bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature Dependence of Magnetic Susceptibilities of (TTT)(TCNQ) and (TTT)(TCNQ)2
Authors: Takahashi Masashi , Sugano Tadashi , Kinoshita Minoru 
Published: July 2006

Abstract
Static magnetic susceptibility and ESR studies of 1:1 and 1:2 charge-transfer complexes of naphthaceno-[5,6-cd:11,12-c′d′]bis[1,2]dithiole and 2,2′-(2,5-cyclohexadiene-1,4-diylidene)bis(propanedinitrile) [(TTT)(TCNQ) and (TTT)(TCNQ)2] in the temperature region of 2–310 K are described. (TTT)(TCNQ)2 exhibits a temperature dependent spin susceptibility, while the spin susceptibility of (TTT)(TCNQ) is almost independent of temperature. Spin susceptibilities of the TTT and TCNQ chains, which are evaluated with a g-value decomposition technique, are interpreted in terms of a one-dimensional Hubbard model. In both complexes, the on-site Coulomb repulsion is comparable with or larger than the band width on the TCNQ chains and is smaller on the TTT chains. Two magnetic phase transitions are observed in (TTT)(TCNQ)2. The transition is driven in each chain independently by the Peierls instability. The amount of charge transfer in (TTT)(TCNQ) is determined to be 0.73±0.05 from an X-ray photoelectron spectroscopic study.
An X-Ray Diffraction Study on the Structures of Mono(glycinato)copper(II) and Tris(glycinato)cuprate(II) Complexes in Aqueous Solution
Authors: Ozutsumi Kazuhiko , Ohtaki Hitoshi 
Published: July 2006

Abstract
The structures of mono(glycinato)copper(II) and tris(glycinato)cuprate(II) complexes in solution were determined by means of X-ray diffraction at 20 °C. The radial distribution curve obtained for solution A, in which comparable amounts of hexaaqua- and mono(glycinato)copper(II) complexes coexisted (the mole ratio Cgly⁄CCu=0.700, where Ci represents the total concentration of species i), showed that the mono(glycinato)copper(II) complex combined with four water molecules, two of which were at the distance of (1.98±0.01) Å at the equatorial position and the other two were of (2.27±0.01) Å at the axial one. The equatorial Cu–OH2 bond length within the mono(glycinato)copper(II) was longer than that within the hexaaquacopper(II) ion (1.94 Å), whereas the axial Cu–OH2 bond distance within the former complex was shorter than that within the latter (2.43 Å). Both lengths of the Cu–O and Cu–N bonds within the mono(glycinato)copper(II) ion were (1.99±0.02) Å. Thus the [Cu(gly)(OH2)4]+ complex has an axially elongated octahedral structure. The X-ray scattering data of solution B with the Cgly⁄CCu mole ratio of 13.7, in which almost all Cu(II) ions formed the tris(glycinato)cuprate(II) complex were well explained in terms of a regular octahedral structure of the complex having the same Cu–O and Cu–N bond distances of (2.02±0.01) Å. The structure of the bis(glycinato)copper(II) complex was not determinable owing to its low solubility.
Crystal Structures and Characterization of Cobalt(II), Manganese(II), and Zinc(II) Complexes of 2-[Bis(2-benzimidazolylmethyl)amino]ethanol
Authors: Takahashi Kazuhiro , Nishida Yuzo , Kida Sigeo 
Published: July 2006

Abstract
Cobalt(II), manganese(II), and zinc(II) complexes with the tripodal ligand, 2-[Bis(2-benzimidazolylmethyl)amino]ethanol, bbt, were prepared and characterized by infrared and electronic spectra, magnetism, and conductivities. Their crystal structures were determined by X-ray diffraction method. Crystal data: [Co(bbt)(NCS)2] (1), space group P212121(orthorhombic), a=12.881(1), b=17.970(2), c=9.076(1) Å; [Mn(bbt)(NCS)2](2), space group P212121(orthorhombic), a=18.179(2), b=13.073(2), c=9.097(2) Å; [Zn(bbt)(NCS)2](3), space group P21/ a(monoclinic), a=15.421(4), b=14.803(4), c=10.589(3) Å, β=115.81(2)°. The final R values are 0.044 (1), 0.054 (2), and 0.079 (3), for non-hydrogen atoms. The coordination geometries of 1 and 2 can be described as a distorted octahedron. In 3, the alcoholic oxygen of bbt is not in coordination, hence the zinc ion is five-coordinated forming a highly distorted trigonal bipyramid. In all the complexes, thiocyanate ions coordinate in cis form with the nitrogen atoms. The magnetic measurements revealed that 1 and 2 are high spin complexes.
The Thermal Decomposition of CF3I in Ar
Authors: Saito Ko , Yoneda Yuji , Tahara Hiroyuki , Kidoguchi Sadao , Murakami Ichiro 
Published: July 2006

Abstract
The thermal decomposition of CF3I behind reflected shock waves was studied by means of the UV absorption over the temperature range of 935–1235 K and in the density range of 6.3×10−6–3.8×10−6 mol cm−3. The decomposition rate was in the fall-off region, and the main process was the C-I bond fission. The rate constants corresponding to the limiting high- and low-pressure regions were determined to be;
k ∞=1014.67exp(−27200⁄T)s−1
and;
k 0⁄[Ar]=1014.71exp(−15000⁄T)cm3mol−1s−1.
Hydrates of Organic Compound IX. Enclathration of Methyl and Ethyl Alcohols within the Water Lattice of Tetrahydrofuran Clathrate Hydrate
Authors: Matsui Hiroshi , Nakayama Haruo 
Published: July 2006

Abstract
The amount of methyl or ethyl alcohol existing in a hydrate solid deposited from ternary mixtures of methyl (or ethyl) alcohol-tetrahydrofuran–water has been determined using 14C-labeled alcohols. It was found that these alcohols could be enclathrated within the water lattice of tetrahydrofuran clathrate hydrate.
Primary Structure and Molecular Evolution of Protein. Internal Homology and Intramolecular Evolutionary Tree of Calmodulin
Authors: Iida Yôichi 
Published: July 2006

Abstract
One notable feature of the primary structure of calmodulin is its internal homology. It can be subdivided into four domains having a similar amino acid sequence. In the present paper, an intramolecular evolutionary tree was constructed with the four domains. The origin and evolution of calmodulin was discussed on the basis of these results.
Studies on Lactams. VII. Conformation of d-Glucono-1,5-lactam
Authors: Ogura Haruo , Furuhata Kimio , Takayanagi Hiroaki , Tsuzuno Nobuyasu , Iitaka Yoichi 
Published: July 2006

Abstract
The structure of d-glucono-lactam (5-amino-5-deoxy-d-glucono-lactam) has been established by means of X-ray crystal structure analysis. The stereochemistry of d-glucono-lactam in crystal was determined to be a half-chair conformation.
Internal Heavy Atom Effects on the Exciplex Fluorescence: Anthracene–N,N-Dimethylaniline System
Authors: Hamai Sanyo 
Published: July 2006

Abstract
Intrinsic fluorescence yields of exciplexes, φf0, have been determined for halogenated systems of anthracene (A)–N,N-dimethylaniline (DMA) in cyclohexane. By the substitution of a chlorine atom for a hydrogen atom in either A or DMA, φf0 is reduced to about 1/5, whereas by the bromine substitution it is reduced to about 1/80. When more than one halogen atom of the same kind are substituted in the A–DMA exciplex, the first substitution causes more prominent reduction in φf0 than the subsequent substitution does. Although there is a remarkable irregularity in the fluorescence quantum yields of halogenated anthracenes which were used as the electron acceptors in the exciplexes, φf0 varies regularly according to the kind and the number of the halogen substitutions. The internal heavy atom effect on φf0 is explained by the enhancement of the intersystem crossing rate to the triplet state.
Stopped-flow Kinetic Studies of Cu2+ Ion Binding to Bovine Serum Albumin
Authors: Kure Naohisa , Nakatsuji Hitoshi , Sano Takayuki , Yasunaga Tatsuya 
Published: July 2006

Abstract
The interaction of Cu2+ ion with bovine serum albumin (BSA) was studied statically by equilibrium dialysis and ultraviolet spectrophotometric titration techniques, and kinetically by the stopped-flow method with transmittance detection at 255 nm. The static measurements showed the presence of one primary binding site and a number of weaker binding sites at pH 5.2. Stopped-flow measurements were undertaken in the pH region of 4–6.4 where a single reaction process was observed on the order of several seconds following the rapid absorbance change within the dead-time of the apparatus. This single reaction process was attributed to reaction of Cu2+ ion with the primary BSA site. The analyses of pH and concentration dependences of both the relaxation time and absorbance change confirmed the presence of two types of bound Cu2+ species to the primary binding site. One type formed during the dead-time of the apparatus is postulated as a square-planar complex formed between Cu2+ and the three N-terminal peptides of BSA. This reaction occurs with Cu2+ being exchanged for hydrogen ions on the N-terminal peptides. The second type of bound Cu2+, observed by stopped-flow method is thought to result from a bimolecular binding of Cu2+ ion a deprotonated imidazolyl group in the third position of the histidyl residue; the value of the molar extinction coefficient for this species, determined kinetically, suggests a further coordination of the β-carboxyl group to the bound Cu2+.
Liquid–Liquid Distribution Study of the Dissociation of Perchloric, Nitric, and Picric Acids in Polar Organic Solvents
Authors: Sekine Tatsuya , Yoshikata Tohru , Saitou Takashi 
Published: July 2006

Abstract
The liquid–liquid distribution equilibria of perchioric, nitric, and picric acids between water and 4-methyl-2-pentanone or 4-methyl-2-pentanol have been determined at 298 K by measuring the concentrations of the anions in the two phases by spectrophotometry. The distribution ratio always increased on increase of the acid concentration; this was explained in terms of an increase in the degree of association of the acids in the organic phase. It was concluded from the analysis of the distribution data that the dissociation constant of perchloric acid was the highest and the value of picric acid was higher than that of nitric acid in 4-methyl-2-pentanone. The dissociation constant of picric acid was also higher in 4-methyl-2-pentanol than that of nitric acid; it was similar to that of perchloric acid. The differences of the dissociation constants were larger in 4-methyl-2-pentanone than in 4-methyl-2-pentanol.
Determination of the Rate Constant for the Reaction NH3+O→NH2+OH
Authors: Fujii Nobuyuki , Sato Hisaaki , Fujimoto Shiro , Miyama Hajime 
Published: July 2006

Abstract
The rate constant for the reaction NH3+O→NH2+OH was determined by the comparison of the calculated ammonia consumption rates with those observed in shock tube experiments in the range of 1690–2310 K, for NH3–N2O–Ar mixtures. The rate constant can be represented by the expression k=3.1×1012exp(−25.5 kJ/RT) cm3 mol−1 s−1.
The Tricritical Point in the n-C8H17SO3Na/n-C4H9OH/H2O/n-C14H30 System
Authors: Kunieda Hironobu , Arai Tsutomu 
Published: July 2006

Abstract
The phase behavior of three coexisting liquid phases has been studied in the four-component system of n-C8H17SO3Na/n-C4H9OH/H2O/n-C14H30. With a rise in the temperature, the three-phase region shrinks to a tricritical point at which the three liquid phases become identical.
The Influence of Culture Conditions on the Fibrillation of Cellulose Gel Produced by Acetobacter xylinum
Authors: Kai Akira 
Published: July 2006

Abstract
The influence of the culture conditions, such as the temperature of incubation and the pH of the culture medium, on the fibrillation of cellulose gels produced by Acetobacter xylinum was studied by means of electron microscopy. The incubation temperature did not show any influence on the fibrillation of cellulose gels as long as it was in the range between 10 to 28 °C. However, in the incubation at 5 °C the fibrillation occurred very slowly. When incubation was carried out at 5 °C, the fibril produced by the 5 °C incubation maintained an amorphous state for about 3h, and the microscopic fibrils appeared in the fibril only after incubation for 12h. However, the width of the microscopic fibril was not influenced by the temperature of incubation. The pH of the medium influenced the linear growth rate of a fibril. The rate increased with an increase in the pH, reached the maximum at pH 6.8, and decreased at higher pHs. The fibrillation occurred more rapidly at a constant temperature as the linear growth rate was lowered, but the width of a microscopic fibril was not influenced by the pH of the medium, just as it was not influenced by the temperature.
Nitrogen-14 Magnetic Resonance Studies of the Exchange of Solvent Pyridine on Bis(β-diketonato)bis(pyridine)nickel(II) and -cobalt(II) Complexes
Authors: Ito Seiko , Yano Yoshiko 
Published: July 2006

Abstract
The analysis of linewidth and shift data of the nitrogen-14 magnetic resonance gave the following activation parameters for the exchange reaction of pyridine (py) on CoA2(py)2 (A=acac, tfa, and tta) and Ni(acac)2(py)2 with a pyridine molecule as bulk solvent: ΔH\eweq=41.4, 51.1, 48.3, and 47.2 kJ mol−1, ΔS\eweq=18, 17, 3, and 10 JK−1 mol−1, and k1 (298K)=2.9×106, 5.3×104, 2.9×104, and 1.3×105 s−1. Here acac=acetylacetonate, tfa=trifluoroacetylacetonate and tta=thenoyltrifluoroacetonate. The electron-withdrawing power of substituent groups on the β-diketonate rings was correlated with more favorable activation of the exchange, that is, the stronger electron withdrawal causes less dissociative activation. This explains qualitatively even the negative ΔS\eweq values observed for similar pyridine exchange in the cases of Co(hfa)2(py)2 (hfa=hexafluoroacetylacetonate) and Ni(tta)2(py)2.
Recovery of Heavy Metals with Calcium Silicon Alloy. III. Stoichiometric Discussion on the Reduction of Copper(II) Ions
Authors: Tokunaga Shuzo 
Published: July 2006

Abstract
For the reduction of Cu2+ ions with Ca–Si alloy in aqueous solutions, the following elementary reactions were postulated:
Ca0+Cu2+=Ca2++Cu0, (1)
Ca0+2H2O=Ca2++H2+2OH−, (2)
Si0+2Cu2++3H2O=H2SiO3+2Cu0+4H+, (3)
Si0+3H2O=H2SiO3+2H2. (4)
From these reactions, amounts of SiIV species were estimated by using those of H2 and increments of H+ ions. Total equivalents of the reduction products showed good agreement with those of the oxidation products, indicating the validity of the elementary reactions. The remained problems of the stoichiometric disagreement and the phenomenon of pH decrease indicated in Part II could be solved by using these elementary reactions. At the beginning of the reaction, a small amount of Cu+ ions formed. Decomposition of water occurred subsequently to the Cu2+ reduction. A contribution of Si0 to the reaction became greater than that of Ca0 at higher Cu2+ concentrations than ca. 10 matom dm−3. Thus, it proved that Si0 in the alloy exhibits a great reducing effect.
Synthesis and Stereochemistry of (Diamine)(2,9-dimethyl-4,7-diazadecane-2,9-dithiolato)cobalt(III) Complexes and Their Derivatives
Authors: Yamanari Kazuaki , Takeshita Norimatsu , Shimura Yoichi 
Published: July 2006

Abstract
Several (diamine)(2,9-dimethyl-4,7-diazadecane-2,9-dithiolato)cobalt(III) complexes, [Co(SNNS)(diamine)]+ (diamine=1,2-ethanediamine and (R,R)-1,2-cyclohexanediamine), were prepared and characterized by the visible-UV absorption, circular dichroism(CD), and 13C NMR spectra. The above SNNS quadridentate ligand gave only the cis-β geometrical isomer, which was chromatographically separated into two diastereomers owing to the configurations of chiral nitrogen atoms. All the thiolato and the corresponding sulfinato complexes exhibited two CD bands of opposite signs in the Co(σ*)←S(σ) ligand-to-metal charge transfer band region. The sign pattern was found to be in connection with the absolute configurations of these complexes.
Selective Adsorption of Molybdenum(VI) and/or Vanadium(V) Using Cross-linked Polystyrene Resins with Bis(2-hydroxyethyl)amino, Bis(carboxymethyl)amino, and Bis(phosphonomethyl)amino Groups
Authors: Nishizawa Masato , Yokoyama Toshiro , Kimura Tetsuo , Suzuki Toshishige M 
Published: July 2006

Abstract
Styrene–divinylbenzene copolymers containing –N(CH2CH2OH)2, –N(CH2CO2H)2, and –N(CH2PO(OH)2)2 moieties have been synthesized and applied to the selective adsorption of molybdenum and/or vanadium from aqueous solution. The equilibrium adsorption capacity vs. pH correlation and exchange kinetics of the resins for MoVI and VV have been studied. The resin containing bis(2-hydroxyethyl)amino group is particularly effective for the selective recovery of MoVI and/or VV by column operation due to its high adsorption capacity and faster exchange rate, whereas other resins required much longer time to attain adsorption equilibrium. The bis(2-hydroxyethyl)amino resin was used for the selective recovery of molybdenum from an acid-leaching solution of waste desulfurization catalyst.
Gas Chromatography–Mass Spectrometry of Trimethylsilyl Derivatives of Some Iminodicarboxylic Acids
Authors: Kawashiro Katsuhiro , Morimoto Shiro , Yoshida Hideyuki 
Published: July 2006

Abstract
Trimethylsilylation of eight iminodicarboxylic acids (IDCAs) with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) or N,O-bis(trimethylsilyl)acetamide was studied under various reaction conditions. The IDCAs include iminodiacetic acid (1), 2- and 3-(carboxymethylamino)propionic acids (2 and 3), 2,2′-, 2,3′-, and 3,3′-iminodipropionic acids (4–6), N-methyliminodiacetic acid (7), and nitrilotriacetic acid (8). For 1–6, both bis- and tris(trimethylsilyl) (TMS) derivatives were formed under usual silylating conditions, although the proportion of amounts of the two derivatives varied depending on reaction conditions. This double derivatization was due to the steric hindrance of N-substituent group. However, under mild silylating conditions (BSTFA alone, 120 °C, 30 min), 1–6 yielded only the di-TMS derivatives. Upon electron impact at 20 eV, both the di- and tri-TMS derivatives showed simple spectra with a molecular (M+) ion and M −15 (loss of CH3). The α,α′-IDCAs (1, 2, 4, 7, and 8) are characterized by fragments M −43 (loss of CH3 and CO) and M −117 (loss of COOTMS) (base peak). On the other hand, the β,β′-IDCA (6) is characterized by fragments M −57 (loss of CH3, CH2, and CO) and prominent M −131 (loss of CH2COOTMS). The α,β′-IDCAs (3 and 5) exhibit both the fragments characteristic of α,α′- and β,β′-IDCAs, M −43, M −57, M −117, and M −131. However, base beaks are usually the fragment M −117 and not M −131.
Reactions of Enolates with Vinyl Selenoxides and Vinyl Selenones. One-step Synthesis of Cyclopropylcarbonyl Compounds
Authors: Ando Ryoichi , Sugawara Tomoo , Shimizu Makoto , Kuwajima Isao 
Published: July 2006

Abstract
In the reactions with enolate anions, organoselenium moieties of aryl vinyl selenoxides and selenones have exhibited two important roles, e.g., activation of C=C bonds for conjugate addition reaction and behaviors as excellent leaving groups. Owing to such characteristic features, ketone enolates react with p-chlorophenyl vinyl selenoxide to afford the corresponding cyclopropyl ketones through an initial conjugate addition followed by substitution processes. On the other hand, use of vinyl selenones usually gives much better results with anionic species of active methylene compounds. Vinyl selenones bearing hydroxyl, ketone, and ester groups can also be employed equally well for this type of transformation.
The Electronic Spectrum of Diphenylhexatriyne. The Interaction of Mutually Perpendicular π and π′ Systems
Authors: Kobayashi Michio , Hoshi Toshihiko , Okubo Jun , Hiratsuka Hiroshi , Harazono Toshie , Nakagawa Masazumi , Tanizaki Yoshie 
Published: July 2006

Abstract
The electronic absorption spectrum of diphenylhexatriyne has been divided into two components polarized along the long and the short molecular axes by means of dichroism analysis using the stretched-polymer-film technique; i.e., a reduced polarization spectrum has been obtained. This reduced polarization spectrum can be explained by a modified PPP calculation including the interaction between mutually perpendicular π and π′ systems in the conjugated system. It has been clarified that the relative intensities of the first and second bands of diphenylhexatriyne reflect the magnitude of interaction between mutually perpendicular π and π′ systems, which is quite great. The magnitude of the electron-repulsion integral between π and π′ electrons is estimated to be about 20–30 per cent of that between ordinary π (or π′) electrons.
A Nuclear Magnetic Resonance Study of the Kinetics of Ligand Exchange Reactions in Uranyl Complexes. VI. N,N-Dimethylformamide Exchange in Bis(acetylacetonato) (N,N-dimethylformamide)dioxouranium(VI)
Authors: Ikeda Yasuhisa , Tomiyasu Hiroshi , Fukutomi Hiroshi 
Published: July 2006

Abstract
The exchange reaction of N,N-dimethylformamide(dmf) in [UO2(acac)2dmf](acac=acetylacetonato) has been studied by the NMR line-broadening method in CD3COCD3 and CD2Cl2. In CD3COCD3, the rate of dmf exchange is independent of the free DMF concentration. The rate constants(s−1) at 25 °C and activation parameters ΔH\eweq(kJ mol−1) and ΔS\eweq(JK−1 mol−1) are 1.19×103, 42.0±1.3, and −45.8±5.5, respectively. In CD2Cl2, the exchange rate depends on the free DMF concentration. The exchange rate constant (kex) is expressed by kex=k1+k2[DMF], where k1(25 °C)=1.90×102s−1, ΔH\eweq=32.8±1.7 kJ mol−1, and ΔS\eweq=−92.0±5.9 JK−1 mol−1, and k2 (25 °C)=5.66×103 M−1s−1(1M=1 mol dm−3), ΔH\eweq=37.0±2.1 kJ mol−1, and ΔS\eweq=−49.6±8.8 JK−1 mol−1. The D and I mechanisms are proposed for the dmf exchange in [UO2(acac)2 dmf].
Magnetic Circular Dichroism and Electronic Absorption Spectra of Mixed (Amine)(carboxylato) Complexes with the [Pd(N)n(O)4–n]-type (n=0–4)
Authors: Nakayama Kazuhiko , Komorita Takashi , Shimura Yoichi 
Published: July 2006

Abstract
Mixed-ligand [Pd(N)n(O)4–n]-type complexes constituting a long systematic series (n=0–4) were synthesized. Ammonia, ethylenediamine, rac-propylenediamine, trimethylenediamine, glycinate, β-alaninate, acetate, oxalate, and malonate were employed as ligands. Their magnetic circular dichroism (MCD) and electronic absorption spectra were discussed together with the CD spectra of the corresponding optically active complexes. The results strongly suggest that the dispersion of MCD observed in the spin-allowed d-d region is primarily a composite of B terms. Moreover, the MCD in the charge transfer region was found to be qualitatively additive with respect to contributions by the constituent ligands. From a detailed examination of the spin-allowed d-d absorption bands, it is noted that the substitution of an N,O-ligand for an N,N-ligand largely affects neither the band area nor band width whereas that of an O,O-ligand for an N,O-ligand does.
The X-Ray Fluorescence Spectroscopy of Inorganic Solids. VI. The P Kα Energy of Phosphate Glasses and Crystals
Authors: Maekawa Takashi , Furukawa Masakazu , Yokokawa Toshio 
Published: July 2006

Abstract
The P Kα emission spectra of several phoshorus compounds and phosphate glasses were examined. The P Kα energies decrease with an increase in the basicities of the matrices. The results also suggest that in order to interprete the chemical shift one must take into account the effects due to changes in the short range structure around the phosphorus atom in the PO4 tetrahedron.
Synthesis of Pharmaceutically Important Heteroaromatics from Methyl Phenyl Sulfone
Authors: Yokoyama Masataka , Tsuji Kouichi , Imamoto Tsuneo 
Published: July 2006

Abstract
Some 5-substituted pyrazoles and pyrimethamine were prepared from 3-methylthio-1-phenyl-4-phenylsulfonyl-2-buten-1-one (5a) or (E)-1-p-chlorophenyl-1-cyano-2-methylthio-3-phenylsulfonylpropene (6b) which could be easily synthesized from methyl phenyl sulfone.