bluuebunny/crossref_metadata_2025_split huggingface dataset:
Construction of an Adiabatic High-Pressure Calorimeter Using Helium Gas for Pressurization
Authors: Yamamuro Osamu , Oguni Masaharu , Matsuo Takasuke , Suga Hiroshi 
Published: July 2006

Abstract
A novel adiabatic high-pressure calorimeter was constructed with using helium gas as a pressure transmitting medium. It works under a constant pressure up to 250 MPa in the temperature range from 12 to 370 K. Sample cell is made of Be–Cu alloy and has internal volume of 26 cm3. The pressure transmitting tube is connected to an external pressure-control system, which enables to keep automatically the inner pressure constant within ±1 kPa over the whole pressure and temperature ranges. Thus the thermodynamic path that any specimen follows during the heat capacity measurement can be described unambiguously. Heat capacities of the sample cells loaded without and with 158.9 MPa He gas were measured in the temperature range from 25 to 370 K. The imprecision of heat capacity data of the compressed He gas was within 0.3%. Thus the present calorimeter enables us to extend the low-temperature thermodynamic study on various kinds of materials to high pressures without a significant loss of the claimed precision.
Extraction Equilibria of Hydrochloric Acid by Trioctylamine in Low-Polar Organic Solvents
Authors: Kojima Takashi , Fukutomi Hiroshi 
Published: July 2006

Abstract
Two-phase emf titrations have been performed for the extraction of hydrochloric acid from aqueous solution containing 1 M NaCl (M=mol dm−3) by trioctylamine (TOA) dissolved in cyclohexane, toluene, benzene, chlorobenzene, nitrobenzene, cyclohexane–benzene mixtures, and benzene–nitrobenzene mixtures. It has been found that the extraction is accompanied with the formation of monomeric trioctylammonium chloride and its successive aggregation from dimer to micell (n-mer) in organic phase: ‾TOA+H++Cl−=‾TOAHCl, Kd; (‾TOAHCl)i−1+‾TOAHCl=(‾TOAHCl)i, \barKi(i=2,3,···,n), where the concentration quotients of successive aggregation, \barKi, satisfy the relation 2 \barK2=3\barK3⁄2=···=n\barKn⁄(n−1). The quotients Kd and \barK2 vary with the total volume fraction of TOA in organic phase, ΨR°, according to equations, In Kd=1nKd°+gΨR° and 1n \barK2=1n\barK2°+h\barΨR°. Diluent effect on the equilibrium constants Kd° and \barK2° are discussed in detail based on the theory of regular solution.
Simultaneous Determinations of Inorganic and Organic Acids by Ion Chromatography
Authors: Itoh Hisaaki , Shinbori Yoshio 
Published: July 2006

Abstract
The elution behavior of seven common inorganic anions (F−, Cl−, NO2−, Br−, NO3−, SO42−, and phosphate) and a large number of organic acids in an AS-5 separator column using a weak carbonate eluent was examined and the possibility of simultaneous determinations of the inorganic and organic acids in a single injection was investigated. For pharmaceutical samples, such as a Ringer’s solution which contains some inorganic anions and a single organic anion as anion contents, each anion could be simultaneously analyzed with a relative standard deviation of below 0.6%. Furthermore, it was found that even in a sample such as the liquor of canned goods having a complex matrix, both inorganic and dicarboxylic acid contents could be simultaneously analyzed without any tedious pretreatment, except for a simple dilution with distilled and deionized water. For the liquor samples, the relative standard deviation for five measurments was less than 5.0%.
The Identification of Insoluble Adducts of Lewis Acids with Bases by Extension of the Continuous Variation Method to Solid-Liquid Reactions
Authors: Hihara Goro , Mitani Kazuhiro , Miyamae Hiroshi , Nagata Miharu 
Published: July 2006

Abstract
A method has been developed for identifying occurrence and composition of all the insoluble adducts formed in solid-liquid reactions by extension of the continuous variation method to the heterogeneous systems that were produced by the reactions of PbX2 (X=Cl, Br, and I) with ethylenediamine(=en) in ethanol solution. Four new adducts, PbX2·i(en) (i=1⁄2 and 1; X=Cl and Br), were found. The developed method was effective in identifying formation of the adducts such as PbCl2·1/2(en) and PbBr2·1/2(en) whose formation is liable to be overlooked in extending the mole ratio method to solid-liquid reactions.
Solid Phase Synthesis of Oligodeoxyribonucleotides Utilizing the Phenylthio Group as a Phosphate Protecting Group
Authors: Matsuzaki Jun-ichi , Kohno Kyoko , Tahara Shin-ichiro , Sekine Mitsuo , Hata Tsujiaki 
Published: July 2006

Abstract
Oligodeoxyribonucleotide synthesis utilizing the phenylthio group as a phosphate protecting group was applied to the solid phase method. The base residues of deoxyguanosine and deoxyadenosine were protected with bis(isobutyryloxy)ethylene (Bibe) and phthaloyl groups to avoid the base modification and depurination, respectively. A key synthetic intermediate of N2-isobutyryl-N1,N2-bis(isobutyryloxy)ethylenedeoxyguanosine was prepared in high yield by four-step reaction from deoxyguanosine and used for preparation of the building blocks of deoxyguanosine required for the polymer support synthesis. Two kinds of polymer supports, i.e., 1% cross-linked polystyrene and controlled pore glass were chosen. The latter was employed for the synthesis of dodecadeoxyribonucleotides by using an automated DNA synthesizer.
Synthesis of 2,2-Di-C-methyl-2-deoxy- and 4,4-Di-C-methyl-4-deoxypyranosides via Michael Addition of Conjugated Enopyranosiduloses
Authors: Kawauchi Nobuya , Sato Ken-ichi , Yoshimura Juji , Hashimoto Hironobu 
Published: July 2006

Abstract
Three hexopyranosides having gem-di-C-methyl group at 2- or 4-positions were synthesized by Michael addition to 2-enopyranosid-4-ulose and 3-enopyranosid-2-ulose derivatives, respectively, followed by hydroboration. A heptopyranosid-6-ulose having gem-di-C-methyl group at C–4 was also synthesized from 4-enopyranosid-6-ulose derivative in a similar way.
Selective 1,4-Chiral Induction in the Reaction of Enolates Generated from t-Butyl δ-Hydroxy Carboxylates
Authors: Narasaka Koichi , Ukaji Yutaka , Watanabe Kazutoshi 
Published: July 2006

Abstract
Lithium enolates generated from t-butyl esters of δ-hydroxy carboxylic acids with lithium dialkylamides in THF–HMPA were alkylated stereoselectively to give the corresponding syn-α-alkylated δ-hydroxy esters. The generation of the enolates was accelerated by the addition of lithium trifluoromethanesulfonate, and the successive aldol and hydroxylation reactions of the enolates also proceeded in a stereoselective manner.
Photo-Excitable Membranes. Effects of Nonactin as a Membrane Adtive on the Photoresponse of Poly(vinyl chloride)/Spirobenzopyran Membrane
Authors: Anzai Jun-ichi , Hasebe Yasushi , Ueno Akihiko , Osa Tetsuo 
Published: July 2006

Abstract
The magnitude of the photoinduced membrane potential across the poly(vinyl chloride)/spirobenzopyran/nonactin composite membrane depends considerably on the concentration of ammonium ion in the aqueous solution. The results are explained in terms of the charge density on the membrane surface.
Hexacarbonylmolybdenum(0)-Catalyzed Reaction of Allylic Carbonates with Arylsulfonyl-Stabilized Carbanions
Authors: Masuyama Yoshiro , Hirai Hidenori , Kurusu Yasuhiko , Segawa Koh-ichi 
Published: July 2006

Abstract
p-Tolylsulfonylacetonitrile reacted with allylic carbonates in the presence of a catalytic amount of hexacarbonylmolybdenum(0) to give monoallylated derivatives. Using sodium hydride as a base, methyl p-tolylsulfonylacetate reacted with those to give mixtures of mono- and di-allylated derivatives. No nucleophilic attack of bulky bis-(phenylsulfonyl)methane occurred, whether sodium hydride was present or absent.
Hexacarbonylmolybdenum(0)-Catalyzed Reductive Coupling of Allylic Acetates
Authors: Masuyama Yoshiro , Otake Kiyotaka , Kurusu Yasuhiko 
Published: July 2006

Abstract
The reaction of allylic acetates with zinc in the presence of a catalytic amount of hexacarbonylmolybdenum(0) led to reductive coupling for the formation of a 1,5-diene framework. Reductive coupling of nerolidyl acetate provided squalene and its isomers in high yield.
Synthesis on 1,4-Diaminocyclitol Antibiotics. III. Synthesis of 4-Hydroxypurpurosamine B Derivatives
Authors: Kanai Kazuaki , Sakamoto Itsuki , Ogawa Seiichiro , Suami Tetsuo 
Published: July 2006

Abstract
Methyl 2,6-di-N-acetyl-4-hydroxy-6-epi-α-purpurosaminide B and -4-hydroxy-α-purpurosaminide B have been prepared from d-glucosamine by sequence of reactions including stereoselective nitro aldol reaction.
Synthesis on 1,4-Diaminocyclitol Antibiotics. V. Synthesis of 3′-Enofortimicin D
Authors: Kanai Kazuaki , Yokoi Shigeki , Ogawa Seiichiro , Suami Tetsuo 
Published: July 2006

Abstract
3′-Enofortimicin D has been prepared by condensation of 1-O-acetyl-2,6-bis(2,4-dinitrophenylamino)-2,3,4,6-tetradeoxy-d-erythro-hex-3-enopyranose with 2,5-di-O-benzoyl-1,4-bis-N-(methoxycarbonyl)fortamine B, followed by deprotection.
Vertical Profiles of CCl3F, CCl2F2, and CH4 in the Stratosphere and Troposphere over Japan as Observed by Balloon Grab-Sampling and by Gas-Chromatographic Analysis
Authors: Makide Yoshihiro , Yokohata Akihito , Tominaga Takeshi , Honda Hideyuki , Kubo Haruya , Itoh Tomizo 
Published: July 2006

Abstract
Stratospheric and tropospheric air samples were collected by means of a balloon-borne grab-sampler launched from Sanriku (39°N, 142°E) in the late summers of 1981, 1983, and 1984. The mixing ratios of CCl3F and CCl2F2 were determined precisely by using gas chromatography with ECD, and that of CH4, by gas chromatography with FID. The vertical profiles of these compounds are presented and compared with the model calculations.
Generation and Reactions of Phosphorin 1-Sulfides
Authors: Tanaka Hideyuki , Motoki Shinichi 
Published: July 2006

Abstract
Phosphorin 1-sulfides generated by the thermolysis of 1-phospha-2-thiabicyclo[4.4.0]deca-3,7,9-triene 1-sulfides reacted with triphenylphosphine, dienophiles, or nucleophiles to give the corresponding phosphorins, 1-phosphabicyclo[2.2.0]octa-2,5-diene 1-sulfide, or 1,2-dihydrophosphorin 1-sulfide derivatives, respectively.
Homogeneous Isomerization of 1-Butene Catalyzed by [MX2(PR3)2]–NaBH4 Systems (M=Co, Ni, X=Halides, SCN, PR3=PPhnEt3−n)− Acceleration by Phosphine Addition and Stereoselectivity
Authors: Kanai Hiroyoshi , Sakaki Shigeyoshi , Sakatani Takenobu 
Published: July 2006

Abstract
The stoichiometric or a little excess amount of NaBH4 was treated with [MX2(PR3)2] (M=Co, Ni, X= halides, SCN, PR3=PPhnEt3−n) in THF–1,2-dimethoxyethane to form monohydride species which were active for isomerization of 1-butene. The reaction was accelerated by excess PPh3 in [CoX2(PPh3)2]–NaBH4 systems. Other catalytic systems have optimum ratios of excess phosphine to metal for getting maximum activities. Thiocyanate–metal complexes are the most active in each Co– and Ni–catalyst system. Cisselectivity depends on the cone angle of PR3, the size of anion ligands, and the congested structure of complexes.
Epitaxial Growth and Its Growth Mechanism in Physical Vapor Deposited Films of Alkyl Octadecanoates
Authors: Takamoto Michiko , Ogihara Seiji , Yase Kiyoshi , Okada Masakazu 
Published: July 2006

Abstract
Esters of octadecanoic acid and three primary alcohols such as methanol, ethanol, and propanol were deposited on substrates of potassium chloride (KCl), mica and amorphous carbon film under vacuum. The surface morphology of their films was observed by transmission electron microscope. They grew epitaxially to form the rectangular crystals with lateral molecular orientations on KCl substrate. On the other hand, ester molecules tend to arrange normal to the surface of mica and amorphous carbon film and construct the molecular layers like to Langmuir-Blodgett films. The crystal axis relationship between esters and KCl(001) surface was followed; c-axisester is parallel to 〈110〉KCl direction and 〈110〉ester direction inclines with an angle of about ±16° corresponding to 〈110〉KCl. These molecules had resemble crystal structures with trans configuration in the ester moiety. The optimum temperatures of substrates in the former epitaxial growth exist and the temperature decreases in proportion to the chain length of alcohol group with the discrepancy of about 10 to 30 °C.
Additivity Law for the Activity of a Counter Ion in Ion-Exchange Resin
Authors: Kimizuka Hideo , Waki Hirohiko , Matsubara Akira , Arimoto Y\={o}ichi 
Published: July 2006

Abstract
The ion-exchange resin–electrolyte solution equilibria were studied on the basis of thermodynamics. The experimental results showed that the external salt activity divided by the co-ion concentration in the ion-exchange resins was linear against the co-ion concentration in the resin. The equilibria were consistently explained by a partition coefficient of salt distribution with the additivity law for the counter ions in the ion-exchange resin. A thermodynamic expression for the ion-exchange reaction was also discussed.
129I Mössbauer Spectroscopic Study of 2:3 Molecular Complexes of Triphenylphosphine Sulfide–Iodine and Acridine–Iodine
Authors: Sakai Hiroshi , Maeda Yutaka 
Published: July 2006

Abstract
The 129I Mössbauer effect has been applied to investigate 2:3 molecular complexes of triphenylphosphine sulfide–iodine and acridine–iodine. The Mössbauer spectra indicate the presence of three unequivalent iodine sites (IA, IB, and IC), as expected from the crystallographic data of these complexes. The iodine atom (IA) coordinating to the sulfur or nitrogen atom of each donor molecule is more positively charged than that of the 1:1 molecular complex containing the same donor atom. This result can be interpreted in terms of the covalency of the S···IA or N···IA bond. The degrees of charge transfer in the 2:3 complexes are close to those in the 1:1 complexes, and the transferred charges are mainly localized on the terminal iodine atoms (IB). The iodine molecule (IC) cross-linked to two IB atoms has a slightly negative charge, consistent with the bond distance of the molecule. The iodine moieties of these complexes are very similar to the structure of I82− in Cs2I8.
Conductance Matrix of Amphoteric Ion-Exchange Membrane in Three Ion System
Authors: Yamauchi Akira , Shinohara Hitoshi , Shinoda Makoto , Date Masashi , Hirata Yutaka , Kimizuka Hideo 
Published: July 2006

Abstract
A conductance matrix describing the ion-transport phenomena in the membrane-three ion system has been determined. It was indicated there that six independent experiments were required in order to determine six independent elements of the conductance matrix. The NaCl–CaCl2–amphoteric membrane system was chosen as the three ion system, and three kinds of fluxes, two kinds of transport numbers, and the membrane conductance were measured. Nine elements were experimentally determined on the assumption of Onsager’s reciprocal relation. The results showed that the order of elements in conductance matrix was gCaCa&gt;gClCl&gt;gNaNa&gt;gCaCl&gt;gNaCl&gt;gCaNa. In addition, it was pointed out that the interactions among ions can never be ignored when the ion-transport phenomena across membrane are studied.
Synthesis and Properties of 5,10,15,20-Tetrakis(3,5-di-t-butyl-2-nitrophenyl)porphyrin: Conformational Stabilities of the Respective Atropisomers and Oxygenation Capabilities of the Iron(III) and Manganese(III) Complexes
Authors: Miyamoto T Ken , Takagi Shigeru , Hasegawa Tai , Tsuzuki Seizi , Takahashi Eitaro , Okude Kojiro , Banno Itsuki , Sasaki Yukiyoshi 
Published: July 2006

Abstract
The synthesis and properties of new, bulky atropisomeric porphyrins are described. Four atropisomers of 5,10,15,20-tetrakis(3,5-di-t-butyl-2-nitrophenyl)porphyrins has been easily separated and purified by column chromatography. The isomers all have different thermal stabilities toward atropisomerization. Below 60 °C, however, they have rather high conformational stabilities, and an iron(III) or manganese(III) ion has been incorporated into each isomer, with a retention of the ligand conformation. By the use of these metal complexes, the catalytic oxygenation reactions, i.e., the epoxidation of olefins (styrene, α-methylstyrene, cyclohexene, and cyclooctene) and the hydroxylation of alkanes (cyclohexane and heptane), have been done in the presence of hypochlorite or iodosylbenzene as an oxidant. Products analyses by GLC show that these new complexes effectively catalyze the oxygenations in higher yields or in more selective ways, than the corresponding TPP complexes.
Calorimetric and Spectrophotometric Studies of Bromo Complexes of Copper(II) in N,N-Dimethylformamide
Authors: Ishiguro Shin-ichi , Ozutsumi Kazuhiko , Nagy László , Ohtaki Hitoshi 
Published: July 2006

Abstract
Complexation of copper(II) with Br− ions has been studied by calorimetry and spectrophotometry in N,N-dimethylformamide (DMF) containing 0.16 mol dm−3 (C2H5)4NClO4, 1 mol dm−3 LiClO4, and 1 mol dm−3 NH4ClO4 as constant ionic media at 25 °C. Calorimetric titration curves obtained in each solution were well explained in terms of formation of [CuBrn](2−n)+ (n=1–4) and their formation constants, enthalpies and entropies were determined. Electronic spectra of individual copper(II) bromo complexes were also determined in the (C2H5)4NClO4, LiClO4, and NH4ClO4 DMF solutions over the range 260–500 nm, the spectra of each complex being kept practically unchanged in these solutions. The complexation of copper(II) with Br− ions is considerably weaker in the LiClO4 solution than in the (C2H5)4NClO4 one and is even more weakened in the NH4ClO4 solution due to the formation of LiBr and NH4Br ion pairs in the relevant solutions. The variation of the stepwise enthalpy and entropy values suggests that the coordination structure around copper(II) ion changes from octahedral to tetrahedral at the formation of [CuBr3]−. The result for the complexation between copper(II) and bromide ions thus obtained was compared with that for the complexation between the metal and chloride ions.
Thermal Rearrangement of 2,5-Bis(allyloxy)tropone, Revisited. Formation of Four Thermolysates under the Claisen Rearrangement Conditions and Structure Revision of the Major Thermolysate
Authors: Takeshita Hitoshi , Mori Akira , Goto Yasutomo , Nagao Tomohiro 
Published: July 2006

Abstract
A reinvestigation of the Claisen rearrangement of 2,5-bis(allyloxy)tropone led to the isolation of three diallyl-5-hydroxytropolones along with an intermediary thermolysate, 3-allyl-5-allyloxytropolone. The structure of the formerly identified product was revised from 3,6-diallyl-5-hydroxytropolone to 4,6-diallyl-5-hydroxytropolone. The involvement of no cleavage-recombination process was established by cross-over deuterium labelling experiments. These derivatives were respectively converted to p-tropoquinones, one of which was further converted to a cyclohepta[b]pyranone derivative by an electrochemical reaction.
Convenient Methods for the Preparation of Vinylic and Allylic Sulfones from Alkenes, Haloalkanes, and Aldehydes. Stereochemistry of the Conversion of Vinylic Sulfones to the Corresponding Allylic Sulfones
Authors: Inomata Katsuhiko , Sasaoka Shin-ichi , Kobayashi Toshifumi , Tanaka Yuhji , Igarashi Susumu , Ohtani Takashi , Kinoshita Hideki , Kotake Hiroshi 
Published: July 2006

Abstract
1- or 2-p-Tolylsulfonyl(=tosyl)-1-alkenes, vinylic sulfones, were regioselectively prepared from 1-alkenes via iodosulfonization or sulfonylmercuration and also from 1-haloalkanes by the homologation or unhomologation methods. The vinylic sulfones thus prepared were further converted to the corresponding allylic sulfones under basic conditions. The stereochemistry of this conversion was discussed. One-carbon homologated allylic sulfones were directly obtained from aldehydes in good yields by the reaction with diethyl phenylsulfonylmethylphosphonate and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) under mild conditions.
Redox-Photosensitized Reactions. XIV. Photochemistry of 4-Alkylated NADH Models, 1-Benzyl-4-(1-hydroxyalkyl)-1,4-dihydronicotinamides
Authors: Ishitani Osamu , Yanagida Shozo , Takamuku Setsuo , Pac Cyongjin 
Published: July 2006

Abstract
There were investigated photochemical behaviors of 4-alkylated 1-benzyl-1,4-dihydronicotinamides (1a–c) having R1R2C(OH) as the substituent (a: R1=Ph and R2=H; b: R1=Ph and R2=CF3; c: R1=p-NC–C6H4 and R2=H). The direct photolysis of 1a–c gave R1R2CO and the dimers of the dihydronicotinamide (BNA) fragment along with a minor amount of [C6H5CH(OH)]2, being thus interpreted in terms of the homolysis between the R1R2(OH) and BNA moieties. In the [Ru(bpy)3]2+-photosensitized reactions, it is suggested that 1a–c+· was generated as a key intermediate by electron transfer to excited [Ru(bpy)3]2+, undergoing a bond cleavage to give R1R2CO and the BNA. dimers. In the case of 1c, however, R1R2CH(OH) was formed, being attributed to a product from 1c−· that is formed by electron transfer from [Ru(bpy)3]+ to 1c.
Oxidation of 2,4-Alkadienoic Esters with Selenium Dioxide. A New Synthesis of Furans and Selenophenes
Authors: Tsuboi Sadao , Mimura Shigetoshi , Ono Shin-ichiro , Watanabe Kenji , Takeda Akira 
Published: July 2006

Abstract
Direct oxidation of 2,4-alkadienoic esters with selenium dioxide gave 5-alkyl-2-furancarboxylic esters along with 5-alkyl-2-selenophenecarboxylic esters. Ethyl 5-methylfurancarboxylate was converted to 5-hydroxymethyl-2-furancarbaldehyde, a component of honey, via ethyl 5-bromomethyl-2-furancarboxylate (5) in good yield. The compound 5 was converted to (5-ethoxycarbonyl-2-furyl)methyl dimethyldithiocarbamate possessing fungicidal activity. Reaction of triphenylphosphonium salt of 5 with nonanal gave ethyl 5-(1-decenyl)-2-furancarboxylate (E/Z=88:12) in 86% yield. Ethyl 5-methyl-2-selenophenecarboxylate was also converted to ethyl 5-(1-decenyl)-2-selenophenecarboxylate (E/Z=7:3) in 30% total yield.
Chemo- and Regioselective Reduction of Epoxides with Sodium Borohydride in Mixed Solvent Containing Methanol
Authors: Ookawa Atsuhiro , Hiratsuka Hiroshi , Soai Kenso 
Published: July 2006

Abstract
Mono- and gem-disubstituted epoxides were reduced to more substituted alcohols in good to high yields (73–100%) and in high regioselectivities (89–100:11–0) by sodium borohydride in a mixed solvent of t-butyl alcohol–methanol or 1,2-dimethoxyethane-methanol. The reaction of disubstituted epoxide depends on the steric hindrance and the position of the substituents. Trisubstituted epoxides were not reduced by the present reducing system. The reactivity order of epoxides by the present reducing system was mono-&gt;2,2-di-&gt;2,3-di-&gt;&gt;trisubstituted epoxides. The chemoselectivity of the present reducing system is excellent. Thus, epoxides were selectively reduced in the presence of such reducible groups as carbamoyl, carboxyl, nitro, cyano, and bromo.