bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis, Crystal Structure, and Physical Properties of the Charge-Transfer Complex Bis[benzo[1,2-c:3,4-c′:5,6-c″]trithiophene]–tetrafluorotetracyanoquinodimethan, (BTT)2(TCNQF4)
Authors: Sugano Tadashi , Hashida Takashi , Kobayashi Akiko , Kobayashi Hayao , Kinoshita Minoru 
Published: July 2006

Abstract
The semiconductive 2:1 charge-transfer complex between benzo[1,2-c:3,4-c′:5,6-c″]trithiophene and 2,2′-(2,3,5,6-tetrafluoro-2,5-cyclohexadiene-1,4-diylidene)bis[propanedinitrile], (BTT)2(TCNQF4), crystallizes in the monoclinic system, space group P21⁄c, with the following cell constants: a=8.893(2) Å, b=10.589(2) Å, c=18.528(4) Å, β=114.52(1)°, V=1587.5(10) Å3, Dx=1.61 g cm−3, and Z=2. The crystal structure of (BTT)2(TCNQF4) consists of stacking columns of alternating donor dyads and acceptor monads (DAD units) along the crystallographic b axis. Side-by-side sulfur-sulfur contacts shorter than the sum of the van der Waals radii were found along the axis between BTT molecules on the neighboring columns. Polarized reflectance spectra were measured with the single crystal of (BTT)2(TCNQF4) at room temperature, showing a charge-transfer band polarized parallel to the stacking direction. The degree of charge transfer was estimated to be 0.21 from the oscillator strength and the transition energy of the charge-transfer band. From this, as well as the electric and magnetic properties of the complexes and the atomic distances for TCNQF4, it was concluded that (BTT)2(TCNQF4) is a weakly ionized charge-transfer complex.
Photoinduced Extraction and Active Transport of Anions by a Triphenyl Methane Derivative
Authors: Sasaki Hiroshi , Ueno Akihiko , Osa Tetsuo 
Published: July 2006

Abstract
Triphenylmethane derivative leukobase (1) was converted to its cation form 2 by UV irradiation. This lipophilic cation form was stable in dichloromethane with green color (λmax=634 nm), and returns to the original colorless form of 1 when shaked with an alkaline solution. Compound 2 exhibited excellent anion extraction ability (from aqueous solution into dichloromethane) under the conditions of appropriate pH, but 1 has no anion extraction ability. Photoinduced active transport of anions across a liquid (dichloromethane) membrane was achieved by using the difference in the extraction ability between 1 and 2 together with the difference in pH between the source and receiving phases.
Asymmetric Grignard Cross-Coupling Reaction Using Chiral Ligands Derived from Carbohydrates
Authors: Iida Akihito , Yamashita Mitsuji 
Published: July 2006

Abstract
Chiral diphenylphosphine and diphenylphosphinite derivatives of carbohydrates such as d-glucose, d-galactose, and l-rhamnose were used as the ligand of metal catalysts for asymmetric Grignard cross-coupling reaction. Coupling of s-butylmagnesium bromide with bromobenzene was carried out in the presence of nickel or palladium chloride with the chiral ligand. The highest optical yield was observed when d-galactose ligand was used.
Selective Preferential Esterification of the Dicarboxylic Acids with Longer Carbon Chain by Diazomethane in the Presence of Dicarboxylic Acids with Shorter Carbon Chain by Adsorbing and Aligning the Acids on Alumina
Authors: Ogawa Haruo , Hiraga Nobuo , Chihara Teiji , Teratani Shousuke , Taya Kazuo 
Published: July 2006

Abstract
Selective monoesterification of a dicarboxylic acid with longer carbon chains by diazomethane in a mixture of dicarboxylic acids, [dodecanedioic acid (C12) plus glutaric acid (C5), adipic acid (C6), pimelic acid (C7), suberic acid (C8), or sebacic acid (C10)] was achieved by adsorbing and aligning the acids on alumina. The larger the difference in the number of carbon atoms, the higher the selectivity. In the case of the combination of C12 and C5 the highest selectivity was observed and the preferential 89% formation of the monomethyl ester of C12 was obtained in contrast to the 9% formation for the monomethyl ester of C5. Selective reactions were also observed in the case of the combination of C10 and C4, and that of C12 and trans-1,4-cyclohexanedicarboxylic acid.
A New Method of Synthesizing 7-(2-Hydroxy-5-oxo-1-cyclopentenyl)heptanoic Acid and Related Compounds
Authors: Naora Hirokazu , Ohnuki Takashi , Nakamura Asao 
Published: July 2006

Abstract
A useful prostanoid synthon, 7-(2-hydroxy-5-oxo-1-cyclopentenyl)heptanoic acid (3), was prepared from commercially available cyclooctanone in two steps. Nine other related cyclopentanoids which are also valuable synthons for prostaglandins were obtained from 3 in reasonable yields via several steps. The procedure is capable of generating these useful synthons on a laboratory scale.
The Synthesis of C-Methyl Branched-Chain Deoxy Sugar Nucleosides by the Deoxygenative Methylation of O-Tosylated Adenosines with Grignard Reagents
Authors: Kawana Masajiro , Takeuchi Kikuko , Ohba Takayo , Kuzuhara Hiroyoshi 
Published: July 2006

Abstract
The reaction of appropriately protected 2′-O-tosyladenosines with methylmagnesium bromide (or iodide) gave 9-(2-deoxy-3-C-methyl-β-d-threo-pentofuranosyl)adenine after deprotection. The same reaction on 3′-O-tosyladenosine derivatives afforded an epimeric pair of 2′-C-methyl-3′-deoxy sugar nucleosides. The modified structures of the sugar moieties were determined unambiguously.
Studies on Lignan Lactone Antitumor Agents. V. 1-O-(Aminoethyl) Ether of 4′-O-Demethyl-1-epipodophyllotoxin
Authors: Saito Hitoshi , Nishimura Yoshio , Kondo Shinichi , Komuro Keiko , Takeuchi Tomio 
Published: July 2006

Abstract
1-O-(2-Aminoethyl)-4′-O-demethyl-1-epipodophyllotoxin derivatives were synthesized by a stereoselective BF3-catalyzed coupling of 4′-O-benzyloxycarbonyl-1-epipodophyllotoxin with the corresponding 2-aminoethanol derivatives, and with ethylene glycol followed by reductive amination of its aldehyde. Some 1-O-(2-aminoethyl) ethers of 4′-O-demethyl-1-epipodophyllotoxin prolonged markedly survival periods in mice with leukemia L-1210.
Addition of Diphenyldiazomethane to Unsubstituted and Chloro-Substituted 1,4-Benzoquinones. Effects of Chloro Substituents on the Addition Modes
Authors: Oshima Takumi , Nagai Toshikazu 
Published: July 2006

Abstract
Unsubstituted 1,4-benzoquinone (1a) reacted with diphenyldiazomethane (DDM) at the C=C double bonds to give dihydroxy-3H-indazole (2a) and its benzhydryl ether (3a) together with benzodipyrazole derivative (4a). Similarly, reactions of 2-chloro- and 2,3-dichloro-1,4-benzoquinones (1b and 1c) with DDM yielded the corresponding dihydroxy-3H-indazoles (2b, 2b′, and 2c) and their benzhydryl ethers (3b, 3b′, and 3c) along with 5–13% benzophenone (6). On the other hand, reaction of 2,6-dichloro-1,4-benzoquinone (1e) with DDM gave bicyclic 5e and tricyclic diones (7e), together with benzophenone dimethyl acetal (9) in the presence of added methanol. In the same conditions, 2,3,5-trichloro-1,4-benzoquinone (1f) provided bicyclic dione (5f) and 9. Formation of 6 and 9 was interpreted as arising from the hydrolysis and methanolysis of the 1:1 betaine intermediates given by the addition of DDM to the quinonoid C=O double bonds. The C=O addition increased with increasing chlorine substituents.
Stereoselective Syntheses of 1,3,5-Trihydroxy-2,4-dimethylpentane Equivalents from Methyl α-Mannopyranosides
Authors: Tatsuta Kuniaki , Koguchi Yoshihito , Kase Motohiro 
Published: July 2006

Abstract
The optically active 1,3,5-trihydroxy-2,4-dimethylpentane equivalents: methyl 2,4-dideoxy-2,4-di-C-methyl-α-d-ido- and talopyranosides and their enantiomers, which should be suitable for the syntheses of propionate-derived natural products, were stereo- and regioselectively prepared from methyl α-d- and l-mannopyranosides through the reactions of the 3,4-anhydro-2-O-mesyl- and 3,4-anhydro-2-C-methylaltropyranoside derivatives with methylmagnesium bromide and methylmagnesium chloride.
Synthesis and Reactions of 2-Arylhydrazinotropones. I. Preparation of 2-(2-Arylhydrazino)tropones and the 4-Substituted Derivatives
Authors: Nozoe Tetsuo , Imafuku Kimiaki , Yin Bing-Zhu , Honda Masaaki , Goto Yasutomo , Hara Yasushi , Andoh Takayoshi , Yamamoto Hiroshi 
Published: July 2006

Abstract
A wide variety of 2-(2-arylhydrazino)tropones were prepared by the reactions of 2-tosyloxytropone with arylhydrazines. The dimeric compounds 6,6′-bis(arylhydrazono)-1,1′-bi(2,4-cycloheptadiene)-7,7′-diones, 2-anilinotropones, and 3-(2-arylhydrazino)tropones were isolated as minor products in some cases. Similarly, starting with 2-tosyloxytropones bearing an isopropyl, isopropenyl, (1-acetamidoethyl), and protected acetyl group at the 5-position, 4-substituted 2-(2-arylhydrazino)tropones were obtained as the major products by the abnormal substitution reaction. These 2-(2-arylhydrazino)tropones are expected to effectively serve as precursors for a convenient synthesis of 5-aryl-substituted tropolones via benzidine-type rearrangement. 1H NMR (200 or 500-MHz) parameters for these 4-substituted 2-(2-arylhydrazino)tropones are given for their unambiguous structural assignments.
Synthesis of C3 and C4 Paraffins from Synthesis Gas with Hybrid Catalyst
Authors: Fujimoto Kaoru , Saima Hitoshi , Tominaga Hiro-o 
Published: July 2006

Abstract
Hybrid catalysts composed of the physical mixture of methanol synthesis catalysts and Y-type zeolites gave C3 and C4 paraffins from synthesis gas at 2.1 MPa, with a selectivity higher than 70%. The product contained small methane and little aromatic hydrocarbons. The hydrid catalyst kept its activity and selectivity at almost constant level for 50 h. The yield of hydrocarbon was much higher than the level estimated from the thermodynamic equilibrium of methanol formation from synthesis gas. The yield of hydrocarbon increased monotonically with the increase in temperature while the carbon number distribution of the product shifted to lower side between 523 and 623 K. The production of hydrocarbon was accompanied by the nearly equal amount of CO2.
Solid-State 2H NMR Study of Discotic Benzenehexayl Hexaheptanoate. Conformational Transition of Alkyl Side Chains
Authors: Toriumi Hirokazu , Shimmura Toru , Watanabe Hiroshi , Saitô Hazime 
Published: July 2006

Abstract
A 2H NMR study of discotic benzenehexayl hexaheptanoate carrying perdeuterated alkyl side chains (BH7-d78) is reported. Solid-state 2H NMR measurements reveal that the conformational transition of the heptanoate chains takes place at 230 K from nearly static to mobile state. The chains above 230 K undergo flip-flop type reorientational motion, with the degree increasing upon heating. This temperature coincides with the solid-to-solid phase transition temperature, indicating that the phase transition takes place accompanied by the conformational melting of the flexible alkyl side chains. A spectrum measured in the discotic mesophase is also reported.
Conductance Study of Alkali Metal Chlorides and Ammonium Chloride in 1,2-Dimethoxyethane–Water Mixtures at 25 °C
Authors: Prabhu P V S S , Ramanamurti M V 
Published: July 2006

Abstract
Conductance data for alkali metal chlorides and ammonium chloride in 1,2-dimethoxyethane (DME)–water mixtures (14.00&lt;dielectric constant&lt;56.76) at 25 °C are reported in the concentration range 0.0001–0.06 mol·dm−3. The data have been analyzed by Fuoss (1978) conductance–concentration relation. Preferential solvation of cations by water does not show systematic trend depending on the cationic size. Walden product variations indicated the complex dependence of conductance of alkali metal cations on solvent sorting and structural effects. The energy (Es) values suggest that alkali metal cations and chloride ions in majority exist as contact pairs in these solutions.
Atomization Enthalpies of Aliphatic Compounds with Alternately Adjacent Carbonyl Groups and Nitrogen Atoms
Authors: Sakiyama Minoru , Kuriyama Nobuhiro , Imamura Akira , Murata Shigeo 
Published: July 2006

Abstract
Hückel MO calculations were made for the title compounds using Hess–Schaad heteroatom parameters. The bond-contribution values were determined for the total π-bonding energies of the acyclic compounds. No resonance stabilization is present for molecules with six-, eight-, and ten-membered rings composed of CO–N linkages. Graph-theoretical calculations gave a similar result. Atomization enthalpies were calculated from the available thermochemical data and analyzed within the framework of the Hess–Schaad theory. The destabilization energies of normal alkanamides and N,N-dimethylformamide are close to zero. Diacetamide is not destabilized, while N-butyldiacetamide and triacetamide showed small destabilization energies. Trimethyl isocyanurate is not significantly strained. The total strengths of the CO–N bonds are in this order: amide&gt;(urea and diacetamide)&gt;internal bond of acetylurea.
Roles of Kinetic and Potential Energies in Conjugation. I. A Study of Prototypes
Authors: Ichikawa Hiroshi , Ebisawa Yukiko , Sameshima Keiichiro 
Published: July 2006

Abstract
The analysis of the potential and kinetic energy changes between conjugative and nonconjugative structure in vinylamine and nitroethene led to the conclusion that there were two different types of conjugations: the conjugative stability caused by a decrease in the kinetic energy and that given by a decrease in the potential energy. Those two types could be termed conjugations of kinetic energy origin and potential energy origin respectively. The cojugative stability in vinylamine is produced by an excess decrease in the kinetic energy over the increase in the potential energy (kinetic energy origin), which was attributed to a release of the kinetic energy pressure of the lone pair of electrons on nitrogen. On the other hand, the conjugation of nitroethene causes an overwhelming decrease in the potential energy, especially in that belonging to the nitro group (potential energy origin).
The CO–H2 Reaction over ZrO2 to Form Isobutene Selectively
Authors: Maruya Ken-ichi , Maehashi Tatsuichi , Haraoka Takashi , Narui Shinichiro , Asakawa Yukihiko , Domen Kazunari , Onishi Takaharu 
Published: July 2006

Abstract
The CO–H2 reaction over ZrO2 was studied in detail. Methanol and isobutene were selectively formed at 473–523 and 623–673 K, respectively. The activation energies for C2, C3, and linear C4 hydrocarbon formation are 79, 84, and 96 kJ mol−1 (523–723 K), while that for branched-chain C4 hydrocarbons is about 210 kJ mol−1 (523–623 K). At 673 K the rate of C4 hydrocarbon formation is as follows: r=kPH2·Pco2, while those of C1, C2, and C3 are written by the functions having the maximum values regarding CO pressure. C4 hydrocarbons consist mostly of isobutene at the temperature. From these results it was concluded that isobutene is formed via different path from those of C1, C2, C3, and linear C4 hydrocarbons. The addition of high electronegative oxides such as SiO2 and Nb2O5 resulted in the decrease of isobutene and the increase of methane. The selective formation of isobutene proceeds over pure ZrO2 and ZrO2 modified with 3a Group and basic metal oxides. The nature of active site for isobutene formation was discussed.
Spectrophotometric Study of Complexation Equilibria between Lanthanoids(III) and 2-(5-Bromo-2-pyridylazo)-5-(N-propyl-3-sulfopropylamino)phenol
Authors: Ohyoshi Emiko 
Published: July 2006

Abstract
Complex formation (1:1) between lanthanoids(III) and 2-(5-bromo-2-pyridylazo)-5-(N-propyl-3-sulfopropylamino)phenol (5-Br-PAPS, HL) has been studied by spectrophotometry at 25 °C and at I=0.1 (NaNO3). The protonated complex MHL is found to exist in equilibrium with the normal complex ML at pH 5–6. The formation constants KML and KMHL are obtained by a graphical analysis. The KML values uniformly increase with increasing atomic number except for those in the Gd–Ho region where a distinct decrease is observed. However, there is little variation in the KMHL values with atomic number. A linear relation holds well between log KML values of 5-Br-PAPS and 4-(2-pyridylazo)resorcinol (PAR) complexes for the elements up to Eu(III), the intercept of which reflects the difference in the basicity of the oxygen atom ortho to the azo group between the two ligands. This is not the case for log KMHL of the two systems.
Dynamic NMR as a Nondestructive Method for the Determination of Rates of Dissociation. XII. Dissociation of the Olefin in trans-Dichloro(4-methyl-1-pentene)(4-substituted pyridine 1-oxide)platinum(II) Complexes
Authors: Toyota Shinji , Oki Michinori 
Published: July 2006

Abstract
The rates of dissociation of the olefin in the title compounds were determined by the dynamic NMR technique by taking advantage of the line shape change due to the isopropyl-methyl protons. The rates of dissociation were independent of concentration in bromoform-d solutions. The free energy of activation was between 17.0 and 19.1 kcal mol−1 at 353 K for the compounds, of which line shapes were fully analyzed, depending upon the substituent in the pyridine ring and electron-withdrawing substituents giving low activation energy. The solvent effect was noticed on the dissociation rates: Aromatic hydrocarbons give higher rates of dissociation than halogenated hydrocarbons. Although solvents of strong affinity toward platinum(II) tend to decompose the complex, tetrahydrofuran-d8 was found to give definitely higher rates of dissociation of the olefin in trans-dichloro(4-methoxycarbonylpyridine 1-oxide)(3-methyl-1-butene)platinum(II) than bromoform-d, when it was used as a solvent. The mechanism of dissociation was discussed from the available data.
Friedel–Crafts Acetylations of Methoxy-4H-cyclopenta[def]phenanthrenes and the 4-Ketones
Authors: Minabe Masahiro , Yoshida Masaaki , Takabayashi Yutaka , Masuda Masatoshi 
Published: July 2006

Abstract
Acetylations of 2- and 3-methoxy-4H-cyclopenta[def]phenanthrene gave predominantly the 1- and 8-acetyl derivatives, respectively. The acetylation of the 1-methoxy compound afforded the 2-, 3-, 5-, 7-, and 8-yl ketones and the reaction of the 8-methoxy derivative yielded the 1- and 3-acetyl derivatives. Similar reactions of 1-, 2-, 3-, and 8-methoxy-4H-cyclopenta[def]phenanthren-4-one occurred mainly at the 2-, 1-, 8-, and 9-positions, respectively.
Surface States of Titania(Rutile and Anatase)-Supported Vanadium Oxide Catalysts as Prepared by a Column-Exchange Adsorption Method and Their Catalytic Features
Authors: Kera Yoshiya , Inoue Takashi , Matsukaze Yoshihiro 
Published: July 2006

Abstract
Monolayer or less monolayer vanadium oxide catalysts supported on TiO2(rutile and anatase), V2O5/R-and A-TiO2, were prepared by a “column-exchange adsorption” method such as passing an oxovanadium ion solution, the pH of which was adjusted at 2, 4, and 7, through a column packed with titania (TiO2) for impregnation. V2O5/R-TiO2 pretreated at 450 °C showed an ESR spectrum with an unresoluved hfs for V(IV) ions at 77 K without depending upon the pH upon impregnation. V2O5/A-TiO2 petreated at room temperature showed quite small ESR signals due to Ti(III) and V(IV) ions. These signals tended to be intensive with increasing pH upon impregnation. After a heat treatment at 400 °C a huge and quite broad spectrum, which was ascribed to some reduced vanadia species(V2O5−δ), appeared in addition to the spectra for the Ti(III) and V(IV) ions, while such a change was never found in V2O5/R-TiO2. Based on a theoretical treatment for the g-values, V(IV) ions on V2O5/R-TiO2 have been confirmed to be replaced just into Ti ion sites on rutile(almost D2h symmetry). With V2O5/A-TiO2, V(IV) ions were shown to be placed so as to be partially subject to an anatase surface field(almost D2d symmetry); that is, to be placed only near the vacant Ti ion site on anatase. From a comparison of the hf-coupling constant the vanadia species on rutile was clearly shown to interact more strongly with the surface than that on anatase. The 2-propanol decomposition rates over the catalysts were measured in the temperature range 270–350 °C as a test reaction. The activity of V2O5/R-TiO2 was generally higher than that of V2O5/A-TiO2. The lowest activation energy was obtained upon the impregnation at pH=2 for V2O5/R-TiO2 and at pH=7 for V2O5/A-TiO2. The best catalyst was not necessarily prepared through conditions with pH=4, which had been suggested as giving an effective monolayer-vanadia species.
A Behavior of Donnan Salt within Membrane
Authors: Yamauchi Akira , Date Masashi , Yamamoto Yukiko , Hirata Yutaka , Kimizuka Hideo 
Published: July 2006

Abstract
In an amphoteric ion exchange membrane-electrolyte system, three independent experiments were carried out, that is, the membrane potential, membrane conductance and concentration of ions within membrane were measured, respectively. The electrolytes adopted in the systems were NaCl, CaCl2, LaCl3. From the analysis of the results, the specific conductance attributed to Donnan salt within membrane was separated. As a result, it was pointed out that the dynamic state of Donnan salt is obviously different from that of salt in aqueous solution. Furthermore, the comparison between the ions constituting Donnan salt and the counterions which interact with the ion-exchange sites suggested us the existance of two different dynamic states on the ions within membrane.
Reactions of Coordination Compounds in the Solid State. II. The Interconversion of the Isomers of Dichloro(triethylenetetramine)cobalt(III) Chloride, [Co(trien)Cl2]Cl, upon Heating in the Solid State
Authors: Fujiwara Terufumi , Bailar John C 
Published: July 2006

Abstract
The three isomers of the ion [Co(trien)Cl2]+, where trien=triethylenetetramine, have been synthesized and their interconversion upon heating in the solid state has been studied. The trans isomer changes to the β-cis isomer, which in turn is converted to the α-cis isomer. The changes have been followed by proton NMR spectroscopy. The first change cannot be explained by a twist mechanism. Experiments with the trans monohydrate or hydrochloride in sealed tubes or in an atmosphere of HCl show that the presence of H2O accelerates the conversion of the trans isomer to the cis-β isomer, and the presence of HCl accelerates the conversion of cis-β to cis-α, suggesting that the former conversion takes place through an aquation, followed by anation and for the latter conversion nucleophilic attack of a chloride ion on the cis-β isomer is important.
Synthesis and Reactions of Selenoketones
Authors: Ishii Akihiko , Okazaki Renji , Inamoto Naoki 
Published: July 2006

Abstract
A new, convenient method for the synthesis of selenoketones has been reported. The reaction of dimagnesium salts of ketone hydrazones with diselenium dichloride affords an intermediate tentatively assigned as tetraselenides, which are converted into selenoketones by heating in the presence of tributylamine. A comparative study on the reactions of 1,1,3,3-tetramethyl-2-indanselone and the corresponding thioketone with Grignard and organolithium reagents have been carried out. Analysis of the reaction products has revealed that the heterophilic attack of the organometallic reagents is much more significant in the reaction with the selone than with the thione.
The Fries Rearrangement of 4H-Cyclopenta[def]phenanthrenyl Acetate
Authors: Minabe Masahiro , Yoshida Masaaki , Amimoto Tsukasa , Nagata Toshihiro , Kobori Masamichi 
Published: July 2006

Abstract
A Fries rearrangement of 4H-cyclopenta[def]phenanthren-1-yl acetate gave 2- and 7-acetyl derivatives. The reaction of isomeric 2-acetoxy compound afforded 1- and 7-acetyl derivatives. The acetyl group of the 3- and 8-acetoxy compounds rearranged into the 2- and 9-positions, respectively. In addition, 1-, 2-, 3-, 4-isopropyl compounds were derived from the corresponding acetyl derivatives.