bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Crystal and Molecular Structure of Bis(methanol)-α,β,γ,δ-tetraphenylporphinatomanganese(III) Perchlorate-Methanol. A Molecular Structure Relevant to the Intermediate-spin Six Coordinate Iron(III) Porphyrin
Authors: Hatano Keiichiro , Anzai Kazunori , Iitaka Yoichi 
Published: July 2006

Abstract
Bis(methanol)-α,β,γ,δ-tetraphenylporphinatomanganese(III) perchlorate crystallizes as the methanol solvate in the triclinic system, space group P\bar1, a=16.225(8), b=13.167(7), c=10.793(5) Å, α=106.51(5)°, β=100.36(5)°, γ=101.60(5)°, and Z=2. The structure was determined by the heavy-atom method and the block-diagonal least-squares refinement using a total of 9992 reflections. The final R and Rw values are 6.3 and 7.1%, respectively. Two slightly different but substantially identical coordination spheres of high-spin Mn(III) porphyrin were revealed. The long axial Mn–O(methanol) bond distance and medium-sized porphyrin core were emphasized as structural characteristics in relation to the intermediate-spin iron(III) porphyrin.
The Reaction of Sodium Nitrite with Silica
Authors: Abe Osami , Utsunomiya Taizo , Hoshino Yoshio 
Published: July 2006

Abstract
The reaction of sodium nitrite with silica has been investigated over the relatively wide composition range (Na/Si=0 to 10.0) below 800 °C. In an argon atmosphere, sodium nitrite reacts with oxygen to form sodium nitrate above 400 °C and decomposes to sodium oxide via other oxide species above 500 °C, irrespective of the coexistence of silica. The reaction of sodium nitrite with silica in an argon atmosphere consists of two stages. In the early stage (&lt;600 °C), the main gaseous product is NO, while in the later stage nearly equimolar amounts of NO and O2 are formed. The early stage is further divided into two reaction processes: Process I, in which peroxide is considered to be formed in the melt by generating NO, and Process II, in which nitrate and silicates are formed by generating NO and a trace amount of O2. Peroxide is supposed to be stabilized at the solid-liquid interface, even if no silicates have been formed at relatively low temperatures. In the later stage, the reaction process or mechanism can be regarded as similar to that of sodium nitrate with silica, as the concentration of nitrite in the melt is very low.
X-Ray Diffraction Studies on the Structures of Hydrated Oxonium Ion, and the Chlorocobalt(II) and Tetrachlorocobaltate(II) Complexes in Aqueous Solutions
Authors: Lee Hyo-Gwang , Matsumoto Yukiei , Yamaguchi Toshio , Ohtaki Hitoshi 
Published: July 2006

Abstract
The structure of hydrated oxonium ion has been determined in a concentrated hydrochloric acid solution by the X-ray diffraction method. The oxonium ion H3O+ combines with four water molecules to form a trigonal pyramid structure in which three water molecules have an H3O+–H2O distance of 2.44 Å, while the water molecule at the apex of the pyramid is separated by 2.90 Å from the central oxygen atom of the oxonium ion. The structure of the CoCl+ determined in a relatively dilute lithium chloride solution (the Cl/Co mole ratio is 3.38) shows that the cobalt(II) ion is coordinated with five water molecules, the Co–OH2 distance being 2.14 Å. The Co–Cl distance within the complex is 2.35 Å. The CoCl42− complex has a regular tetrahedral structure both in a concentrated lithium chloride (Cl/Co=22.1) and a hydrochloric acid (Cl/Co=21.1) solutions with the Co–Cl bond length of 2.29 Å.
Studies of the Metal Complexes of Cyclohexane Derivatives. VII. Preparation and Properties of Platinum(II) and Cobalt(III) Complexes of (1R,2S)-1-Aminomethyl-2-methylcyclohexylamine
Authors: Saito Reiko , Kidani Yoshinori 
Published: July 2006

Abstract
Optically active (1R,2S)-1-aminomethyl-2-methylcyclohexylamine (R,S-2m-amcha) was synthesized and two Pt(II) and two types of Co(III) complexes containing this ligand were prepared. 1H-NMR and 13C-NMR spectra of the Pt(II) complexes and CD spectrum of trans-[CoCl2(R,S-2m-amcha)2]+ indicated that the chelate ring takes predominantly the λ conformation with the equatorial C1–C2 bond of the cyclohexane ring. The absolute configuration of the ligand has been assigned on the basis of the conformation of the complexes. All possible isomers of the tris Co(III) complex, fac-Δ(lel3), mer-Δ(lel3), mer-Λ(ob3), and fac-Λ(ob3), were isolated and characterized.
Synthesis of Octachlorobicyclo[3.3.0]octa-1,4,6-triene and Lewis Acid Catalyzed Isomerization of Hexachlorobicyclo[3.3.0]octa-3,5,8-trien-2-one
Authors: Kusuda Kousuke 
Published: July 2006

Abstract
Treatment of decachloro(4-allylidenecyclopentene) with enneacarbonyldiiron(0) gave octachlorobicyclo[3.3.0]octa-1,3,7-triene (δ-C8Cl8) in 40% yield. Dechlorination of decachlorobicyclo[3.3.0]octa-2,6-diene with powdered selenium, sulfur, phosphorus, or titanium in the presence of anhydrous aluminium chloride without any added solvent at 90–100 °C afforded octachlorobicyclo[3.3.0]octa-1,4,6-triene (2) (ε-C8Cl8) in good yield. Hexachlorobicyclo[3.3.0]octa-3,5,8-trien-2-one obtained from 2 was chlorinated by a concentrated solution of antimony(V) chloride in refluxing dichloromethane to give octachlorobicyclo[3.3.0]octa-3,6(or 7)-dien-2-one, but in a dilute solution (less than 0.1 g of antimony(V) chloride/cm3 of dichloromethane) hexachlorobicyclo[3.3.0]octa-4,6,8-trien-2-one (14) was obtained. Mechanism of the isomerization is discussed in terms of antiaromaticity of cyclopentadienyl cation. Reaction of 14 with methanol afforded pentachloro-4-methoxybicyclo[3.3.0]octa-3,5,7-trien-2-one. Ethanol or 2-propanol reacted with 14 similarly giving pentachloro-4-ethoxybicyclo[3.3.0]octa-3,5,7-trien-2 -one or pentachloro-4-isopropoxybicyclo[3.3.0]octa-3,5,7-trien-2-one, respectively.
Studies on 2-Aziridinecarboxylic Acid. IX. Convenient Synthesis of Optically Active S-Alkylcysteine, threo-S-Alkyl-β-methylcysteine, and Lanthionine Derivatives via the Ring-opening Reaction of Aziridine by Several Thiols
Authors: Nakajima Kiichiro , Oda Hitomi , Okawa Kenji 
Published: July 2006

Abstract
A convenient synthesis of optically active S-alkylcysteine, threo-S-Alkyl-β-methylcysteine, and lanthionine derivatives has been investigated. Benzyl 1-benzyloxycarbonyl-(2S)-2-aziridinecarboxylate and benzyl (2S,3S)-1-benzyloxycarbonyl-3-methyl-2-aziridinecarboxylate, and their enantiomers were treated with several thiols, and the corresponding S-alkylcysteine, threo-S-alkyl-β-methylcysteine, and lanthionine derivatives were prepared via the ring-opening reaction of aziridine in the presence of a catalytic amount of boron trifluoride etherate in good yields.
Pure Spectra of Actinomycin D Bound to DNA at Various Ionic Strengths Extracted by the Principal-component-analysis Method
Authors: Matsuda Takumi , Kashiramoto Saburo , Yamaoka Kiwamu 
Published: July 2006

Abstract
The interaction between actinomycin D (AMD) and native and heat-denatured DNA was studied spectrophotometrically at 25 °C. By applying the principal-component-analysis (PCA) method to the series of observed spectra, the number of light-absorbing components was determined. Two spectroscopically different species of bound AMD, i.e., AMD–DNA complexes, were formed when an aqueous AMD solution was titrated with either the native or the denatured DNA solution over a wide range of the nucleotide residue-to-AMD mixing ratios (P/D) between 0 and 30. The pure spectra of AMD bound to DNA were extracted in the P/D range 0–4 by the extended PCA method with an appropriate binding scheme. These bound-AMD spectra were affected by the DNA conformation but not by the addition of NaCl (1–500 mmol dm−3). The fractions of bound AMD were calculated as a function of P/D.
Concentration Dependence of the Conversion between the Intermolecular β-Structure and the Disordered State of Poly(S-carboxymethyl-l-cysteine) in Aqueous Solutions
Authors: Maeda Hiroshi , Saito Kaoru , Ikeda Shoichi 
Published: July 2006

Abstract
The effects of polymer concentration on the reversible conversion between the intermolecular β-structure and the disordered state of poly(S-carboxymethyl-l-cysteine) were examined by means of circular dichroism at constant pHs in 20 mM NaClO4 solutions. The data were tentatively analyzed based on an assumed all-or-none model. A value of −1.1 kJ (−250 cal) per mole of residues was obtained for the standard free energy of association. It was suggested that the obtained results depended significantly on the molecular weight distribution of the used samples.
Magnetic-superexchange Interactions of Uranium(IV) Chloride-addition Complexes with Amides. II. Complexes with Lactams
Authors: Miyake Chie , Hinatsu Yukio , Imoto Shosuke 
Published: July 2006

Abstract
The magnetic susceptibilities of five cyclic amide (lactam)-addition complexes of uranium(IV) chloride were measured between room temperature and 2 K. Magnetic-exchange interaction was found only for N-methyl-substituted amide complexes, and a dimer structure was assumed for them on the basis of their chemical properties. Treating interdimer interaction with a molecular-field approximation, the magnetic susceptibilities were calculated to be in good agreement with the experimental results in the temperature region of the maxima in χA. The transmission of antiparallel spin coupling via the π orbitals of the bridging amide ligands is proposed to explain the strong intradim er superexchange interaction for the uranium(IV) chloride–amide complexes with the magneticsusceptibility maximum.
Distribution and Chemical Behavior of 21 Elements in River Water in the Yakushima Island
Authors: Tanizaki Yoshiyuki , Nagatsuka Sumiko 
Published: July 2006

Abstract
The concentrations of 21 elements dissolved in the river water collected from around the Yakushima Island were determined by a neutron activation analysis (NAA). From the analytical results, the distribution and chemical behavior of each element in the water were discussed. The chemical composition of the river water was nearly uniform all around the island, and the concentration of each element determined in this work was extremely close to the geochemical background value of river water, since our experimental area had scarcely any pollution. Among the 21 elements chlorine, sodium, and magnesium were mainly supplied into the river water from the ocean, while the others were chiefly driven from the rocks and their efflorescences in the drainage basin. The enrichment factors for the granitic earth crust (FE-value) were very close to 1 for calcium, strontium, and zinc, while those of selenium, arsenic, tungsten, and antimony were much higher than 1. For the elements such as aluminium, iron, manganese, etc., on the other hand, the FE-values were very low. These differences in the FE-values among the elements correspond to differences in their solubilities in the water.
The Relation between the Proton-induced Quenching Rate Constants and the Charge Densities of Aromatic Compounds
Authors: Shizuka Haruo , Tsutsumi Kinzo 
Published: July 2006

Abstract
A plot of log k′q (the proton-induced quenching rate constants) vs. the charge densities PΣ* (or superdelocalizabilities SΣ*) in the excited state gave a straight line. The linear relation strongly supports the proton-induced quenching mechanism involving electrophilic protonation at the proper carbon atoms in the aromatic ring.
Photolysis of Ozonides in the Gas Phase
Authors: Hatakeyama Shiro , Akimoto Hajime 
Published: July 2006

Abstract
Photolysis of four kinds of simple ozonides (ethene, propene, 2-butene, and isobutene ozonides) in the gas phase were carried out. The contribution of the double-β-scission mechanism was 4–13%. The main reaction path is proposed to be intramolecular hydrogen abstraction followed by radical forming unimolecular decomposition.
Crystal Structures of (1,5-Cyclooctadiene)di-μ-methoxo-dirhodium(I) and Tetrakis(η3-allyl)di-μ-hydroxo-dirhodium(III)
Authors: Tanaka Isao , Jin-no Naoki , Kushida Takanori , Tsutsui Noriyoshi , Ashida Tamaichi , Suzuki Hiroharu , Sakurai Humio , Moro-oka Yoshihiko , Ikawa Tsuneo 
Published: July 2006

Abstract
The crystal structures of (1,5-cyclooctadiene)di-μ-methoxo-dirhodium(I) and tetrakis(η3-allyl)di-μ-hydroxodirhodium(III) were determined by the X-ray method. The former belongs to the triclinic space group P\bar1 with cell dimensions, a=7.347(4), b=6.471(3), c=9.554(6) Å, α=87.06(4), β=82.50(5) and γ=77.98(4)°. The space group of the latter is also P\bar1 but two crystallographically independent molecules exist in a cell with dimensions, a=11.704(7), b=9.793(6), c=7.948(5) Å, α=113.49(5), β=54.59(5), and γ=110.99(5)°. Both structures were determined by the heavy atom method and refined by the block-diagonal least-squares method. The final R values were 0.054 for the former and 0.075 for the latter. The coordination of the rhodium atom in the former compound is square planar, the cyclooctadiene ligand being regarded as a bidentate donor. The latter coordination is, in a formal sense, octahedral.
The Ion-exchange Properties toward Hexaamminecobalt(III) and the Characterization of the Complex Cation Form of α-Zirconium Phosphate
Authors: Hasegawa Yoshitsugu , Kizaki Seiichi , Amekura Hiroshi 
Published: July 2006

Abstract
The ion-exchange properties of α-zirconium phosphate have been investigated for the H+–[Co(NH3)6]3+ system. The ion-exchange process was examined by means of the variation in the pH values of the supernatant. α-Zirconium phosphate loaded with hexaamminecobalt(III) was also characterized by chemical analysis, X-ray diffractometry, infrared spectroscopy, and thermal analysis. In spite of the steric hindrance in the crystal structure of α-zirconium phosphate, the ion exchange proceeded gradually. About 30% of the hydrogen ions in α-zirconium phosphate were replaced by hexaamminecobalt(III). The interlayer distance of the exchanger expanded from 0.76 to 1.12 nm.
The Synthesis of 2,7-Bis(dimethylamino)pyrene and -tetrahydropyrene and the Electrical Conductivities of Their Complexes
Authors: Ueda Naomi , Natsume Bunji , Yanagiuchi Kazumi , Sakata Yoshiteru , Enoki Toshiaki , Saito Gunzi , Inokuchi Hiroo , Misumi Soichi 
Published: July 2006

Abstract
New π-donors containing a pyrene or a tetrahydropyrene ring were synthesized by means of a unique transannular reaction of the corresponding [2.2]metacylcophane derivatives. The CT complexes of these donors with a series of TCNQ derivatives different in electron affinity were prepared, and their electrical conductivities on single crystals were measured. The highest conductivity (0.36 Ω−1 cm−1) was that of the tetrahydropyrene derivative-TCNQ complex. It was reconfirmed that the partial charge-transfer from a donor to an acceptor is very important for high conductivity.
Reaction of the Azomethine Moiety Buried in Bilayer Membranes
Authors: Okahata Yoshio , Ando Reiko , Kunitake Toyoki 
Published: July 2006

Abstract
The reaction with water and amines of the azomethine moiety that is part of single-chain ammonium amphiphiles was examined. These amphiphiles form stable bilayer aggregates when they have the alkyl tail of C7 or C12. The reaction with water of the bilayer-forming amphiphiles ceases at the hydration stage and are 10–2000 times slower than those of the amphiphiles which do not form bilayers and undergo hydrolytic cleavage. The reactivity of the azomethine moiety in bilayers decreases with increasing distance from the membrane surface. The Arrhenius plots for the bilayer-forming amphiphiles show discontinuities at temperatures corresponding to phase transition of the respective bilayer (Tc). The apparent activation energy is larger at temperatures below Tc than at temperatures above Tc. This suggests that water penetration is facilitated in the fluid bilayer. The reaction with amines was affected by their solubility in the bilayer matrix, and poly(ethylenimine) gave a much reduced reaction rate when the azomethine moiety was buried deep in the bilayer matrix.
Conformational Changes of the Poly(α-l-glutamic acid)–Cu(II) Macromolecular Complexes in the pH Range of 4–7. A Light Scattering Study with Emphasis on Aggregation and Helix-coil Transitions
Authors: Masujima Tsutomu 
Published: July 2006

Abstract
The overall conformational changes of the macromolecular complex between poly(α-l-glutamic acid), poly(Glu), and Cu(II) in 0.15 M NaCl were investigated by means of the light scattering method at three mixing ratios of Glu residues to Cu2+, R, (32, 16, and 8) in the pH range of 4–7. The root-mean-square radius of gyration and the weight-averaged molecular weight of poly(Glu) were determined by means of the Zimm plot, and those pH dependences show that the poly(Glu) shrinks in the course of the coil-to-helix transition and that it forms aggregates at pH values lower than 4.7, where helix formation is almost completed. In the presence of Cu2+ ions, the bound Cu(II) accelerates the shrinking of the poly(Glu) conformation and induces the aggregation in a high pH region, where the helix is imperfect. With the aid of theoretical treatments in the text, the aggregation scheme in the helix region was disclosed to be side-by-side, in which a 70–95% length of a helix overlaps one another. All these results and the pH dependence of the radius of gyration per poly(Glu) molecule were discussed in relation to the complex formation between Cu(II) and poly(Glu).
Pressure Effect on Transference Numbers for KCl in Ethanol–Water Mixtures at 25 °C
Authors: Ueno Masakatsu , I Sh\={o}go , Shimizu Kiyoshi 
Published: July 2006

Abstract
Cation transference numbers for 0.02 mol dm−3 KCl in 0-, 5-, 10-, 15-, 20-, and 30-mol% ethanol–water mixtures were determined by the moving boundary method at 25 °C up to 1500 kg cm−2 (1 kg cm−2=0.9807×105 Pa). The cation transference number, t+, initially increases with increasing ethanol content up to 10–15 mol% and then decreases at all the pressures studied. In water and ethanol–water mixtures below 20 mol%, t+ at the definite solvent decreases with increasing pressure. The decreasing rate becomes smaller as the ethanol content increases, and the tendency is reversed finally at 30 mol%. To account for the variation of t+ with solvent composition and pressure, specific interactions between the ions and solvent have been taken into consideration.
The Effect of the Difference in the Oxidation State of the Second Component Added to MoO3 on the Generation of the Acidic Property
Authors: Ai Mamoru 
Published: July 2006

Abstract
The effect of the difference in the oxidation state of the second component added to MoO3 on the generation of acidic sites was studied with regard to Sn2+—Sn4+, Fe2+—Fe3+, Cr3+—Cr6+, and Cu+—Cu2+. It was found that a markedly lager amount of acidic sites is generated by the combination of Sn2+, Fe2+, or Cr3+ with MoO3 than by that of Sn4+, Fe3+, or Cr6+ respectively. As a general feature of metal-oxide combination, it is proposed that the addition of a metal ion in a lower oxidation state to MoO3 brings about a markedly more significant acidity generation than that of a metal ion in a higher oxidation state. An explanation to account for the results was attempted in relation to the reducing function of the second component.
A Conductance Study of 18-Crown-6 and Dibenzo-18-crown-6 Complexes with K+ in Various Solvents
Authors: Takeda Yasuyuki 
Published: July 2006

Abstract
Limiting ionic molar conductivities (λ°) of 18-crown-6 (18C6) and dibenzo-18-crown-6 (DB18C6) complexes with K+ in several protic and aprotic solvents have been determined at 25 °C. The crystal ionic radius of 18C6 complex with K+ is nearly identical with that of tetrabutylammonium ion ((n-C4H9)4N+). For CH3OH, the mobility of the 18C6 complex with K+ is nearly equal to that of (n-C4H9)4N+. However, for H2O, the former is much larger than the latter, but the contrary is true for aprotic solvents. Walden products of 18C6 complexes with K+ for the solvents are nearly equal to each other. For acetonitrile and DMSO, the λ° value of the DB18C6 complex with K+ is smaller than those for the tetrapentylammonium ion ((n-C5H11)4N+) and for the tetraisopentylammonium ion ((i-C5H11)4N+). For nitrobenzene and propylene carbonate, that of the DB18C6 complex with K+ is smaller than those of (n-C5H11)4N+ and (i-C5H11)4N+, respectively. In contrast to the case of the aprotic solvents, the λ° value of the DB18C6 complex with K+ for CH3OH is nearly equal to those of (n-C5H11)4N+ and (i-C5H11)4N+. Walden products of the DB18C6 complexes with K+ for the solvents are nearly equal to each other. From the above data, it appears that a solute which contains a unit of 18C6 in its structure does not enforce a hydrogen-bonded structure for a protic solvent.
Reactions of the Octahedral Bis(α-diketone dioximato)iron(II) Complexes with Carbon Monoxide and Benzyl Isocyanide
Authors: Sasaki Yoshihiro 
Published: July 2006

Abstract
The reactions of bis(α-diketone dioximato)iron(II) coordinated by two nitrogeneous base molecules (X) with carbon monoxide and benzyl isocyanide were studied kinetically in chloroform; here α-diketone dioxime=2,2′-difurylglyoxime (H2fr) and dimethylglyoxime (H2dg). The reactions proceeded reversibly through a dissociative mechanism. For the reaction Fe(Hfr)2(X)2\oversetk1\undersetk−1\ightleftharpoonsFe(Hfr)2(X)+X, plots of logk1 vs. pKa (Ka : dissociation constant of conjugate acid of base) for pyridines gave a negative correlation. The logk1 values of 4-cyanopyridine and 4-acetylpyridine systems were smaller and that of 2,6-dimethylpyridine system larger than predicted by their pKa values. Imidazole and 1-methylimidazole were more inert than pyridines. For the reaction Fe(Hfr)2(X)+(CO)\oversetk2\undersetk−2\ightleftharpoonsFe(Hfr)2(X)(CO), logk−2 vs. pKa plots for sterically unhindered pyridines showed a linear relationship, but the basicity of pyridine bases did not affect the CO dissociation processes very much. 2-Methylpyridine, 2,4-dimethylpyridine, and 2,6-dimethylpyridine facilitated the dissociation of CO slightly as compared with pyridine. Imidazole and 1-methylimidazole allowed CO to be more inert and piperidine more labile than pyridines. The dissociation of the base was significantly affected by the change of substituents in α-diketone dioxime, and the dissociation of CO was slightly affected by the change of substituents. The reaction behavior was discussed on the basis of the activation parameters and infrared data.
Zeta Potentials of Metal Oxides Coated with Titanate Coupling Agents in Aqueous Solution
Authors: Esumi Kunio , Suzuki Toshio , Meguro Kenjiro 
Published: July 2006

Abstract
The zeta potentials of metal oxide surfaces coated with titanate coupling agents were measured as a function of pH in the suspensions. The treatment by titanium(IV) isopropoxide tris(2-methylheptadecanoate) on the metal oxides, such as iron oxide, titanium dioxide, and silica, provided lower zeta potential values over a wide pH range than those of untreated samples. On the other hand, the treatment of the samples by titanium(IV) tris[2-(2-aminoethylamino)ethoxide] isopropoxide rendered the surfaces more cationic. Further, it was found that the titanate coupling layer was almost removed from the surfaces after one day they were immersed in aqueous solution.
Preparation of Tetraethylammonium Hexamolybdate by the Use of Extraction Method
Authors: Murata Katsuo , Yamamoto Etsuko , Ikeda Shigero 
Published: July 2006

Abstract
It was found that cyclohexanone selectively extracts hexamolybdate from weakly acidic solutions. Tetraethylammonium hexamolybdate was prepared as precipitate in the extracted phase by the addition of alcoholic tetraethylammonium chloride solution. This compound was confirmed to be [(C2H5)4N]2Mo6O19 by elementary analysis and Raman measurements.
197Au-Mössbauer Spectroscopic Studies of Monomeric and Trimeric Gold(I) Azolates
Authors: Katada Motomi , Sato Kumiko , Uchida Yoshio , Iijima Seiichiro , Sano Hirotoshi , Wei H H , Sakai Hiroshi , Maeda Yutaka 
Published: July 2006

Abstract
The identical chemical state of three gold atoms in trimeric gold(I) azolates and the Au(I)–Au(III) mixed-valence state in their iodine adducts, Au3(az)3I2, were confirmed by means of 197Au-Mössbauer spectroscopy.