutral species by the electrolytic reduction in N,N-dimethylformamide. Splitting constants are satisfactorily explained in terms of the calculated spin densities by the McLachlan procedure, confirming that the unpaired spin orbital belongs to an a2 symmetrical species. The complete delocalization of the π-electrons was assumed for the anion radical.
Generation and Cycloaddition of 8,8-Dimethylisobenzofulvene
Authors: Tanida Hiroshi , Irie Tadashi , Tori Kazuo 
Published: July 2006

Abstract
Transient 8,8-dimethylisobenzofulvene (5) was generated by thermal decomposition of two materials; one is formally an adduct of cyclopentadienone with 9-isopropylidenebenzonorbornadiene (6), and the other an adduct of 3,6-di(2′-pyridyl)-S-tetrazine with 6. The former was prepared by cycloaddition of 6 to tetrachlorodimethoxycyclopentadiene followed by dechlorination giving a ketal, then hydrolysis of the ketal function. Generation without any trapping reagent instantaneously yielded one kind of dimer of a stereospecific structure. In the presence of dimethyl maleate, dimethyl 9-isopropylidenebenzonorbornene-exo,cis-2,3-dicarboxylate and its endo-cis isomer were formed. In the presence of dimethyl fumarate, the trans isomer was obtained. Trapping with tropone led to a 1 : 1 adduct resulting from participation of the exocyclic C2–C8 double bond in 5. All attempts to isolate 5 or prepare a stable metal complex of 5 by conventional means were unsuccessful.
Studies of Rare Earth Oxyfluorides in the High-temperature Region
Authors: Niihara Koichi , Yajima Seishi 
Published: July 2006

Abstract
The behavior of the rhombohedral LnOF and the tetragonal Ln4O3F6 at high temperatures was investigated by differential thermal analysis and the high-temperature X-ray diffraction technique. In the case of the rare earth oxyfluorides, LnOF (Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y), the high-temperature transition rhombohedral\ightleftarrowscubic was observed by means of DTA and a high-temperature X-ray camera. The heat of transformation from rhombohedral to cubic was obtained by means of DTA. The transition temperatures and the heat of transformation, ΔH, shift to higher temperatures and to greater values respectively as the atomic numbers of the rare earth elements increase, although there are some anomalies. One endothermic peak was observed for the rare earth oxyfluorides, Ln4O3F6, from Sm to Lu. On the other hand, no peak was observed up to 1300°C for La, Pr, Nd, and Y. The behavior of the peak temperature of DTA against the atomic number for Ln4O3F6 is similar to that for LnF3; this indicates a transformation from an orthorhombic to a hexagonal structure.
Kinetic Study on Homolysis of Aryl Arylazo Sulfones
Authors: Kojima Minoru , Minato Hiroshi , Kobayashi Michio 
Published: July 2006

Abstract
Aryl arylazo sulfones were prepared, and the rates of homolyses in chlorobenzene were determined in the presence of a base for suppression of acid catalysis at 80–118°C. An isokinetic relationship was found to hold between ΔH\eweq and ΔS\eweq (β=101.0°C). The substituents on the benzenesulfonyl group influenced the rates very little, whereas the substituents on the phenylazo group decreased the rates (especially the electron-releasing substituents).
Chemical Constituents of the Male Flower of Alnus pendula (BETULACEAE)
Authors: Suga Takayuki , Iwata Nobuo , Asakawa Yoshinori 
Published: July 2006

Abstract
The structure of alnustone (1) isolated from the male flower of Alnus pendula Matsum. has been established to be 1,7-diphenyl-1,3-heptadien-5-one. Previously-known compounds, β-phenylethyl cinnamate (6), cinnamaldehyde, benzylacetone, β-phenylethyl alcohol, pinocembrin (7), pinostrobin (8), alpinetin (9), galangin (11), pinosylvin (13), and its monomethyl ether (14), eugenol, chavicol, cinnamic acid, β-phenylpropionic acid, and benzoic acid, were identified along with the above new ketone.
ESR of Hot Ions: Zn(I), Cd(I), and Hg(I) in γ-Irradiated Potassium Tetracyano Zincate(II), Cadmate(II), and Mercurate(II)
Authors: Isoya Jun-Ichi , Fujiwara Shizuo 
Published: July 2006

Abstract
It is known that X-ray or γ-ray irradiation of inorganic complexes produces hot ions which have lower valence states than the original ones and yet are sited in the regular crystalline array of the undamaged mother complexes. ESR study reveals that the hot ions of paramagnetic Zn(I), Cd(I), and Hg(I) complexes are formed by γ-irradiation of K2[Zn(CN)4], K2[Cd(CN)4], and K2[Hg(CN)4], respectively. Hyperfine structures of the ESR signals shows that the Zn(I) and Cd(I) complexes have C3v, symmetry instead of Td symmetry of the original complex, and Hg(I) complex has a slightly distorted C3v symmetry. In Zn(I) complex, one of the four symmetry axes along Zn(II)–CN bondings is stretched. This occurs evenly with respect to each axis, resulting in the formation of four sites of the electron spins. For Cd(I) complexes, four species are produced as an irradiation product, where each species has four sites which are axially symmetric with respect to any one of the four Cd(II)–CN bondings. In Hg(I) complex, there exist twenty-four sites and the symmetry axis of each site lies along a direction slightly deviated from the original Hg(II)–CN bonding. From the behavior of the decay of ESR signal intensity at liquid nitrogen temperature, it is concluded that the stability is in the order Hg(I)&gt;Cd(I)&gt;Zn(I).
Dimerization of Ethylene Catalyzed by σ-Aryl Nickel Compound in the Presence of Trifluoro Boron Etherate
Authors: Maruya Ken-ichi , Mizoroki Tsutomu , Ozaki Atsumu 
Published: July 2006

Abstract
It was found that σ-aryl nickel(II) complex catalyzes the dimerization of ethylene rapidly and selectively when trifluoro boron etherate is added. The rate of dimerization increases in order Br&lt;&lt;mesityl&lt;naphthyl&lt;o-tolyl. The aryl ligands remain in the nickel complexes during the course of dimerization, since vinyl naphthalene, butenyl-naphthalene, etc., which are expected to be the reaction products of ethylene with the σ-aryl lingands, were not detected. The isotopic exchange between ethylene and deuteroethylene and the dimerization of deuteroethylene were studied to confirm the active species of this catalyst system. The isotopic exchange is faster than both the dimerization and isomerization of 1-butene formed. No increase in the atomic fraction of hydrogen of deuteroethylene was observed after treatment with the catalyst system. Thus it is concluded that the nickel hydride formed by the dissociative addition of ethylene is the active species of the catalyst system. The role of trifluoroboron etherate was also elucidated by a comparison of its effect on the rate of ethylene dimerization with that of sodium tetraphenyl borate.
The Orientation Overgrowth of Polycyclic Aromatic Quinones on the Cleavage Surface of Alkali Halide Single Crystals
Authors: Ashida Michio , Hamada Akihiko , Watanabe Teizo 
Published: July 2006

Abstract
Vacuum-condensed films of polycyclic aromatic quinones (flavanthrone, indanthrone, and pyranthrone) were found to grow epitaxially on the cleavage faces of NaCl and KCl. Electron microscopy studies have shown that all the films on NaCl were composed of small, needle-like crystallites crossing orthogonally. The needle axis of the crystals coincides with the 〈110〉 directions of NaCl. When a cleavage surface of KCl was used as the substrate, vacuum-condensed films of flavanthrone and indanthrone were composed of dendroid crystals which assumed the standing b-axis orientation with an apparent C4v symmetry. On the other hand, a pyranthrone film on KCl was composed of wedge-like crystals which assumed the standing b-axis orientation. The electron-diffraction pattern of the film revealed that the b-axis of each crystal tilts against the normal of the substrate face at an angle of 29° and takes a random orientation. When the films assume the standing b-axis orientation, the planar molecule in the crystal comes into parallel contact with the cleavage face of KCl. It may be presumed that the nitrogen atoms in both flavanthrone and indanthrone molecules are placed on potassium ions in the (001) plane of KCl.
The Surface Properties of Rutile Prepared by the Hydrolysis of Titanium Tetrachloride. I. The Heat of Immersion in Water
Authors: Iwaki Toru , Komuro Masayoshi , Miura Masaji 
Published: July 2006

Abstract
The surface properties of rutile prepared by hydrolyzing titanium tetrachloride have been studied by measuring the heat of immersion in water as a function of the outgassing temperature. The heat of immersion showed an extremely large value at outgassing temperatures between 300 and 400°C. However, when the rutile was calcined at 800°C, it showed a heat-of-immersion curve similar to those hitherto reported. In order to examine the phenomenon found on uncalcined rutile, the amounts of water physically and chemically adsorbed on the surface were estimated by measuring the water-vapor adsorption. We found that hydroxyl groups were formed in bulk as well as on the surface by means of the chemisorption, resulting in the formation of a hydrous structure because of the low crystallinity of the sample at temperatures below 400°C.
Studies of the Properties of the Basic Sites on the Silica-alumina Surface through the Reaction of the Basic Sites with Copper(II) Complexes Containing 2,2′-Bipyridine
Authors: Takimoto Kazuto 
Published: July 2006

Abstract
The substitution reactions of complexes with basic sites on the surfaces of silica-alumina and alumina and the properties of the basic sites were studied through the adsorption of the complexes onto the surfaces. The hydroxyl groups with basic strengths of two kinds, H0&gt;9.3 and 7.2&lt;H0&lt;9.3, exist on the silica-alumina surface pretreated at 300°C. They are present in a cluster state. The basic strength becomes higher as the outgassing temperature becomes lower. The complexes predominantly interact with the O2− ions on the surface pretreated at a relatively high temperature, resulting in new chemical species. The basic strength of the O2− ions is lower than that of the hydroxyl groups on the surface pretreated at a lower temperature. The hydroxyl groups on the alumina surface outgassed at 300°C are distributed, on the whole, homogeneously in comparison with those of the silica-alumina surface, and their basic strength is H0&gt;9.3. The nature of the basic sites on the alumina surface tends to vary with the outgassing temperature, similarly to those on the silica-alumina surface. These analyses were performed on the basis of the ESR spectra for complexes in basic solutions.
Studies on Nucleosides and Nucleotides. II. Selective Acylation of 5’-Hydroxyl Group of Thymidine
Authors: Mitsunobu Oyo , Kimura Junji , Fujisawa Yoshiyuki 
Published: July 2006

Abstract
Treatment of thymidine and either acetic acid or benzoic acid with diethyl azodicarboxylate (1) and triphenyl-phosphine (2) in dioxane afforded 5′-O-acetyl or 5′-O-benzoyIthymidine along with a trace of 3′,5′-di-O-acylated product. When thymidine and benzoic acid or p-substituted benzoic acids were allowed to react with 1 and 2 in hexamethylphosphoric triamide(HMPA), the corresponding 5′-O-aroylthyinidines were selectively obtained. The aroyl groups having electron-withdrawing substituents were much more readily removed than those having electronreleasing groups under mild alkaline conditions.