bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Crystal and Molecular Structure of 12-Bromo[2.2][2.2]triple-Layered Paracyclophane
Authors: Koizumi Yosuke , Toyoda Toshihiro , Miki Kunio , Kasai Nobutami , Misumi Soichi 
Published: July 2006

Abstract
The molecular structure of 12-bromo[2.2][2.2]paracyclophane has been determined by means of X-ray diffraction. The crystal is orthorhombic, space group Pbcn, a=12.768(1), b=11.515(1), c=13.074(1) Å, Z=4. The structure was solved by the heavy-atom method, and refined anisotropically by the block-diagonal leastsquares procedure; R=0.062. The Br–C···C–H axis of the central benzene ring lies on a crystallographic two-fold axis. The outer benzene rings take a boat form, and the central benzene ring is twisted.
Raman Spectral Characteristics of [Co(ida)n(dien)2−n]-Type and Related Complexes
Authors: Kawamoto Tatsuya , Maruyama Toshihide F , Yasui Takaji , Okamoto Ken-ichi , Hidaka Jinsai , Einaga Hisahiko 
Published: July 2006

Abstract
The Raman spectra of [Co(ida)n(dien)2−n](3−2n)+(n=0, 1, and 2), where ida and dien denote iminodiacetate and diethylenetriamine respectively, and related complexes in the skeletal vibration region were measured in order to deduce the relation between their spectra and their geometrical structures. The Raman bands could be classified into five vibration modes: Totally symmetric stretching vibration modes (polarized bands in the 510–625 cm−1 region); Co–O and Co–N stretching vibration modes (depolarized bands in the 430–525 cm−1 region); metal-ligand skeletal breathing vibration modes (polarized bands in the 360–480 cm−1 region); skeletal bending deformation modes (depolarized bands in the 290–405 cm−1 region), and chelate ring deformation modes (polarized bands in the 220–260 cm−1 region). The polarized bands around 400 cm−1 were regarded as characteristic of the mono and bis(terdentate)cobalt(III) complexes. The mer isomers of each complex gave Raman spectra clearly different from those of the fac isomers in the stretching vibration region.
Crystal Structure and Molecular Motion of Tetramethylammonium Hexaiodotellurate(IV–Iodine (1/1) Compound
Authors: Kiriyama Hideko , Nishizaki Kyoko 
Published: July 2006

Abstract
The crystal structure of the title compound was determined by means of X-ray diffraction. The crystal data and the final R value are: [(CH3)4N]2TeI6·I2, tetragonal I41/acd, a=20.356(3) and c=27.571(5) Å, V=11,424(3) Å3, Z=16, R=0.082 for 1562 observed unique reflections. The structure consists of discrete [TeI6]2− anions and Me4N+ cations in an arrangement analogous to the K2PtCl6 structure and of additional I2 molecules bridging adjacent complex anions. The TeI6 octahedron is considerably distorted with Te-I distances of 2.933 (2), 3.017 (2), and 2.857 (2) Å, owing to different interaction with the surrounding I2 molecules. Two of three independent Me4N+ cations are orientationally disordered and distributed over each two positions. A phase transition was found at 234 K from DTA and its molar enthalpy was estimated to be approximately 2.4 kJ mol−1 from DSC. Proton NMR studies offered direct evidences for threefold reorientation of CH3 groups and overall rotation of Me4N+ cations taking place consecutively far below room temperatures. At 234 K the spin-lattice relaxation time T1 changes discontinuously by about one order of magnitude, suggesting the first order of transition. The activation energies of such composite reorientation in the fast regions (ωτc&lt;&lt;1) are 5.4 and 14.2 kJ mol−1 in the high- and low-temperature phases, respectively.
N-Hydroxy Amides. IV. Synthesis and Properties of a Trihydroxamic Acid Anilide as a Model for Ferrioxamines
Authors: Shimizu Kazuyuki , Nakayama Kazuyuki , Akiyama Masayasu 
Published: July 2006

Abstract
A trihydroxamic acid having a 6-aminohexanoyl–3-(hydroxyamino)propanoyl sequence has been synthesized in a stepwise manner, starting with glycinanilide. The trihydroxamic acid anilide bears a good structural resemblance with N-benzoyl-deferriferrioxamine B (Benzoyl-DFB). A plot of the absorbance vs. the molar ratio of iron(III) to the hydroxamate group indicates the formation of a 1:1 intramolecular iron(III) complex for the trihydroxamic acid anilide and Benzoyl-DFB. Cyclic voltammetry also shows that the iron complexes of both compounds have similar electrochemical properties. A solid iron(III) complex was obtained when the trihydroxamic acid anilide was mixed with tris(2,4-pentanedionato)iron(III) in methanol.
Effect of Pressure on the Pre-Steady-State Kinetics of the Hydrolysis of p-Nitrophenyl Pivalate Catalyzed by α-Chymotrypsin
Authors: Makimoto Syoichi , Suzuki Keizo , Taniguchi Yoshihiro 
Published: July 2006

Abstract
The pre-steady-state of the hydrolysis of p-nitrophenyl pivalate (pNPT) catalyzed by α-chymotrypsin (α-CHT) in Tris buffer solutions was measured up to 2.4 k bar at 25 °C. The reaction was initiated by substrate binding, and followed by acylation and deacylation processes. From the pressure dependence on the dissociation constants (Ks), the volume change ΔVKs was −14±1 cm3 mol−1. From the pressure dependence on the rate constants (kacyl and kdeacyl) of the acylation and deacylation processes, the activation volumes ΔVacyl\eweq and ΔVdeacyl\eweq were −24±1 and −2±1 cm3 mol−1, respectively. The reaction mechanisms of α-CHT are discussed in terms of the reaction and activation volumes.
Regioselective Carboxylation of Silicon-Stabilized Allylic Carbanions and the Synthetic Utility of 2-Silyl-3-butenoates
Authors: Uno Hidemitsu 
Published: July 2006

Abstract
Carbanions of allylic dimethylphenylsilanes show remarkable regioselectivity toward both carboxylation with carbon dioxide and methylation with methyl iodide. Methylation of these compounds occurred preferentialy at α position, although allyltrimethylsilane and allyltriphenylsilane are known to give γ selectivity toward the same electrophiles. Moreover, their aluminum “ate” complexes react with carbon dioxide regioselectively at the a position irrespective of methyl substitution pattern of the allylic moieties. The α-carboxylated allylic silanes proved to be useful synthons of 3-(methoxycarbonyl)allyl anions after esterification.
Methylation of Alcohols, Phenols, and Carboxylic Acids, and Selective Monomethylation of Diols and Dicarboxylic Acids with Dimethyl Sulfate by Use of Alumina
Authors: Ogawa Haruo , Ichimura Youko , Chihara Teiji , Teratani Shousuke , Taya Kazuo 
Published: July 2006

Abstract
Alcohols in cyclohexane give their methyl ethers in high yields by the use of a combination of dimethyl sulfate and alumina. Some diols and dicarboxylic acids adsorbed on alumina react with dimethyl sulfate and produce the corresponding monomethyl ethers and esters in high selectivities.
The Regulation of Emulsion Polymerization with Fluorocarbon–Hydrocarbon Emulsifiers Mixture
Authors: Kato Kazufumi , Esumi Kunio , Meguro Kenjiro 
Published: July 2006

Abstract
The emulsion polymerization of styrene using a mixture of sodium dodecyl sulfate (SDS) and lithium fluorooctane sulfonate (LiFOS) has been studied. The polymerization rate decreased upon increasing the mole fraction of LiFOS, and was dependent on the solubilized amount of styrene in mixed surfactant solutions of SDS and LiFOS. The particle size increased upon increasing the mole fraction of LiFOS on the whole, and the molecular weight of the polymer formed in latices decreased upon increasing the mole fraction of LiFOS. Furthermore, the molecular-weight distribution of the latex polymer formed in mixed emulsifier solutions was considerably wider than that of the latex polymer formed in a single-emulsifier solution. It was confirmed from the above results that LiFOS had a repressive effect on the polymerization rate, and that it affected the number of particles and the molecular weight in the emulsion-polymerization process.
Stability Constants and Some Other Properties of the Lanthanoid Nitrate Complexes with Tri-, Tetra-, and Pentaethylene Glycols
Authors: Hirashima Yoshiyuki , Kanetsuki Koji , Yonezu Ikuo , Isobe Noriyuki , Shiokawa Jiro 
Published: July 2006

Abstract
The lanthanoid nitrate complexes of tri-, tetra-, and pentaethylene glycols (EO3, EO4, and EO5) exhibited anomalous stability trends attributed to structures similar to those of crown complexes. The stability constants of the EO4 and the EO5 complexes decreased with an increase in the atomic number of the lanthanoid in contrast to the lanthanoid complexes with most other ligands. A maximum stability was found at europium for EO3 complexes. The decomposition temperatures of EO3 complexes were higher than those of the corresponding EO4 and EO5 complexes. The yields of the solid complexes in reactions of the lanthanoids with EO5 decreased with an increase in the atomic number of the lanthanoid (with some exceptions). The separation factors observed for fractional precipitation using EO5 as the separating reagents were comparable to those reported regarding reagents practically used for lanthanoid separation.
Rearrangement Approaches to Cyclic Skeletons. IV. The Total Synthesis of (±)-Pinguisone and (±)-Deoxopinguisone Based on Photochemical [1,3] Acyl Migration of a Bicyclo[3.2.2]non-6-en-2-one
Authors: Uyehara Tadao , Kabasawa Yasuhiro , Kato Tadahiro 
Published: July 2006

Abstract
The total synthesis of (±)-Pinguisone (2) and (±)-deoxopinguisone (3), [5–6] fused-ring sesquiterpenes, has been achieved starting from 1-methoxy-3,4,5-trimethylbenzene. 1-Methoxy-4,5,endo-8-trimethylbicyclo[2.2.2]non-5-en-2-one (9) was prepared selectively via facial selective Diels–Alder reaction of the diene derived from the benzene and 2-chloroacrylonitrile. Ring enlargement of 9 using (CH3)3SiCHN2 and BF3 etherate gave the corresponding bicyclo[3.2.2]oct-6-en-2-one (8). The photochemical [1,3] acyl migration of 8 gave the [5–6] fused-ring compound (7). The fourth methyl was introduced selectively by the conjugate addition of (CH3)2CuLi to the spiro[bicyclo[4.3.0]non-8-ene-3,2′-[1,3]dioxolan]-7-one prepared from 7. Each furan ring of 2 and 3 was constructed via the corresponding butenolide derived from the γ-keto acid by acid-catalyzed dehydration.
Reactions of 2,4,6-Tri-t-butylphenyllithium with O-Alkyl Selenoformates: Intermediate Formation of 2,4,6-Tri-t-butylselenobenzaldehyde
Authors: Ishii Akihiko , Okazaki Renji , Inamoto Naoki 
Published: July 2006

Abstract
2,4,6-Tri-t-butylphenyllithium reacts with O-alkyl selenoformates (1) at three different sites (i. e., the selenoformyl carbon, the selenoformyl hydrogen, and the selenium) to give 1,3,5-tri-t-butylbenzene, 2,4,6-tri-t-butylbenzaldehyde, 6,8-di-t-butyl-3,4-dihydro-4,4-dimethyl-1H-2-benzoselenin(11), bis(2,4,6-tri-t-butylphenylmethyl) di(and tri) selenides, bis(2,4,6-tri-t-butylphenyl) diselenide, and dibutyl diselenide depending on the reaction conditions and the alkyl group in 1. The formation of 11 is explained in terms of the intermediacy of 2,4,6-tri-t-butylselenobenzaldehyde, which is trapped by condensation reaction with butylamine leading to N-(2,4,6-tri-t-butylbenzylidene)butylamine. Mechanism for the formation of these products is also discussed.
Mercury- and Cadmium-Photosensitized Reactions of β-Propiolactone
Authors: Yamamoto Shunzo , Gohda Rinko , Morikawa Rie , Takahoso Hiroshi , Sueishi Yoshimi , Nishimura Norio 
Published: July 2006

Abstract
The mercury- and cadmium-photosensitized reactions of β-propiolactone (PL) have been investigated. The gaseous products from the mercury-photosensitized reaction were carbon dioxide, ethylene, carbon monoxide, ethylene oxide, acetaldehyde, and methane, while the products obtained in the cadmium-photosensitized reaction were carbon monoxide, ethylene oxide, and acetaldehyde. In the mercury-photosensitized reaction, the quantum yields of the products were independent of the lactone pressure at pressures higher than 1500 Pa, while in the cadmium-photosensitized reaction, the quantum yields of the products decreased with the increase in the lactone pressure. Several possible reaction schemes have been proposed to explain the above kinetic behavior. The mercury- and cadmium-photosensitized reactions proceed through different intermediates, that is, a triplet lactone in the former and an excited complex between an excited cadmium atom and a lactone molecule in the latter.
Selective Formation of 2-Phenylethanol in the Homologation of Benzyl Alcohol
Authors: Watanabe Kazuhiro , Kudo Kiyoshi , Mori Sadayuki , Sugita Nobuyuki 
Published: July 2006

Abstract
High selectivity of 2-phenylethanol (87%) in the homologation of benzyl alcohol was obtained with cobalt–ruthenium mixed catalyst. The formation of toluene as the major by-product was suppressed by adding water at low reaction temperature. Bromide as promoter was more effective for the homologation than chloride or iodide. From in situ IR observation, [Co(CO)4]−, which was active species for the homologation, was found to be produced by the dissociation of [CoH(CO)4] but not by the disproportionation of [Co2(CO)8] under the reaction temperature employed (120 °C). It was also revealed that ruthenium chloride as precatalyst was converted into a bromocarbonyl complex of ruthenium under the homologation conditions.
Relationship between Donor and Acceptor Numbers and Intrinsic Molecular Properties from Gas-Phase Ion Equilibria
Authors: Hiraoka Kenzo 
Published: July 2006

Abstract
Molecular and bulk solvent properties of protic and aprotic solvent molecules were discussed in the respects of donor numbers (DN) and acceptor numbers (AN) proposed recently by Gutmann, and the intrinsic molecular properties obtained from gas-phase ion equilibria measurements. For aprotic solvent molecules, good correlations are generally found between the gas-phase thermochemical data and both of DN and AN. This indicates that DN and AN for aprotic solvents well reflect the intrinsic molecular properties. On the other hand, the correlations for H2O and lower alcohols are not good. This is due to the more effective enhancement effect in the intermolecular interactions for protic solvents than for aprotic solvents.
Production of Cyclohexene and Reactive Sulfur Species in Vapor-Phase Catalytic Oxidative Dehydrogenation of Cyclohexane with Carbonyl Sulfide
Authors: Akimoto Masamichi , Kashita Yoshinori , Niiyama Hiroo 
Published: July 2006

Abstract
The vapor-phase catalytic oxidative dehydrogenation of cyclohexane with COS over SiO2 and Al2O3 catalysts (e.g., C6H12+COS→C6H10+CO+H2S) has been investigated with respect to the production of cyclohexene and cyclohexadiene as well as the mechanism of the dehydrogenation reaction. The representative value of the combined yield of cyclohexene+cyclohexadiene is 8.0% and the combined selectivity to these two products at this yield obtained is 34.0%. These values are comparable to the values 8.0 and 30.8% reported in a recent Japanese patent. The comparison of the catalytic performance between two types of flow fixed-bed reactors demonstrates that the role of solid catalysts is to decompose COS into CO and sulfur, which then dehydrogenates hydrocarbons through a homogeneous mechanism. The results of the kinetic analysis of these reactions, together with the simulation of the overall catalytic reaction system, suggest a contribution of atomic sulfur to the oxidative dehydrogenation of cyclohexane in a conventional flow fixed-bed reactor.
Spectrophotometric Determination of Gentamicin by Using a Membrane Filter Preconcentration Technique with o-Hydroxyhydroquinonephthalein and Uranium(VI)
Authors: Mori Itsuo , Fujita Yoshikazu , Fujita Kinuko , Tanaka Takeshi , Kawabe Hiroshi , Koshiyama Yozo 
Published: July 2006

Abstract
Color reactions among amino glycoside antibiotics such as gentamicin (GM), a metal ion such as uranium(VI), and o-hydroxyhydroquinonephthalein (Qnph) as a xanthene dye were studied by using a preconcentration technique based on membrane filtration. A simple, new, and highly sensitive spectrophotometric determination of GM has been established by using a preconcentration to collect Qnph-uranium(VI)-GM ternary complex. Beer’s law is obeyed over the range 0–5.4 μg of GM in 5 cm3 of dimethyl sulfoxide at 565 nm, and the apparent molar absorptivity for GM is 4.2×105 dm3 cm−1 mol−1 with a Sandell sensitivity of 0.0013 μg cm−2 GM at 565 nm. The procedure is about 2.5-fold as sensitive as the method employing aqueous medium, and is applicable to determination of GM in calf serum.
Comparison of ESR Signal Intensities of Some Binuclear Copper Complexes
Authors: Nakano Kunio , Tadano Hiroshi , Oshige So , Wada Nobuaki , Yamaguchi Mari , Ojima Heijiro 
Published: July 2006

Abstract
ESR signal intensities of two kinds of binuclear copper complex were measured by the two-step integral method with a multi-mode resonator cavity. The intensities standardized with CuSO4·5H2O are the proper values for these substances, and can be compared with each other. The intensities of oxamide type complexes (A-group) were a few tens of percent of the intensity of CuSO4·5H2O, while the intensities of binuclear complexes having a bridge of two oxygens (B-group) were less than one percent. This suggests that the two coppers in each binuclear molecule interact, and that the magnitude of the interaction of the B-group can be considered to be much greater than that of the A-group.
Thermodynamic Quantities of Transfer of Glycinato and β-Alaninato Complexes of Silver(I) and Related Species from Water to an Aqueous Dioxane Solution
Authors: Ishiguro Shin-ichi , Suzuki Honoh , Zama Masayuki , Basak Arup K , Ohtaki Hitoshi 
Published: July 2006

Abstract
Complexation of silver(I) with glycinate (gly−) and β-alaninate (β-ala−) ions have been studied by potentiometry and calorimetry in 0.2 mole fraction (55.0 %w/w) dioxane–water mixture containing 3 mol dm−3 LiClO4 as a constant ionic medium at 25 °C. Potentiometric titration curves obtained were well-explained in terms of formation of [AgL], [AgL2]−, and [AgHL]+ (L−=gly− or β-ala−) in both systems, together with [Ag(OH)L]− in the Ag(I)–β-alanine system, and their formation constants were determined. Enthalpies of formation of the complexes in the mixed solvent, as well as in water containing the same ionic medium, were calorimetrically determined on the basis of the formation constants potentiometrically determined. Solubilities and enthalpies of solution of the neutral [AgL] (L−=gly− and β-ala−) complexes and some related compounds were determined in water and the mixture, the Gibbs energies of transfer, ΔGt°, of silver(I) ion and proton from water to the mixture being also determined by potentiometry. By combining the thermodynamic quantities thus obtained, thermodynamic quantities of transfer of single species from water to the mixture were evaluated. Compared to the enthalpy, ΔHt°, and entropy, ΔSt°, of transfer of a neutral species, the ΔHt° and ΔSt° values of any charged species were significantly large with the negative sign for cations and positive one for anions. As to neutral species, [HL] and [AgL], the relation, ΔGt°&gt;ΔHt°≅0 and ΔSt°&lt;0, was found, suggesting that the [AgL] complexes have a similar zwitterionic structure to that of glycine and β-alanine zwitterions.
Adsorption of Phosphorus Oxoacid on Hydrous Titanium(IV) Oxide in an Aqueous Solution
Authors: Fujii Satoshi , Sugie Yosohiro , Sakamoto Chiaki 
Published: July 2006

Abstract
The adsorption behavior of phosphorus oxoacid, such as phosphinate, phosphonate, and phosphate, on hydrous titanium(IV) oxide in an aqueous solution was studied in detail. Hydrous titanium(IV) oxide has a pronounced activity for the adsorption of phosphonate and phosphate ions. However, phosphinate ion is little adsorbed on hydrous titanium(IV) oxide. The pH of aqueous solution remarkably affects the adsorption. Amounts of adsorbed phosphonate or phosphate ion from solutions of 500 mg l−1 concentration are about 0.5 mmol g−1 near pH 2. The Langmuir equation, applicable to the adsorption of phosphonate ion, has evaluated the maximum adsorption as being about 0.9 and 0.3 mmol g−1 at pHs 2 and 7, respectively. The heat of adsorption of phosphonate is −5.9 kJ mol −1 at pH 2. The adsorptive activity of hydrous titanium(IV) oxide for phosphonate is suppressed by coexisting ions, such as phosphate and anionic nickel(II) complexes.
Magnetism, Electronic State, and Local Structure of Iron-Containing Organometallic Polymers
Authors: Sugano Tadashi , Nomura Masaharu , Awaga Kunio , Kieng Poh Lee , Ohta Toshiaki , Kinoshita Minoru 
Published: July 2006

Abstract
Schiff-base polymers were synthesized by the reaction of 2,6-pyridinedicarbaldehyde with 1,4-butane-, 1,6-hexane-, 1,8-octane-, and 1,12-dodecanediamine. Each of the polymers, when combined with iron(II) sulfate or iron(II) chloride, exhibited anomalously large magnetization and a nonlinear relation of the magnetization curve at room temperature. These iron-containing solids were found to be amorphous and, hence, the local structures around the iron atoms in the compounds were determined by the measurements of Fe K-edge X-ray absorption spectra. It was found that the iron atoms were each surrounded by six nitrogen atoms with the almost equivalent distance of 1.93±0.02Å. This was consistent with a possible geometry in which the tridentate ligand moieties of the polymers were coordinated with the iron atoms in a ratio 2 : 1. It was also found from the results of X-ray photoelectron and Mössbauer spectroscopies that the iron atoms in the solid obtained from the reaction between poly(2,6-pyridinediylmethylidynenitrilohexamethylenenitrilomethylidyne) and iron(II) sulfate were in two valence states consisted of the high spin (S=5⁄2) irons(III) which were responsible for the observed magnetism and the low-spin (S=0) irons(II) which gave no contribution to the magnetism.
Determination of the Solvation Number of Sodium Anion in Hexamethylphosphoric Triamide
Authors: Saji Tetsuo , Aoki Katsunori , Suga Kosaku , Fujihira Masamichi , Aoyagui Shigeru 
Published: July 2006

Abstract
Electronic absorption spectra for saturated solutions of Na in HMPA–THF mixtures with HMPA mole fractions 0.39–0.061 exhibit only a band for Na−. A log–log plot of maximum absorbance vs. HMPA concentration has led to a numerical value 3 for the number of HMPA molecules solvating a Na− ion.
Synthesis of β-ZrClN by Thermal Decomposition of Zirconium(IV) Amide Trichloride
Authors: Ohashi Masao , Yamanaka Shoji , Hattori Makoto 
Published: July 2006

Abstract
The zirconium amide trichloride ZrCl3(NH2)·7NH3 was prepared by the reaction of ZrCl4 with liquid ammonia. On heating up to 600°C in flowing ammonia gas, the amide was efficiently converted into β-ZrClN, whereas under vacuum it was decomposed to a different product. The decomposition processes were followed by using a quartz spring balance.
Direct Evidence for the Peroxo Substitution of the Oxo Group in the Oxotitanium(IV) Porphyrin Complex in the Aqueous Solution
Authors: Inamo Masahiko , Funahashi Shigenobu , Tanaka Motoharu 
Published: July 2006

Abstract
Labeling experiments for IR and NMR spectra of oxo- and peroxotitanium(IV) complexes show that the oxo group of oxotitanium(IV) porphyrin is fully substituted by a peroxo group in the course of the reaction with hydrogen peroxide in the aqueous solution, i.e. the O–O bond of H2O2 remains intact in the peroxo complex.
Reactions of Trifluoroacetonitrile Oxide or -nitrilimines with β-Diketones and β-Keto Esters
Authors: Tanaka Kiyoshi , Kishida Munehisa , Maeno Seiji , Mitsuhashi Keiryo 
Published: July 2006

Abstract
N-Phenyl-C-(trifluoromethyI)nitrilimine cyclized with β-diketones or β-keto esters under alkaline conditions to give the corresponding 3-trifluoromethylpyrazoles with acyl or alkoxycarbonyl group at the 4-position of the ring, respectively. While trifluoroacetonitrile oxide with β-diketones provided the corresponding trifluoromethylisoxazoles, its reactions with β-keto esters gave 4-acyl-5-hydroxy-3-trifluoromethylisoxazoles as well as the expected isoxazoles without the regioselectivity.